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  • 1.
    Aldred, Nick
    et al.
    Newcastle University.
    Ekblad, Tobias
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    Andersson, Olof
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    Clare, Anthony S.
    Newcastle University.
    Real-Time Quantification of Microscale Bioadhesion Events In situ Using Imaging Surface Plasmon Resonance (iSPR)2011In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 3, no 6, p. 2085-2091Article in journal (Refereed)
    Abstract [en]

    From macro- to nanoscales, adhesion phenomena are all-pervasive in nature yet remain poorly understood. In recent years, studies of biological adhesion mechanisms, terrestrial and marine, have provided inspiration for "biomimetic" adhesion strategies and important insights for the development of fouling-resistant materials. Although the focus of most contemporary bioadhesion research is on large organisms such as marine mussels, insects and geckos, adhesion events on the micro/nanoscale are critical to our understanding of important underlying mechanisms. Observing and quantifying adhesion at this scale is particularly relevant for the development of biomedical implants and in the prevention of marine biofouling. However, such characterization has so far been restricted by insufficient quantities of material for biochemical analysis and the limitations of contemporary imaging techniques. Here, we introduce a recently developed optical method that allows precise determination of adhesive deposition by microscale organisms in situ and in real time; a capability not before demonstrated. In this extended study we used the cypris larvae of barnacles and a combination of conventional and imaging surface plasmon resonance techniques to observe and quantify adhesive deposition onto a range of model surfaces (CH(3)-, COOH-, NH(3)-, and mPEG-terminated SAMs and a PEGMA/HEMA hydrogel). We then correlated this deposition to passive adsorption of a putatively adhesive protein from barnacles. In this way, we were able to rank surfaces in order of effectiveness for preventing barnacle cyprid exploration and demonstrate the importance of observing the natural process of adhesion, rather than predicting surface effects from a model system. As well as contributing fundamentally to the knowledge on the adhesion and adhesives of barnacle larvae, a potential target for future biomimetic glues, this method also provides a versatile technique for laboratory testing of fouling-resistant chemistries.

  • 2. Ali, A.
    et al.
    Rafique, A.
    Kaleemullah, M.
    Abbas, G.
    Ajmal Khan, M.
    Ahmad, M. A.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Chinese Academy of Sciences, China.
    Effect of Alkali Carbonates (Single, Binary, and Ternary) on Doped Ceria: A Composite Electrolyte for Low-Temperature Solid Oxide Fuel Cells2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 1, p. 806-818Article in journal (Refereed)
    Abstract [en]

    Samarium-doped ceria (SDC) carbonate has become an attractive electrolyte for fuel cells because of its remarkable ion conductivity and high performance. Different doped ceria-carbonate (single-carbonate SDC, binary-carbonate SDC, and ternary-carbonate SDC) electrolytes were synthesized by the coprecipitation/oxalate method, to optimize the electrochemical performance. The structure; morphology; and thermal, optical, and surface properties have been studied using a variety of techniques. The X-ray diffraction results confirmed the successful incorporation of samarium into ceria as a crystalline structure and inclusion of carbonate, which is amorphous in nature. To analyze the conduction mechanism, direct current conductivity was measured in a H2/O2 atmosphere. Doped ceria-binary carbonate ((Li/Na)CO3-SDC) showed the best conductivity of 0.31 S cm-1 and power density of 617 mW cm-2, at 600 °C. The enhancement in the ionic conductivity and performance of the composites is due to the contribution of hybrid ions (O2-, H+). The crystallite size of the composites was in the range 21-41 nm. For the calculation of band gaps, optical absorption spectra of the synthesized powders were analyzed, and they showed a red shift with the band gap energy in the range 2.6-3.01 eV, when compared to that of pure ceria (3.20 eV).

  • 3.
    Alipour, Nazanin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Andersson, Richard L.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Olsson, Richard T.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gedde, Ulf W.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hedenqvist, Mikael S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    VOC-Induced Flexing of Single and Multilayer Polyethylene Films As Gas Sensors2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 15, p. 9946-9953Article in journal (Refereed)
    Abstract [en]

    The differential swelling and bending of multilayer polymeric films due to the dissimilar uptake of volatile organic compounds (VOCs; n-hexane, limonene) in the different layers was studied. Motions of thin polyethylene films triggered by the penetrant were investigated to learn more about how their deformation is related to VOC absorption. Single layers of metallocene or low-density polyethylene, and multilayers (2-288-layers) of these in alternating positions were considered. Single-, 24-, and 288 layer films displayed no motion when uniformly subjected to VOCs, but they could display simple curving modes when only one side of the film was wetted with a liquid VOC. Two-layer films displayed simple bending when uniformly subjected to VOCs due to the different swelling in the two layers, but when the VOC was applied to only one side of the film, more complex modes of motion as well as dynamic oscillations were observed (e.g., constant amplitude wagging at 2 Hz for ca. 50 s until all the VOC had evaporated). Diffusion modeling was used to study the transport behavior of VOCs inside the films and the different bending modes. Finally a prototype VOC sensor was developed, where the reproducible curving of the two-layer film was calibrated with n-hexane. The sensor is simple, cost-efficient, and nondestructive and requires no electricity.

  • 4. Al-Shammari, Rusul M.
    et al.
    Baghban, Mohammad Amin
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Al-attar, Nebras
    Gowen, Aoife
    Gallo, Katia
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Rice, James H.
    Rodriguez, Brian J.
    Photoinduced Enhanced Raman from Lithium Niobate on Insulator Template2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 36, p. 30871-30878Article in journal (Refereed)
    Abstract [en]

    Photoinduced enhanced Raman spectroscopy from a lithium niobate on insulator (LNOI)−silver nanoparticle template is demonstrated both by irradiating the template with 254 nm ultraviolet (UV) light before adding an analyte and before placing the substrate in the Raman system (substrate irradiation) and by irradiating the sample in the Raman system after adding the molecule (sample irradiation). The photoinduced enhancement enables up to an ∼sevenfold increase of the surface-enhanced Raman scattering signal strength of an analyte following substrate irradiation, whereas an ∼threefold enhancement above the surface-enhanced signal is obtained for sample irradiation. The photoinduced enhancement relaxes over the course of ∼10 h for a substrate irradiation duration of 150 min before returning to initial signal levels. The increase in Raman scattering intensity following UV irradiation is attributed to photoinduced charge transfer from the LNOI template to the analyte. New Raman bands are observed following UV irradiation, the appearance of which is suggestive of a photocatalytic reaction and highlight the potential of LNOI as a photoactive surface-enhanced Raman spectroscopy substrate.

  • 5.
    Annamalai, Alagappan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sandström, Robin
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Gracia-Espino, Eduardo
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boulanger, Nicolas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boily, Jean-Francois
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mühlbacher, Inge
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Influence of Sb5+ as a Double Donor on Hematite (Fe3+) Photoanodes for Surface-Enhanced Photoelectrochemical Water Oxidation2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 19, p. 16467-16473Article in journal (Refereed)
    Abstract [en]

    To exploit the full potential of hematite (α-Fe2O3) as an efficient photoanode for water oxidation, the redox processes occurring at the Fe2O3/electrolyte interface need to be studied in greater detail. Ex situ doping is an excellent technique to introduce dopants onto the photoanode surface and to modify the photoanode/electrolyte interface. In this context, we selected antimony (Sb5+) as the ex situ dopant because it is an effective electron donor and reduces recombination effects and concurrently utilize the possibility to tuning the surface charge and wettability. In the presence of Sb5+ states in Sb-doped Fe2O3 photoanodes, as confirmed by X-ray photoelectron spectroscopy, we observed a 10-fold increase in carrier concentration (1.1 × 1020 vs 1.3 × 1019 cm–3) and decreased photoanode/electrolyte charge transfer resistance (∼990 vs ∼3700 Ω). Furthermore, a broad range of surface characterization techniques such as Fourier-transform infrared spectroscopy, ζ-potential, and contact angle measurements reveal that changes in the surface hydroxyl groups following the ex situ doping also have an effect on the water splitting capability. Theoretical calculations suggest that Sb5+ can activate multiple Fe3+ ions simultaneously, in addition to increasing the surface charge and enhancing the electron/hole transport properties. To a greater extent, the Sb5+- surface-doped determines the interfacial properties of electrochemical charge transfer, leading to an efficient water oxidation mechanism.

  • 6.
    Anoshkin, Ilya V.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Campion, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Lioubtchenko, Dmitri V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Freeze-Dried Carbon Nanotube Aerogels for High-Frequency Absorber Applications2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, ISSN 1944-8244, Vol. 10, no 23, p. 19806-19811Article in journal (Refereed)
    Abstract [en]

    A novel technique for millimeter wave absorber material embedded in a metal waveguide is proposed. The absorber material is a highly porous carbon nanotube (CNT) aerogel prepared by a freeze-drying technique. CNT aerogel structures are shown to be good absorbers with a low reflection coefficient, less than -12 dB at 95 GHz. The reflection coefficient of the novel absorber is 3-4 times lower than that of commercial absorbers with identical geometry. Samples prepared by freeze-drying at -25 degrees C demonstrate resonance behavior, while those prepared at liquid nitrogen temperature (-196 degrees C) exhibit a significant decrease in reflection coefficient, with no resonant behavior. CNT absorbers of identical volume based on wet-phase drying preparation show significantly worse performance than the CNT aerogel absorbers prepared by freeze-drying. Treatment of the freeze-dried CNT aerogel with n- and p-dopants (monoethanolamine and iodine vapors, respectively) shows remarkable improvement in the performance of the waveguide embedded absorbers, reducing the reflection coefficient by 2 dB across the band.

  • 7.
    Ao, Xianyu
    et al.
    South China Normal Univ, South China Acad Adv Optoelect, Ctr Opt & Electromagnet Res, Guangzhou 510006, Guangdong, Peoples R China..
    Xu, Xinan
    South China Normal Univ, South China Acad Adv Optoelect, Ctr Opt & Electromagnet Res, Guangzhou 510006, Guangdong, Peoples R China..
    Dong, Jinwu
    South China Normal Univ, South China Acad Adv Optoelect, Ctr Opt & Electromagnet Res, Guangzhou 510006, Guangdong, Peoples R China..
    He, Sailing
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering. South China Normal Univ, South China Acad Adv Optoelect, Ctr Opt & Electromagnet Res, Guangzhou 510006, Guangdong, Peoples R China.;Zhejiang Univ, Natl Engn Res Ctr Opt Instruments, Ctr Opt & Electromagnet Res, JORCEP, Hangzhou 310058, Zhejiang, Peoples R China..
    Unidirectional Enhanced Emission from 2D Monolayer Suspended by Dielectric Pillar Array2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 41, p. 34817-34821Article in journal (Refereed)
    Abstract [en]

    Monolayers of transition metal dichalcogenides show great promise for optoelectronic devices as atomically thin semiconductors. Although dielectric or metal nanostructures have been extensively studied for tailoring and enhancing emission from monolayers, their applications are limited because of the mode concentrating inside the dielectric or the high optical losses in metals, together with the low quantum yield in monolayers. Here, we demonstrate that a metal-backed dielectric pillar array can suspend monolayers to increase the radiative recombination, and simultaneously, create strongly confined band-edge modes on surface directly accessible to monolayers. We observe unidirectional enhanced emission from WSe2 monolayers on polymer pillar array.

  • 8.
    Apaydin, Dogukan H.
    et al.
    Johannes Kepler University of Linz, Austria.
    Gora, Monika
    University of Warsaw, Poland.
    Portenkirchner, Engelbert
    University of Innsbruck, Austria.
    Oppelt, Kerstin T.
    Johannes Kepler University of Linz, Austria.
    Neugebauer, Helmut
    Johannes Kepler University of Linz, Austria.
    Jakesoya, Marie
    Johannes Kepler University of Linz, Austria.
    Glowacki, Eric D.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Kunze-Liebhaeuser, Julia
    University of Innsbruck, Austria.
    Zagorska, Malgorzata
    Warsaw University of Technology, Poland.
    Mieczkowski, Jozef
    University of Warsaw, Poland.
    Serdar Sariciftci, Niyazi
    Johannes Kepler University of Linz, Austria.
    Electrochemical Capture and Release of CO2 in Aqueous Electrolytes Using an Organic Semiconductor Electrode2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 15, p. 12919-12923Article in journal (Refereed)
    Abstract [en]

    Developing efficient methods for capture and controlled release of carbon dioxide is crucial to any carbon. capture and utilization technology. Herein we present an approach using an organic. semiconductor electrode to electrochemically capture dissolved CO2 in aqueous electrolytes. The process relies on electrochemical reduction of a thin film of a naphthalene bisimide derivative, 2,7,bis (4-(2- (2-ethylhexyl)thiazol-4-yl)phenyObenzo [lmn][3,8] phenanthroline-1,3,6,8(2H,7H)-tetraone (NBIT). This molecule is specifically tailored to afford one-electron reversible and one-electron quasi-reversible reduction in aqueous conditions while, not dissolving or degrading. The reduced NBIT reacts with CO2 to form a stable aemicarbonate salt, which can be subsequently oxidized electrochemically to release CO2. The semicarbonate structure is confirmed by in situ IR spectroelectrochemistry. This process of capturing and releasing carbon dioxide can be realized in an oxygen-free environment under ambient pressure and temperature, with uptake efficiency for CO2 capture of similar to 2.3 mmol g(-1). This is on par with the best solution-phase amine chemical capture technologies available today.

  • 9.
    Arbring Sjöström, Theresia
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Jonsson, Amanda
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Stanford University, CA 94305 USA.
    Gabrielsson, Erik
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Kergoat, Loig
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Aix Marseille University, France.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Cross-Linked Polyelectrolyte for Improved Selectivity and Processability of lontronic Systems2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 36, p. 30247-30252Article in journal (Refereed)
    Abstract [en]

    On-demand local release of biomolecules enables fine-tuned stimulation for the next generation of neuromodulation therapies. Such chemical stimulation is achievable using iontronic devices based on microfabricated, highly selective ion exchange membranes (IEMs). Current limitations in processability and performance of thin film LEMs hamper future developments of this technology. Here we address this limitation by developing a cationic IEM with excellent processability and ionic selectivity: poly(4-styrenesulfonic acidco-maleic acid) (PSS-co-MA) cross-linked with polyethylene glycol (PEG). This enables new design opportunities and provides enhanced compatibility with in vitro cell studies. PSSA-co-MA/PEG is shown to out-perform the cation selectivity of the previously used iontronic material.

  • 10.
    Arvizu, Miguel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Wen, Rui-Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Klemberg-Sapieha, Jolanta Ewa
    Martinu, Ludvik
    Niklasson, Gunnar A.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Granqvist, Claes-Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Galvanostatic ion de-trapping rejuvenates oxide thin films2015In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 48, p. 26387-26390Article in journal (Refereed)
    Abstract [en]

    Ion trapping under charge insertion-extraction is well-known to degrade the electrochemical performance of oxides. Galvano-static treatment was recently shown capable to rejuvenate the oxide, but the detailed mechanism remained uncertain. Here we report on amorphous electrochromic (EC) WO3 thin films prepared by sputtering and electrochemically cycled in a lithium-containing electrolyte under conditions leading to severe loss of charge exchange capacity and optical modulation span. Time-of-flight elastic recoil detection analysis (ToF-ERDA) documented pronounced Li+ trapping associated with the degradation of the EC properties and, importantly, that Li+ detrapping, caused by a weak constant current drawn through the film for some time, could recover the original EC performance. Thus, ToF-ERDA provided direct and unambiguous evidence for Li+ detrapping.

  • 11.
    Aulin, C.
    et al.
    RISE, Innventia.
    Karabulut, E.
    Tran, A.
    Waisgberg, L.
    Lindström, T.
    RISE, Innventia.
    Transparent nanocellulosic multilayer thin films on polylactic acid with tunable gas barrier properties2013In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, no 15, p. 7352-7359Article in journal (Refereed)
  • 12. Aulin, C.
    et al.
    Yun, S. H.
    Wåberg, L.
    Lindström, Tom
    RISE, STFI-Packforsk.
    Design of highly oleophobic cellulose surfaces from structured silicon templates2009In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 1, no 11, p. 2443-2452Article in journal (Refereed)
    Abstract [en]

    Structured silicon surfaces, possessing hierarchical porous characteristics consisting of micrometer-sized cavities superimposed upon a network of nanometer-sized pillars or wires, have been fabricated by a plasma-etching process. These surfaces have superoleophobic properties, after being coated with fluorinated organic trichlorosilanes, on intrinsically oleophilic surfaces. By comparison with flat silicon surfaces, which are oleophilic, it has been demonstrated that a combination of low surface energy and the structured features of the plasma-etched surface is essential to prevent oil from penetrating the surface cavities and thus induce the observed macroscopic superoleophobic phenomena with very low contact-angle hysteresis and low roll-off angles. The structured silicon surfaces were coated with cellulose nanocrystals using the polyelectrolyte multilayer technique. The cellulose surfaces prepared in this way were then coated with a monolayer of fluorinated trichlorosilanes. These porous cellulose films displayed highly nonwetting properties against a number of liquids with low surface tension, including alkanes such as hexadecane and decane. The wettability and chemical composition of the cellulose/silicon surfaces were characterized with contact-angle goniometry and X-ray photoelectron spectroscopy, respectively. The nano/microtexture features of the cellulose/silicon surfaces were also studied with field-emission scanning electron microscopy. The highly oleophobic structured cellulose surfaces are very interesting model surfaces for the development of biomimetic self-cleaning surfaces in a vast array of products, including green constructions, packaging materials, protection against environmental fouling, sports, and outdoor clothing, and microfluidic systems.

  • 13.
    Aulin, Christian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Karabulut, Erdem
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Tran, Amy
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindström, Tom
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Transparent Nanocellulosic Multilayer Thin Films on Polylactic Acid with Tunable Gas Barrier Properties2013In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 5, no 15, p. 7352-7359Article in journal (Refereed)
    Abstract [en]

    The layer-by-layer (LbL) deposition method was used for the build-up of alternating layers of nanofibrillated cellulose (NFC) or carboxymethyl cellulose (CMC) with a branched, cationic polyelectrolyte, polyethyleneimine (PEI) on flexible poly (lactic acid) (PLA) substrates. With this procedure, optically transparent nanocellulosic films with tunable gas barrier properties were formed. 50 layer pairs of PEI/NFC and PEI/CMC deposited on PLA have oxygen permeabilities of 0.34 and 0.71 cm(3).mu m/m(2).day.kPa at 23 degrees C and 50% relative humidity, respectively, which is in the same range as polyvinyl alcohol and ethylene vinyl alcohol. The oxygen permeability of these multilayer nanocomposites outperforms those of pure NFC films prepared by solvent-casting. The nanocellulosic LbL assemblies on PLA substrates was in detailed characterized using a quartz crystal microbalance with dissipation (QCM-D). Atomic force microscopy (AFM) reveals large structural differences between the PEI/NFC and the PEI/CMC assemblies, with the PEI/NFC assembly showing a highly entangled network of nanofibrils, whereas the PEI/CMC surfaces lacked structural features. Scanning electron microscopy images showed a nearly perfect uniformity of the nanocellulosic coatings on PLA, and light transmittance results revealed remarkable transparency of the LbL-coated PLA films. The present work demonstrates the first ever LbL films based on high aspect ratio, water-dispersible nanofibrillated cellulose, and water-soluble carboxymethyl cellulose polymers that can be used as multifunctional films and coatings with tailorable properties, such as gas barriers and transparency. Owing to its flexibility, transparency and high-performance gas barrier properties, these thin film assemblies are promising candidates for several large-scale applications, including flexible electronics and renewable packaging.

  • 14.
    Azuma, Tomoyuki
    et al.
    Univ Tokyo, Dept Bioengn, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan..
    Teramura, Yuji
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology. Univ Tokyo, Dept Bioengn, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan..
    Takai, Madoka
    Univ Tokyo, Dept Bioengn, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan..
    Cellular Response to Non-contacting Nanoscale Sublayer: Cells Sense Several Nanometer Mechanical Property2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 17, p. 10710-10716Article in journal (Refereed)
    Abstract [en]

    Cell adhesion is influenced not only from the surface property of materials but also from the mechanical properties of the nanometer sublayer just below the surface. In this study, we fabricated a well-defined diblock polymer brush composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-aminoethyl methacrylate (AEMA). The underlying layer of poly(MPC) is a highly viscous polymer, and the surface layer of poly(AEMA) is a cell-adhesive cationic polymer. The adhesion of L929 mouse fibroblasts was examined on the diblock polymer brush to see the effect of a non contacting underlying polymer layer on the cell-adhesion behavior. Cells could sense the viscoelasticity of the underlying layers at the nanometer level, although the various fabricated diblock polymer brushes had the same surface property and the functional group. Thus, we found a new factor which could control cell spread at the nanometer level, and this insight would be important to design nanoscale biomaterials and interfaces.

  • 15. Badea, Adina
    et al.
    McCracken, Joselle M.
    Tillmaand, Emily G.
    Kandel, Mikhail E.
    Oraham, Aaron W.
    Mevis, Molly B.
    Rubakhin, Stanislav S.
    Popescu, Gabriel
    Sweedler, Jonathan V.
    Nuzzo, Ralph G.
    KTH, School of Chemical Science and Engineering (CHE).
    3D-Printed pHEMA Materials for Topographical and Biochemical Modulation of Dorsal Root Ganglion Cell Response2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 36, p. 30318-30328Article in journal (Refereed)
  • 16.
    Bakoglidis, Konstantinos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Univ Manchester, England.
    Palisaitis, Justinas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    dos Santos, Renato B.
    Univ Fed Bahia, Brazil.
    Rivelino, Roberto
    Univ Fed Bahia, Brazil.
    Persson, Per O A
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Gueorguiev, Gueorgui Kostov
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Self-Healing in Carbon Nitride Evidenced As Material Inflation and Superlubric Behavior2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 19, p. 16238-16243Article in journal (Refereed)
    Abstract [en]

    All known materials wear under extended mechanical contacting. Superlubricity may present solutions, but is an expressed mystery in C-based materials. We report negative wear of carbon nitride films; a wear-less condition with mechanically induced material inflation at the nanoscale and friction coefficient approaching ultralow values (0.06). Superlubricity in carbon nitride is expressed as C-N bond breaking for reduced coupling between graphitic-like sheets and eventual N-2 desorption. The transforming surface layer acts as a solid lubricant, whereas the film bulk retains its high elasticity. The present findings offer new means for materials design at the atomic level, and for property optimization in wear-critical applications like magnetic reading devices or nanomachines.

  • 17. Balitskii, Olexiy A.
    et al.
    Sytnyk, Mykhailo
    Stangl, Julian
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Groiss, Heiko
    Heiss, Wolfgang
    Tuning the Localized Surface Plasmon Resonance in Cu2-xSe Nanocrystals by Postsynthetic Ligand Exchange2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 20, p. 17770-17775Article in journal (Refereed)
    Abstract [en]

    Nanoparticles exhibiting localized surface plasmon resonances (LSPR) are valuable tools traditionally used in a wide field of applications including sensing, imaging, biodiagnostics and medical therapy. Plasmonics in semiconductor nanocrystals is of special interest because of the tunability of the carrier densities in semiconductors, and the possibility to couple the plasmonic resonances to quantum confined excitonic transitions. Here, colloidal Cu2-xSe nanocrystals were synthesized, whose composition was shown by Rutherford backscattering analysis and electron dispersive X-ray spectroscopy, to exhibit Cu deficiency. The latter results in p-type doping causing LSPRs, in the present case around a wavelength of 1100 nm, closely matching the indirect band gap of Cu2-xSe. By partial exchange of the organic ligands to specific electron trapping or donating species the LSPR is fine-tuned to exhibit blue or red shifts, in total up to 200 nm. This tuning not only provides a convenient tool for post synthetic adjustments of LSPRs to specific target wavelength but the sensitive dependence of the resonance wavelength on surface charges makes these nanocrystals also interesting for sensing applications, to detect analytes dressed by functional groups.

  • 18.
    Baloukas, Bill
    et al.
    Polytech Montreal, Dept Engn Phys, Montreal.
    Arvizu, Miguel A
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Wen, Rui-Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Niklasson, Gunnar A.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Granqvist, Claes Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Vernhes, Richard
    Polytech Montreal, Dept Engn Phys, Montreal.
    Klemberg-Sapieha, Jolanta E.
    Polytech Montreal, Dept Engn Phys, Montreal.
    Martinu, Ludvik
    Polytech Montreal, Dept Engn Phys, Montreal.
    Galvanostatic Rejuvenation of Electrochromic WO3 Thin Films: Ion Trapping and Detrapping Observed by Optical Measurements and by Time-of-Flight Secondary Ion Mass Spectrometry2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 20, p. 16996-17002Article in journal (Refereed)
    Abstract [en]

    Electrochromic (EC) smart windows are able to decrease our energy footprint while enhancing indoor comfort and convenience. However, the limited durability of these windows, as well as their cost, result in hampered market introduction. Here, we investigate thin films of the most widely studied EC material, WO3. Specifically, we combine optical measurements (using spectrophotometry in conjunction with variable-angle spectroscopic ellipsometry) with time-of-flight secondary ion mass spectrometry and atomic force microscopy. Data were taken on films in their as-deposited state, after immersion in a Li-ion-conducting electrolyte, after severe degradation by harsh voltammetric cycling and after galvanostatic rejuvenation to regain the original EC performance. Unambiguous evidence was found for the trapping and detrapping of Li ions in the films, along with a thickness increase or decrease during degradation and rejuvenation, respectively. It was discovered that (i) the trapped ions exhibited a depth gradient; (ii) following the rejuvenation procedure, a small fraction of the Li ions remained trapped in the film and gave rise to a weak short-wavelength residual absorption; and (iii) the surface roughness of the film was larger in the degraded state than in its virgin and rejuvenated states. These data provide important insights into the degradation mechanisms of EC devices and into means of achieving improved durability.

  • 19.
    Bao, Qinye
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. East China Normal University, Peoples R China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Li, Yanqing
    Soochow University, Peoples R China.
    Tang, Jianxin
    Soochow University, Peoples R China.
    Duan, Chungang
    East China Normal University, Peoples R China.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Energy Level Alignment of N-Doping Fullerenes and Fullerene Derivatives Using Air-Stable Dopant2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 40, p. 35476-35482Article in journal (Refereed)
    Abstract [en]

    Doping has been proved to be one of the powerful technologies to achieve significant improvement in the performance of organic electronic devices. Herein, we systematically map out the interface properties of solution-processed air-stable n-type (4(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl) doping fullerenes and fullerene derivatives and establish a universal energy level alignment scheme for this class of n-doped system. At low doping levels at which the charge-transfer doping induces mainly bound charges, the energy level alignment of the n-doping organic semiconductor can be described by combining integer charger transfer-induced shifts with a so-called double-dipole step. At high doping levels, significant densities of free charges are generated and the charge flows between the organic film and the conducting electrodes equilibrating the Fermi level in a classic "depletion layer" scheme. Moreover, we demonstrate that the model holds for both n- and p-doping of pi-backbone molecules and polymers. With the results, we provide wide guidance for identifying the application of the current organic n-type doping technology in organic electronics.

  • 20.
    Bao, Qinye
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. East China Normal Univ, Peoples R China; Soochow Univ, Peoples R China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Yang, Jianming
    East China Normal Univ, Peoples R China.
    Li, Yanqing
    Soochow Univ, Peoples R China.
    Tang, Jianxin
    Soochow Univ, Peoples R China.
    Duan, Chungang
    East China Normal Univ, Peoples R China.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    The Effect of Oxygen Uptake on Charge Injection Barriers in Conjugated Polymer Films2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 7, p. 6491-6497Article in journal (Refereed)
    Abstract [en]

    The energy offset between the electrode Fermi level and organic semiconductor transport levels is a key parameter controlling the charge injection barrier and hence efficiency of organic electronic devices. Here, we systematically explore the effect of in situ oxygen exposure on energetics in n-type conjugated polymer P(NDI2OD-T2) films. The analysis reveals that an interfacial potential step is introduced for a series of P(NDI2OD-T2) electrode contacts, causing a nearly constant downshift of the vacuum level, while the ionization energies versus vacuum level remain constant. These findings are attributed to the establishment of a so-called double-dipole step via motion of charged molecules and will modify the charge injection barriers at electrode contact. We further demonstrate that the same behavior occurs when oxygen interacts with p-type polymer TQ1 films, indicating it is possible to be a universal effect for organic semiconductOrs.

  • 21.
    Barba, Albert
    et al.
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Diez-Escudero, Anna
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Espanol, Montserrat
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Bonany, Mar
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Maria Sadowska, Joanna
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Guillem-Marti, Jordi
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain.
    Öhman-Mägi, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Manzanares, Maria-Cristina
    Univ Barcelona, Dept Pathol & Expt Therapeut, Human Anat & Embryol Unit, Barcelona 08907, Spain.
    Franch, Jordi
    Univ Autonoma Barcelona, Sch Vet, Small Anim Surg Dept, Bone Healing Grp, E-08193 Barcelona, Spain.
    Ginebra, Maria-Pau
    Univ Politecn Cataluna, Dept Mat Sci & Met Engn, Biomat Biomech & Tissue Engn Grp, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Univ Politecn Cataluna, Barcelona Res Ctr Multiscale Sci & Engn, Ave Eduard Maristany 10-14, Barcelona 08019, Spain;Barcelona Inst Technol BIST, Inst Bioengn Catalonia IBEC, Barcelona 08028, Spain.
    Impact of Biomimicry in the Design of Osteoinductive Bone Substitutes: Nanoscale Matters2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 9, p. 8818-8830Article in journal (Refereed)
    Abstract [en]

    Bone apatite consists of carbonated calcium-deficient hydroxyapatite (CDHA) nanocrystals. Biomimetic routes allow fabricating synthetic bone grafts that mimic biological apatite. In this work, we explored the role of two distinctive features of biomimetic apatites, namely, nanocrystal morphology (plate vs needle-like crystals) and carbonate content, on the bone regeneration potential of CDHA scaffolds in an in vivo canine model. Both ectopic bone formation and scaffold degradation were drastically affected by the nanocrystal morphology after intramuscular implantation. Fine-CDHA foams with needle-like nanocrystals, comparable in size to bone mineral, showed a markedly higher osteoinductive potential and a superior degradation than chemically identical coarse-CDHA foams with larger plate-shaped crystals. These findings correlated well with the superior bone-healing capacity showed by the fine-CDHA scaffolds when implanted intraosseously. Moreover, carbonate doping of CDHA, which resulted in small plate-shaped nanocrystals, accelerated both the intrinsic osteoinduction and the bone healing capacity, and significantly increased the cell-mediated resorption. These results suggest that tuning the chemical composition and the nanostructural features may allow the material to enter the physiological bone remodeling cycle, promoting a tight synchronization between scaffold degradation and bone formation.

  • 22.
    Barba, Albert
    et al.
    Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Universitat Politecnica de Catalunya.
    Diez-Escudero, Anna
    Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Universitat Politecnica de Catalunya.
    Maazouz, Yassine
    Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Universitat Politecnica de Catalunya.
    Rappe, Katrin
    Bone Healing Group, Small Animal Surgery Department, Veterinary School, Universitat Autonoma de Barcelona.
    Espanol, Montserrat
    Barcelona Research Center in Multiscale Science and Engineering, Universitat Politecnica de Catalunya.
    Montufar, Edgar B
    Barcelona Research Center in Multiscale Science and Engineering, Universitat Politecnica de Catalunya.
    Bonany, Mar
    Barcelona Research Center in Multiscale Science and Engineering, Universitat Politecnica de Catalunya.
    Sadowska, Joanna M
    Barcelona Research Center in Multiscale Science and Engineering, Universitat Politecnica de Catalunya.
    Guillem-Marti, Jordi
    Barcelona Research Center in Multiscale Science and Engineering, Universitat Politecnica de Catalunya.
    Öhman, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Manzanares, Maria-Cristina
    Human Anatomy and Embryology Unit, Department of Pathology and Experimental Therapeutics, Universitat de Barcelona.
    Franch, Jordi
    Bone Healing Group, Small Animal Surgery Department, Veterinary School, Universitat Autonoma de Barcelona.
    Ginebra, Maria-Pau
    Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Universitat Politecnica de Catalunya.
    Osteoinduction by Foamed and 3D-Printed Calcium Phosphate Scaffolds: Effect of Nanostructure and Pore Architecture2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 48, p. 41722-41736Article in journal (Refereed)
    Abstract [en]

    Some biomaterials are osteoinductive, that is, they are able to trigger the osteogenic process by inducing the differentiation of mesenchymal stem cells to the osteogenic lineage. Although the underlying mechanism is still unclear, microporosity and specific surface area (SSA) have been identified as critical factors in material-associated osteoinduction. However, only sintered ceramics, which have a limited range of porosities and SSA, have been analyzed so far. In this work, we were able to extend these ranges to the nanoscale, through the foaming and 3D-printing of biomimetic calcium phosphates, thereby obtaining scaffolds with controlled micro- and nanoporosity and with tailored macropore architectures. Calcium-deficient hydroxyapatite (CDHA) scaffolds were evaluated after 6 and 12 weeks in an ectopic-implantation canine model and compared with two sintered ceramics, biphasic calcium phosphate and β-tricalcium phosphate. Only foams with spherical, concave macropores and not 3Dprinted scaffolds with convex, prismatic macropores induced significant ectopic bone formation. Among them, biomimetic nanostructured CDHA produced the highest incidence of ectopic bone and accelerated bone formation when compared with conventional microstructured sintered calcium phosphates with the same macropore architecture. Moreover, they exhibited different bone formation patterns; in CDHA foams, the new ectopic bone progressively replaced the scaffold, whereas in sintered biphasic calcium phosphate scaffolds, bone was deposited on the surface of the material, progressively filling the pore space. In conclusion, this study demonstrates that the high reactivity of nanostructured biomimetic CDHA combined with a spherical, concave macroporosity allows the pushing of the osteoinduction potential beyond the limits of microstructured calcium phosphate ceramics.

  • 23.
    Ben Dkhil, Sadok
    et al.
    Aix Marseille University, France.
    Gaceur, Meriem
    Aix Marseille University, France.
    Karim Diallo, Abdou
    Aix Marseille University, France.
    Didane, Yahia
    Aix Marseille University, France.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Margeat, Olivier
    Aix Marseille University, France.
    Ackermann, Jorg
    Aix Marseille University, France.
    Videlot-Ackermann, Christine
    Aix Marseille University, France.
    Reduction of Charge-Carrier Recombination at ZnO Polymer Blend Interfaces in PTB7-Based Bulk Heterojunction Solar Cells Using Regular Device Structure: Impact of ZnO Nanoparticle Size and Surfactant2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 20, p. 17257-17265Article in journal (Refereed)
    Abstract [en]

    Cathode interfacial layers, also called electron extraction layers (EELs), based on zinc oxide (ZnO) have been studied in polymer-blend solar cells toward optimization of the opto-electric properties. Bulk heterojunction solar cells based on poly( {4, 8-bis [(2- ethylhexyl) oxy]b enzo [1,2- b :4,5-b dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]- thieno[3,4-b]thiophenediy1}) (PTB7) and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM) were realized in regular structure with all-solution-processed interlayers. A pair of commercially available surfactants, ethanolamine (EA) and ethylene glycol (EG), were used to modify the surface of ZnO nanoparticles (NPs) in alcohol-based dispersion. The influence of ZnO particle size was also studied by preparing dispersions of two NP diameters (6 versus 11 nm). Here, we show that performance improvement can be obtained in polymer solar cells via the use of solution-processed ZnO EELs based on surface-modified nanoparticles. By the optimizing of the ZnO dispersion, surfactant ratio, and the resulting morphology of EELs, PTB7/PC70BM solar cells with a power-conversion efficiency of 8.2% could be obtained using small sized EG-modified ZnO NPs that allow the clear enhancement of the performance of solution processed photovoltaic devices compared to state-of-the-art ZnO-based cathode layers.

  • 24.
    Bi, Dongqin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    El-Zohry, Ahmed M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Improved Morphology Control Using a Modified Two-Step Method for Efficient Perovskite Solar Cells2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 21, p. 18751-18757Article in journal (Refereed)
    Abstract [en]

    A two-step wet chemical synthesis method for methylammonium lead(II) triiodide (CH3NH3PbI3) perovskite is further developed for the preparation of highly reproducible solar cells, with the following structure: fluorine-doped tin oxide (FTO)/TiO2 (compact)/TiO2 (mesoporous)/CH3NH3PbI3/spiro-OMeTAD/Ag. The morphology of the perovskite layer could be controlled by careful variation of the processing conditions. Specifically, by modifying the drying process and inclusion of a dichloromethane treatment, more uniform films could be prepared, with longer emission lifetime in the perovskite material and longer electron lifetime in solar cell devices, as well as faster electron transport and enhanced charge collection at the selective contacts. Solar cell efficiencies up to 13.5% were obtained.

  • 25.
    Blomfeldt, Thomas O. J.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Nilsson, Fritjof
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Holgate, Tim
    Xu, Jianxiao
    Johansson, Eva
    Hedenqvist, Mikael S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Thermal Conductivity and Combustion Properties of Wheat Gluten Foams2012In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, no 3, p. 1629-1635Article in journal (Refereed)
    Abstract [en]

    Freeze-dried wheat gluten foams were evaluated with respect to their thermal and fire-retardant properties, which are important for insulation applications. The thermal properties were assessed by differential scanning calorimetry, the laser flash method and a hot plate method. The unplasticised foam showed a similar specific heat capacity, a lower thermal diffusivity and a slightly higher thermal conductivity than conventional rigid polystyrene and polyurethane insulation foams. Interestingly, the thermal conductivity was similar to that of closed cell polyethylene and glass-wool insulation materials. Cone calorimetry showed that, compared to a polyurethane foam, both unplasticised and glycerol-plasticised foams had a significantly longer time to ignition, a lower effective heat of combustion and a higher char content. Overall, the unplasticised foam showed better fire-proof properties than the plasticized foam. The UL 94 test revealed that the unplasticised foam did not drip (form droplets of low viscous material) and, although the burning times varied, self-extinguished after flame removal. To conclude both the insulation and fire-retardant properties were very promising for the wheat gluten foam.

  • 26.
    Boge, Lukas
    et al.
    RISE Res Inst Sweden, S-50115 Boras, Sweden;Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden.
    Browning, Kathryn L.
    Univ Copenhagen, Dept Pharm, DK-2100 Copenhagen, Denmark.
    Nordström, Randi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Campana, Mario
    Rutherford Appleton Lab, Didcot OX11 0DE, Oxon, England.
    Darngaard, Liv S. E.
    Univ Copenhagen, Dept Pharm, DK-2100 Copenhagen, Denmark.
    Caous, Josefin Seth
    RISE Res Inst Sweden, S-50115 Boras, Sweden.
    Hellsing, Maja
    RISE Res Inst Sweden, S-50115 Boras, Sweden.
    Ringstad, Lovisa
    RISE Res Inst Sweden, S-50115 Boras, Sweden.
    Andersson, Martin
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden.
    Peptide-Loaded Cubosomes Functioning as an Antimicrobial Unit against Escherichia coil2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 24, p. 21314-21322Article in journal (Refereed)
    Abstract [en]

    Dispersions of cubic liquid crystalline phases, also known as cubosomes, have shown great promise as delivery vehicles for a wide range of medicines. Due to their ordered structure, comprising alternating hydrophilic and hydrophobic domains, cubosomes possess unique delivery properties and compatibility with both water-soluble and-insoluble drugs. However, the drug delivery mechanism and cubosome interaction with human cells and bacteria are still poorly understood. Herein, we reveal how cubosomes loaded with the human cathelicidin antimicrobial peptide LL-37, a system with high bacteria-killing effect, interact with the bacterial membrane and provide new insights into the eradication mechanism. Combining the advanced experimental techniques neutron reflectivity and quartz crystal microbalance with dissipation monitoring, a mechanistic drug delivery model for LL-37-loaded cubosomes on bacterial mimicking bilayers was constructed. Moreover, the cubosome interaction with Escherichia coli was directly visualized using super-resolution laser scanning microscopy and cryogenic electron tomography. We could conclude that cubosomes loaded with LL-37 adsorbed and distorted bacterial membranes, providing evidence that the peptide-loaded cubosomes function as an antimicrobial unit.

  • 27.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Browning, Kathryn
    University of Copenhagen, Denmark.
    Nordström, Randi
    Uppsala University, Sweden.
    Campana, Mario
    Rutherford Appleton Laboratory, UK.
    Damgaard, Liv
    University of Copenhagen, Denmark.
    Seth Caous, Josefin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Hellsing, Maja
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Peptide-Loaded Cubosomes Functioning as an Antimicrobial Unit against Escherichia coli2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 24, p. 21314-21322Article in journal (Refereed)
    Abstract [en]

    Dispersions of cubic liquid crystalline phases, also known as cubosomes, have shown great promise as delivery vehicles for a wide range of medicines. Due to their ordered structure, comprising alternating hydrophilic and hydrophobic domains, cubosomes possess unique delivery properties and compatibility with both water-soluble and -insoluble drugs. However, the drug delivery mechanism and cubosome interaction with human cells and bacteria are still poorly understood. Herein, we reveal how cubosomes loaded with the human cathelicidin antimicrobial peptide LL-37, a system with high bacteria-killing effect, interact with the bacterial membrane and provide new insights into the eradication mechanism. Combining the advanced experimental techniques neutron reflectivity and quartz crystal microbalance with dissipation monitoring, a mechanistic drug delivery model for LL-37-loaded cubosomes on bacterial mimicking bilayers was constructed. Moreover, the cubosome interaction with Escherichia coli was directly visualized using super-resolution laser scanning microscopy and cryogenic electron tomography. We could conclude that cubosomes loaded with LL-37 adsorbed and distorted bacterial membranes, providing evidence that the peptide-loaded cubosomes function as an antimicrobial unit.

  • 28.
    Boujemaoui, Assya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Carlsson, Linn
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lahcini, Mohammed
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Sehaqui, Houssine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Facile Preparation Route for Nanostructured Composites: Surface-Initiated Ring-Opening Polymerization of epsilon-Caprolactone from High-Surface-Area Nanopaper2012In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, no 6, p. 3191-3198Article in journal (Refereed)
    Abstract [en]

    In this work, highly porous nanopaper, i.e., sheets of papers made from non-aggregated nanofibrillated cellulose (NFC), have been surface-grafted with poly(epsilon-caprolactone) (PCL) by surface-initiated ring-opening polymerization (SI-ROP). The nanopaper has exceptionally high surface area (similar to 300 m(2)/g). The "grafting from" of the nanopapers was compared to "grafting from" of cellulose in the form of filter paper, and in both cases either titanium n-butoxide (Ti(On-Bu)(4)) or tin octoate (Sn(Oct)(2)) was utilized as a catalyst. It was found that a high surface area leads to significantly higher amount of grafted PCL in the substrates when Sn(Oct)2 was utilized as a catalyst. Up to 79 wt % PCL was successfully grafted onto the nanopapers as compared to filter paper where only 2-3 wt % PCL was grafted. However, utilizing Ti(On-Bu)4 this effect was not seen and the grafted amount was essentially similar, irrespectively of surface area. The mechanical properties of the grafted nanopaper proved to be superior to those of pure PCL films, especially at elevated temperatures. The present bottom-up preparation route of NFC-based composites allows high NFC content and provides excellent nanostructural control. This is an important advantage compared with some existing preparation routes where dispersion of the filler in the matrix is challenging.

  • 29.
    Boujemaoui, Assya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Sanchez, Carmen Cobo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Engström, Joakim
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Bruce, Carl
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. RISE Innventia AB, Stockholm, Sweden.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Polycaprolactone Nanocomposites Reinforced with Cellulose Nanocrystals Surface-Modified via Covalent Grafting or Physisorption: A Comparative Study2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 40, p. 35305-35318Article in journal (Refereed)
    Abstract [en]

    In the present work, cellulose nanocrystals (CNCs) have been surface-modified either via covalent grafting or through physisorption of poly(n-butyl methacrylate) (PBMA) and employed as reinforcement in PCL. Covalent grafting was achieved by surface-initiated atom transfer radical polymerization (SI-ATRP). Two approaches were utilized for the physisorption: using either micelles of poly(dimethyl aminoethyl methacrylate)-block-poly(n-butyl methacrylate) (PDMAEMA-b-PBMA) or latex nanoparticles of poly(dimethyl aminoethyl methacrylate-co-methacrylic acid)-block-poly(n-butyl methacrylate) (P(DMAEMA-co-MAA)-b-PBMA). Block copolymers (PDMAEMA-b-PBMA)s were obtained by ATRP and subsequently micellized. Latex nanoparticles were produced via reversible addition-fragmentation chain-transfer (RAFT) mediated surfactant-free emulsion polymerization, employing polymer-induced self-assembly (PISA) for the particle formation. For a reliable comparison, the amounts of micelles/latex particles adsorbed and the amount of polymer grafted onto the CNCs were kept similar. Two different chain lengths of PBMA were targeted, below and above the critical molecular weight for chain entanglement of PBMA (M-n,M-c similar to 56 000 g mo1(-1)). Poly(epsilon-caprolactone) (PCL) nanocomposites reinforced with unmodified and modified CNCs in different weight percentages (0.5, 1, and 3 wt %) were prepared via melt extrusion. The resulting composites were evaluated by UV-vis, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and tensile testing. All materials resulted in higher transparency, greater thermal stability, and stronger mechanical properties than unfilled PCL and nanocomposites containing unmodified CNCs. The degradation temperature of PCL reinforced with grafted CNCs was higher than that of micelle-modified CNCs, and the latter was higher than that of latex-adsorbed CNCs with a long PBMA chain length. The results clearly indicate that covalent grafting is superior to physisorption with regard to thermal and mechanical properties of the final nanocomposite. This unique study is of great value for the future design of CNC-based nanocomposites with tailored properties.

  • 30.
    Bridarolli, Alexandra
    et al.
    UCL Eastman Dental Institute, United Kingdom.
    Odlyha, Marianne
    Birkbeck College, United Kingdom.
    Nechyporchuk, Oleksandr
    RISE - Research Institutes of Sweden, Materials and Production, IVF. Chalmers University of Technology, Sweden.
    Holmberg, Krister
    Chalmers University of Technology, Sweden.
    Ruiz-Recasens, Cristina
    University of Barcelona, Spain.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Bozec, L.
    UCL Eastman Dental Institute, United Kingdom; University of Toronto, Canada.
    Evaluation of the Adhesion and Performance of Natural Consolidants for Cotton Canvas Conservation2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 39, p. 33652-33661Article in journal (Refereed)
    Abstract [en]

    Recent developments in paper and canvas conservation have seen the introduction of nanocellulose (NC) as a compatible treatment for the consolidation of historical cellulosic artifacts and manuscripts. However, as part of the assessment of these new materials for canvas consolidation, the adhesion of the consolidation treatment (which takes place between the applied material and the substrate) has not yet been evaluated, and as a result, it is poorly understood by both the scientific and conservation communities. After evaluating the potential of NC treatments for the consolidation of cotton painting canvas, we investigate a route to promote the interaction between the existing canvas and the nanocellulose treatment, which is in our case made of cellulose nanofibrils (CNF). This was carried out by introducing a cationic polymer, polyamidoamine-epichlorohydrin (PAAE), as an intermediate layer between the canvas and the CNF. The morphological, chemical, and mechanical evaluation of the canvas samples at different relative humidity (RH) levels demonstrated how the adhesion of the added PAAE layer is a dominant factor in the consolidation process. Improvement in the coating of canvas single fibers by the CNF, higher adhesion energy between the canvas fibers and the CNF treatment, and finally overall stronger canvas reinforcement were observed following the introduction of PAAE. However, an increase in mechanical response to moisture sorption and desorption was also observed for the PAAE-treated canvases. Overall, this study shows the complexity of such systems and, as such, the relevance of using a multiscale approach for their assessment.

  • 31.
    Budnyak, Tetyana
    et al.
    KTH. Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov St, UA-03164 Kiev, Ukraine..
    Gladysz-Plaska, Agnieszka
    Marie Curie Sklodowska Univ, 2 Marie Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Strizhak, Alexander V.
    Taras Shevchenko Natl Univ Kyiv, 64-13 Volodymyrska St, UA-01601 Kiev, Ukraine..
    Sternik, Dariusz
    Marie Curie Sklodowska Univ, 2 Marie Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Komarov, Igor V.
    Taras Shevchenko Natl Univ Kyiv, 64-13 Volodymyrska St, UA-01601 Kiev, Ukraine..
    Majdan, Marek
    Marie Curie Sklodowska Univ, 2 Marie Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Tertykh, Valentin A.
    Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov St, UA-03164 Kiev, Ukraine..
    Imidazole-2yl-Phosphonic Acid Derivative Grafted onto Mesoporous Silica Surface as a Novel Highly Effective Sorbent for Uranium(VI) Ion Extraction2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 7, p. 6681-6693Article in journal (Refereed)
    Abstract [en]

    A new imidazol-2yl-phosphonic acid/mesoporous silica sorbent (ImP(O)(OH)(2)/SiO2) was developed and applied for uranium(VI) ion removal from aqueous solutions. The synthesized material was characterized by fast kinetics and an extra-high adsorption capacity with respect to uranium. The highest adsorption efficiency of U(VI) ions was obtained for the reaction system at pH 4 and exceeded 618 mg/g. The uranium(VI) sorption proceeds quickly in the first step within 60 min of the adsorbent sites and ion interactions. Moreover, the equilibrium time was determined to be 120 min. The equilibrium and kinetic characteristics of the uranium(VI) ions uptake by synthesized sorbent was found to follow the Langmuir-Freundlich isotherm model and pseudo-second-order kinetics rather than the Langmuir, Dubinin-Radushkevich, and Temkin models and pseudo-first-order or intraparticle diffusion sorption kinetics. The adsorption mechanism for uranium on the sorbent was clarified basing on the X-ray photoelectron spectroscopy (XPS) analysis. The model of UO22+ binding to surface of the sorbent was proposed according to the results of XPS, i.e., a 1:1 U-to-P ratio in the sorbed complex was established. The regeneration study confirms the ImP(O)(OH)(2)/SiO2 sorbent can be reused. A total of 45% of uranium ions was determined as originating from the sorbent leaching in the acidic solutions, whereas when the basic solutions were used, the removal efficiency was 12%.

  • 32.
    Bulota, Mindaugas
    et al.
    Department of Forest Products Technology, School of Chemical Technology, Aalto University.
    Tanpichai, Supachok
    Materials Science Centre, School of Materials, School of Materials, University of Manchester.
    Hughes, Mark R.
    Department of Forest Products Technology, School of Chemical Technology, Aalto University.
    Eichhorn, Stephen J.
    College of Engineering, Mathematics and Physical Sciences, University of Exeter.
    Micromechanics of TEMPO-oxidized fibrillated cellulose composites2012In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, no 1, p. 331-337Article in journal (Refereed)
    Abstract [en]

    Composites of poly(lactic) acid (PLA) reinforced with TEMPO-oxidized fibrillated cellulose (TOFC) were prepared to 15, 20, 25, and 30% fiber weight fractions. To aid dispersion and to improve stress transfer, we acetylated the TOFC prior to the fabrication of TOFC-PLA composite films. Raman spectroscopy was employed to study the deformation micromechanics in these systems. Microtensile specimens were prepared from the films and deformed in tension with Raman spectra being collected simultaneously during deformation. A shift in a Raman peak initially located at ∼1095 cm -1, assigned to C-O-C stretching of the cellulose backbone, was observed upon deformation, indicating stress transfer from the matrix to the TOFC reinforcement. The highest band shift rate, with respect to strain, was observed in composites having a 30% weight fraction of TOFC. These composites also displayed a significantly higher strain to failure compared to pure acetylated TOFC film, and to the composites having lower weight fractions of TOFC. The stress-transfer processes that occur in microfibrillated cellulose composites are discussed with reference to the micromechanical data presented. It is shown that these TOFC-based composite materials are progressively dominated by the mechanics of the networks, and a shear-lag type stress transfer between fibers.

  • 33.
    Byeon, Ayeong
    et al.
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA; Korea Adv Institute Science and Technology, South Korea.
    Zhao, Meng-Qiang
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Ren, Chang E.
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Halim, Joseph
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Kota, Sankalp
    Drexel University, PA 19104 USA.
    Urbankowski, Patrick
    Drexel University, PA 19104 USA.
    Anasori, Babak
    Drexel University, PA 19104 USA.
    Barsoum, Michel W.
    Drexel University, PA 19104 USA.
    Gogotsi, Yury
    Drexel University, PA 19104 USA.
    Two-Dimensional Titanium Carbide MXene As a Cathode Material for Hybrid Magnesium/Lithium-Ion Batteries2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 5, p. 4296-4300Article in journal (Refereed)
    Abstract [en]

    As an alternative to pure lithium-ion, Lit, systems, a hybrid magnesium, Mg2+, and Li+ battery can potentially combine the high capacity, high voltage, and fast Li+ intercalation of Li-ion battery cathodes and the high capacity, low cost, and dendrite-free Mg metal anodes. Herein, we report on the use of two-dimensional titanium carbide, Ti3C2Tx (MXene), as a cathode in hybrid Mg2+/Li+ batteries, coupled with a Mg metal anode. Free-standing and flexible Ti3C2Tx/carbon nanotube composite "paper" delivered-,100 mAh at 0.1 C and similar to 50 mAh g(-1) at 10 C. At 1 C the capacity was maintained for amp;gt;500 cycles at 80 mAh g(-1). The Mo2CTx MXene also demonstrated good performance as a cathode material in this hybrid battery. Considering the variety of available MXenes, this work opens the door for exploring a new large family of 2D materials with high electrical conductivity and large intercalation capacity as cathodes for hybrid Mg2+/Li+ batteries.

  • 34.
    Cailotto, Simone
    et al.
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Piazza del Viminale 1, 00184 Roma, Italy.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Selva, Maurizio
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Cattaruzza, Elti
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Cristofori, Davide
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy;Centro di microscopia elettronica “G. Stevanato”, Via Torino 155b, 30172 Venezia-Mestre, Italy.
    Amadio, Emanuele
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Perosa, Alvise
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Design of Carbon Dots for Metal-free Photoredox Catalysis2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 47, p. 40560-40567Article in journal (Refereed)
    Abstract [en]

    The photoreduction potential of a set of four different carbon dots (CDs) was investigated. The CDs were synthesized by using two different preparation methods—hydrothermal and pyrolytic—and two sets of reagents—neat citric acid and citric acid doped with diethylenetriamine. The hydrothermal syntheses yielded amorphous CDs, which were either nondoped (a-CDs) or nitrogen-doped (a-N-CDs), whereas the pyrolytic treatment afforded graphitic CDs, either non-doped (g-CDs) or nitrogen-doped (g-N-CDs). The morphology, structure, and optical properties of four different types of CDs revealed significant differences depending on the synthetic pathway. The photocatalytic activities of the CDs were investigated as such, that is, in the absence of any other redox mediators, on the model photoreduction reaction of methyl viologen. The observed photocatalytic reaction rates: a-N-CDs ≥ g-CDs > a-CDs ≥ g-N-CDs were correlated with the presence/absence of fluorophores, to the graphitic core, and to quenching interactions between the two. The results indicate that nitrogen doping reverses the photoredox reactivity between amorphous and graphitic CDs and that amorphous N-doped CDs are the most photoredox active, a yet unknown fact that demonstrates the tunable potential of CDs for ad hoc applications.

  • 35.
    Cappel, Ute B.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Svanström, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Lanzilotto, Valeria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Johansson, Fredrik O. L.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Aitola, Kerttu
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Giangrisostomi, Erika
    Helmholtz Zentrum Berlin GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Ovsyannikov, Ruslan
    Helmholtz Zentrum Berlin GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Leitner, Torsten
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Foehlisch, Alexander
    Helmholtz Zentrum Berlin GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, Albert Einstein Str 15, D-12489 Berlin, Germany.;Univ Potsdam, Inst Phys & Astron, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany..
    Svensson, Svante
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Mårtensson, Nils
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Uppsala Berlin Joint Lab Next Generat Photoelectr, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Rensmo, Håkan
    Partially Reversible Photoinduced Chemical Changes in a Mixed-Ion Perovskite Material for Solar Cells2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 40, p. 34970-34978Article in journal (Refereed)
    Abstract [en]

    Metal halide perovskites have emerged as materials of high interest for solar energy-to-electricity conversion, and in particular, the use of mixed-ion structures has led to high power conversion efficiencies and improved stability. For this reason, it is important to develop means to obtain atomic level understanding of the photoinduced behavior of these materials including processes such as photoinduced phase separation and ion migration. In this paper, we implement a new methodology combining visible laser illumination of a mixed-ion perovskite ((FAP-bI(3))(0.85)(MAPbBr(3))(0.15)) with the element specificity and chemical sensitivity of core-level photoelectron spectroscopy. By carrying out measurements at a synchrotron beamline optimized for low X-ray fluxes, we are able to avoid sample changes due to X-ray illumination and are therefore able to monitor what sample changes are induced by visible illumination only. We find that laser illumination causes partially reversible chemistry in the surface region, including enrichment of bromide at the surface, which could be related to a phase separation into bromide- and iodide-rich phases. We also observe a partially reversible formation of metallic lead in the perovskite structure. These processes occur on the time scale of minutes during illumination. The presented methodology has a large potential for understanding light-induced chemistry in photoactive materials and could specifically be extended to systematically study the impact of morphology and composition on the photostability of metal halide perovskites.

  • 36. Cappel, Ute B
    et al.
    Svanström, Sebastian
    Lanzilotto, Valeria
    Johansson, Fredrik O L
    Aitola, Kerttu
    Philippe, Bertrand
    Giangrisostomi, Erika
    Ovsyannikov, Ruslan
    Leitner, Torsten
    Föhlisch, Alexander
    Svensson, Svante
    Mårtensson, Nils
    Boschloo, Gerrit
    Lindblad, Andreas
    Rensmo, Håkan
    Partially Reversible Photoinduced Chemical Changes in a Mixed-Ion Perovskite Material for Solar Cells.2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 40, p. 34970-34978Article in journal (Refereed)
    Abstract [en]

    ) with the element specificity and chemical sensitivity of core-level photoelectron spectroscopy. By carrying out measurements at a synchrotron beamline optimized for low X-ray fluxes, we are able to avoid sample changes due to X-ray illumination and are therefore able to monitor what sample changes are induced by visible illumination only. We find that laser illumination causes partially reversible chemistry in the surface region, including enrichment of bromide at the surface, which could be related to a phase separation into bromide- and iodide-rich phases. We also observe a partially reversible formation of metallic lead in the perovskite structure. These processes occur on the time scale of minutes during illumination. The presented methodology has a large potential for understanding light-induced chemistry in photoactive materials and could specifically be extended to systematically study the impact of morphology and composition on the photostability of metal halide perovskites.

  • 37. Carmona, Francisco J.
    et al.
    Maldonado, Carmen R.
    Ikemura, Shuya
    Romao, Carlos C.
    Huang, Zhehao
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Xu, Hongyi
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kitagawa, Susumu
    Furukawa, Shuhei
    Barea, Elisa
    Coordination Modulation Method To Prepare New Metal-Organic Framework-Based CO-Releasing Materials2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 37, p. 31158-31167Article in journal (Refereed)
    Abstract [en]

    Aluminum-based metal organic frameworks (MOFs), [Al(OH)(SDC)](n), (H2SDC: 4,4'-stilbenedicarboxylic acid), also known as CYCU-3, were prepared by means of the coordination modulation method to produce materials with different crystal size and morphology. In particular, we screened several reagent concentrations (20-60 mM) and modulator/ligand ratios (0-50), leading to 20 CYCU x_y materials (x: reagent concentration, y = modulator/ligand ratio) with different particle size and morphology. Noteworthy, the use of high modulator/ligand ratio gives rise to a new phase of CYCU-3 (CYCU-3' x_50 series), which was structurally analyzed. Afterward, to test the potential of these materials as CO-prodrug carriers, we selected three of them to adsorb the photo- and bioactive CO-releasing molecule (CORM) ALF794 [Mo(CNCMe2CO2H)(3)(CO)(3)] (CNCMe2CO2H = 2-isocyano-2-methyl propionic acid): (i) CYCU-3 20_0, particles in the nanometric range; (ii) CYCU-3 50_5, bar-type particles with heterogeneous size, and (iii) CYCU-3' 50_50, a new phase analogous to pristine CYCU-3. The corresponding hybrid materials were fully characterized, revealing that CYCU-3 20_0 with the smallest particle size was not stable under the drug loading conditions. Regarding the other two materials, similar ALF794 loadings were found (0.20 and 0.19 CORM/MOF molar ratios for ALF794@CYCU-3 50_5 and ALF794@CYCU-3' 50_50, respectively). In addition, these hybrid systems behave as CO-releasing materials (CORMAs), retaining the photoactive properties of the pristine CORM in both phosphate saline solution and solid state. Finally, the metal leaching studies in solution confirmed that ALF794@CYCU-3' 50_50 shows a good retention capacity toward the potentially toxic molybdenum fragments (7S% of retention after 72 h), which is the lowest value reported for a MOF-based CORMA to date.

  • 38.
    Carosio, Federico
    et al.
    Politecn Torino, I-15121 Alessandria, Italy.
    Kochumalayil, Jose
    Cuttica, F.
    Camino, G.
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Oriented Clay Nanopaper from Biobased Components Mechanisms for Superior Fire Protection Properties2015In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 10, p. 5847-5856Article in journal (Refereed)
    Abstract [en]

    The toxicity of the most efficient fire retardant additives is a major problem for polymeric Materials. Cellulose nanofiber (CNF)/clay nanocomposites, with unique brick-and-mortar structure and prepared by simple filtration, are characterized from the morphological point of view by scanning electron microscopy and X-ray diffraction. These nanocomposites have superior fire protection properties to Other clay nanocomposites and fiber composites. The Corresponding mechanisms are evaluated in terms of flammability (reaction to a flame) and cone calorimetry (exposure to heat flux). These two tests provide a wide spectrum characterization of fire protection properties in CNF/montmorrilonite (MTM) Materials. The morphology of the collected residues after flammability testing is investigated. In addition, thermal and thermo-oxidative stability are evaluated by thermogravimetric analyses performed in inert (nitrogen) and oxidative (air) atmospheres. Physical and chemical mechanisms are identified and related to the unique nanostructure and its low thermal conductivity, high gas barrier properties and CNF/ MTM interactions for char formation.

  • 39.
    Carrick, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Pendergraph, Samuel A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Nanometer Smooth, Macroscopic Spherical Cellulose Probes for Contact Adhesion Measurements2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 23, p. 20928-20935Article in journal (Refereed)
    Abstract [en]

    Cellulose spheres were prepared by dissolving cellulose fibers and subsequently solidifying the solution in a nonsolvent. Three different solution concentrations were tested and several nonsolvents were evaluated for their effect on the formation of spheres. Conditions were highlighted to create cellulose spheres with a diameter of similar to 1 mm and a root-mean-square surface roughness of similar to 1 nm. These solid spheres were shown to be easily chemically modified without changing the mechanical properties significantly. Contact adhesion measurements were then implemented with these spheres against a poly(dimethylsiloxane) (PDMS) elastomer in order to quantify the adhesion. Using Johnson-Kendall-Roberts (JKR) theory, we quantified the adhesion for unmodified cellulose and hydrophobic cellulose spheres. We highlight the ability of these spheres to report more accurate adhesion information, compared to spin-coated thin films. The application of these new cellulose probes also opens up new possibilities for direct, accurate measurement of adhesion between cellulose and other materials instead of using uncertain surface energy determinations to calculate the theoretical work of adhesion between cellulose and different solid materials.

  • 40.
    Cervin, Nicholas Tchang
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Johanson, Erik
    Larsson, Per A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Strong, Water-Durable, and Wet-Resilient Cellulose Nanofibril-Stabilized Foams from Oven Drying2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 18, p. 11682-11689Article in journal (Refereed)
    Abstract [en]

    Porous materials from cellulose nanofibrils (CNFs) have been prepared using Pickering foams from aqueous dispersions. Stable wet foams were first produced using surface-modified CNFs as stabilizing particles. To better maintain the homogeneous pore structure of the foam after drying, the foams were dried in an oven on a liquid-filled porous ceramic frit. The cell structure was studied by scanning electron microscopy and liquid porosimetry, the mechanical properties were studied by compression testing, and the liquid absorption capacity was determined both with liquid porosimetry and by soaking in water. By controlling the charge density of the CNFs, it was possible to prepare dry foams with different densities, the lowest density being 6 kg m(-3), that is, a porosity of 99.6%. For a foam with a density of 200 kg m(-3) the compressive Young's modulus was 50 MPa and the energy absorption to 70% strain was 2.3 MJ M-3. The use of chemically modified CNFs made it possible to prepare cross-linked foams with water-durable and wet-resilient properties. These foams absorbed liquid up to 34 times their own weight and were able to release this liquid under compression and to reabsorb the same amount when the pressure was released.

  • 41.
    Chateau, Denis
    et al.
    Laboratoire de Chimie, Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR5182, Lyon 69364, France.
    Chaput, Frederic
    Laboratoire de Chimie, Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR5182, Lyon 69364, France.
    Lopes, Cesar
    Information Systems, Swedish Defence Research Agency (FOI), Linköping SE-581 11, Sweden.
    Lindgren, Mikael
    Department of Physics, Norwegian University of Science and Technology, Trondheim NO-7491, Norway.
    Brännlund, Carl
    Information Systems, Swedish Defence Research Agency (FOI), Linköping SE-581 11, Sweden.
    Öhgren, Johan
    Information Systems, Swedish Defence Research Agency (FOI), Linköping SE-581 11, Sweden.
    Djourelov, Nikolay
    Institut de Physique Nucléaire, Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Villeurbanne, France.
    Nedelec, Patrick
    Institut de Physique Nucléaire, Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Villeurbanne, France.
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kindahl, Tomas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lerouge, Frederic
    Laboratoire de Chimie, Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR5182, Lyon 69364, France.
    Andraud, Chantal
    Laboratoire de Chimie, Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR5182, Lyon 69364, France.
    Parola, Stephane
    Laboratoire de Chimie, Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR5182, Lyon 69364, France.
    Silica hybrid sol-gel materials with unusually high concentration of Pt-organic molecular guests: Studies of luminescence and nonlinear absorption of light2012In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, no 5, p. 2369-2377Article in journal (Refereed)
    Abstract [en]

    The development of new photonic materials is a key step towards improvement of existing optical devices and for the preparation of a new generation of systems. Therefore synthesis of photonic hybrid materials with a thorough understanding and control of the microstructure-to-properties relationships is crucial. In this perspective, a new preparation method based on fast gelation reactions using simple dispersion of dyes without strong covalent bonding between dye and matrix has been developed. This new sol-gel method is demonstrated through synthesis of monolithic siloxane-based hybrid materials highly doped by various platinum(II) acetylide derivatives. Concentrations of the chromophores as high as 400 mM were obtained and resulted in unprecedented optical power limiting (OPL) performance at 532 nm of the surface-polished solids. Static and time-resolved photoluminescence of the prepared hybrid materials were consistent with both OPL data and previous studies of similar Pt(II) compounds in solution. The impacts of the microstructure and the chemical composition of the matrix on the spectroscopic properties, are discussed.

  • 42.
    Chen, Cheng
    et al.
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Li, Hongping
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Ding, Xingdong
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Cheng, Ming
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Li, Henan
    Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Peoples R China..
    Xu, Li
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Qiao, Fen
    Jiangsu Univ, Sch Energy & Power Engn, Zhenjiang 212013, Peoples R China..
    Li, Huaming
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Molecular Engineering of Triphenylamine-Based Non-Fullerene Electron-Transport Materials for Efficient Rigid and Flexible Perovskite Solar Cells2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 45, p. 38970-38977Article in journal (Refereed)
    Abstract [en]

    There has been a growing interest in the design and synthesis of non-fullerene electron transport materials (ETMs) for perovskite solar cells (PSCs), which may overcome the drawbacks of traditional fullerene derivatives. In this work, a novel donor-acceptor (D-A) structured ETM termed TPA-3CN is presented by molecular engineering of triphenylamine (TPA) as the donor group and (3-cyano-4,5,5-trimethyl-2(5H)-furanylidene) malononitrile as the acceptor group. To further improve the electron mobility and conductivity and achieve excellent photovoltaic performance, a solution processable n-type dopant is introduced during the ETM spin-coating step. After device optimization, PSCs based on the doped TPA-3CN exhibit an impressive power conversion efficiency (PCE) of 19.2% with a negligible hysteresis. Benefitting from the low temperature and good solution processability of ETM TPA-3CN, it was further applied in flexible inverted PSCs and an impressive PCE of 13.2% was achieved, which is among the highest values reported for inverted flexible fullerene-free PSCs.

  • 43. Chen, Cheng
    et al.
    Yang, Xichuan
    Cheng, Ming
    Zhang, Fuguo
    Zhao, Jianghua
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Efficient Panchromatic Organic Sensitizers with Dihydrothiazole Derivative as pi-Bridge for Dye-Sensitized Solar Cells2013In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 5, no 21, p. 10960-10965Article in journal (Refereed)
    Abstract [en]

    Novel organic dyes CC201 and CC202 with dihydrothiazole derivative as pi-bridge have been synthesizedand applied in the DSSCs. With the synergy electron-withdrawing of dihydrothiazole and cyanoacrylic acid, these two novel dyes CC201 and CC202 show excellent response in the region of 500-800 nm. An efficiency as high as 6.1% was obtained for the device fabricated by sensitizer CC202 together with cobalt electrolyte under standard light illumination (AM 1.5G, 100 mW cm(-2)). These two novel D-pi-A panchromatic organic dyes gave relatively high efficiencies except common reported squaraine dyes.

  • 44. Chen, Song
    et al.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Li, Yuanyuan
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Wang, Xingzhu
    Ong, Beng
    Wong, Wai-Kwok
    Zhu, Xunjin
    Study of Arylamine-Substituted Porphyrins as Hole-Transporting Materials in High-Performance Perovskite Solar Cells2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 15, p. 13231-13239Article in journal (Refereed)
    Abstract [en]

    To develop new hole-transporting materials (HTMs) for efficient and stable perovskite solar. cells (PSCs), 5,10,15,20-tetrakis{4-[N,N-di(4-thethoxylphenyl)amino-phenyl]}-porphyrin was prepared in gram scale through the direct condensation of pyrrole and 4-[bis(4-methoxyphenyl)amino]-benzaldehyde. Its Zn(II) and Cu(II) complexes exhibit excellent thermal and electrochemical stability, specifically a high hole Mobility and very favorable energetics for hole extraction that render them a new class of HTMs in organometallic halide PSCs. As expected, ZnP as HTM in PSCs affords a competitive power conversion efficiency (PCE) of 17.78%,which is comparable to that of the most powerful HTM of Spiro-MeOTAD (18.59%) under the same working conditions. Mean-While, the metal centers affect somewhat the photovoltaic performances that CuP as HTM produces a lower PCE of 15.36%. Notably, the PSCs employing ZnP show a much,better stability than Spiro-OMeTAD. Moreover, the two-porphyrin-based HTMs can be prepared from relatively cheap raw materials with a facile synthetic route. The results demonstrate that ZnP and CuP can be a new class of HTMs for efficient and stable PSCs. To the best of our knowledge, this is the best performance that porphyrin-based solar cells could show with PCE > 17%.

  • 45.
    Chen, Song
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Shi, Liyang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Hunan Univ, Coll Biol, Changsha 410082, Hunan, Peoples R China.
    Luo, Jun
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Novel Fast-Setting Mineral Trioxide Aggregate: Its Formulation, Chemical-Physical Properties, and Cytocompatibility2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 24, p. 20334-20341Article in journal (Refereed)
    Abstract [en]

    One of the main drawbacks that limits the application of mineral trioxide aggregate (MTA) in dental field is its long setting time. Mineral trioxide aggregate with accelerated setting properties and excellent chemical-physical and biological properties is still required. In this study, an innovative mineral trioxide aggregate, which consists of calcium silicates, calcium aluminates, and zirconium oxide, was designed to obtain fast-setting property. The optimized formulation can achieve initial setting in 10 min and final setting in 15 min, which are much faster than commercial mineral trioxide aggregate. In addition, the optimized fast-setting MTA showed adequate radiopacity and good biocompatibility. The ion concentrations after storage in water for 1 day were 52.3 mg/L Ca, 67.7 mg/L Al, 48.8 mg/L Si, and 11.7 mg/L Mg. The hydration products of hardened cements were investigated by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared, showing the accelerated setting time was due to the formation of honeycomb-like calcium silicate hydrate gel. The novel MTA could be a promising material for dental applications.

  • 46. Chen, Zhe
    et al.
    Lu, Jinfeng
    Ai, Yuejie
    Ji, Yongfei
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Adschiri, Tadafumi
    Wan, Lijun
    Ruthenium/Graphene-like Layered Carbon Composite as an Efficient Hydrogen Evolution Reaction Electrocatalyst2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 51, p. 35132-35137Article in journal (Refereed)
    Abstract [en]

    Efficient water splitting through electrocatalysis has been studied extensively in modern energy devices, while the development of catalysts with activity and stability comparable to those of Pt is still a great challenge. In this work, we successfully developed a facile route to synthesize graphene-like layered carbon (GLC) from a layered silicate template. The obtained GLC has layered structure similar to that of the template and can be used as support to load ultrasmall Ru nanoparticles on it in supercritical water. The specific structure and surface properties of GLC enable Ru nanoparticles to disperse highly uniformly on it even at a large loading amount (62 wt %). When the novel Ru/GLC was used as catalyst on a glass carbon electrode for hydrogen evolution reaction (HER) in a 0.5 M H2SO4 solution, it exhibits an extremely low onset potential of only 3 mV and a small Tafel slope of 46 mV/decade. The outstanding performance proved that Ru/GLC is highly active catalyst for HER, comparable with transition-metal dichalcogenides or selenides. As the price of ruthenium is much lower than platinum, our study shows that Ru/GLC might be a promising candidate as an HER catalyst in future energy applications.

  • 47. Chernyy, Sergey
    et al.
    Järn, Mikael
    Shimizu, Kyoko
    Swerin, Agne
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Pedersen, Steen Uttrup
    Daasbjerg, Kim
    Makkonen, Lasse
    Claesson, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Iruthayaraj, Joseph
    Superhydrophilic Polyelectrolyte Brush Layers with Imparted Anti-Icing Properties: Effect of Counter ions2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 9, p. 6487-6496Article in journal (Refereed)
    Abstract [en]

    This work demonstrates the feasibility of superhydrophilic polyelectrolyte brush coatings for anti-icing applications. Five different types of ionic and nonionic polymer brush coatings of 25-100 nm thickness were formed on glass substrates using silane chemistry for surface premodification followed by polymerization via the SI-ATRP route. The cationic [2-(methacryloyloxy)ethyl]trimethylammonium chloride] and the anionic [poly(3-sulfopropyl methacrylate), poly(sodium methacrylate)] polyelectrolyte brushes were further exchanged with H+, Li+, Na+, K+, Ag+, Ca2+, La3+, C16N+, F-, Cl-, BF4-, SO42-, and C12SO3- ions. By consecutive measurements of the strength of ice adhesion toward ion-incorporated polymer brushes on glass it was found that Li+ ions reduce ice adhesion by 40% at 18 degrees C and 70% at 10 degrees C. Ag+ ions reduce ice adhesion by 80% at -10 degrees C relative to unmodified glass. In general, superhydrophilic polyelectrolyte brushes exhibit better anti-icing property at -10 degrees C compared to partially hydrophobic brushes such as poly(methyl methacrylate) and surfactant exchanged polyelectrolyte brushes. The data are interpreted using the concept of a quasi liquid layer (QLL) that is enhanced in the presence of highly hydrated ions at the interface. It is suggested that the ability of ions to coordinate water is directly related to the efficiency of a given anti-icing coating based on the polyelectrolyte brush concept.

  • 48.
    Cheung Mak, Wing
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Kwan Yee, Cheung
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Orban, Jenny
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Lee, Chyan-Jang
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Surface-Engineered Contact Lens as an Advanced Theranostic Platform for Modulation and Detection of Viral Infection2015In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 45, p. 25487-25494Article in journal (Refereed)
    Abstract [en]

    We have demonstrated an entirely new concept of a wearable theranostic device in the form of a contact lens (theranostic lens) with a dual-functional hybrid surface to modulate and detect a pathogenic attack, using a the corneal HSV serotype-1 (HSV-1) model. The theranostic lenses were constructed using a facile layer-by-layer surface engineering technique, keeping the theranostic lenses with good surface wettability, optically transparency, and nontoxic toward human corneal epithelial cells. The theranostic lenses were used to capture and concentrate inflammatory cytokines such as interleukin-1 alpha (IL-1 alpha), which is upregulated during HSV-1 reactivation, for sensitive, noninvasive diagnostics. The theranostic lens also incorporated an antiviral coating to serve as a first line of defense to protect patients against disease. Our strategy tackles major problems in tear diagnostics that are mainly associated with the sampling of a relatively small volume of fluid and the low concentration of biomarkers. The theranostic lenses show effective anti-HSV-1 activity and good analytical performance for the detection of IL-1a, with a limit of detection of 1.43 pg mL(-1) and a wide linear range covering the clinically relevant region. This work offers a new paradigm for wearable noninvasive healthcare devices combining diagnosis and protection against disease, while supporting patient compliance. We believe that this approach holds immense promise as a next-generation point-of-care and decentralized diagnostic/theranostic platform for a range of biomarkers.

  • 49.
    Choi, Hyungryul J.
    et al.
    MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;1 Infinite Loop, Cupertino, CA 95014 USA..
    Park, Kyoo-Chul
    MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA..
    Lee, Hyomin
    MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;Harvard Univ, John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA..
    Crouzier, Thomas
    KTH, School of Biotechnology (BIO). MIT, Dept Biol Engn, 77 Massachusetts Ave, Cambridge, MA 02139 US.
    Rubner, Michael F.
    MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA..
    Cohen, Robert E.
    MIT, Dept Chem Engn, Cambridge, MA 02139 USA..
    Barbastathis, George
    MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;Singapore MIT Alliance Res & Technol SMART Ctr, Singapore, Singapore..
    McKinley, Gareth H.
    MIT, Dept Mech Engn, Cambridge, MA 02139 USA..
    Superoleophilic Titania Nanoparticle Coatings with Fast Fingerprint Decomposition and High Transparency2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 9, p. 8354-8360Article in journal (Refereed)
    Abstract [en]

    Low surface tension sebaceous liquids such as human fingerprint oils are readily deposited on high energy surfaces such as clean glass, leaving smudges that significantly lower transparency. There have been several attempts to prevent formation of these dactylograms on glass by employing oil-repellent textured surfaces. However, nanotextured superoleophobic coatings typically scatter visible light, and the intrinsic thermodynamic metastability of the composite superoleophobic state can result in failure of the oil repellency under moderate contact pressure. We develop titania-based porous nanoparticle coatings that are superoleophilic and highly transparent and which exhibit short time scales for decomposition of fingerprint oils under ultraviolet light. The mechanism by which a typical dactylogram is consumed combines wicking of the sebum into the nanoporous titania structure followed by photocatalytic degradation. We envision a wide range of applications because these TiO2 nanostructured surfaces remain photocatalytically active against fingerprint oils in natural sunlight and are also compatible with flexible glass substrates.

  • 50. Chouhan, Dimple
    et al.
    Thatikonda, Naresh
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology.
    Nilebäck, Linnea
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Widhe, Mona
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology.
    Hedhammar, My
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology.
    Mandal, Biman B.
    Recombinant Spider Silk Functionalized Silkworm Silk Matrices as Potential Bioactive Wound Dressings and Skin Grafts2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 28, p. 23560-23572Article in journal (Refereed)
    Abstract [en]

    Silk is considered to be a potential biomaterial for a wide number of biomedical applications. Silk fibroin (SF) can be retrieved in sufficient quantities from the cocoons produced by silkworms. While it is easy to formulate into scaffolds with favorable mechanical properties, the natural SF does not contain bioactive functions. Spider silk proteins, on the contrary, can be produced in fusion with bioactive protein domains, but the recombinant procedures are expensive, and large-scale production is challenging. We combine the two types of silk to fabricate affordable, functional tissue-engineered constructs for wound-healing applications. Nanofibrous mats and microporous scaffolds made of natural silkworm SF are used as a bulk material that are top-coated with the recombinant spider silk protein (4RepCT) in fusion with a cell-binding motif, antimicrobial peptides, and a growth factor. For this, the inherent silk properties are utilized to form interactions between the two silk types by self-assembly. The intended function, that is, improved cell adhesion, antimicrobial activity, and growth factor stimulation, could be demonstrated for the obtained functionalized silk mats. As a skin prototype, SF scaffolds coated with functionalized silk are cocultured with multiple cell types to demonstrate formation of a bilayered tissue construct with a keratinized epidermal layer under in vitro conditions. The encouraging results support this strategy of fabrication of an affordable bioactive SF-spider silk-based biomaterial for wound dressings and skin substitutes.

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