Application of supercritical CO2 and ionic liquids for the preparation of fluorinated nanocomposites

This work is focused on the tailoring of dispersions of layered silicates, such as MICA SOMASIF (ME-100) within a fluoride matrix (polytetrafluoroethylene) through two strategies: the physicochemical interactions between filler and matrix and the processing of materials. The interactions in these complex systems are modified by new environmentally friendly thermally stable surfactants. The ionic liquids used are based on alkyltriphenyl phosphonium and perfluorinated alkylpyridinium cations. The influences of the cation-anion combination and functionalization were investigated. The use of the supercritical carbon dioxide (ScCO2) as a solvent is relevant to generate structuring within the material based on ionic liquid phase separation. The tunability of ionic liquids and their combination with the supercritical carbon dioxide enables to design materials with optimized thermal and mechanical properties. (C) 2011 Elsevier Inc. All rights reserved.