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Title: Transition from transparent aerogels to hierarchically porous monoliths in polymethylsilsesquioxane sol-gel system.
Authors: Kanamori, Kazuyoshi  kyouindb  KAKEN_id  orcid https://orcid.org/0000-0001-5087-9808 (unconfirmed)
Kodera, Yasunori
Hayase, Gen
Nakanishi, Kazuki  KAKEN_id  orcid https://orcid.org/0000-0002-8069-4780 (unconfirmed)
Hanada, Teiichi
Author's alias: 金森, 主祥
Keywords: Polymethylsilsesquioxane
Sol–gel
Macroporous
Mesoporous
Aerogels
Hierarchically porous gels
Issue Date: 15-May-2011
Publisher: Elsevier Inc.
Journal title: Journal of colloid and interface science
Volume: 357
Issue: 2
Start page: 336
End page: 344
Abstract: 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.
Rights: © 2011 Elsevier Inc.
この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。
This is not the published version. Please cite only the published version.
URI: http://hdl.handle.net/2433/158373
DOI(Published Version): 10.1016/j.jcis.2011.02.027
PubMed ID: 21377166
Appears in Collections:Journal Articles

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