ABSTRACT
I. INTRODUCTION Microcapsules are tiny containers made of natural or synthetic polymers, with diameters in the range 1 to 500 jam and varying wall thicknesses [1]. From the viewpoint of membrane science and technology, a microcapsule can be re garded as a spherical ultrathin polymer membrane because it is a matrix of polymer molecules assembled in a very thin spherical shell [2],
Among many useful functions of microcapsules, protection of the encapsu lated material from environmental conditions and release of the core material into the surrounding medium in a sustained manner are particularly important when microcapsules are treated as a sort of polymer membrane. Both of these functions of microcapsules arise from the common cause that the microcapsule wall serves as a barrier for solute molecules permeating through the mem brane. Hence an understanding of the permeability of microcapsule membranes toward solutes is very important [1].
