Hofmeister effects on the colloidal stability of poly(ethylene glycol)-decorated nanoparticles
| Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
|---|---|
| Data(s) |
22/10/2013
22/10/2013
2012
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| 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. CNPq CNPq CAPES CAPES FAPESP [2010/51219-4] FAPESP ProReitoria de Graduacao da Universidade de Sao Paulo Pro-Reitoria de Graduacao da Universidade de Sao Paulo |
| Identificador |
COLLOID AND POLYMER SCIENCE, NEW YORK, v. 290, n. 15, p. 1537-1546, OCT, 2012 0303-402X http://www.producao.usp.br/handle/BDPI/35480 10.1007/s00396-012-2684-0 |
| Idioma(s) |
eng |
| Publicador |
SPRINGER NEW YORK |
| Relação |
COLLOID AND POLYMER SCIENCE |
| Direitos |
closedAccess Copyright SPRINGER |
| Palavras-Chave | #COLLOIDAL STABILITY #SURFACE TENSION #SAXS #HOFMEISTER SERIES IONS #POLY(ETHYLENE GLYCOL) #LATEX PARTICLE #X-RAY-SCATTERING #CLOUD POINT #NONIONIC SURFACTANTS #INORGANIC ADDITIVES #CHAOTROPIC ANIONS #SWELLING BEHAVIOR #AQUEOUS-SOLUTIONS #LIPID-BILAYERS #TRITON X-100 #SALTS #CHEMISTRY, PHYSICAL #POLYMER SCIENCE |
| Tipo |
article original article publishedVersion |
