Clay properties cation exchange capacity

Many properties of shale are controlled by the clay components (for example gamma radiation, electrical properties, cation exchange capacity, neutron response). 

The sorption behavior of 11 PAH compounds (a training set, Table 11) on various solid phases (e.g., three soils and two sediments) with different properties to relevant sorption (e.g., organic carbon content, clay content, pH, cation exchange capacity CEC Table 12), was determined by batch equilibrium studies [1]. Batch equilibrium tests were designed to determine rates of equilibrium sorption under conditions of high mixing and high surface areas of the solid particles (see Chap. 3). 

Bentonite rocks have many uses in the chemical and oil industries and also in agriculture and environmental protection. The usefulness of bentonite for each of these applications is based on its interfacial properties. These properties are determined by geological origin, chemical and mineral composition (especially montmorillonite content), and particle size distribution, and they include the specific surface area (internal and external), cation-exchange capacity (CEC), acid-base properties of the edge sites, viscosity, swelling, water permeability, adsorption of different substances, and migration rate of soluble substances in bentonite clay. 

Relationship Between Adsorbent Properties and Adsorptive Performance Add-activation Properties for bleaching clays (surface area, porosity, cation exchange capacity, surface acidity) vary considerably depending on the degree of acid-activation. Taylor and Jenkins (12) showed that surface area... 

Nowadays nanocomposites are used in a broad variety of technical and scientific fields since they possess useful mechanical and chemical properties. Nanocomposite systems can be derived from different materials. Among these, clays are widely applied because their layered structure with high active surface area and cation exchange capacity has advantages for nanocomposite production. A possible way to improve and accelerate the incorporation of polymers (surfactants) into clay layers is the application of high-intensity ultrasonic treatment on to the suspension of a clay mineral in the presence of polymer (surfactants) molecules. Sonication promotes a drastic decrease of the incorporation time increasing the interlamellar space of clay minerals. 

Smectite clays have three important properties related to catalytic activity, intercalation, swelling and cation exchange capacity. When smectites are immersed in water, both intercalation of water molecules and swelling occur. The suspended clay can also freely exchange its interlayer cations for other cations in solution. Interlayer water molecules are dissociated producing protons and exhibit Bronsted acidity (Reaction l).8... 

Chemical Properties. An important chemical property of clays, which directly affects fines migration is the cation exchange capacity (CEC) (6-9). CEC is a measure of the capacity of a clay to exchange cations. It is usually reported in units of milliequivalents per 100 g of clay (meq/100 g). The CEC depends on the concentration of exchangeable cations in the diffuse Gouy-Chapman layer (see later). This concentration depends on the total particle charge, which may vary with pH. Unless stated otherwise, the reported values of CEC are measured at neutral pH. CEC values (meq/lOOg) of common clay minerals are as follows smectites, 80-150 vermiculites, 120-200 illites, 10-40 kaolinite, 1-10 and chlorite, <10 (10). 

---