Grafting of swelling clay materials with 3-aminopropyltriethoxysilane

Hongping He; Jannick Duchet; Jocelyne Galy; Jean-François Gerard

doi:10.1016/j.jcis.2005.02.092

Grafting of swelling clay materials with 3-aminopropyltriethoxysilane

J Colloid Interface Sci. 2005 Aug 1;288(1):171-6. doi: 10.1016/j.jcis.2005.02.092.

Authors

Hongping He¹, Jannick Duchet, Jocelyne Galy, Jean-François Gerard

Affiliation

¹ Laboratoire des Matériaux Macromoléculaires/IMP, UMR 5627 - IMP, INSA Lyon, Bât. Jules Verne, 20 avenue A. Einstein, 69621 Villeurbanne, France.

PMID: 15927576
DOI: 10.1016/j.jcis.2005.02.092

Abstract

The grafting reaction between a trifunctional silylating agent and two kinds of 2:1 type layered silicates was studied using FTIR, XRD, TGA, and 29Si CP/MAS NMR. XRD patterns clearly indicate the introduction of 3-aminopropyltriethoxysilane (gamma-APS) into the clay interlayer. In the natural montmorillonite, gamma-APS adopts a parallel-bilayer arrangement, while it adopts a parallel-monolayer arrangement in the synthetic fluorohectorite. These different silane arrangements have a prominent effect on the mechanism of the condensation reaction within the clay gallery. In natural montmorillonite, the parallel-bilayer arrangement of gamma-APS results in bidentate (T2) and tridendate (T3) molecular environments, while the parallel-monolayer arrangement leads to monodentate (T1), as indicated by 29Si CP/MAS NMR spectra. This study demonstrates that the silylation reaction and the interlayer microstructure of the grafting products strongly depend on the original clay materials.