Structure-property relationships in thin films and membranes
Tóm tắt
The molecular-scale species distributions and intermediate-scale structure of silicate sols influence the microstructures of the corresponding thin films prepared by dip-coating. Using multi-step hydrolysis procedures, we find that, depending on the sequence and timing of the successive steps, the species distributions (determined by 29Si NMR) and intermediate scale structure (determined by SAXS) can change remarkably for sols prepared with the same nominal composition. During film formation, these kinetic effects cause differences in the efficiency of packing of the silicate species, leading to thin film structures with different porosities.
Tài liệu tham khảo
C.J. Brinker, A.J. Hurd, P.R. Schunk, G.C. Frye, and C.S. Ashley, J. Non-Cryst. Solids, 147&148, 424 (1992).
B.B. Mandelbrot, The Fractal Geometry of Nature (W.H. Freeman, New York, 1983).
C.J. Brinker, K.D. Keefer, D.W. Schaefer, R.A. Assink, B.D. Kay, and C.S. Ashley, J. Non-Cryst. Solids, 63, 45 (1984).
D.L. Logan, C.S. Ashley, and C.J. Brinker in Better Ceramics through Chemistry V, edited by M.J. Hampden-Smith, W.G. Klemperer, and C.J. Brinker (Materials Research Society, Pittsburgh, 1992), 271, p. 541.
D.L. Logan, C.S. Ashley, R.A. Assink, and C.J. Brinker in Sol-Gel Optics II, edited by J.D. Mackenzie (SPIE—The International Society of Optical Engineering, Bellingham, WA, 1992), 1758, p. 519.
R.A. Assink and B.D. Kay, Annu. Rev. Mater. Sci., 21, 491 (1991).
C.J. Brinker, T.L. Ward, R. Sehgal, N.K. Raman, S.L. Hietala, D.M. Smith, D.-W. Hua, and T.J. Headley, J. Membrane Science, 77, 165 (1993).
V.G. Engelhardt, W. Altenburg, D. Hoebbel, and W.Z. Weiker, Anorg. Allg. Chem., 418, 43 (1977).
L.W. Kelts, N.J. Effinger, and S.M. Melpolder, J. Non-Cryst. Solids, 83, 353 (1986).
C.A. Balfe and S.L. Martinez in Better Ceramics Through Chemistry II, edited by C.J. Brinker, D.E. Clark, and D.R. Ulrich (Materials Research Society, Pittsburgh, 1986), 73, p. 27.
C.J. Brinker, R. Sehgal, N.K. Raman, P.R. Schunk, and T.J. Headley, J. Sol-Gel Sci. & Tech., in Press.
W.G. Klemperer, V.V. Mainz, and D.M. Millar in Better Ceramics Through Chemistry II, edited by C.J. Brinker, D.E. Clark, and D.R. Ulrich (Materials Research Society, Pittsburgh, 1986), 73, p. 3.
C.J. Brinker and G.W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, San Diego, 1990), p. 214.
C.J. Brinker and G.W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, San Diego, 1990), p. 194.
K. Keizer, R.J.R. Uhlhorn, R.J. Van Vuren, and A.J. Burggraaf, J. Membrane Science, 39, 285 (1988).
R. Zellen, The Physics of Amorphous Solids (John Wiley and Sons, New York, 1983), p. 183.