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Superior Nanoporous Polyimides via Supercritical CO 2 Drying of Jungle‐Gym‐Type Polyimide Gels
Author(s) -
Kawagishi Ken,
Saito Hiromu,
Furukawa Hidemitsu,
Horie Kazuyuki
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200600587
Subject(s) - polyimide , nanoporous , supercritical fluid , materials science , supercritical drying , chemical engineering , porosity , crystallization , polymer , polymer chemistry , composite material , nanotechnology , organic chemistry , chemistry , layer (electronics) , engineering
We report novel nanoporous polyimides formed from jungle‐gym‐type rigid polyimide gels by supercritical CO 2 drying. By virtue of supercritical CO 2 drying to avoid the collapse of nanostructure, porosity above 90 vol.‐% was achieved. We found a rich variety of nanoporous structures in the range of 50–800 nm such as crisp fragments, minute network, and highly‐connected beads. These characteristic structures were formed by the competitive progress of liquid‐liquid phase separation and crystallization induced due to the two chemical reactions of end‐crosslinking and thermal imidization during gelation.