4 シリコンアルコキシドのゾルゲルプロセスに対する超音波照射の影響

DOI

書誌事項

タイトル別名
  • 4 Ultrasonic Effects on Sol-Gel Process of Silicon Alkoxide
公開日
2002
DOI
  • 10.20577/pamjss.11.0_18
公開者
日本ソノケミストリー学会

説明

Sol-gel process in the ternary system of tetraethylorthosilicate (TEOS)-H_2O-ethanol was subjected to a power ultrasound of 20kHz-15W/cm^2. Sonication abruptly reduced the gelling time, and enhanced polycondensation to form Si-O-Si bonds. The ultrasonic effect increased with the increasing time up to 〜2 hours, and decreased with the increasing temperature. The latter is due to the "sonochemical effect" which prefers lower pressure of solvent vapor in the bubbles at lower temperature. On the other hand, argon-substituted atmospehre which should have higher effect of sonochemistry did have a lower effect than unsubstituted atmosphere (air). Comparing the sol-gel processes in N_2, O_2, Ar, and air, we found that oxygen has a positive effect on emulsification between TEOS and water. Ultrasonic-derived xerogels have higher density and specific surface area, and smaller pore size than normal ones. Incorporation of ammonia in the ternary causes the catalytic enhancement of polycondensation, resulting in the formation of spherical particles at a certain concentration condition. Ultrasonication to the system induced the polymerization at the surface of particles. The spherical shape was preserved when the particle size is as large as 300nm, while it was not when as small as 50nm. Ultrasonic effect on the sol-gel process might involve different mechanisms for homogeneous and heterogeneou systems.

収録刊行物

詳細情報 詳細情報について

  • CRID
    1390282681027941120
  • NII論文ID
    110009710178
  • DOI
    10.20577/pamjss.11.0_18
  • ISSN
    24241512
  • 本文言語コード
    ja
  • データソース種別
    • JaLC
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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