Microstructure of Single Chain Quaternary Ammonium Cations Intercalated into Montmorillonite: A Molecular Dynamics Study

摘要

This study uses molecular dynamics (MD)nmodeling to examine the interlayer microstructures ofnmontmorillonite intercalated with single chain QACs. Threentypes of QACstetramethylammonium (TMA), decyltrimethylammoniumn(DTMA), and hexadecyltrimethylammoniumn(HDTMA)were selected to synthesize the organoclayncomplex, and the surfactant arrangement was analyzednquantitatively in systems in the absence of water. A series ofnarrangement patterns of interlayer QAC surfactant werenobserved, including lateral monolayers, lateral bilayers, pseudotrilayers,nand paraffin monolayers, in agreement with previousnexperimental results. The effects of increasing one carbon chainnlength and amount of loading of QAC on the resultant QACnarrangement are summarized, yielding a model that providesninsight into the prediction of synthesized QAC−clay microstructurenand engineering behavior in practice.