Transition from transparent aerogels to hierarchically porous monoliths in polymethylsilsesquioxane sol-gel system.

• 金森, 主祥

• Kodera, Yasunori

• Hayase, Gen

• Nakanishi, Kazuki

• Hanada, Teiichi

抄録

A transition from hierarchical pore structures (macro- and meso-pores) to uniform mesopores in monolithic polymethylsilsesquioxane (PMSQ, CH(3)SiO(1.5)) gels has been investigated using a sol-gel system containing surfactant Pluronic F127. The precursor methyltrimethoxysilane (MTMS) undergoes an acid/base two-step reaction, in which hydrolysis and polycondensation proceed in acidic and basic aqueous media, respectively, as a one-pot reaction. Porous morphology is controlled by changing the concentration of F127. Sufficient concentrations of F127 inhibit the occurrence of micrometer-scale phase separation (spinodal decomposition) of hydrophobic PMSQ condensates and lead to well-defined mesoporous transparent aerogels with high specific pore volume as a result of the colloidal network formation in a large amount of solvent. Phase separation regulates well-defined macropores in the micrometer range on decreasing concentrations of F127. In the PMSQ-rich gelling domain formed by phase separation, the PMSQ colloidal network formation forms mesopores, leading to monolithic PMSQ gels with hierarchical macro- and meso-pore structures. Mesopores in these gels do not collapse on evaporative drying owing to the flexible networks and repulsive interactions of methyl groups in PMSQ.

収録刊行物

• Journal of colloid and interface science

  Journal of colloid and interface science 357 (2), 336-344, 2011-05-15

  Elsevier Inc.

キーワード

• Polymethylsilsesquioxane
• Sol–gel
• Macroporous
• Mesoporous
• Aerogels
• Hierarchically porous gels

詳細情報

• CRID: 1050001335734802560
• NII論文ID: 120004397871
• NII書誌ID: AA00695804
• ISSN: 00219797
• HANDLE: 2433/158373
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles
  • KAKEN