Aluminum-silicate

Thin films of mixed metal oxides are usually obtained from a mixture of two different kinds of alkoxide precursors. However, this method suffers from problems with stoichiometry control since extensive efforts must be made to control the vapor phase concentration of two precursors with often dissimilar vapor pressures. Also of importance here is the near impossible task of matching rates of hydrolysis/oxidation to give pure , non-phase segregated films, i.e., those having a homogeneous composition and structure. In an effort to solve these problems, research effort has been aimed at single-source precursors, i.e., those containing both aluminum and silicon. 

Films grown from the single-source precursor Al(0/-Pr)2(0SiMe3) crystallize to kyanite, A SiO, whereas those grown from [Al(OSiEt3)3]2 remained amorphous even after annealing. The predisposition to crystallization in the films formed from a single- 

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Other heavy fuel contaminants are metals (vanadium, nickel, sodium) coming from the crude oil itself or metallic salts (aluminum silicates) coming from catalysts in conversion steps. The aluminum silicates should not exceed 300 ppm (30 ppm of aluminum), for these materials exert a strong abrasive action on the engine cylinders and injection systems. They can however be eliminated partially by centrifuging and filtration. 

Spodumcnc. A mixture of quartz, feldspar, and spodumene is being calcined in rotary kilns at 1475 K to produce lithium aluminum silicate. 

Zeolite Pellets or granules of aluminum silicate, used in water treatment or aircleaning applications. 

Clay. This material is found at the surface of the earth and often is the major component of soils. The material is plastic when wetted, but becomes hard and brittle when dried and heated. It is composed mainly of hydrous aluminum silicates as well as other minerals. 

Shale. This sedimentary rock is formed by the consolidation of clay, mud and silt. It contains substantial amounts of hydrous aluminum silicates. 

To improve the yield of mono- and dimethylamines, a shape selective catalyst has been tried. Carhogenic sieves are microporous materials (similar to zeolites), which have catalytic as well as shape selective properties. Comhining the amorphous aluminum silicate catalyst (used for producing the amines) with carhogenic sieves gave higher yeilds of the more valuable MMA and DMA. ... 

Several different possible zeolite structures may result, and if the sodium content is too high, calcium and magnesium are excluded and a hard zeolite scale of sodium-aluminum silicate preferentially forms. If only calcium is present, calcium-aluminum silicate zeolite forms, also as a hard scale. If only magnesium is present in solution, it forms the flocculant magnesium aluminate, MgAl204. 

Today n-paraffms are exclusively produced from the corresponding distillation cuts of paraffin-rich oils with the use of molecular sieves. Molecular sieves are synthetically manufactured aluminum silicates of the zeolite type, which after dehydration have hollow spaces of specific diameters with openings of specific diameters. The molecules are then able to penetrate the openings in the correct size and form and are held in the hollow spaces by electrostatic or van der Waals forces. The diameter of the zeolite type used for the production of paraffins is 5 A and is refined so that the n-paraffins (C5-C24) can penetrate the hollow spaces while the iso- and cyclic paraffins are unable to pass through [15]. 

No aluminum silicates of alkali metals are known in which the A1+3 R+1 ratio is less than 1 1. 

It is further shown that the theory requires that no stable basic silicates of divalent metals exist, and that in aluminum silicates of alkali metals there should be at least one aluminum ion for every alkali ion. 

The structures of aluminum silicates of divalent metals which are simplest from the coordination standpoint are shown to correspond to the formulas R3 + +Al2Si30i2 and R3++Al2Si60i8, which include the most important minerals of this class, the garnets and beryl. 

If the materials of interest are adsorbed on the surface of the solid impurities by polar forces, for example, due to contamination by substances such as silica, aluminum silicate or metal oxide, then they... 

Silicates also lead to uptake of CO2. Weathering of a non-aluminum silicate like Mg-olivine may be written... 

A study was made of the comparative stabilities at various exposures of an upset stomach remedy suspension. This product consisted of a dispersion of bismuth subsalicylate and phenylsalicylate in an aqueous system. Methyl-cellulose and magnesium aluminum silicate were selected as the suspending agents, because the presence of polyvalent metallic ions precluded the use of hydrocolloids affected by these ions. In addition, it was found that methyl-cellulose contributed a demulcent effect. The viscosity, as well as the suspension characteristics of the combination of protective colloids used, was of a synergistic nature. These colloids formed a thixotropic system. The thixotropy undoubtedly aids in stabilizing this system. In order to make this product palatable and impart elegance, color and flavor were added. Sample 1 (with protective colloids) showed no separation, while sample 2 (without... 

The stability characteristics of two different antiperspirant lotion systems were compared. Sample 1 represented an aqueous emulsion containing an aluminum salt. The internal phase consisted of stearyl alcohol and ethylene oxide reaction products, polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan tristearate. Methylcellulose was used as a stabilizer and bodying agent. Sample 2 represented a dispersion of magnesium aluminum silicate in an aqueous system containing aluminum ions. Because of its com-... 

Figure 6. Effect of magnesium aluminum silicate and cellu-losic hydrocolloids on stability of suspensions...

Figure 7. Synergistic stabilizing effect of magnesium aluminum silicate with carboxymethylcellulose on medicated liquid cream...

Consists of clay, mud, and silt, mainly aluminum silicates Dense fine-grained rock containing mainly clay Contains silicates secondary product... 

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