Clays and Clay Minerals, Vol. 56, No. 1, 49–65, 2008.
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Authors
Minase, Makoto
Kondo, Mitsuji
Onikata, Masanobu
Kawamura, Katsuyuki
Issue Date
2008
Type
Article
Language
Keywords
Periodicals , Geology , FTIR Absorption Spectra , Organophilic Bentonite , Particle Morphology , Relative Sediment Volume , Specific Gel Volume , Specific Plastic Viscosity , Stoichiometry , Structure , Trimethyldococylammonium , XRD 00l Reflection
Alternative Title
The Viscosity Of Organic Liquid Suspensions Of Trimethyldococylammonium-montmorillonite Complexes
Abstract
An organophilic bentonite was prepared by means of a reaction of natural Na-montmorillonite with trimethyldococylammonium which has an especially long n-alkyl chain. The addition of trimethyldococylammonium to montmorillonite was in the range 0.25-3.0 times the cation exchange capacity (CEC) of the clay (i.e. 0.23-2.82 mmol/g clay). The particle morphology in organic liquid suspensions of organoclay complexes was studied by measuring the viscosity based on Eyring’s rate process and Robinson’s relative sediment volume. In toluene, montmorillonite with 1.17 mmol/g clay trimethyldococylammonium (1.25 times the CEC) had the largest specific gel volume, relative sediment volume, and K-factor. The results of the stoichiometry for trimethyldococylammonium-montmorillonite show that practically all of the quaternary ammonium was adsorbed to montmorillonite. Maximum half widths of 001 reflections from X-ray diffraction patterns were obtained in the range 0.74-1.17 mmol/g clay, indicating a disordered arrangement of the organic cation molecules intercalated between the layers. Appreciable shifts to lower-frequency regions in the Fourier transform infrared absorption spectra as a result of CH2-stretching vibrations were observed with increasing amounts of the organic cation. When increasing the amount of organic cation added to the clay from 0.94 to 1.41 mmol/g clay, a large shift occurred to the lower-frequency side, approaching the frequency of the organic cation alone. This indicates that the interaction between adjacent hydrocarbon chains becomes progressively stronger, due to van der Waals attraction, with increases in the amount of organic cation. Interactions of the alkyl chains in trimethyldococylammonium-montmorillonite complexes with irregularly distributed and randomly arranged alkyl chains between the silicate layers were weak, and, as a result, solvation with external organic liquids occurred and gel formation developed through macroscopic swelling of the organoclay.
Description
Clays and Clay Minerals, Vol. 56, No. 1, 49–65, 2008. The Viscosity Of Organic Liquid Suspensions Of Trimethyldococylammonium-montmorillonite Complexes. Makoto Minase; Mitsuji Kondo; Masanobu Onikata; Katsuyuki Kawamura. DOI: 10.1346/CCMN.2008.0560105. Copyright © 2008, The Clay Minerals Society.
Citation
Clays and Clay Minerals, Vol. 56, No. 1, 49–65, 2008.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018, The Clay Minerals Society