Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Interfacial concentrations of chloride and bromide in zwitterionic micelles with opposite dipoles: Experimental determination by chemical trapping and a theoretical description

Texto completo
Autor(es):
de Souza, Tereza Pereira [1, 2] ; Chaimovich, Hernan [1] ; Fahr, Alfred [2] ; Schweitzer, Bianca [1, 3] ; Neto, Augusto Agostinho [4] ; Cuccovia, Iolanda Midea [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05508900 Sao Paulo - Brazil
[2] Univ Jena, Inst Pharm, Dept Pharmaceut Technol, D-07743 Jena - Germany
[3] EPAGRI, Empresa Pesquisa Agr & Extensao Rural Santa Catar, Cacador, SC - Brazil
[4] UNESP, Inst Biociencias Letras & Ciencias Exatas, Dept Fis, BR-15054350 Sao Jose Do Rio Preto, SP - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Journal of Colloid and Interface Science; v. 371, p. 62-72, APR 1 2012.
Citações Web of Science: 5
Resumo

Interfacial concentrations of chloride and bromide ions, with Li+, Na+, K+, Rb+, Cs+, trimethylammonium (TMA(+)), Ca2+, and Mg2+ as counterions, were determined by chemical trapping in micelles formed by two zwitterionic surfactants, namely N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS) and hexadecylphosphorylcholine (HDPC) micelles. Appropriate standard curves for the chemical trapping method were obtained by measuring the product yields of chloride and bromide salts with 2,4,6-trimethyl-benzenediazonium (BF4) in the presence of low molecular analogs (N,N,N-trimethyl-propane sulfonate and methyl-phosphorylcholine) of the employed surfactants. The experimentally determined values for the local Br- (Cl-) concentrations were modeled by fully integrated non-linear Poisson Boltzmann equations. The best fits to all experimental data were obtained by considering that ions at the interface are not fixed at an adsorption site but are free to move in the interfacial plane. In addition, the calculation of ion distribution allowed the estimation of the degree of ion coverage by using standard chemical potential differences accounting for ion specificity. (C) 2012 Elsevier Inc. All rights reserved. (AU)

Processo FAPESP: 07/50970-5 - Reatividade química e biológica em interfaces
Beneficiário:Hernan Chaimovich Guralnik
Linha de fomento: Auxílio à Pesquisa - Temático