Influence of Energy State of Montmorillonite Interlayer Cations on Organic Intercalation

Limei Wu,Guocheng Lv,Shiyue Cao

doi:10.1155/2018/3489720

Abstract

It is well known that the intercalation of montmorillonite (Mt) with organic cations is a fast process. During the intercalation, the interaction between the original cations and the structure layer of Mt keeps changing, and the basal spacing of Mt keeps increasing until an organic environment has been built in the interlayer. Many properties of Mt also change during the intercalation, such as hydrophobic or hydrophilic property and thermal stability. In this research, the impact of intercalation on the properties of Mt was studied by investigating the change in basal spacing and energy that coordinates the interlayer cations during the intercalation of Mt with organic cations. The interaction between interlayer cations and the layers in the Mt structure and the change in the system energy were obtained by using molecular dynamics simulation. All the experiment and calculation results provide a theoretical proof in organic intercalation mechanism.

Highlights

Clay minerals have a wide range of properties, which make them important to the earth sciences, engineering, and industry
Properties of Na-Mt and C4-Mt. e nature of organic intercalation is exchanging the interlayer cation of Mt with the organic cation, and the process is affected by the energy of the interlayer cation
There are Na+ ions with three energy states in Mt gallery, which affect the order of organic cations intercalating and their position in gallery

Summary

Introduction

Clay minerals have a wide range of properties, which make them important to the earth sciences, engineering, and industry. Clay minerals have a layered structure at the nanoscale, and each layer consists of some combinations of two layer types with silicon tetrahedra and aluminum octahedra as basic units [1, 2]. Due to the positive charge, the interlayer cations can interact through electrostatic interactions with the silicon tetrahedral [3]. Numerous previous studies have focused on the characterization of alkyl ammonium cations arrangement and conformation after intercalation in the interlayer of layered silicates [5,6,7]. Only few studies on the organic intercalation mechanism have been reported. The researches in organic intercalation of Mt are not systematic, which have not resolved the essential problems [10, 11]

Methods

Results

Conclusion