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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Hofmeister effects on the colloidal stability of poly(ethylene glycol)-decorated nanoparticles

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Author(s):
Blachechen, Leandro S. [1] ; Silva, Jaqueline O. [1] ; Barbosa, Leandro R. S. [2] ; Itri, Rosangela [2] ; Petri, Denise F. S. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Fis, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: COLLOID AND POLYMER SCIENCE; v. 290, n. 15, p. 1537-1546, OCT 2012.
Web of Science Citations: 9
Abstract

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)

FAPESP's process: 10/51219-4 - Interactions between macromolecules and surfaces
Grantee:Denise Freitas Siqueira Petri
Support Opportunities: Regular Research Grants