Characterization of Rheology, Electrokinetic Properties, and Surface
Micromorphology of DTABr-MMT and CPBr-MMT Organoclays
S. Isci1,
O. I. Ece2,
N. Gungor1*
1 Faculty of Science and Letters, Department of Physics, Istanbul
Technical University, Maslak 34469, Istanbul, Turkey
2 Faculty of Mines, Department of Geology, Istanbul Technical University,
Maslak 34469, Istanbul, Turkey
* To whom correspondence should be addressed.
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Abstract |
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In this study, the characterization of sodium-activated montmorillonite (NaMMT)
dispersions (2 wt%) are examined in detail using rheological parameters, such as
viscosity, yield value, apparent and plastic viscosity, and electrokinetic parameters,
such as mobility and zeta potentials. Besides, the influence of solid content on
viscosity is also evaluated. Dodecyltrimethylammonium bromide (DTABr) and
cetylpyridinium bromide (CPBr) cationic surfactants are added to the NaMMT dispersions
in different concentrations in the range of 10 - 3-5 x 10 -
2 mol/L. The rheological and electrokinetic properties, and the morphology of the
organoclays (DTABr-NaMMT and CPBr-NaMMT) prepared with surfactants are compared in
detail. Atomic force microscopy (AFM) techniques are used to characterize the morphology
of NaMMT before and after intercalation of DTABr and CPBr surfactants. The intercalation
of the surfactants in NaMMT dispersion has been studied by X-ray diffraction to examine
whether the interlayer spacing swells or not. The basal spacings have been changed with
the alkyl chain length of the surfactants. The morphology of bentonite dispersions is
analyzed by scanning electron microscopy.
Key Words:
montmorillonite, rheology, zeta potential, dodecyltrimethylammonium bromide, cetylpyridinium bromide
