Preparation of Polymer Hybrids of the SiO2-PVA or SiO2-PEG System and Porous Materials Made from the Hybrid Gels

Apparently homogeneous transparent gels (polymer hybrid gels) were prepared from TEOS and PVA or PEG. IR spectra and DTA curves for the gels and pore characteristics of porous materials obtained by heating gels were examined. PVA incorporated into a gel seemd to be bound to the surrounding _??_Si-O-Si_??_ network more firmly than PEG. The pore volume by N2 adsorption on a porous material made from the SiO2-PEG system was much larger than that from the SiO2-PVA system. Pore size distribution curve showed that most of pores in the porous material from the gel in the SiO2-PEG6000 system were about 20Å in diameter, involving a little portion of somewhat larger pores. Difference in thermal behavior between PVA and PEG in polymer hybrid gel was discussed in terms of the difference in the ratio of hydrophilic to hydophobic groups in the original organic polymer.