Abstract
Hydrolysis of Ti(OR)4 (R = Et, iPr, nBu) at various concentrations of titanium alkoxides and ratios h = [H2O] /[Ti(OR)4] is studied in alcoholic medium by means of calorimetry, electron microscopy, SAXS, and chemical analysis. The measured values for heat of hydrolysis of Ti(OR)4 by excess water (−Δ H h ) at 298.15 K comprise 14.2, 64.9, 19.3 kJ/mol for R = Et, R = Et, iPr, nBu respectively. −Δ H h increases drastically in the region of 0<h<1 and demonstrates practically no changes with further increase of h ratio. In the solid hydrolysis product with the composition TiO x (OR)4−2x ·y ROH, both x and y increase with increase of Ti(OR)4 concentration in solution. Bushy network first formed in solution as a result of hydrolysis gradually structures with formation of well-shaped spherical particles with diameters ≥0.2μm. SAXS curves analysis in the range of scattering vector values s = 0.07–4.26 nm−1 for Ti(OBu)4 hydrolysis products allows us to suggest their multilevel nature. Speculations on the structure of titanium oxobutoxide were made on the basis of the well-known structural data for crystalline first hydrolysis products of Ti(OEt)4 and Ti(Oi Pr)4. It is suggested to perform hydrolysis of Ti(OBu)4 with addition of water in two steps which allows us to decrease the rate of the solid precipitate formation, to regulate particles morphology in a wide range and to obtain well-shaped spherical species more than one micron in size. The influence of the powder size distribution on the grain growth during ceramic sintering is discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
J.C. Brinker and G.W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, San Diego, 1990).
J. Livage, M. Henry, and C. Sanchez, Progr. Solid State Chem. 18, 259 (1988).
M.T. Harris, A. Singhal, J.L. Look, J.R. Smith-Kristensen, J.S. Lin, and L.M. Toth, J. Sol-Gel Sci. and Techn. 8, 41 (1997).
J. Blanchard, S. Barboux-Doeuff, J. Maquet, and C. Sanchez, New J. Chem. 19, 929 (1995).
V.W. Day, T.A. Eberspacher, W.G. Klemperer, and C.W. Park, J. Am. Chem. Soc. 115, 8469 (1993).
V.W. Day, T.A. Eberspacher, Y. Chen, J. Hao, and W.G. Klemperer, Inorganica Chimica Acta. 229, 391 (1995).
T. Boyd, J. Polymer Sci. 7, 591 (1951).
V.K. LaMer and R.H. Dinegar, J. Am. Chem. Soc. 72, 4847 (1950).
J.H. Jean and T.A. Ring, Langmuir. 2, 251 (1986).
E.A. Barringer and H.K. Bowen, J. Am. Ceram. Soc. 65, C-199 (1982).
E.A. Barringer and H.K. Bowen, Langmuir. 1, 414 (1985).
J.H. Jean and T.A. Ring, Am. Ceram. Soc. Bull. 65, 1574 (1986).
M. Kallala, C. Sanchez, and B. Cabane, Physical Review E. 48, 3692 (1993).
E.P. Kovsman, S.I. Andruseva, L.I. Solovjeva, V.I. Fedyaev, M.N. Adamova, and T.V. Rogova, J. Sol-Gel Sci. and Techn. 2, 61 (1994).
I.P. Romm, A.M. Lepeshkin, B.D. Roschin, A.D. Mukhin, and E.N. Gur'yanova Russian J. Phys. Chem. 65, 450 (1991).
L.A. Feigin and D.I. Svergun, Structure Analysis by Small-Angle X-ray and Neutron Scattering (Plenum Press, New-York, 1987).
A. Guinier, Ann. Phys. 12, 161 (1939).
J.E. Martin and A.J. Hurd, J. Appl. Cryst. 20, 61 (1987).
G. Porod and Z. Kolloid, 125, 51, 109 (1952).
C.N. Caughlan, W. Katz, and Wm. Hodgson, J. Am. Chem. Soc. 73, 5654 (1951).
F. Babonneau, S. Doeuff, A. Leaustic, C. Sanchez, C. Cartier, and M. Verdaguer, Inorg. Chem. 27, 3166 (1988).
A.N. Nesmeyanov, E.M. Brainina, and R.H. Freidlina, Doklady Academii Nauk SSSR, 85, 571 (1952) (Russian).
G. Beaucage, J. Apll. Cryst. 28, 717 (1995).
G. Beaucage, J. Apll. Cryst. 29, 134 (1996).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Golubko, N., Yanovskaya, M., Romm, I. et al. Hydrolysis of Titanium Alkoxides: Thermochemical, Electron Microscopy, Saxs Studies. Journal of Sol-Gel Science and Technology 20, 245–262 (2001). https://doi.org/10.1023/A:1008769918083
Issue Date:
DOI: https://doi.org/10.1023/A:1008769918083