Titanium zinc oxide

Titanium white pigments, commercial production of, 19 388 Titanium white rutile pigment, 19 391 Titanium zinc oxide, 5 603 Titanium-zirconium-molybdenum (TZM) alloy, 17 14-15 Titanocene, 25 118 Titanocene catalysts, 16 19 Titanocene dichloride, 25 105 Titanocene synthons, 25 116 Titanocycles, 25 116... 

Titanium Oxides hydroxides Titanium zinc oxide ... 

If the normal carbonate is used, the basic carbonate or white lead, Pb(OH),. 2PbCO,. is precipitated. The basic carbonate was used extensively as a base in paints but is now less common, having been largely replaced by either titanium dioxide or zinc oxide. Paints made with white lead are not only poisonous but blacken in urban atmospheres due to the formation of lead sulphide and it is hardly surprising that their use is declining. 

White Pigments. Opaque white pigments commonly used in inks, in order of decreasing opacity, ate titanium dioxide and zinc oxide. TiO is by fat the most popular white pigment. Mixtures of whites ate often made with the various colored pigments to add opacity or to make pastel colors. 

Heterogeneous Photocatalysis. Heterogeneous photocatalysis is a technology based on the irradiation of a semiconductor (SC) photocatalyst, for example, titanium dioxide [13463-67-7] Ti02, zinc oxide [1314-13-2] ZnO, or cadmium sulfide [1306-23-6] CdS. Semiconductor materials have electrical conductivity properties between those of metals and insulators, and have narrow energy gaps (band gap) between the filled valence band and the conduction band (see Electronic materials Semiconductors). 

It is also possible to deflect uv radiation by physically blocking the radiation using an opaque makeup product. A low particle size titanium dioxide can reflect uv light without the undesirable whitening effect on the skin that often results from products containing, for example, zinc oxide or regular grades of titanium dioxide. 

The formulation of calcium chelate materials is based upon the formation of a low-solubiUty chelate between calcium hydroxide and a sahcylate. Dycal utilizes the reaction product of a polyhydric compound and sahcyhc acid. Other sahcyhc acid esters can be similarly used. Vehicles used to carry the calcium hydroxide, extenders, and fillers may include mineral oil, A/-ethyl- -toluenesulfonamide [80-39-7] and polymeric fluids. The filler additions may include titanium dioxide [13463-67-7] zinc oxide, sihca [7631-86-9], calcium sulfate, and barium sulfate [7727-43-7]. Zinc oxide and barium sulfate are useflil as x-ray opacifying agents to ensure a density greater than that of normal tooth stmcture. Resins, rosin, limed rosins, and modified rosins may serve as modifiers of the physical characteristics in both the unset and set states. 

Disclosing waxes include soft paraffins, petrolatums, coconut oil, zinc oxide, titanium dioxide, and suitable dyes. 

The role of antimony oxide is not entirely understood. On its own it is a rather weak fire retardant although it appears to function by all of the mechanisms listed above. It is, however, synergistic with phosphorus and halogen compounds and consequently widely used. Other oxides are sometimes used as alternatives or partial replacements for antimony oxide. These include titanium dioxide, zinc oxide and molybdenic oxide. Zinc borate has also been used. 

Titanium dioxide is a common pigment, and zinc oxide and magnesium oxide are common fillers in rubber base adhesives. 

There are two ways in which chemicals can protect the skin from ultraviolet light they can either absorb the light or reflect the light. Zinc oxide and titanium dioxide reflect or scatter light of many frequencies, from infrared through ultraviolet. That is why these chemicals appear opaque white. 

Zinc oxide is a white powder that makes a very opaque paste when mixed with water or oils. It is used as a sunblock and as a colorant in toothpastes and cosmetics. Zinc oxide is used in many of the same products as titanium dioxide. 

Physical agents include zinc oxide and titanium dioxide. These are the most effective sunscreens because they reflect UVA and UVB. When applied to the skin, they induce a white or ashen color, which many patients find cosmetically unacceptable. New micronized formulations of these agents are available which enhance cosmetic acceptability. Sunscreens... 

All commercial materials are based on calcium hydroxide and liquid alkyl salicylates (Prosser, Grolfman Wilson, 1982) and are supplied as a two-paste pack. Zinc oxide is sometimes added to the calcium hydroxide, as are neutral fillers. A paste is formed from this powder by the addition of a plasticizer examples include A-ethyl toluenesulphonamide (o- orp-) and paraffin oil, with sometimes minor additions of polypropylene glycol. The other paste is based on an alkyl salicylate as the active constituent containing an inorganic filler such as titanium dioxide, calcium sulphate, calcium tungstate or barium sulphate. Alkyl salicylates used include methyl salicylate, isobutyl salicylate, and 1-methyl trimethylene disalicylate. An example of one commercial material, Dycal, is given in Table 9.7, but its composition has been subjected to change over the years. 

Many inorganic oxides can be manufactured to provide granular, porous materials with high surface areas, which can readily adsorb organic liquids. Preliminary screening of a range of oxides, namely aluminium oxides, titanium dioxides, zinc oxide, hydrotalcites, zeolites and silicas, indicated that the latter two materials were able to retain the largest quantities of biocide. 

Wu, W Cai, Y.W., Chen, J.F., Shen, S.L., Martin, A. and Wen, L.X. (2006) Preparation and properties of composite particles made by nano zinc oxide coated with titanium dioxide. Journal of Materials Science, 41, 5845-5850. 

Sunblocks are opaque substances such as zinc oxide, titanium dioxide, and iron oxide that protect by forming a shield on the skin, which reflects and scatters incident radiation. In essence, sunblocks provide physical protection against sun exposure, including both visible and ultraviolet light. Sunscreens are substances that chemically absorb ultraviolet light in the top layer of the epidermis, protecting the underlying layers. 

The sunblocks zinc oxide, titanium dioxide, and iron oxide are inorganic chemicals that are not absorbed into the skin. These substances consist of opaque particles that reflect both visible and ultraviolet light. In addition, zinc oxide blocks virtually the entire UVA and UVB spectrum and thus offers overall protection. The particulate nature of these sunblocks enhances their effectiveness at reflecting sunlight. The smaller the particle size, the greater the surface area available for reflection, and the more effective the sun protection offered by the formulation. 

Although, because of its cost, titanium dioxide is usually only used as a whitening agent for rubber compounds, it is in fact a reinforcing agent comparable on a volume basis with the reinforcement found with zinc oxide. 

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