Facile preparation of transparent monolithic titania gels utilizing a chelating ligand and mineral salts

• Hasegawa, George

• Kanamori, Kazuyoshi

• Nakanishi, Kazuki

• Hanada, Teiichi

Abstract

Highly homogeneous transparent titania gels have been successfully prepared from titanium alkoxide by a sol–gel method utilizing chelating agent, ethyl acetylacetate (EtAcAc), in the presence of strong acid anions. Only catalytic amount of a strong acid anion suppress the rapid hydrolysis of titanium alkoxide by blocking the nucleophilic attack of HO− and H2O, and the resultant moderate sol–gel reactions thus afford homogeneous gelation, leading to transparent monolithic titania gels. Gelation time can be widely controlled by changing amounts of water, chelating agent and salt. The ability of salts to suppress the too abrupt sol–gel reactions is strongly dependent on the electronegativity of anions and valence of cations. With employing NH4NO3 as a suppressing electrolyte, the obtained titania gels can be converted to pure TiO2 by simple washing and heat-treatment, and transformations to anatase and rutile structures were found to start at 400 and 600 °C, respectively

Journal

• Journal of Sol-Gel Science and Technology

  Journal of Sol-Gel Science and Technology 53 (1), 59-66, 2010-01

  Springer Verlag

Keywords

• Chelating agent
• Crystallization
• Mineral salts
• Monolithic gels
• Titania gels
• Titanium alkoxide

Details

• CRID: 1050282810607382784
• NII Article ID: 120001887681
• ISSN: 09280707
• HANDLE: 2433/97924
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles