Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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Synthesis of TiO2 Fine Powder by Sol-Gel Process and Reaction Mechanism(I): Hydrolysis of Titanium Isopropoxide

졸-겔법에 의한 TiO2 미분말 합성과 반응메카니즘(I): Titanium isopropoxide의 가수분해

  • Received : 1996.05.03
  • Accepted : 1996.07.08
  • Published : 1996.08.10
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Abstract

$TiO_2$ fine powders were synthesized via hydrolysis reaction of titanium isopropoxide in isopropanol solvent and the reaction rates were studied by use of UV spectroscopic method. The reactions were controlled to proceed to pseudo-first-order reaction in the presence of excess water in isopropanol solvent. The rate constants which varied with temperature and concentration of water were calculated by Guggenheim method. Reactions using $D_2O$ were also carried out to determine the catalytic character of water. n value of water molecules in transition state and the thermodynamic parameters showed that the reaction proceeded by $S_N2$ mechanism. $TiO_2$ powders synthesized in this reaction were almost spheric forms and had average particle size of $0.3{\mu}m$ diameter.

Isopropanol 용매 내에서 titanium isopropoxide($Ti(O-^iPr)_4$)의 가수분해반응에 의하여 $TiO_2$ 미분말을 합성하였고 가수분해 반응 속도를 자외선분광법에 의하여 측정하였다. 반응은 $Ti(O-^iPr)_4$의 농도에 비하여 물 농도를 크게 하여 유사일차반응으로 진행시켰고, 물 농도 및 온도의 변화에 따른 반응속도상수를 Guggenheim method로 계산하였다. 또한 물의 동위원소 효과를 측정하여 반응에 참여하는 물분자의 촉매성을 확인하였다. 입도분석과 미세구조 관찰 결과, 얻어진 $TiO_2$ 미분말은 $0.3{\mu}m$정도의 입자크기를 갖는 구형의 입자로 확인되었다. 또한 반응속도로부터 전이상태에 참여하는 n value와 열역학적 파라메타를 계산한 결과, $Ti(O-^iPr)_4$의 가수분해반응은 이분자 반응인 $S_N2$ mechanism으로 진행하는 것으로 추정되었다.

Keywords

Acknowledgement

Supported by : 한양대학교

References

  1. ニュ-セラミックス v.4 no.1 セラミックス材料としてのTiO₂の化學 菱田 俊一
  2. ニュ-セラミックス v.4 no.1 ペロブスカイト型化合物の造成變動 掛天 一辛
  3. J. Ceram. Soc. Jpn. v.100 M.Ikeda;S. K. Lee;K. Shinozaki;N. Mizutani
  4. J. Coll inter f. Sci. v.26 W. Stober;A. Fink;E. Bohn
  5. Bull. Am. Cream. Soc. v.61 T. C. Huynh;a. Bleier;H. K. Bowen
  6. Bull. Am. Ceram. Soc. v.62 B. Fegley;H. K. Bowen;L. J. Rigione;D. Todd
  7. Mater. Res. Soc. v.73 R. W. Hartel;K. A. Gerglund
  8. Mater. Res. Soc. v.121 Florence Babonneau;Anne Leaustic;Jacques Livage
  9. J. Non-Cryst. Solids v.89 S. Doeuff;M. Henry;C. Sanchez;J. Livage
  10. Mater. Res. Soc. v.121 R. A. Assink;B. D. Kay
  11. J. Non-Cryst. Solids v.89 J. C. Pouxviel;J. P. Boilot;J. C. Beloeil;J. P. Lallemand
  12. Phil. Mag. v.2 E. A. Guggenheim
  13. Introduction to Ceramics v.2/e W. D. Kingery;H. K. Bowen;D. R. Uhlmann
  14. Materials Science and Technology v.2B C. E. Williams;R. P. May;A. Guinier;R. W. Cahn(ed.);P. Hassen(ed.);E. J. Kramer(ed.)
  15. Commun. the Am. Ceram. Soc. E. A. Barringer;H. K. Bowen
  16. J. Am. Chem. Soc. v.83 C. A. Bunton;V. J. Shiner, Jr.
  17. J. Am. Chem. Soc. v.87 L. R. Fedor;T. C. Bruice
  18. J. Org. Chem. v.46 G. Gopalakrishnan;J. L. Hogg
  19. Ber. Bunsenges Physic. Chem. v.68 R. F. Hudson
  20. J. Chem. Soc. D. A. Brown;R. F. Hudson
  21. Acta. Chem. Scand. v.19 A. Kivinen
  22. Chemical Processing of Ceramics J. Livage;B. I. Lee(ed.);E. J. A. Poep(ed.)