A. Di Biasio et al., Effect of polymer adsorption on PEO-coated latex particles during salt-induced aggregation, COLL SURF A, 160(3), 1999, pp. 189-198
Citations number
23
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
The salt-induced aggregation of polystyrene particles in dilute aqueous sol
utions has been studied by means of dynamic light scattering measurements a
nd the hydrodynamic radius of the resulting aggregates has been evaluated d
uring the time evolution of the whole process. Poly(ethylene oxide) (PEO) p
olymer adsorbed on the particle surface at different amounts has been used
to modify the inter-particle interactions resulting in the formation of clu
sters of increasing size or in the stabilization of the suspension, dependi
ng on the polymer molecular weight. The aggregation regime, i.e. a diffusio
n limited cluster aggregation (DLCA) occurring in the polymer-free latex su
spension, is partially modified according to the polymer percentage adsorbe
d on the particle surface. At high polymer content, the polystyrene latex u
ndergoes a complete steric stabilization. The deviation from a DLCA regime
has been observed for different polymer contents and for polymers of differ
ent molecular weights, from 1.5 to 2000 kD. The alterations of the aggregat
ion rates, induced by the polymer interactions, are presented and briefly d
iscussed. (C) 1999 Elsevier Science B.V. All rights reserved.