By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the effects on sol particle growth and network &morphology control were discussed in detail, and then the model on sol particle growing was suggested on the basis of growth unit theory of anion coordinate polyhedron. The results showed that PEO PPO PEO additive limited particle growth but also restrained particle agglomeration and then made the SiO2 sol high stable. It was found that the action of EPE was similar to that of organic structure directing agent and made the sol cluster cross linked branch network.
