Organic intercalation of structure modified vermiculite

Nian Wu; Limei Wu; Libing Liao; Guocheng Lv

doi:10.1016/j.jcis.2015.07.031

Organic intercalation of structure modified vermiculite

J Colloid Interface Sci. 2015 Nov 1:457:264-71. doi: 10.1016/j.jcis.2015.07.031. Epub 2015 Jul 14.

Authors

Nian Wu¹, Limei Wu¹, Libing Liao², Guocheng Lv³

Affiliations

¹ Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083, China.
² Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083, China. Electronic address: clayl@cugb.edu.cn.
³ Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083, China. Electronic address: guochenglv@cugb.edu.cn.

PMID: 26196709
DOI: 10.1016/j.jcis.2015.07.031

Abstract

The experiment used cationic surfactants of different chain lengths to intercalate structure modified vermiculites. The influences of structure modification, chain length and dosage of surfactants on the intercalation behavior of vermiculites were studied, and intercalation mechanism and features of interlayer chemical reactions were discussed. Results indicate that structure modified vermiculites with different layer charge have different intercalation behavior. The basal spacing of the organic intercalated modified vermiculite is the largest when acid concentration used in structure modification is 0.003 mol/L, and increases with increasing the chain length and dosage of the organics. Molecular dynamics simulation verifies that interlayer organics align almost parallel to structure layer of vermiculite, with alkyl chain stretching to the middle of interlayer space. -N(+) groups of the three surfactants locate above the leached [SiO4], which has stronger interaction with interlayer organic cations. Electrostatic force is the main interaction force between interlayer organics and structure layer of vermiculite, and then is Van der Waals force, no chemical bond formed.

Keywords: Cationic surfactant; Intercalation; Molecular dynamics simulation; Structure modification; Vermiculite.