EFFECT OF DRYING METHOD ON MESOPOROSITY OF RESORCINOL–FORMALDEHYDE DRYGEL AND CARBON GEL
- 31 July 2001
- journal article
- Published by Taylor & Francis in Drying Technology
- Vol. 19 (7), 1319-1333
- https://doi.org/10.1081/drt-100105291
Abstract
Resorcinol–formaldehyde hydrogels were synthesized by sol–gel polycondensation of resorcinol with formaldehyde in a slightly basic aqueous solution. RF cryogels, RF xerogels, and RF xerogels (MW gels) were respectively prepared from RF hydrogels by freeze drying, hot air drying, and microwave drying. Carbon cryogels, carbon xerogels and carbon MW gels were subsequently obtained by pyrolyzing RF drygels in an inert atmosphere. Freeze drying and microwave drying were effective to prepare mesoporous RF drygels and carbon gels. RF cryogels and carbon cryogels showed high mesoporosity over wide ranges of the molar ratio of resorcinol to catalyst (R/C) and the ratio of resorcinol to water (R/W) used in sol–gel polycondensation. Although RF xerogels had a few mesopores, carbon xerogels had no mesopores. RF MW gels and carbon MW gels showed mesoporosity if appropriate values of R/C and R/W were selected.Keywords
This publication has 10 references indexed in Scilit:
- Influence of freeze-drying conditions on the mesoporosity of organic gels as carbon precursorsCarbon, 2000
- PREPARATION OF ORGANIC MESOPOROUS GEL BY SUPERCRITICAL/FREEZE DRYINGDrying Technology, 1999
- Preparation of mesoporous carbon by freeze dryingCarbon, 1999
- Control of mesoporous structure of organic and carbon aerogelsCarbon, 1998
- Porous structure of organic and carbon aerogels synthesized by sol-gel polycondensation of resorcinol with formaldehydeCarbon, 1997
- Aerogels derived from multifunctional organic monomersJournal of Non-Crystalline Solids, 1992
- Carbon Aerogels and XerogelsMRS Proceedings, 1992
- AerogelsSpringer Proceedings in Physics, 1986
- Studies on pore systems in catalysts V. The t methodJournal of Catalysis, 1965
- An improved method for the calculation of pore size distribution from adsorption dataJournal of Chemical Technology & Biotechnology, 1964