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

Abstract

"> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>Sodium montmorillonite (Na-MMT) was organically modified using 11-</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>aminoundecanoic acid (AUA) and methacryloxyethyltrimethylammonium chloride</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>(MAETAC) via cation exchange reaction. The effect of the modifier type and</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>concentration on the structure and surface properties of the organically modified</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>montmorillonites (OMMTs) was investigated. According to the results, the basal</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>spacing of organoclays was enlarged considerably with increasing the AUA</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>concentration, while increasing the MAETAC concentration had no significant</em> <span style="font-family: Times New Roman,Italic; font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>influence on OMMT's gallery height. On the other hand, contact angle measurements</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>revealed that increasing the modifiers concentration would increase the</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>hydrophobicity of pristine montmorillonite. The FTIR spectra showed that the</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>OMMTs interlayer environment changed from liquid-like to solid-like as the modifier</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>concentration increased. A mean-field lattice-based model was applied to various</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>polymer/OMMT systems to predict the affinity between the prepared OMMTs and</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>some polymers with different hydrophobicity. The model results showed that high</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>polar and hydrophilic polymers, such as poly(ethylene oxide), exhibit more negative</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>free energy change and stronger interaction with the OMMTs and, consequently,</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>higher potential for preparation of composites with desirable nanostructure and</em> <span style="font-size: 9pt; color: #000000; font-style: normal; font-variant: normal;"><em>mechanical properties.</em></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /></span>