Hostname: page-component-7b7567c8c-kwt9d Total loading time: 0 Render date: 2026-11-14T17:01:46.515Z Has data issue: false hasContentIssue false

Interlayer structure and dynamics of alkylammonium-intercalated smectites with and without water: A molecular dynamics study

Published online by Cambridge University Press:  01 January 2024

Xiandong Liu
Affiliation:
State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, PR China
Xiancai Lu*
Affiliation:
State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, PR China
Rucheng Wang
Affiliation:
State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, PR China
Huiqun Zhou
Affiliation:
State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, PR China
Shijin Xu
Affiliation:
State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Hankou Road 22, Nanjing 210093, PR China
*
*E-mail address of corresponding author: xcljun@nju.edu.cn
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

The structure and dynamics of alkylammonium-intercalated smectites were simulated using molecular dynamics employing the clayff-CVFF force field, the reliability of which was firstly validated for these systems. The layering behaviors of alkyl chains confirm the scenarios of the monolayer, transition and bilayer configurations for short, medium-length and long carbon tails, respectively. In the systems without water, the alkylammonium groups are all anchored firmly above the surface six-member rings through H bonds between ammonium hydrogen and surface oxygen, and the alkyl tails are a little more mobile. With water involved, some ammoniums are dragged out of the potential barriers of the six-member rings by water molecules through the strong H bonds between water oxygen and ammonium hydrogen. The intercalated water scarcely affects the basal spacing, alkyl chain layering or alkylammonium dynamics. It is also found that the systems with alkyl chains of 11 to 14 exhibit the greatest density, resulting in the extremely limited mobility of the intercalated species.

Information

Type
Research Article
Copyright
Copyright © 2007, The Clay Minerals Society