Clays, inorganic films

In this article, we will discuss the use of physical adsorption to determine the total surface areas of finely divided powders or solids, e.g., clay, carbon black, silica, inorganic pigments, polymers, alumina, and so forth. The use of chemisorption is confined to the measurements of metal surface areas of finely divided metals, such as powders, evaporated metal films, and those found in supported metal catalysts. 

Layered materials are of special interest for bio-immobilization due to the accessibility of large internal and external surface areas, potential to confine biomolecules within regularly organized interlayer spaces, and processing of colloidal dispersions for the fabrication of protein-clay films for electrochemical catalysis [83-90], These studies indicate that layered materials can serve as efficient support matrices to maintain the native structure and function of the immobilized biomolecules. Current trends in the synthesis of functional biopolymer nano composites based on layered materials (specifically layered double hydroxides) have been discussed in excellent reviews by Ruiz-Hitzky [5] and Duan [6] herein we focus specifically on the fabrication of bio-inorganic lamellar nanocomposites based on the exfoliation and ordered restacking of aminopropyl-functionalized magnesium phyllosilicate (AMP) in the presence of various biomolecules [91]. 

Different types of inorganic materials, such as metal oxides, clays, and zeolites, can also be deposited on electrode surfaces. Such films are of interest, because they frequently show well-defined structures (e.g., they have unique pore or interlayer sizes), they are thermally and chemically very stable, and are usually inexpensive and readily available. A few examples will be described. 

The mechanical properties of fire protecting interfacial film are essential for the final stability level of the W/0 emulsions. Concentrated polymeric interfacial films may display either elastic or viscous properties that make the destabilization process difficult and time consuming. The aromatic asphaltene molecules will normally undergo a stacking into sandwich-like structures as a consequence of tire molecular association. The presence of other nanosized-particles like organic wax particles and inorganic clay particles will further enhance the stability level. However, fliese compounds are not further dealt wifli in the present chapter. 

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