Abstract
A series of microporous silica gels were synthesized by hydrolyzing tetramethylorthosilicate (TMOS) with varying amounts of water. No catalyst or alcohal was added. The gels were characterized by water sorption isotherms, the BET nitrogen surface area measurements, and differential thermal analysis. Although the gelation time for all H2O/TMOS molar ratios (R) was approximately the same (about 3 hr), the pore-size (pore diameter) and sorption capacity were found to be minimum in the R range 4.96–5.37 but increased with both increasing and decreasing R. Water sorption isotherms measured at 25°C after degassing at 200°C of gels prepared with R = 4.96–5.37 exhibited moderate Type I (Brunauer classification) isotherm which changed to intermediate between Type I and Type IV with decreasing or increasing R. These results indicated that the amount of organic or water which was not utilized in the reaction and the degree of cross-linking apparently played a role for the observed variations in pore-size or shape of water isotherms.
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References
M.W. Shafer, D.D. Awschalom, and J. Warnock, J. Appl. Phys. 61(12), 5438 (1987).
J-B. Chan, D-W. Hua, R. Winter, and J. Jonas, J. Mater. Res. Soc. 4 (3), 693 (1989).
R.K. Colier, T.S. Cole, and Z. Lavan, “Advanced Desiccation Materials Assessment-Final Report.” Gas Research Institute, Contract 5084-243-1089 (1986).
S. Yamanaka and S. Komarneni, U.S. Patent (filed) (1988).
J. Hagymassy, Jr., S. Brunauer, and R. Sh. Mikhail, J. colloid & Interface Sci. 29 (3) 485 (1969).
J. Hagymassy and S. Brunauer, J. Colloid & Interface Sci. 33 (2), 317 (1970).
D. Avnir and V.R. Kaufman, J. Non-Cryst. Solids 192, 180 (1987).
P. B. Malla, S. Yamanaka and S. Komarneni, Solid State Ionics 32/33, 354 (1989).
M.M. Dubinin, in Progress in Surface & Membrane Sci., edited by J.F. Danielli, M.D. Rosenberg, and D.A. Cadenhead (Academic Press, New York, 1975) 9, 1–70.
K.S.W. Sing, in Colloid Science, edited by D.H. Everett (The Chemical Society, London, 1973) 1, 1–48.
D.H. Everett and J.C. Powl, J. Chem. Soc. Faraday Trans. I, 72, 619 (1976).
S. Sakka and K. Komiya, J. Non-Cryst. Solids 48, 31 (1982).
K.D. Keefer, in Better Ceramics Through Chemistry, edited by C. J. Brinker, D.E. Clark, and D.R. Ulrich (Mater. Res. Soc. Proc. 32, Pittsburg. PA 1984) pp. 15–24.
L. C. Klein and G.J. Garvey, in Better Ceramics Through Chemistry, edited by C. J. Brinker, D.E. Clark, and D.R. Ulrich (Mater. Res. Soc. Proc.32, Pittsburg, PA 1984) pp. 33–39.
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Kido, H., Malla, P.B. & Komarneni, S. Designing Pore-Size in Silica Gels: [H2O] – [TMOS] System. MRS Online Proceedings Library 175, 219–224 (1989). https://doi.org/10.1557/PROC-175-219
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DOI: https://doi.org/10.1557/PROC-175-219