Zinc Oxide

Description

ZINC OXIDE

HS Code: 28170010
Chemical Formula:ZnO

Having Zinc oxide White seal and Rubber grade

Description

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. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.

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 valuable in emerging applications for: transparent electrodes in liquid crystal displays, energy-saving or heat-protecting windows, and electronics as thin-film transistors and light-emitting diodes.

Properties

Formula: ZnO
Molar mass: 81.38 g/mol
Lattice constant: a = 3.25 Å, c = 5.2 Å
Band gap: 3.3 eV (direct)
Refractive index (nD): 2.0041
Other names: Zinc white, calamine, philosopher’s wool, Chinese white, flowers of zinc

Uses

Rubber manufacture

Between 50% and 60% of ZnO use is in the rubber industry. Zinc oxide along with stearic acid is used in the vulcanization of rubber. ZnO additive also protect rubber from fungi (see medical applications) and UV light.

Ceramic industry

Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. Zinc oxide as a low expansion, secondary flux improves the elasticity of glazes by reducing the change in viscosity as a function of temperature and helps prevent crazing and shivering. By substituting ZnO for BaO and PbO, the heat capacity is decreased and the thermal conductivity is increased. Zinc in small amounts improves the development of glossy and brilliant surfaces. However, in moderate to high amounts, it produces matte and crystalline surfaces. With regard to color, zinc has a complicated influence.

Medicine

Zinc oxide as a mixture with about 0.5% iron(III) oxide (Fe2O3) is called calamine and is used in calamine lotion. Two minerals, zincite and hemimorphite, have been historically called calamine. When mixed with eugenol, a ligand, zinc oxide eugenol is formed, which has applications as a restorative and prosthodontic in dentistry.

Reflecting the basic properties of ZnO, fine particles of the oxide have deodorizing and antibacterial properties and for that reason are added into materials including cotton fabric, rubber, oral care products,and food packaging. Enhanced antibacterial action of fine particles compared to bulk material is not exclusive to ZnO and is observed for other materials, such as silver.This property results from the increased surface area of the fine particles.

Zinc oxide is widely used to treat a variety of skin conditions, including dermatitis, itching due to eczema, diaper rash and acne.