Silicates solid-liquid properties

The public and, more particularly, industrial workers in workplaces, are exposed to different kinds and forms of toxic chemical substances—for instance, solids, liquids, gases, vapors, dusts, fumes, hbers, and mists. How a chemical substance gets into the body and its effect on health depend on the form or the physical properties of the candidate chemical substance. Welding fumes are a complex mixture of metallic oxides, silicates, and fluorides. Many kinds of occupations, such as welding, cutting, and allied processes, produce fumes and gases, leading to serious health effects on workers. 

Silacrowns which may be readily immobilized on siliceous supports are the methoxysilacrowns. Like other members of the series the compounds are prepared by transesterification. In this case the starting materials are trimethoxysilanes. The methoxysilacrowns behave similarly to the other silacrowns in solid/liquid phase transfer catalysis. The catalytic properties of these compounds were translated to solid supports by... 

Electrolytic conductance, a property of the so called conductors of the second class, is encountered mainly in the case of salts in dissolved, melted and solid state. Among these compounds are sulphates, halides, nitrates, silicates, also many oxides, hydroxides, sulphides and so on. The same group includes also the potential electrolytes, i. e. the substances from which ions are formed only in mutual reaction with a solvent (solutions of acids in basic solvents, solution of bases in acid solvents, further amines and different chlorine derivatives of organic compounds in liquid sulphur dioxide, nitro-compounds in liquid amines etc.). Finally also numerous colloidal solutions (such as proteins and soaps) conduct the current like electrolytes. 

Lime/fly ash pozzolanic processes combine the properties of lime and fly ash to produce low-strength cementation. Kiln dust processes involve the addition of kiln dust to eliminate free liquids and usually form a low-strength solid. Lime-based processes for solidification use reactions of lime with water and pozzolanic (siliceous) materials, such as fly ash or dust from cement kilns, to form concrete, called a pozzolanic concrete. Wastes of desulfurization of gases and other inorganic wastes can be immobilized by this method. 

Silica gel is jelly-like species formed from silicate solution under certain conditions, with properties between those of a solid and those of a liquid. It consists of a cross-linked network of SiC>2 colloidal particles in three-dimensional space. If it is an aqueous gel, the pores inside the gel will be filled with water or dilute solution. 

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