Modification of Montmorillonite and Prediction of Polymer/Clay Affinity Using Surface Properties and Lattice Model

Sodium montmorillonite (na-mmt) was organically modified using 11-aminoundecanoic acid (aua) and methacryloxyethyltrimethylammonium chloride(maetac) via cation exchange reaction. the effect of the modifier type andconcentration on the structure and surface properties of the organically modifiedmontmorillonites (ommts) was investigated. according to the results, the basalspacing of organoclays was enlarged considerably with increasing the auaconcentration, while increasing the maetac concentration had no significantinfluence on ommt’s gallery height. on the other hand, contact angle measurementsrevealed that increasing the modifiers concentration would increase thehydrophobicity of pristine montmorillonite. the ftir spectra showed that theommts interlayer environment changed from liquid-like to solid-like as the modifierconcentration increased. a mean-field lattice-based model was applied to variouspolymer/ommt systems to predict the affinity between the prepared ommts andsome polymers with different hydrophobicity. the model results showed that highpolar and hydrophilic polymers, such as poly(ethylene oxide), exhibit more negativefree energy change and stronger interaction with the ommts and, consequently,higher potential for preparation of composites with desirable nanostructure andmechanical properties.