Effect of acetonitrile and N,N-dimethylformamide on the formation of poly(ethylene oxide)-sodium alkyl sulfate aggregates

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MetadadosDescriçãoIdioma
Autor(es): dc.creatorFerreira, Guilherme M. D.-
Autor(es): dc.creatorFerreira, Gabriel M. D.-
Autor(es): dc.creatorHespanhol, Maria C.-
Autor(es): dc.creatorAgudelo, Álvaro J. P.-
Autor(es): dc.creatorRezende, Jaqueline P.-
Autor(es): dc.creatorPires, Ana C. S.-
Autor(es): dc.creatorSilva, Luis H. M.-
Data de aceite: dc.date.accessioned2026-02-09T12:45:26Z-
Data de disponibilização: dc.date.available2026-02-09T12:45:26Z-
Data de envio: dc.date.issued2018-10-26-
Data de envio: dc.date.issued2018-10-26-
Data de envio: dc.date.issued2018-
Fonte completa do material: dc.identifierhttps://repositorio.ufla.br/handle/1/31479-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/capes/1167663-
Descrição: dc.descriptionThe effects of low contents of acetonitrile (AN) or N,N-dimethylformamide (DMF) on the aggregation of sodium alkyl sulfate surfactants, in the absence and presence of poly(ethylene oxide) (PEO), were investigated using conductivity and isothermal titration calorimetry. The cosolvents slightly changed the critical micellar concentrations and did not alter the critical aggregation concentrations of the surfactants sodium decyl sulfate (DSS) and sodium dodecyl sulfate (SDS) with PEO. However, AN and DMF turned the micellization of the surfactants and their binding to the polymer enthalpically more favorable. For instance, for SDS, the micellization enthalpy, ΔHomic, decreased from close to 0 kJ mol-1 in water to -14.3 kJ mol-1 in the presence of 2.50 mol% AN, and the integral enthalpy change for aggregate formation with the polymer, ΔHagg(int), decreased from -1.1 kJ mol-1 in water to -15.5 kJ mol-1 in the same AN concentration. This was attributed to the modification of the solvation shells of both SDS and PEO by the cosolvent molecules, which reduced the entropic contribution to formation of the aggregates. Consequently, when SDS was replaced with DSS, the AN affected ΔHomic to a lesser extent, with a decrease of 9.1 kJ mol-1, while the ΔHagg(int) values were not altered, highlighting the influence of hydrophobic interactions in the surfactant aggregation process.-
Formato: dc.formatapplication/pdf-
Idioma: dc.languageen-
Publicador: dc.publisherSociedade Brasileira de Química-
Direitos: dc.rightsAttribution 4.0 International-
Direitos: dc.rightsAttribution 4.0 International-
Direitos: dc.rightsacesso aberto-
Direitos: dc.rightshttp://creativecommons.org/licenses/by/4.0/-
Direitos: dc.rightshttp://creativecommons.org/licenses/by/4.0/-
???dc.source???: dc.sourceJournal of the Brazilian Chemical Society-
Palavras-chave: dc.subjectPoly(ethylene oxide)-
Palavras-chave: dc.subjectSodium alkyl sulfates-
Palavras-chave: dc.subjectAcetonitrile-
Palavras-chave: dc.subjectN,N-dimethylformamide-
Palavras-chave: dc.subjectIsothermal titration calorimetry-
Título: dc.titleEffect of acetonitrile and N,N-dimethylformamide on the formation of poly(ethylene oxide)-sodium alkyl sulfate aggregates-
Tipo de arquivo: dc.typeArtigo-
Aparece nas coleções:Repositório Institucional da Universidade Federal de Lavras (RIUFLA)

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