Digitala Vetenskapliga Arkivet

Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Chitosan-Silica Hybrid Composites for Removal of Sulfonated Azo Dyes from Aqueous Solutions
KTH.
Visa övriga samt affilieringar
2018 (Engelska)Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, nr 6, s. 2258-2273Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In this study,. the influence of the chitosan immobilization method on the properties of final hybrid materials was performed. Chitosan was immobilized on the surface of mesoporous (ChS2) and fumed silica (ChS3) by physical adsorption and the sol gel method (ChS1). It was found that physical immobilization of chitosan allows to obtain hybrid composites (ChS) with a homogeneous distribution of polymer on the surface, relatively wide pores, and specific surface area of about 170 m(2)/g, PHpzc = 5.7 for ChS3 and 356 m(2)/g and pH(pzc) = 6.0 for ChS2. The microporous chitosan silica material with a specific surface area of 600 m(2)/g and a more negatively charged surface (pH(pzc) = 4.2) was obtained by the sol gel reaction. The mechanisms of azo dye adsorption were studied, and the correlation with the composite structure was distinguished. The generalized Langmuir equation and its special cases, that is, Langmuir-Freundlich and Langmuir equations, were applied for the analysis of adsorption isotherm data. The adsorption study showed that physically adsorbed chitosan (ChS1 and ChS2) on a silica surface has a higher sorption capacity, for example, 0.48 mmol/g for the acid red 88 (AR88) dye (ChS2) and 0.23 mmol/g for the acid orange 8 (AO8) dye (ChS1), compared to the composite obtained by the sol-gel method [ChS1, 0.05 mmol/g for the A08 dye]. For a deeper understanding of the behavior of immobilized chitosan in the adsorption processes, various kinetic equations were applied: first-order, second-order, mixed 1,2-order (MOE), multiexponential, and fractal-like MOE as well as intraparticle and pore diffusion model equations. In the case of AO8 dye, the adsorption rates were differentiated for three composites: for ChS3, 50% of the dye was removed from the solution after merely 5 min and almost 90% after 80 min. The slowest adsorption process controlled by the diffusion rate of dye molecules into the internal space of the pore structure was found for ChS1 (225 min halftime). In the case of ChS2, the rates for various dyes change in the following order: acid orange (AO7) > orange G (OG) > acid red 1 (AR1) > AR88 > AO8 (halftimes: 10.5 < 15.7 < 23.7 < 34.9 < 42.9 min).

Ort, förlag, år, upplaga, sidor
AMER CHEMICAL SOC , 2018. Vol. 34, nr 6, s. 2258-2273
Nationell ämneskategori
Annan kemi
Identifikatorer
URN: urn:nbn:se:kth:diva-224029DOI: 10.1021/acs.langmuir.7b04076ISI: 000425474800005PubMedID: 29345945Scopus ID: 2-s2.0-85041958756OAI: oai:DiVA.org:kth-224029DiVA, id: diva2:1191801
Anmärkning

QC 20180320

Tillgänglig från: 2018-03-20 Skapad: 2018-03-20 Senast uppdaterad: 2024-03-15Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextPubMedScopus

Sök vidare i DiVA

Av författaren/redaktören
Budnyak, Tetyana M.
Av organisationen
KTH
I samma tidskrift
Langmuir
Annan kemi

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetricpoäng

doi
pubmed
urn-nbn
Totalt: 127 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf