Organoclays with carbosilane dendrimers containing ammonium or phosphonium groups†
Abstract
New composite materials could reveal attractive capabilities and favourable properties. Herein, we present novel layered nanocomposites consisting of inorganic clay (montmorillonite) and cationic carbosilane dendrimers. A comparative study was performed to evaluate cationic moieties (ammonium or phosphonium) and various generations of dendrimers (first, second and third) and their influence on the characteristics of resulting materials. The target nanocomposites were characterized by XRD, TEM, TGA, IR and MAS NMR. Interestingly, with multivalent dendritic cations, as opposed to monovalent cations, we detected a new connection of cationic species to the inorganic matrix by both ammonium and phosphonium dendrimers. To evaluate the mechanism of thermal degradation of the prepared materials, non-oxidative pyrolysis coupled with analysis of the resulting products by IR and MS was performed. To illustrate the catalytic activity of the as-prepared materials, selected samples were tested as catalysts in the cycloaddition of CO2 with epoxide (allyl glycidyl ether).