Clays physico-chemical properties

Miyata, S. (1980). Physico-chemical properties of synthetic hydrotalcites in relation to composition. Clays Clay Miner. 28, 50. 

The variations in structures of these clays are responsible for the differences in buffering capacity, surface charge, and other physico-chemical properties. 

Soil ped models with peculiar features were obtained in our study. The nature of the bridge-cation binding clay and organic matter considerably affected the distinct morphological, mineralogical, mechanical, chemical and physico-chemical properties of the... 

Pluta, M., Paul, M.A., Alexandre, M., Dubois, P. Plasticized polylactide/clay nanocomposites. I. the role of filler content and its surface organo-modification on the physico-chemical properties. J. Polym. Sci., Part B Polym. Phys. 44, 299-311 (2006)... 

The fate of organic contaminants in soils and sediments is of primary concern in environmental science. The capacity to which soil constituents can potentially react with organic contaminants may profoundly impact assessments of risks associated with specific contaminants and their degradation products. In particular, clay mineral surfaces are known to facilitate oxidation/reduction, acid/base, polymerization, and hydrolysis reactions at the mineral-aqueous interface (1, 2). Since these reactions are occurring on or at a hydrated mineral surface, non-invasive spectroscopic analytical methods are the preferred choice to accurately ascertain the reactant products and to monitor reactions in real time, in order to determine the role of the mineral surface in the reaction. Additionally, the in situ methods employed allow us to monitor the ultimate changes in the physico-chemical properties of the minerals. 

The ecological behaviour of cationic surfactants is basically determined by their basic physico-chemical property, i.e. the strong adsorption on surfaces, e.g. on clay minerals or activated sludge, thus leading to their elimination in water treatment plants and water courses. Although physico-chemical processes are primarily effective in the elimination of cationic surfactants of the quaternary-ammonium-ion type in waste-water treatment, there are indications on the basis of experiments that these substances are aerobically biodegradable. 

Ca and Cw are the air and water phase concentrations, both expressed in mol L . In addition to the physico-chemical properties of the pesticide, the volatilization rate from soil also depends on soil moisture content, temperature, humidity, airflow rate over the surface and soil properties (e.g., organic matter content, clay content, porosity, density) (10). 

Rosenqvist, I. T. (1962). The influence of physico-chemical factors upon the mechanical properties of clays. Proc. 9th Nat. Conf. Clays and Clay Minerals, pp. 12-27. 

The engineered barriers of a repository (waste form, container, clay buffer and backfill material and repository stmcmre) which will degrade with time due to various physico-chemical processes, strongly affect the geochemistry of fluids and rocks of the near field environment (redox properties, sorption properties, solubility limits, equilibrium chemistry, etc.) and determine the speciation and the subsequent migration behaviour of the radionuclides into the far field. Extensive... 

However, until relatively recently, most workers concerned with waste management have tended to consider chemical processes primarily because they may affect the physical containment properties of engineered barrier systems. Several texts have examined these physical aspects of containment in considerable detail (e.g. Bentley 1996). Implicitly, there has been a tendency to view chemical containment as an aspect of physical containment. For example, any collapse of expandable clay minerals, such as may be caused by interactions involving polar organic molecules, will affect the physical integrity of clay barriers (e.g. Bowders Daniele 1987 Hettirachi et al. 1988). However, this view of containment is simplistic. In reality, chemical and physical processes must be considered holistically. For example, where clay is used to confine a waste, it should be considered as a physico-chemical barrier to contaminant migration (Horseman et al. 1996). 

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