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  • 1.
    Bergström, Lars Magnus
    et al.
    KTH, Tidigare Institutioner, Kemi. YKI, Institute for Surface Chemistry, Sweden .
    Eriksson, Jan Christer
    KTH, Tidigare Institutioner, Kemi. YKI, Institute for Surface Chemistry, Sweden .
    Synergistic effects in binary surfactant mixtures2004Inngår i: Progress in Colloid and Polymer Science, ISSN 0340-255X, E-ISSN 1437-8027, Vol. 123, s. 16-22Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By considering the main contributions to the micellar free energy we have analysed the synergistic effect often seen on the CMC of a binary surfactant mixture. The synergistic effects are due mainly to the entropic free energy contributions related with the surfactant head groups. Several cases have been treated: (i) For a mixture of a monovalent ionic and a non-ionic surfactant in the absence of added salt we obtain, entirely because of electrostatic reasons, a negative deviation from the ideal behaviour corresponding to an interaction parameter β≈-1. Upon adding an inert salt we found that the magnitude of the synergistic effect first increases, reaches a maximum and eventually decreases. (ii) For mixtures of two ionic surfactants with the same charge number but with different hydrocarbon moieties β-values as low as -10 may arise. (iii) For mixtures of an anionic and a cationic surfactant enormous effects are anticipated yielding β≤-20 depending on the CMCs of respective pure surfactant. (iv) Synergistic effects due to different cross-section areas of the head groups are found to be rather small, with 0 > β > -1, provided the difference in head group size is modest but can become more significant when the size difference is larger.

  • 2.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Henriksson, Ulf
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Thermodynamic Properties of Bridging Clusters in Thin Films of Water between Hydrophobic Surfaces Assessed from Surface Force Isotherms2013Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, nr 15, s. 4789-4795Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the course of a long-term effort to cope with surface force data for thin films of water between hydrophobic surfaces, we have applied the bridging-cluster model (Eriksson, J. C.; Henriksson, U. Bridging-cluster model for hydrophobic attraction. Langmuir 2007, 23, 10026-10033) to the recently published surface force isotherms for water films between hexadecylthiolated gold surfaces in the thickness range of 20-100 nm and temperature range of 10-40 degrees C (Wang, J.; Yoon, R.-H.; Eriksson, J. C. Excess thermodynamic properties of thin water films confined between hydrophobized gold surfaces. J. Colloid Interface Sci. 2011, 364, 257-263). We show that these isotherms can be faithfully reproduced on the basis of the bridging-cluster model. The thermodynamic excess properties (Delta G(c), Delta H-c, and T Delta S-c) of linear clusters that are assumed to bridge the core of the films were calculated from the experimental surface force isotherms. A crucial step taken was to infer two-dimensional ideal mixing of the clusters with the surrounding film water. We find that Delta H-c and T Delta S-c are both negative quantities, with the latter being larger than the former, which implies a positive excess Gibbs energy of a cluster, Delta G(c) = Delta H-c - T Delta S-c. Typically, for temperatures between 10 and 40 degrees C, these cluster properties are of the order of some k(B)T units, corresponding to 10(-4)-10(-3)k(B)T per water molecule entailed. Our analysis yields support of the notion that elongated aggregates can arise in thin films of water between hydrophobic surfaces driven by entropy of mixing.

  • 3.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Henriksson, Ulf
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Thermodynamic surface properties of single crystal faces of xenon calculated by employing the Einstein model of crystalline solids2012Inngår i: Colloid Journal of the Russian Academy of Science, ISSN 1061-933X, E-ISSN 1608-3067, Vol. 74, nr 2, s. 186-193Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By broadening the scope of the Einstein statistical-mechanical treatment of a crystalline solid to cover also low-index faces, and using the Lennard-Jones interaction potential and, in addition, adopting an approximate monolayer-nearest-neighbor model, we have calculated the thermodynamic properties of (100) and (111) single crystal faces of Xe(s) in the temperature range 20-80 K. The reversible cleavage work (that corresponds to the Gibbs sigma-quantity of interfaces) was found to be on the order of 20-30 mJ m(-2) and is largely due to reduction of the pair-wise dispersion interactions for monolayer atoms as compared with the atoms in the bulk of the crystal. For an unstrained crystal, sigma diminishes slightly with temperature for both energetic as well as entropic reasons. On the other hand, the differential work of stretching a solid interface, gamma, is a negative quantity (-5 to -30 mN m(-1)), corresponding to surface pressure, the main reason being that upon (elastic, homogeneous) stretching, the vibration energy levels of the top monolayer are shifted upward, at the same time becoming more closely spaced. It is shown that such a stretching operation causes the T x surface excess entropy term to increase at a faster rate than the corresponding surface energy term, which accounts for the negative sign found for gamma. On the same basis, we can also verify that the general, though sometimes questioned, Shuttleworth relation, is necessarily fulfilled for an ideally terminated (metastable) Xe crystal face with a filled monolayer of immobile Xe atoms. As a matter of fact, this equation merely represents an alternative mathematical disguise of the basic energy differential expression for the monolayer.

  • 4.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Rusanov, A. I.
    Additional remarks related with the discussion inaugurated by the article "Incompatibility of the Shuttleworth equation with Hermann's mathematical structure of thermodynamics" by D. J. Bottomley et al. [Surf. Sci. 603 (2009) 97]2010Inngår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 604, nr 11-12, s. 1062-1063Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Jan Christer Eriksson and Anatoly I. Rusanov critically analyze a paper titled 'Incompatibility of the Shuttleworth equation with Hermann's mathematical structure of thermodynamics' by D. J. Bottomley and co-researchers. According to him, the problem of double counting that Bottomley and co-researchers supposed to be due to involving pairs of terms of the kind xdy + ydx, is not a true research issue but rather a pedagogical one. Within the formal scheme adopted by Gibbs, this problem is properly dealt with by means of a Gibbs Duhem condition. The critics underline that the incompatibility with the mathematical structure of thermodynamics erroneously claimed by Bottomley and co-researchers would apply not just to solid but to liquid interfaces as well, thus invalidating even the firmly rooted Gibbs surface tension equation.

  • 5.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Rusanov, A. I.
    Comments on the article entitled "Incompatibility of the Shuttleworth equation with Hermann's mathematical structure of thermodynamics" by D.J. Bottomley et al.2009Inngår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 603, nr 15, s. 2348-2349Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Jan Christer Eriksson and Anatoly I. Rusanov present their views on the article entitled 'incompatibility of the Shuttleworth equation with Hermann's mathematical structure of thermodynamics'. They derive the the general free energy differential expression for a solid fluid interface to continue their discussions. They also focus on discussing the derivation of the Shuttleworth equation within a thermodynamic framework. A pure solid phase composed of a single component is considered for simplicity that is surrounded by a adsorbing and inert gas at low pressure. They also assume that the symmetry of the solid surface is sufficiently high so as to make the surface two-dimensionally isotropic. They have been able to obtain the relevant Helmholtz energy differential expression for an arbitrarily positioned dividing surface by assuming the excess number of moles of the solid component to always remain the same on the basis of the first equation.

  • 6.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Rusanov, A. I.
    Response to the Reply by D. J. Bottomley et al. to the comments written by J. C. Eriksson and A. I. Rusanov entitled Additional remarks related with the discussion inaugurated by the article Incompatibility of the Shuttleworth equation with Hermann's mathematical structure of thermodynamics by D. J. Bottomley et al. [Surf. Sci. 603 (2009) 97]2010Inngår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 604, nr 21-22, s. 2069-2071Artikkel i tidsskrift (Fagfellevurdert)
  • 7.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Rusanov, Anatoly I.
    Reply to the Comments by E. M. Gutman on the article entitled "Additional remarks related with the discussion ... " by J. C. Eriksson and AI Rusanov [Surf. Sci. 604 (2010) 1062-1063]2011Inngår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 605, nr 5-6, s. 646-647Artikkel i tidsskrift (Annet vitenskapelig)
  • 8.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Yoon, R. -H
    Hydrophobic Attraction in the Light of Thin-Film Thermodynamics2010Inngår i: Colloids and Interface Science Series, Wiley-Blackwell, 2010, Vol. 1, s. 99-131Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 9.
    Eriksson, Jan Christer
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Yoon, Roe-Hoan
    Hydrophobic Attraction in the Light of Thin-Film Thermodynamics2011Inngår i: Colloid Stability: The Role of Surface Forces - Part I, Weinheim: Wiley-VCH Verlagsgesellschaft, 2011, Vol. 1, s. 99-131Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 10.
    Hultquist, Gunnar
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Szakalos, Peter
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Graham, M. J.
    Belonoshko, Antoly B.
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Kondenserade materiens teori.
    Sproule, G. I.
    Grasjo, L.
    Dorogokupets, P.
    Danilov, B.
    Aastrup, T.
    Wikmark, G.
    Chuah, G. K.
    Eriksson, Jan Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Rosengren, Anders
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Kondenserade materiens teori.
    Water Corrodes Copper2009Inngår i: Catalysis Letters, ISSN 1011-372X, E-ISSN 1572-879X, Vol. 132, nr 3-4, s. 311-316Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    According to a current concept, copper canisters of thickness 0.05 m will be safe for nuclear waste containment for 100,000 years. We show that more than 1 m copper thickness might be required for 100,000 years durability based on water exposures of copper for 20 h, 7 weeks, 15 years, and 333 years. An observed evolution of hydrogen which involves heterogeneous catalysis of molecular hydrogen, first principles simulations, thermodynamic considerations and corrosion product characterization provide further evidence that water corrodes copper resulting in the formation of a copper hydroxide. These findings cast additional doubt on copper for nuclear waste containment and other important applications.

  • 11.
    Kumpulainen, Atte J.
    et al.
    KTH, Tidigare Institutioner, Kemi.
    Persson, C M
    KTH, Tidigare Institutioner, Kemi.
    Eriksson, Jan Christer
    KTH, Tidigare Institutioner, Kemi.
    Headgroup and hydrocarbon tail effects on the surface tension of sugar-based surfactant solutions2004Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 20, nr 25, s. 10935-10942Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Measurements of surface tension isotherms were conducted for water solutions of pure and mixed n-decyl-beta-D-glucopyranoside (C-10-Glu) and n-deCyl-beta-D-maltopyranoside (C-10-Mal) surfactants. By applying the Gibbs surface tension equation, the surface densities of Glu and Mal were derived for different compositions and concentrations. The surface fractions were compared with theoretically calculated values where the headgroups were modeled as hard disks. Satisfactory agreement was found for hard-disk sizes of 22.9 and 11.3 Angstrom(2) in the case of a 1:1 mixture. The results of the hard-disk calculations were employed to estimate the configurational free energy of the n-decyl-hydrocarbon chain. The results obtained agree well with previous calculations for the n-dodecyl chain. Comparison with n-dodecyl beta-D-maltopyranoside (C-12-Mal) indicated a further contribution, with the longer hydrocarbon chain giving rise to a higher surface tension in good agreement with data for hydrocarbon liquids. Furthermore, the interpenetration of the headgroup into the hydrocarbon film was studied by means of comparing surface-tension data for n-decyl- and n-dodecyl-ethylene-oxide-based surfactants and n-decyl- and n-dodecyl-beta-D-thiomaltopyranosides (C-10-S-Mal and C-12-S-Mal, respectively) and -maltopyranosides. It was found that lengthening the tetra(etylene oxide) chain by one segment affects the surface tension only marginally, indicating little interpenetration of the additional ethylene-oxide group into the hydrocarbon film. For the thiomaltosides, however, the corresponding effect was found to be remarkably high.

  • 12.
    Kumpulainen, Atte J
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Tyrode, Eric C.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Eriksson, Jan Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Soluble monolayers of sugar-based surfactants at the air-solution interface2009Inngår i: Sugar-Based Surfactants / [ed] Cristobal Carnero Ruiz, CRC Press, 2009, Vol. 143, nr Sugar-Based Surfactants, s. 153-206Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    A review. Surface activity, thermodn. relations for sol. monolayers, surface tension isotherms, adsorption, VSFS spectroscopy, Henry range, micelle formation, mixed solns., surface entropy, and some types of surfactants are discussed. [on SciFinder(R)]

  • 13.
    Kumpulainen, Atte
    et al.
    KTH, Tidigare Institutioner, Kemi.
    Persson, Clas
    KTH, Tidigare Institutioner, Materialvetenskap.
    Eriksson, Jan Christer
    KTH, Tidigare Institutioner, Kemi.
    n-decyl-glucopyranoside and n-decyl-maltopyranoside Gibbs monolayers. Phase changes in the dilute liquid-expanded range2004Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 20, nr 24, s. 10534-10541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface tension isotherms were recorded for n-decyl-beta-(D)-glucopyranoside (Glu) and n-deCyl-beta-(D)-maltopyranoside (Mal) solutions at temperatures of 8,22, and 29degreesC. Comparison was made with isotherms of n-deCyl-beta-(D)-thiomaltopyranoside (S-Mal) at 22 degreesC. In addition to the transition from the gaseous to the liquid-expanded (LE) state, a second transition was observed in the early stages of the LE regime for Glu, Mal, and S-Mal at room temperature. The adsorption isotherm of Mal and Glu obtained at 22 degreesC shows the presence of an adsorption step at an average area/molecule of about 79 Angstrom(2) between, approximately, 0.02 and 0.1 mM (the critical micelle concentration (cmc) is 2 mM) and 0.015 and 0.03 mM (the cmc is 2 mM), respectively. Similarly, for S-Mal an adsorption plateau is observed at 70 Angstrom(2) between 0.01 and 0.03 mM (the cmc is 0.7 mM). From the temperature dependence of the surface tension, we have seen that there are considerable differences in the adsorption of Glu and Mal. For Mal, the adsorption plateau is also observed at 29 degreesC at around 79 Angstrom(2), whereas Glu exhibits no adsorption plateau at this temperature. At 8 degreesC, both Mal and Glu exhibit saturation behaviour in the dilute part of the liquid-expanded range, but at this temperature the average molecular areas are lower than at 22 degreesC: around 66 Angstrom(2) for Glu and 75 Angstrom(2) for Mal. Thus, the temperature sensitivity of Glu is considerably greater than for Mal in this range. The saturation regime coincides with a pronounced surface entropy minimum for Mal. The transition in the dilute liquid-expanded range supposedly occurs from a state with deformed surface micelles arranged in a hexagonal pattern, referred to as the granular range, to a true LE monolayer with a fluid hydrocarbon tail layer covering the entire surface.

  • 14. Stålgren, Johan J. R.
    et al.
    Boschkova, Katrin
    Ericsson, Jan-Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Frank, Curtis W.
    Knoll, Wolfgang
    Satija, Sushil
    Toney, Michael F.
    Enrichment of deuterium oxide at hydrophilic interfaces in aqueous solutions2007Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 23, nr 24, s. 11943-11946Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The structure of water at aqueous interfaces is of the utmost importance in biology, chemistry, and geology. We use neutron reflectivity and quartz crystal microbalance to probe an interface between hydrophilic quartz and bulk liquid solutions of H2O/D2O mixtures. We find that near the interface the neutron scattering length density is larger than in the bulk solution and there is an excess adsorbed mass. We interpret this as showing that there is a region adjacent to the quartz that is enriched in D2O and extends 5-10 nm into the solution. This suggests caution when interpreting results where D2O is substituted for H2O in aqueous interfacial chemistry.

  • 15.
    Wang, Jialin
    et al.
    Virginia Tech, Blacksburg, VA USA.
    Li, Zuoli
    Virginia Tech, Blacksburg, VA USA.
    Yoon, Roe-Hoan
    Virginia Tech, Blacksburg, VA USA.
    Eriksson, Jan Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Surface forces in thin liquid films of n-alcohols and of water-ethanol mixtures confined between hydrophobic surfaces2012Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 379, s. 114-120Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An atomic force microscope (AFM) was used to measure the surface forces in thin liquid films (TLFs) confined between gold surfaces hydrophobized by chemisorption of alkylthiols. The measurements were conducted in different H-bonding liquids and in water-ethanol solutions. Attractive forces stronger and longer-ranged than the van der Waals force were observed in water, ethanol, and 1-butanol in a descending order. The attractive force measured in methanol was much weaker. The surface forces measured in ethanol solutions varied with concentration. Initially, the attractive forces decreased rapidly upon ethanol addition, passed through a broad minimum centered around mole fractions in the range of 0.15-0.20, and then increased as the ethanol mole fraction was further increased above similar to 0.5. Thermodynamic analysis of the data suggests that clusters of water and ethanol may form in TLFs. Thus, the attractive forces may arise from changes in liquid structure. It appears that structuring is a consequence of H-bonding liquid to minimize its free energy in the vicinity of hydrophobic surfaces and in the presence of foreign species in solution.

  • 16. Wang, Jialin
    et al.
    Yoon, Roe-Hoan
    Eriksson, Jan Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Excess thermodynamic properties of thin water films confined between hydrophobized gold surfaces2011Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 364, nr 1, s. 257-263Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface forces between gold surfaces were measured in pure water at temperatures in the range of 10-40 degrees C using an atomic force microscope (AFM). The surfaces were hydrophobized by self-assembly of alkanethiols (C(n)SH) with n = 2 and 16 in ethanol solutions. The data were used to determine the changes in excess free energies (Delta G(f)) of the thin water films per unit area by using the Derjaguin approximation [1]. The free energy data were then used to determine the changes in excess film entropy (Delta S(f)) and the excess film enthalpy (Delta H(f)) per unit area. The results show that both Delta S(f) and Delta H(f) decrease with decreasing film thickness, suggesting that the macroscopic hydrophobic interaction involves building some kind of structures in the intervening thin films of water. It was found that vertical bar Delta H(f)vertical bar > vertical bar T Delta S(f)vertical bar, which is a necessary condition for an attractive force to appear when the enthalpy and entropy changes are both negative. That macroscopic hydrophobic interaction is enthalpically driven is contrary to the hydrophobic interactions at molecular scale. The results obtained in the present work are used to discuss possible origins for the long-range attractions observed between hydrophobic surfaces.

  • 17. Zhang, Jinhong
    et al.
    Yoon, Roe-Hoan
    Eriksson, Jan Christer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    AFM surface force measurements conducted with silica in C(n)TACl solutions: Effect of chain length on hydrophobic force2007Inngår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 300, nr 3, s. 335-345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface forces were measured using an AFM with silica surfaces immersed in C(n)TACl (n = 12-18) solutions in the absence of added salt. The results showed long-range attractive forces that cannot be explained by the DLVO theory. The long-range attractions increased with increasing surfactant concentration, reaching a maximum at the point of charge neutralization (p.c.n.) and then decreased. The long-range forces decayed exponentially, with the decay lengths increasing from 3 to 32 run as the chain length of the surfactants increased from C-12 to C-18. The measured forces can be fitted to the charged-patch model of Miklavic et al. [S.J. Miklavic, D.Y.C. Chan, L.R. White, T.W. Healy, J. Phys. Chem. 98 (1994) 9022-9032] by assuming patch sizes that are much larger than the values reported in the literature. It was found that the decay length decreases linearly with the effective concentration of the CH2/CH3 groups of the C(n)TACl homologues raised to the power of -1/2, which is in line with the Eriksson et al.'s hydrophobic force model derived using a mean-field approach. It appears, therefore, that the long-range attractions observed in the present work are hydrophobic forces originating from changes in water structure across the thin surfactant solution film between the silica surfaces. It is conceivable that hydrocarbon chains in solution disrupt the surface-induced water structure and cause a decrease in hydrophobic force. This observation may also provide an explanation for the very long-range forces observed with silylated, LB-deposited, and thiol-coated surfaces.

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