engleski

Morphology and Structure of calcium Dodecylbenzenesulphonate Under the Influence of Natural Sea Water

Cadmium dodecylbenzenesulphonate [Cd(DBS)2] precipitates from water solutions both in the crystal form and as liquid crystalline phase. In the sea water of different salinity the precipitation synergistic effect takes place. The precipitation reactions include the anionic and cationic macro constituents of the sea water and dodecylbenzenesulphonic acid. The chemical composition and the structure of mixed crystals and liquid crystalline phases have been determined in the solution of the sea water by using the qualitative and quantitative analysis of chemical elements on scanning electron microscope. The concentration of sea water is expressed by the chloride ion [Cl-] = 10-2 mol dm-3. A good agreement of the results achieved by the complexometric analysis, atomic absorption, X-ray diffraction, as well as, thermogravimetric analysis, was found. These methods showed that cadmium partly was included into the lamellar bilayers, and it was partly crystallized within the liquid crystal matrix in the form of Cd(DBS)2 and CdCl2. It can be assumed that some amount of cadmium has been adsorbed at negatively charged surface of the surfactant micelles. These investigations present an approach to the application of precipitation processes before filtering the waste waters; the extraction of heavy metals can be promoted with surface-active agents.

Morphology; Sea-water

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