Encapsulation of platelets by physical and chemical approaches

The Eindhoven group on emulsion polymerization has contributed to the field of encapsulation of many types of particles like pigments, fillers and clay particles, preparation of hollow multicompartment particles and encapsulation of nanotubes with latex particles. All these developments are very relevant for the next generation of coatings in which, more than in the past, improved properties are related to nanostructuring of the components in the coatings. Recently, interest has grown for the encapsulation of natural layered silicates, better known as clay platelets, and the formation of subsequent polymer-clay nanocomposites. In this paper we summarize our recent successful attempts to encapsulate platelet particles by a physical approach (controlled heterocoagulation of gibbsite and polymer latex particles, followed by thermal annealing of the polymer) and a chemical approach (starved-feed, surfactant-free emulsion polymerization in the presence of covalently modified clays).