Coatings, diatomite

Fig. 7.12 SEM images ofthe diatomite substrate through sequential assembly of positively-at low (A) and high (B) magnification. The di- charged PDDA and negatively-charged zeolite atomite has a disk-like shape about 1.2 pm in nanocrystals (C). The inset in (C) shows an thickness and 20-40 pm in diameterwith a nearly enlarged view of the nanoparticle-modified sur-regular array of submicrometer-sized pores face. (Reprinted from [129] with permission of (about 300-500 nm). SEM images of diatomite Wiley-VCH.) coated with three layers of zeolite ( nanocrystals...

Filtering Media.—Filter cloths soon become coated with a thin, slimy film of the suspended matters, which completely stops filtration, so that various substances have been tried with the object of obtaining a dry, firm cake in the filter press. Bagasse has been used, but has a tendency to give the juice a gummy consistency. Peat, lignite, kaolin, or China clay and diatomite, have aU found more or less application for this purpose. Sand filters of various forms are also used. In Hawaii wood fibre called Excelsior has proved satisfactory. 

The primary methods used in cell immobilization are surface adhesion, covalent attachment and entrapment. Surface adhesion involves adsorption of cells to microcarriers such as calcium alginate beads, collagen-coated plastic beads, diatomite silica, and dextrans [68]. Immobilization can be achieved simply by suspending the cells and microcarrier together under slow agitation. Examples of such systems include immobilized bacteria for waste water treatment and adsorbed Azotobacter vinelandii on Cellex E for nitrogen fixation... 

P-11 15-P-13 15-P-20 DFT periodic calculations Diagenetic zeolites Diamond anvil cell Diaromatics hydrodecyclisation Diatomite, coating by zeolites Diazine adsorption, FAU... 

The most commonly used gas-chromatographic column consists of a tube filled with solid particles of fairly uniform size the particles are coated with the liquid stationary phase. Perhaps the most commonly used support is marine diatomite (for instance, Johns-Manville Chromosorb ). The choice of tubing material depends... 

Matting agents are used to produce coatings with a matt, semi-matt, or silk finish. They include natural mineral products such as talc or diatomites and synthetic materials such as pyrogenic silicas or polyolefin waxes. Matting can also be obtained by special formulations that exploit the incompatibility between binder components and their cross-linked structures. 

Ammonium nitrate granules and fertilizers based on these are coated with a layer consisting of sodium phosphates (trimetaphosphate and polyphosphate) and salts of alkylaryl sulfo-acids. These reagents may be added either both together to the ammonium nitrate melt or separately the sodium phosphates to the melt and the sodium salts of the alkylaryl sulfo-acids to the granules. The granules with added polyphosphates are then powdered with diatomite [538]. 

These columns are usually of length 0.3-4.0 m and internal diameter 2-4 mm and are packed with solid granules (the solid support ) on which is coated the liquid stationary phase. The ideal material as the support medium in a packed column should be of uniform particle size of large specific area and be chemically, thermally and mechanically stable. The frequently used diatomite supports are prepared from diatomaceous earths by a calcination process and differ from each other in their particle size, level of inertness and available surface areas. The surfaces are usually deactivated by acid washing and are silanized prior to coating with liquid phaste. 

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