| Texto completo | |
| Autor(es): |
Blachechen, Leandro S.
[1]
;
Silva, Jaqueline O.
[1]
;
Barbosa, Leandro R. S.
[2]
;
Itri, Rosangela
[2]
;
Petri, Denise F. S.
[1]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Fis, BR-05508000 Sao Paulo - Brazil
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | COLLOID AND POLYMER SCIENCE; v. 290, n. 15, p. 1537-1546, OCT 2012. |
| Citações Web of Science: | 9 |
| Resumo | |
The colloidal stability of poly(ethylene glycol)-decorated poly(methyl methacrylate), PMMA/Tween-20, particles was investigated by means of phase separation measurements, in the presence of sodium fluoride (NaF), sodium chloride, sodium bromide, sodium nitrate, or sodium thiocyanate (NaSCN) at 1.0 mol L-1. Following Hofmeister's series, the dispersions of PMMA/Tween-20 destabilized faster in the presence of NaF than with NaSCN. After the phase separation, the systems were homogenized and except for the dispersions in NaF, re-dispersed particles took longer to destabilize, indicating that anions adsorbed on the particles, creating a new surface. Except for F- ions, the adsorption of anions on the polar outmost shell was evidenced by means of tensiometry and small-angle X-ray scattering measurements. Fluoride ions induced the dehydration of the polar shell, without affecting the polar shell electron density, and the formation of very large aggregates. A model was proposed to explain the colloidal behavior in the presence of Hofmeister ions. (AU) | |
| Processo FAPESP: | 10/51219-4 - Interação entre macromoléculas e superfícies |
| Beneficiário: | Denise Freitas Siqueira Petri |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |