Studies on interaction of dodecyltrimethylammonium bromide with Na- and Al-montmorillonite
- Academia Sinica, Beijing (China). Inst. of Chemistry
Adsorption of surfactants on clay minerals can change such surface properties, as wetting, flocculation, aggregation, and reduction of swelling. Thus, they have been used widely in environmental control and enhancement of oil recovery. The adsorption isotherms and adsorption enthalpies of dodecyltrimethylammonium bromide (DDTMAB) on Na- and Al-montmorillonite were determined in the pH range 2--12. The basal spacings of the clays were also studied by X-ray diffraction. Interactions of DDTMAB with the two montmorillonites predominate mostly through cation exchange in the pH range studied. In the case of Na-montmorillonite, the amount of adsorption increases with pH, but adsorption enthalpy decreases with pH. For Al-montmorillonite, adsorption enthalpy exhibits nonmonotonic variation with pH, although the amount of adsorption increases with pH monotonously. The adsorption enthalpies of DDTMAB on the clays are negative. The adsorbed DDTMAB molecules in clay interlayers present a bilayer arrangement at saturation.
- OSTI ID:
- 556668
- Journal Information:
- Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 2 Vol. 194; ISSN 0021-9797; ISSN JCISA5
- Country of Publication:
- United States
- Language:
- English
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