DIFFUSION CHARACTERISTICS IN MICROCAPSULES

An equation of diffusion for microcapsules(hollow sphere) was develope d, employing the mathematical model for the diffusion characteristics of solid sphere. In the proposed equation.a combination diffusion coef ficient was introduced as a substitute for the diffusion coefficient i n the solid.sphere mathematical model and expressed as a function of t he diffusion coefficient inside solution of hollow sphere, as well as in the polymer membrane. With this modified models the diffusion coeff icients of glucose in NaCS (sodium cellulose sulfate)-PDADMAC(Poly-dia llyl-dimethyl-ammonium chloride) membrane and in Ca-alginate gel membr ane were determined. The diffusion coefficient in NaCS-PDADMAC membran e was found to be 2. 12x10(-11) m(2).s(-1) and that in Ca-alginate mem brane 2. 62 x 10(-10) m(2).s(-1).