Polystyrene coating of Fe3O4 particles using dispersion polymerization

Polystyrene coating of Fe3O4 particles by dispersion polymerization was studied. The coating process was carried out in methanol with 2,2'-azobisisobutyronitrile as initiator, poly(N-vinylpyrrolidone) as stabilizer, and divinyl benzene as a cross-linking reagent. The cross-linking reagent played an important role in the dispersion polymerization. A continuous and dense polymer layer coating was formed on the Fe3O4 particles in the presence of the cross-linking reagent. The coating process was studied by sampling at fixed time intervals and the particle morphology of the samples was analyzed by TEM and the coating quantity by TG. In the presence of the cross-linking reagent, the layer coating on the Fe3O4 particles was formed by the adsorption of polymer sols that joined together to form a thick layer coating. (c) 2006 Elsevier B.V. All rights reserved.