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Sol-gel preparation of TiO2 ceramic coating films from aqueous solutions of titanium sulfate (IV) containing polyvinylpyrrolidone

Published online by Cambridge University Press:  31 January 2011

Tomoko Kishimoto  and
Hiromitsu Kozuka
Tomoko Kishimoto
Affiliation:
Department of Materials Science and Engineering, Kansai University 3-3- 35 Yamate-cho, Suita, 564–8680, Japan
Hiromitsu Kozuka
Affiliation:
Department of Materials Science and Engineering, Kansai University 3-3- 35 Yamate-cho, Suita, 564–8680, Japan
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Abstract

TiO2 ceramic coating films were deposited on silica glass substrates by the sol- gel method using aqueous solutions of Ti(SO4)2 containing polyvinylpyrrolidone (PVP) as the coating solutions. Unless PVP was added to the solution, the wettability of the substrate was poor, leading to failure in gel film formation. When PVP was added to the solution, on the other hand, homogeneous gel films could be deposited on the substrate, which could be converted to crack- free, transparent TiO2 ceramic thin films about 0.1 μm in thickness. The TiO2 films thus obtained had refractive index, porosity, and surface roughness Ra (the arithmetic average deviation of the assessed profile) of 2.68, 2.1%, and 0.94 nm, respectively. For comparison, a TiO2 film was also prepared from an alcoholic solution of Ti(OC3H7i)4, showing refractive index, porosity, and Ra of 2.65, 3.0%, and 0.98 nm, respectively. These values indicate that the TiO2 films prepared from the Ti(SO4)2 aqueous solutions containing PVP are as smooth and dense as those prepared from conventional alkoxide solutions. The solutions were found to be stable in viscosity for more than five months at room temperature in sealed containers. Thermal analysis, infrared absorption spectra measurement, and x- ray diffraction analysis indicated that the gel films are converted to ceramic films on firing via (i) vaporization of H2O; (ii) decomposition of H2SO4 and/or vaporization of H2SO4 · H2O; (iii) decomposition of SO42− coordinating Ti atoms and oxidation and decomposition of PVP, the latter of which leads to formation of residual carbons; (iv) oxidation of the carbonaceous residues; and (v) crystallization of the titania phase. During the gel- to- ceramic film conversion, the thickness decreased by 90%.

Type
Articles
Information
Journal of Materials Research , Volume 18 , Issue 2 , February 2003 , pp. 466 - 474
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

Hashimoto, T., Yoko, T., and Sakka, S., J. Ceram. Soc. Jpn. 101, 64 (1993).CrossRefGoogle Scholar
Tsuchiya, T. and Koizumi, A., J. Ceram. Soc. Jpn. 98, 1011 (1990) (in Japanese).CrossRefGoogle Scholar
Kawano, T., Sei, T., and Tsuchiya, T., Jpn. J. Appl. Phys. Pt. 1 30, 2178 (1991).CrossRefGoogle Scholar
Tu, Y., Calzada, M.L., Phillips, N.J., and Milne, S.J., J. Am. Ceram. Soc. 79, 441 (1996).CrossRefGoogle Scholar
Israelachvili, J.N., Intermolecular and Surface Forces (Academic Press, London, U.K., 1985), Chap. 11.Google Scholar
Kozuka, H. and Kishimoto, T., Chem. Lett. 1150 (2001).Google Scholar
Yoshida, S. and Yajima, H., Optical Thin Films and Devices (University of Tokyo Press, Tokyo, Japan, 1994, in Japanese).Google Scholar
Riter, E., in Physics of Thin Films, Vol. 8, edited by Hass, G., Francombe, M.H., and Hoffmann, R.W. (Academic Press, New York, NY, 1975), pp. 1–45.Google Scholar
Kingery, W.D., Bowen, H.K., and Uhlmann, D.R., Introduction to Ceramics (John Wiley, New York, NY, 1976), p. 669.Google Scholar
Joe, I.H., Vasudevan, A.K., Aruldhas, G., Damodaran, A.D., and Warrier, K.G.K., J. Solid State Chem. 131, 181 (1997).CrossRefGoogle Scholar
Marchant, R.E., Yu, D., and Khoo, C., J. Polym. Sci. Pt. A 27, 881 (1989).CrossRefGoogle Scholar
Colthup, N.B., Daly, L.H., and Wiberley, S.E., Introduction to Infrared and Raman Spectroscopy, 2nd ed. (Academic Press, New York, NY, 1975).Google Scholar
Hava, S. and Auslender, M., Infrared Phys. Technol. 41, 149 (2000).CrossRefGoogle Scholar
Kozuka, H., Takenaka, S., Tokita, H., Hirano, T., Higashi, Y., and Hamatani, T., J. Sol-Gel Sci. Technol. 26, 681 (2003).CrossRefGoogle Scholar