Vitreous glasses

Bond Type. Most bonded abrasive products are produced with either a vitreous (glass or ceramic) or a resinoid (usually phenoHc resin) bond. Bonding agents such as mbber, shellac, sodium siHcate, magnesium oxychloride, or metal are used for special appHcations. 

Suarez PAZ, Consort CS, De Souza RF, Dupont J, Goncalves RS (2002) Electrochemical behavior of vitreous glass carbon and platinum electrodes in the ionic liquid l-n-butyl-3-methyUmidazolium trifluoroacetate. J Brazil Chem Soc 13 106-109... 

In this equation, l is a range of molecular interaction. For low molecular weight liquid-liquid and vitreous glass systems (16, 17) y l is 5-20 A (10 A is a typical value). For polymer solutions, Debye has shown that l = R/ 6 where R is the root mean square end-to-end distance of the polymer chain. Similarly, for polymer-polymer systems, l = R yj3 on the basis of a derivation analogous to that given by DebyejFpr pplymer jolvept systems. In the latter case,... 

Substitution of a typical value, T8 = 400°K, into this equation suggests that 5 < Am/Z < 20 for 10° < Tg — T < 150°C. Hence, a range for the scale of phase separation can be estimated for various systems (see Table II). This scale of phase separation has been well documented for low molecular weight and vitreous glass systems (I, 2, 17, 18, 19, 20). There is also reasonably good agreement for poly(phenylene oxide) in several solvents (6, 7, 8, 9). 

For the manufacture of glass and vitreous (glass-like) enamels ... 

Alkaline earth and rare earth metal cocation effects are reported in this paper for copper ion-exchanged ZSM-5 zeolites used for the catalytic decomposition of nitric oxide in 02- free, 02- rich, and wet streams. Severe steaming (20% H2O) of Na-ZSM-5 at temperatures above 6(X)°C leads to partial vitreous glass formation and dealumination. Unpromoted Cu-ZSM-5 catalysts suffer drastic loss of NO decomposition activity in wet gas streams at 500°C. Activity is partially recovered in dry gas. Copper migration out of the zeolite channels leading to CuO formation has been identified by STEM DX. In Ce/Cu-ZSM-5 catalysts the wet gas activity is greatly improved. CuO particle formation is less extensive and the dry gas activity is largely recovered upon removal of the water vapor. 

Amorphous silica lacks a definite shape and an orderly atomic latticework. Types of amorphous silica include glass, vitreous glass fiber, large flocculated silica gel, diatomaceous earth, and opaline phase-fused silica in granular and powder form. These products provide high purity, reinforcement, great surface area, flatting properties, and thixotropy. Fused silica has an extremely low coefficient of linear thermal expansion and has become quite popular, especially in electronics applications. The amorphous silicas are compatible with thermosets, thermoplastics, silicone rubber, and other elastomers. 

Dielectric overglaze materials are vitreous glasses designed to fire at a relatively low temperature, usually around 550° C. They are designed to provide mechanical protection to the circuit, to prevent contaminants and water from spanning the area between conductors, to create solder dams, and to improve the stability of thick-film resistors after trimming. 

Porcelain Enamel A fused or melted glass powder and subsequently, cooled on a metal surface that acts as an inert vitreous-glass coating to water. 

In the corresponding crystalline oxides, the polyhedra can have common summits, edges, or faces. In its different crystalline forms, silica (quartz, cristobalite, tridymite, etc.) exhibits a lattice built with Si04 tetrahedra linked together by their summits. In the case of vitreous (glass) silica, the glass lattice is made of the same tetrahedral Si04 units, linked by their summits, but the mutual orientation of the constitutive tetrahedra is variable. 

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