Preparation of Divinylbenzene Homopolymeric Microcapsules with Highly Porous Membranes by in situ Polymerization with Solvent Evaporation

Abstract

Divinylbenzene homopolyineric microcapsules with porous membranes, where pores act as channels for extraction, were prepared using various solvents in the dispersed phase such as toluene, benzene, 4-methyl-2-pentanone and Exxsol D-80. Experimental evidence suggested that addition of volatile solvents resulted in the formation of divinylbenzene homopolymeric microcapsules with highly porous membranes by in situ polymerization accompanied by a solvent evaporation process. Solvent type was found to be a significant factor to change the surface morphology of the microcapsules. A membrane structure with macropores could be prepared by using volatile solvents. However, for a system of microcapsules with non-volatile solvents or without any solvent, only mesopores were formed in the microcapsule membrane. Using microcapsules with macroporous membranes, hydrochloric acid can be sufficiently extracted from aqueous solution. This infers that macropores formed by solvent evaporation function as efficient channels for extraction. The influence of preparation conditions such as solvent type and monomer concentration on extraction properties was also discussed.