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|Section2= |Section3= |Section5= |Section6= |Section7= |Section8= }} Zinc oxide is an inorganic compound with the formula ZnO. ZnO is a white powder that is insoluble in water, and it is widely used as an additive in numerous materials and products including rubbers, plastics, ceramics, glass, cement, lubricants,〔 paints, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, and first-aid tapes. It occurs naturally as the mineral zincite, but most zinc oxide is produced synthetically.〔Marcel De Liedekerke, "2.3. Zinc Oxide (Zinc White): Pigments, Inorganic, 1" in Ullmann's Encyclopdia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. 〕 ZnO is a wide-bandgap semiconductor of the II-VI semiconductor group. The native doping of the semiconductor due to oxygen vacancies or zinc interstitials is n-type. This semiconductor has several favorable properties, including good transparency, high electron mobility, wide bandgap, and strong room-temperature luminescence. Those properties are used in emerging applications for transparent electrodes in liquid crystal displays, in energy-saving or heat-protecting windows, and in electronics as thin-film transistors and light-emitting diodes. ==Chemical properties== Pure ZnO presents as a white powder, but in nature it occurs as the rare mineral zincite, which usually contains manganese and other impurities that confer a yellow to red color. Crystalline zinc oxide is thermochromic, changing from white to yellow when heated and in air reverting to white on cooling. This color change is caused by a small loss of oxygen to the environment at high temperatures to form the non-stoichiometric Zn1+xO, where at 800 °C, x = 0.00007.〔 Zinc oxide is an amphoteric oxide. It is nearly insoluble in water, but it is soluble in (degraded by) most acids, such as hydrochloric acid: :ZnO + 2 HCl → ZnCl2 + H2O Bases also degrade the solid to give soluble zincates: :ZnO + 2 NaOH + H2O → Na2() ZnO reacts slowly with fatty acids in oils to produce the corresponding carboxylates, such as oleate or stearate. ZnO forms cement-like products when mixed with a strong aqueous solution of zinc chloride and these are best described as zinc hydroxy chlorides. This cement was used in dentistry. ZnO also forms cement-like material when treated with phosphoric acid; related materials are used in dentistry.〔 A major component of zinc phosphate cement produced by this reaction is hopeite, Zn3(PO4)2·4H2O. ZnO decomposes into zinc vapor and oxygen at around 1975 °C with a standard oxygen pressure. In a carbothermic reaction, heating with carbon converts the oxide into zinc vapor at a much lower temperature (around 950 °C). :ZnO + C → Zn(Vapor) + CO Zinc oxide can react violently with aluminium and magnesium powders, with chlorinated rubber and linseed oil on heating causing fire and explosion hazard.〔(International Occupational Safety and Health Information Centre (CIS) ) Accessdate January 25, 2009.〕〔(Zinc oxide ) MSDS. hazard.com. Accessdate January 25, 2009.〕 It reacts with hydrogen sulfide to give the sulfide. This reaction is used commercially. :ZnO + H2S → ZnS + H2O 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Zinc oxide」の詳細全文を読む スポンサード リンク
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