Chemical optical glasses

Microelectronic circuits for communications. Controlled permeability films for drug delivery systems. Protein-specific sensors for the monitoring of biochemical processes. Catalysts for the production of fuels and chemicals. Optical coatings for window glass. Electrodes for batteries and fuel cells. Corrosion-resistant coatings for the protection of metals and ceramics. Surface active agents, or surfactants, for use in tertiary oil recovery and the production of polymers, paper, textiles, agricultural chemicals, and cement. 

Used industrially as a chemical intermediate in the production of rayon, carbon tetrachloride, xanthogenates, flotation agents, and pesticides used in the cold vulcanization of vulcanized rubber, in adhesive compositions for food packaging as a solvent for phosphorus, sulfur, selenium, bromine, iodine, fats, resins, rubbers, waxes, lacquers, camphor, resins and in the production of optical glass, paints, enamels, varnishes, paint removers, tallow, putty preservatives, rubber cement, soil disinfectants, explosives, rocket fuel, and electronic vacuum tubes. 

The effect of pressure and velocity on the removal rate of oxide and metal films in a chemical-mechanical polish process has been widely investigated. Yet, there is no consensus and several different theoretical models have been proposed. Most of them take the form R = KP V where R denotes the polish rate, K is a proportionality constant, P is the applied downward pressure, V is the velocity, and a and b are constants that take fractional values between 1/3-1. When a and b are both equal to 1, this equation becomes the Preston equation, well known in optical glass polishing industry. 

Optical glasses are used in optical devices and instruments, and are characterized by specified and precisely maintained values of refractive index and dispersion. The other main properties required are high chemical and physical homogeneity, colourlessness and a high optical transmissivity. The optical industry has at its disposal hundreds of types of optical glasses, but only a limited number suffice to meet current requirements. 

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