Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/59490
Title: Thermodynamics of aggregation between the cationic aurfactant and polymer based on biodegradable poly(vinyl Alcohol)
Keywords: Polímeros biodegradáveis
Álcool polivinílico
Surfactantes catiônicos
Agregação micelar
Calorimetria de titulação isotérmica
Biodegradable polymers
Polyvinyl alcohol
Cationic surfactants
Micelle aggregation
Isothermal titration calorimetry
Issue Date: 8-Nov-2022
Publisher: American Chemical Society
Citation: PATIÑO-AGUDELO, Álvaro Javier; BARBOSA, Mylene Lourdes; SILVA, Luis Henrique Mendes da; FERREIRA, Guilherme Max Dias. Thermodynamics of aggregation between the cationic surfactant and polymer based on biodegradable poly(vinyl alcohol). Journal of Physical Chemistry B, Washington, D.C., v. 126, p. 9424-9434, 2022. Disponível em: https://doi.org/10.1021/acs.jpcb.2c05054. Acesso em: 23 set. 2023.
Abstract: The formation of aggregates between carboxylated (PVCOOH) or neutral hydrolyzed (PVOH) poly(vinyl alcohol) and hexadecylpyridinium chloride (C16PyCl) was examined by conductimetry, turbidimetry, and isothermal titration calorimetry (ITC) in the presence of different NaCl concentrations. The interaction between the polymers and C16PyCl in pure water showed a critical aggregation concentration (cac = 0.8 mmol L–1) only for the neutral polymer. PVCOOH interacted with the surfactant through electrostatic attraction, forming macroscopic aggregates. Integral enthalpy changes for aggregate formation (ΔHagg) obtained from ITC curves varied from −0.61 (for the PVOH system in pure water) to −4.14 kJ mol–1 (for PVOH in the presence of 10.0 mmol L–1 NaCl), indicating that the formation of the aggregates was enthalpically favored. However, hydrophobic interactions drove the process for low surfactant concentration for both polymers. Saturation concentrations (C2) obtained from conductimetry were smaller than those from ITC, revealing that the binding of C16PyCl on the chain of the polymers at higher surfactant concentrations shows the same electric properties as that of free micelles on the solution. Increase of the ionic strength favored the aggregation and decreased the complexity of the ITC curves, suggesting that the reorganization of the surfactant monomers on the polymeric chain with the increase in their concentration was suppressed.
Description: As licenças de acesso aberto aplicáveis a este artigo estão em conformidade com as políticas do periódico em que foi publicado, disponíveis no link: https://v2.sherpa.ac.uk/id/publication/21299. Consulta realizada em 24 de set. de 2024.
URI: https://doi.org/10.1021/acs.jpcb.2c05054
http://repositorio.ufla.br/jspui/handle/1/59490
Appears in Collections:DCF - Artigos publicados em periódicos



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