蒙脱土的价电子结构与其同晶置换

为研究蒙脱土结构与其性能的关系,根据蒙脱土的晶体结构,设定其结构单元,运用"固体与分子经验电子理论(EET)"对蒙脱土的价电子结构进行计算.研究表明:与理想蒙脱土相比,八面体中0.66个铝被镁同晶置换后蒙脱土结构单元的结合能基本不变,且与氧桥相连的四面体和八面体中主要键的共价电子分布差距变小;蒙脱土3个亚层之间的作用力比片层之间的分子间作用力大两个数量级,证明了蒙脱土的3个亚层结构稳定;在极性介质中可以改变蒙脱土片层间距,但其3个亚层不易分离.

The relationship of valence electron structure and multiple isomorphous replacement of Montmorillonite

In order to research the relationship of structure and property of montmorillonite,according to the crystal structure of montmorillonite,we designed the cell of montmorillonite structure.The valence electron structure of montmorillonite was calculated by means of "EET"(empirical electron theory of solids and molecules) theory.The solution shows that compared with ideal montmorillonite,binding energy of montmorillonite where 0.66 Al~(3+) is replaced by Mg~(2+) has little change and the difference of covalence electron distributing between tetrahedron and octahedron was diminished.The result also shows that binding forces of three sub-layer of MMT layer are stronger than the Van Der Waals force between layers of montmorillonite,so the distance between layers of montmorillonite can be enlarged when in polar medium while that of three sub-layers is invariable.