Journal of Sol-Gel Science and Technology

, Volume 19, Issue 1–3, pp 759–763

Preparation of SnO2 Monolithic Gel by Sol-Gel Method

  • Haruhisa Shiomi
  • Chisato Kakimoto
  • Atsushi Nakahira
  • Shinichi Takeda
Article

DOI: 10.1023/A:1008751814783

Cite this article as:
Shiomi, H., Kakimoto, C., Nakahira, A. et al. Journal of Sol-Gel Science and Technology (2000) 19: 759. doi:10.1023/A:1008751814783

Abstract

The effects of aging of a wet gel at room temperature and a use of a drying control chemical additive (DCCA) were investigated on the prevention of cracking of the gel during drying. N,N-Dimethylformamide (DMF) having low surface tension was used as a DCCA in this study. Before drying, the aged wet gel was immersed in DMF for several days to replace the pore liquid in the wet gel with DMF.

The longer the aging and DMF immersing times became, a fewer cracks generated during drying. Especially, the immersion in DMF for over 8 days made it possible to obtain the SnO2 gel monolith without cracking from the wet gel aged for short time (1 day). However, the wet gel aged for long time without immersing in DMF could not be dried without cracking. Therefore, the replacement of the pore liquid in the wet gel with DMF having low surface tension is thought to be more effective on avoiding a crack generation than aging. From a pore size distribution measurement by N2 gas adsorption, it was found that the pore size and the breadth of the pore size distribution of the dried gel became larger and narrower respectively with increasing DMF immersing time. DMF is thought to be capable of forming strong hydrogen bonding to hydroxyl groups remaining on the surface of the wet gel and providing a shielding cage around the reactants (Sn–OH), thus further condensation reaction is probably suppressed. Consequently, a large pore distribution is developed in the gel, which reduces the magnitude of capillary stress induced during drying.

tin oxide monolithic gel drying avoiding fracture drying control chemical additive pore size distribution 

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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Haruhisa Shiomi
    • 1
  • Chisato Kakimoto
    • 2
  • Atsushi Nakahira
    • 2
  • Shinichi Takeda
    • 3
  1. 1.Department of Chemistry and Materials Technology, Faculty of Engineering and DesignKyoto Institute of TechnologyKyotoJapan
  2. 2.Department of Chemistry and Materials Technology, Faculty of Engineering and DesignKyoto Institute of TechnologyKyotoJapan
  3. 3.Department of Applied Chemistry, Faculty of EngineeringOkayama UniversityOkayamaJapan

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