Chemical properties of glass

PHYSICAL AND CHEMICAL PROPERTIES OF GLASS Thermal Capacity... 

Graeral Chemical Properties of Glass Metbtance to Chemical Actions... 

Chemical Properties of Glass.—Among the chemical properties of glass, there are some which merit an attentive examination. Dumas classes them as follows—namely, the effect of tire air or of deoxidizing bodies that of water that of acids and that of bases. - ... 

Shelby, J. E. Introduction to Glass Science and Technology. Cambridge, England Royal Society of Chemistry, 2005. A college-level textbook with detailed information on the physical and chemical properties of glass. 

The physical and chemical properties of silicate glasses depend on the composition of the material, ion size, and cation coordination number (9). A melt or glass having a Si02/Na20 ratio of 1, ie, sodium metasiUcate [1344-09-8] is expected to possess a high proportion of (SiO ) chains. At a ratio of 2, sheets might predominate. However, litde direct evidence has been shown for a clear predominance of any of these stmctures. The potential stmctures of sihcate melts of different ratios are discussed in detail elsewhere (10—12). 

The effects of corrosion on other properties need similar direct assessment in many cases. However, in the absence of accepted standard tests the BS, DIN, ISO tests for laboratory glassware are often used. At the present time, the British Standard BS 3473 Methods of testing and classification of the chemical resistance of glass used in the production of laboratory glassware is being re-issued in six parts, of which the first five parts are identical to recently revised ISO test procedures. There are also corresponding DIN tests in some cases which are very similar. The current situation is ... 

The highest mechanical strengths are usually obtained when the fibre is used in fine fabric form but for many purposes the fibres may be used in mat form, particularly glass fibre. The chemical properties of the laminates are largely determined by the nature of the polymer but capillary attraction along the fibre-resin interface can occur when some of these interfaces are exposed at a laminate surface. In such circumstances the resistance of both reinforcement and matrix must be considered when assessing the suitability of a laminate for use in chemical plant. Glass fibres are most commonly used for chemical plant, in conjunction with phenolic resins, and the latter with furane, epoxide and, sometimes, polyester resins. 

A pyrolysis technique was investigated as a method for the chemical recycling of glass fibre-reinforced unsaturated polyester SMC composites. The proeess yielded liquid products and gases and also a solid residue formed in the pyrolysis of glass fibres and fillers. The solid residue was used as a reinforeement/filler in unsaturated polyester BMC composites, and the influenee on mechanical properties was studied in comparison with BMC prepared entirely from virgin materials. 

Glass has been the container of choice for pharmaceutical dosage forms because of its resistance to decomposition by atmospheric conditions or by solid or liquid contents of different chemical compositions [1]. Furthermore, by varying the chemical composition of glass, it is possible to adjust the chemical behavior and radiation protective properties of glass. 

It seems that sometime during the third millennium b.c.e., somewhere in the Middle East, it was discovered that when a mixture of silica sand and soda is heated to relatively high temperatures, the mixture fuses to form glass. Few other human-made materials are derived, as is glass, from such common and abundant raw materials. Its remarkable physical and chemical properties made glass, already in antiquity, one of the most useful and ubiquitous materials in many areas of the world. 

The physical and chemical properties of MgO films prepared by the sol-gel technique were the area interest of the examinations presented by Shukla75. The aim of mentioned work was to produce films with nano size particles so as to employ them for the sensor applications, as adsorption in such films increases many folds due to the increase of surface area. Infra-red spectroscopic studies indicated the presence of solvent in the precursor, which helped in decomposition to nano-particles during nucleation of the film. The MgO sol-gel films were deposited on the glass rod bend in U-shape for humidity sensor. 

The chemical properties of BA have been studied in detail (Lapin et al., 1984). Low temperature epr spectroscopy shows clearly that the ground state of BA is the triplet (3BA). The zero field parameters (Table 3) reveal some details of this structure. When the irradiation is performed at 4.6 K in a 2-methyltetrahydrofuran glass no epr signals from radical species are apparent. The optical spectrum under these conditions shows absorptions (Table 4) which disappear when the glass is warmed. From these findings the absorption bands are assigned tentatively to 3BA. This conclusion is strongly supported by results from laser flash photolysis experiments. 

See also Methacrylate monomers polymerization data for, 16 279t Methacrylic ester polymers, 16 271-298. See also Methacrylate monomers Methacrylic esters analytical test methods and specifications for, 16 291-293 bulk polymerization of, 16 281-282 chemical properties of, 16 276-277 electrical properties of, 16 276 emulsion polymerization of, 16 285-288 glass transition temperature of, 16 273-274... 

In the modern world, we are accustomed to taking the chemical stability of glass very much for granted - we rely on the durability of glass for so many things, such as windows and (until the widespread availability of plastics) bottles, as well as its use in the chemical laboratory as an extremely inert and unreactive container. In addition to its apparent inertness, glass has a number of other beneficial properties, such as its transparency or the ability to take on virtually any colour as the result of the addition of a small amount of transition metals. 

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