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Title: | Transition from transparent aerogels to hierarchically porous monoliths in polymethylsilsesquioxane sol-gel system. |
Authors: | Kanamori, Kazuyoshi https://orcid.org/0000-0001-5087-9808 (unconfirmed) Kodera, Yasunori Hayase, Gen Nakanishi, Kazuki 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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