Supercritical CO2-ionic liquid mixtures for modification of organoclays

Sébastien Livi; Jannick Duchet-Rumeau; Jean-François Gérard

doi:10.1016/j.jcis.2010.09.049

Supercritical CO2-ionic liquid mixtures for modification of organoclays

J Colloid Interface Sci. 2011 Jan 1;353(1):225-30. doi: 10.1016/j.jcis.2010.09.049. Epub 2010 Oct 14.

Authors

Sébastien Livi¹, Jannick Duchet-Rumeau, Jean-François Gérard

Affiliation

¹ Université de Lyon, F-69003 Lyon, France.

PMID: 20950819
DOI: 10.1016/j.jcis.2010.09.049

Abstract

The use of supercritical CO(2) as solvent in the modification of montmorillonite by imidazolium and phosphonium ionic liquids bearing long alkyl chains (C(18)) known for their excellent thermal stability is described. The objective is to combine the environmentally friendly character of ionic liquids and supercritical carbon dioxide for the organophilic treatment of lamellar silicates. Dialkyl imidazolium and alkyl phosphonium salts were synthesized to be used as new surfactants for cationic exchange of layered silicates. Then, the synthesized phosphonium (MMT-P) or imidazolium (MMT-I) modified montmorillonites, cationically exchanged under supercritical carbon dioxide with or without co-solvent, have been analyzed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) and compared to montmorillonites treated by conventional cationic exchange.