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Formation and Pore Structure of Boron Nitride Aerogels
Author(s) -
Lindquist David A.,
Borek Theodore T.,
Kramer Stephen J.,
Narula Chaitanya K.,
Johnston Gregory,
Schaeffer Riley,
Smith Douglas M.,
Paine Robert T.
Publication year - 1990
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1990.tb06588.x
Subject(s) - materials science , supercritical fluid , porosity , boron nitride , microstructure , chemical engineering , supercritical drying , thermal stability , ceramic , evaporation , pyrolysis , tetrahydrofuran , composite material , solvent , chemistry , organic chemistry , physics , engineering , thermodynamics
Gels containing a poly(borazinyl amine) and tetrahydrofuran were processed by CO 2 supercritical drying techniques followed by pyrolysis. The resulting BN ceramic aerogels are highly porous, and the microstructure, porosity, and surface area characteristics have been examined. The aerogels show excellent thermal stability exhibiting surface areas in excess of 350 m 2 /g and porosities greater than 0.8 even when heated in argon at 1500°C for 8 h. By removing solvent via evaporation before supercritical drying, the mean pore radius can be varied between 3.6 and 10 nm.