Polymers and organics; Sol-gels (xerogels); Porosity
Abstract :
[en] Organic and carbon xerogels were prepared by polycondensation of resorcinol with formaldehyde in water, followed by evaporative drying and, eventually, pyrolysis. The pH of the precursor's solution was fixed at 6.0 in all cases by adding various hydroxides as basification agent. Three alkali metal hydroxides (LiOH, NaOH and KOH) and three alkaline earth metals hydroxides (Ca(OH)(2), Ba(OH)(2), Sr(OH)(2)) were used. It was found that the pore texture of the organic and carbon xerogels is totally independent on the cation size, but depends on the charge and concentration of the counter-cation. Indeed, the pore size of the alkaline earth metal loaded samples is larger than that of the alkali metal-doped xerogels. As a matter of fact, to reach the same initial pH, the concentration in alkali metal hydroxide must be twice that of the alkaline earth metal base. The effect of ions on the pore texture was thus attributed to electrostatic effects on the microphase separation process that occurs prior to gelation. (C) 2008 Elsevier B.V. All rights reserved.
Disciplines :
Materials science & engineering Chemistry Chemical engineering
Author, co-author :
Job, Nathalie ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Chimie physique appliquée
Gommes, Cédric ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Chimie physique appliquée
Pirard, René ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Chimie physique appliquée
Pirard, Jean-Paul ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Chimie physique appliquée
Language :
English
Title :
Effect of the counter-ion of the basification agent on the pore texture of organic and carbon xerogels
Publication date :
2008
Journal title :
Journal of Non-Crystalline Solids
ISSN :
0022-3093
Publisher :
Elsevier Science, Amsterdam, Netherlands
Volume :
354
Issue :
40-41
Pages :
4698-4701
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE]