酸化对蒙脱石成分和结构影响的研究

通过对高州蒙脱石及其酸化产物的X射线衍射、化学全分析、魔角旋转核磁共振谱（MASNMR）的研究发现，酸化导致蒙脱石成分和结构都发生一定程度的变化，特别是魔角旋转核磁共振谱研究发现，高州蒙脱石分别在八面体片和四面体片中存在六配位铝和四配位铝；其酸化产物由于八面体片内脱羟基，新出现了一类四配位铝。蒙脱石酸化后物化性能的改善至少与酸化引起的层间域中离子交换、八面体片内阳离子溶出及八面体片内脱羟基等因素有关。

ACIDIFICATION EFFECTS ON THE COMPOSITION AND STRUCTURE OF MONTMORILLONITE

Montmorillonite sample from Gaozhou and its acidified products have been studied byXRD,chemical analysis and MAS NMR. By acidification,some changes in composition and struc-ture have been found. Before acidified,two kinds of Al with different structures (one is of four-coor-dination in the tetrahedral structural layer and the other is of six-coordination in the octahedralstructural layer) were identified by 27Al MAS NMR,and a new kind of four-coordination Al wasfound in the acidification products. It was formed because of dehydroxylation of the octahedralstructural layer. The properties of acidified montmorillonite were considered to be related to ex-change reaction in the interlayer region,dissolution of cations within the octahedral structural lay-er,and dehydroxylation of the octahedra1 structural layer.