Pores and diffusion characteristics of porous gels

A simple porous gel synthesis method is proposed in this paper. We found th at the sequential modification of conventional radical polymerization gives rise to pore formation in acrylamide gels and investigated the parameters that are responsible for controlling the number and the size of pores. Pore formation is dominated by the amount of polymerization initiator (ammonium persulfate), accelerator (N, N, N', N'-tetramethylethylenediamine) and pol ymerization temperature. The initiator works as a pore nucleus. The acceler ator helps the pore growth. However, temperature control is the easiest and the most effective way to create a number of large pores. Especially if th e pregel solution is heated to or above 80 degrees C, the pore formation is effectively promoted resulting in an increase in the number of pores and t heir size. Increase in the volume fraction of macro pores was found to resu lt in the increase in the diffusion coefficients of the solution flowing th rough gels. (C) 2000 Elsevier Science Ltd. All rights reserved.