Polymer network systems spinodal decomposition

Monolithic silica can also be prepared by hydrolytic condensation of tetra-alk-oxysilanes, a process similar to the preparation of particles [13-19], The formation of the network structure utilizes spinodal decomposition of the polymerization system of tetramethoxysilane in aqueous acetic acid in the presence of a water-soluble polymer (e.g., polyethylene glycol) [20-22]. The preparation processes starting from monomers seem to be simpler than those starting from a particle-packed column, and the products can have higher permeability. 

Spinodal decomposition is the second mechanism of liquid-liquid phase separation. Here, the solution spontaneously separates into interconnected regions of high and low polymer concentration with intertwined networks. The authors report that for chemically Induced systems (polymer/solvent/nonsolvent), the nucleation and growth kinetics are much too rapid to permit spinodal decomposition. 

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