Interactions of hairy latex particles with cationic copolymers.
Interactions between polycations and core-corona particles are governed by ion-exchange reactions, entropically favored by the release of counterions. This complexation process allows the chains to penetrate into the shell, leading to adsorbed amounts greater than 1 mg m(-2). The destabilization occurs quickly, the domain of flocculation becomes larger when the concentration of monovalent salts is increased, and aggregates are composed of small and very compact clusters in a more or less self-similar structure at large scale. The adsorption of copolymers of low cationicity is characterized by still larger adsorbed amounts and layers thicker than the radius of gyration of the macromolecules. Depending on the charge content, the enhancement of the ionic strength can either promote the destabilization of the suspension or conversely induce the desorption of the chain. In pure water the structure of the flocs is long-range ordered and it becomes more heterogeneous in ionic media.
Borget
Pascal
P
Laboratoire de Physico-Chimie Macromoléculaire UMR CNRS 7615, Université Pierre et Marie Curie, ESPCI, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
Lafuma
Françoise
F
Bonnet-Gonnet
Cécile
C