Pan J, Yang G, Han B, Yan H
Institute of Chemistry, Academia Sinica, Beijing, 100080, China
J Colloid Interface Sci. 1997 Oct 15;194(2):276-80. doi: 10.1006/jcis.1997.5119.
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. Copyright 1997 Academic Press. Copyright 1997Academic Press
在pH值2至12的范围内，测定了十二烷基三甲基溴化铵（DDTMAB）在钠蒙脱石和铝蒙脱石上的吸附等温线及吸附焓。还通过X射线衍射研究了粘土的基面间距。在所研究的pH范围内，DDTMAB与这两种蒙脱石的相互作用主要通过阳离子交换进行。对于钠蒙脱石，吸附量随pH值升高而增加，但吸附焓随pH值降低。对于铝蒙脱石，尽管吸附量随pH值单调增加，但吸附焓随pH值呈现非单调变化。DDTMAB在粘土上的吸附焓为负值。在饱和状态下，粘土夹层中吸附的DDTMAB分子呈现双层排列。版权所有1997，学术出版社。版权所有1997，学术出版社
