TY - GEN
T1 - Organosiloxane transparent aerogels and hierarchically porous monoliths
AU - Kodera, Yasunori
AU - Hayase, Gen
AU - Kanamori, Kazuyoshi
AU - Nakanishi, Kazuki
AU - Hanada, Teiichi
N1 - Funding Information:
The present work was supported by the Grant-in-Aid for Scientific Research (No. 22750203 for K.K. and No. 20350094 for K.N.) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Also acknowledged is the Global COE Program “International Center for Integrated Research and Advanced Education in Materials Science” (No. B-09) of the MEXT, Japan, administrated by the Japan Society for the Promotion of Science (JSPS).
PY - 2011
Y1 - 2011
N2 - A transition of porous structures in monolithic poly(methylsilsesquioxane) (PMSQ, CH 3SiO 1.5) gels from uniform mesopores to hierarchical pore structures consisting of macro- and mesopores, has been investigated using a sol-gel system containing surfactant Pluronic F127. A broad variation of porous morphology is controlled by changing the concentration of F127. Sufficient concentrations of F127 inhibit the occurrence of macroscopic phase separation of hydrophobic PMSQ condensates and lead to well-defined mesoporous transparent aerogels with high specific pore volume. Mesopores are developed through microscopic phase separation of PMSQ colloid-surfactant complexes in the solvent. Macroscopic phase separation regulates well-defined macropores in the micrometer range on decreasing concentrations of F127, in which microscopic phase separation concurrently takes place in the PMSQ-rich gelling phase after the onset of macroscopic phase separation. Monolithic PMSQ gels with hierarchical macro- and mesopore structures are consequently obtained.
AB - A transition of porous structures in monolithic poly(methylsilsesquioxane) (PMSQ, CH 3SiO 1.5) gels from uniform mesopores to hierarchical pore structures consisting of macro- and mesopores, has been investigated using a sol-gel system containing surfactant Pluronic F127. A broad variation of porous morphology is controlled by changing the concentration of F127. Sufficient concentrations of F127 inhibit the occurrence of macroscopic phase separation of hydrophobic PMSQ condensates and lead to well-defined mesoporous transparent aerogels with high specific pore volume. Mesopores are developed through microscopic phase separation of PMSQ colloid-surfactant complexes in the solvent. Macroscopic phase separation regulates well-defined macropores in the micrometer range on decreasing concentrations of F127, in which microscopic phase separation concurrently takes place in the PMSQ-rich gelling phase after the onset of macroscopic phase separation. Monolithic PMSQ gels with hierarchical macro- and mesopore structures are consequently obtained.
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U2 - 10.1557/opl.2011.96
DO - 10.1557/opl.2011.96
M3 - Conference contribution
AN - SCOPUS:84860182498
SN - 9781618395139
T3 - Materials Research Society Symposium Proceedings
SP - 54
EP - 59
BT - Aerogels and Aerogel-Inspired Materials
T2 - 2010 MRS Fall Meeting
Y2 - 29 November 2010 through 3 December 2010
ER -