不同超临界压力下有机超细蒙脱土的结构性质演变

Structure Properties Evolution of Prepared Organic Super-refined Montmorillonite under Different Supercritical Pressure

为了促进层间阳离子交换,将原始蒙脱土进行超细化和接枝处理后以超临界二氧化碳（scSO2）为介质、以十四烷基三己基氯化鏻（TTPC）为插层剂对其进行插层改性.结果表明：经scCO2处理后蒙脱土的亲水性减弱,颗粒变得蓬松,且随着压力从10 MPa提高到20 MPa再至30 MPa,TTPC在scCO2中的溶解度先增加后降低,20 MPa时达到饱和,在该压力下制备的有机超细蒙脱土FTIR曲线中2 927 cm-1和2 855 cm-1的-CH2不对称和对称伸缩振动峰峰强最强,TG曲线中200 ～550℃的热失重率最高,（001）衍射面对应的衍射角最小,蒙脱土片层间距最大,制备的改性蒙脱土颗粒最蓬松.

To facilitate ionic exchange cations of clay layers,the as-received clay was super-refined and grafted treated before modifying it with trihexyltetradecylphosphonium chloride （TTPC） in supercritical carbon dioxide （ scCO2 ）. The results showed that super-refined montmorillonite after modified treated in supercritical carbon dioxide had a weak bydrophilic property and a fluffy morphology. When the supercritical carbon dioxide pressure increased from 10 MPa to 20 MPa and then 30 MPa, solubility of TTPC in supercritical carbon dioxide firstly increased and then decreased and reached saturation at 20 MPa. At this condition,the peaks at 2 927 cm^-1 and 2 855 cm^-1 corresponding to asymmetric and symmetric vibrations of -CH2 were strongest,the decomposition from 200 -550 ℃ was the biggest,the diffraction angle corresponding to（001 ）diffraction face was the smallest,the inter-lamellar spacing of modified montmorillonite was the biggest and the particle of modified super-refined montmorillonite was most fluffy.