Phase Separation in Gelling Silica–Organic Polymer Solution: Systems Containing Poly(sodium styrenesulfonate)

Journal of the American Ceramic Society - Tập 74 Số 10 - Trang 2518-2530 - 1991
Kazuki Nakanishi1, Naohiro Soga1
1Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Kyoto 606-01, Japan

Tóm tắt

Phase separation which occurs in parallel to the hydrolysis and gelation of alkoxysilane solution containing poly(sodium styrenesulfonate) (NaPSS) has been investigated. Depending on the reaction conditions, gel morphologies such as isolated pores, particle aggregates, and interconnected continuous pores from 0.1 to 100 μm long have been observed. Time‐resolved light scattering of gelling solution suggested the occurrence of spinodal phase separation through the polymerization of silica and the subsequent freezing of the developing structure by sol‐gel transition. The effects of reaction parameters on the periodic size are explained mainly in terms of their influence on the “chemical cooling” rate which is determined by the polymerizatica rate of silica and the solubility of NaPSS in the reacting solution.

Từ khóa


Tài liệu tham khảo

H. P.HoodandM. E.Nordberg “Method of Treating Borosilicate Glasses ” U.S. Pat. No. 2215039 Sept. 17 1940.

Schaefer D. W., 1984, Better Ceramics through Chemistry, 1

Schaefer D. W., 1990, Polymer‐Based Molecular Composites, 57

Chung Y. J., 1990, Better Ceramics Through Chemistry IV, 981

H.KozukaandS.Sakka “Formation of Highly Porous Opaque Gels from Alkoxysilane Solutions ”Chem. Lett. 1791–94(1987).

Shoup R. D., 1976, Controlled Pore Silica Bodies Gelled from Silica Sol–Alkali Silicate Mixtures, J. Colloid Interf. Sci., 3, 63, 10.1016/B978-0-12-404503-3.50010-0

K.Nakanishi N.Soga H.Matsuoka andN.Ise “SAXS Studies of Gelling Silica–Organic Polymer Solution: System Containing Poly(sodium styrenesulfonate) ”J. Am. Ceram. Soc. in review.

10.1016/0022-3093(89)90578-4

10.1021/ma00238a030

10.1246/bcsj.64.1283

Iler R. K., 1979, The Chemistry of Silica

10.1016/0022-3093(84)90382-X

10.1021/ma00143a009

Hashimoto T., 1989, Morphology Control of Polymer Blends by a Chemical Pinning of Spinodal Decomposition, Polym. Commun., 30, 177

10.1016/0032-3861(89)90355-8

Flory P. J., 1971, Principles of Polymer Chemistry

10.1016/0032-3861(89)90151-1

10.1002/polb.1989.090270807

Takenaka M., 1989, Multiphase Macromolecular Systems Symposium

10.1063/1.451477

Cahn J. W., 1965, The Initial Stages of Phase Separation in Glasses, Phys. Chem. Glasses, 6, 181

10.1016/0022-3093(84)90385-5

K.Nakanishi N.Soga T.Inoue andN.Nemoto; in preparation.

10.1016/0022-3093(85)90170-X

10.1016/S0022-3093(86)80078-3