The Preparation And Anti-Uv Transmittance Of Pyrophyllite Compound Titanium Oxide

Since the1980s, increasing attention has been paid to the issue on environment protection. An American scientist called Scotto and his group, after measuring the values of the ground ultraviolet radiation on various observation points, declared that the radiation on the surface of the earth which significantly increased had a greater impact on both environment and human health. Therefore, the study on ultraviolet radiation shield is becoming a big issue all over the world. The titanium oxide, as a sort of inorganic anti-ultraviolet material, has a good performance on anti-ultraviolet, hence, it has been widely applied in coating plastic and cosmetics and so on. However, it cannot help condensing in use. What is worse, the cost is too high due to the great consumption of raw materials. As a result, there is no doubt that the intense desire of discovering a cheap substitute for titanium is imperative. In this paper, we make a new kind of anti-UV material using pyrophyllite and titanium oxide through a process of mechanochemical method.Specifically As Follows:Firstly, do the research on the anti-UV performance of the pyroplryllite, as well as the pyrophyllite powder through the processing of calcination, pickling, ball-milling. The primary experimental parameters are as follows:calcination temperature is400℃～1000℃; calcination time is1h～5h; acid concentration is10%～30%; pickling time is1h-5h; pickling temperature is20℃～80℃; milling time is1h-5h; rotating speed is175r/min-225r/min. It proves under the circumstance that the powder has been processed in diverse conditions, the ultraviolet light transmittance is slightly lower, not obviously, compared with the original one.Then, study the anti-UV performance of pyrophyllite coated with titanium dioxide composite powders. The main parameters are as follows: coating ratio is6:4; calcination temperature is400～1000℃; calcination time is2h～5h; milling time is2h～5h; rotating speed is150r/min～240r/min. The UV light transmittance of the composite powder is measured by means of ultraviolet spectrophotometer with wave length of330nm,350nm,370nm,390nm respectively. The result shows that the ultraviolet light transmittance of the composite power is greatly influenced by the parameters above. To those powders in optimized condition, the UV light transmittance, less than5%, is obviously lower than pyrophyllite and commercial ZnO. Additionally, the result of SEM analysis indicates that there are thousands of spherical particles, whose diameter is about200～450nm, titanium oxide called, covering uniformly on the surface of pyrophyllites.Subject to single factor experiment, it seems possible to get the best process parameters using orthogonal experiment:pulp ratio is1:1; calcination temperature is800℃; calcination time is4h; rotating speed is210r/min; milling time is3h. Under this circumstance, its ultraviolet light transmittance almost closes to pure TiO2and can substitute for titanium dioxide in some areas.Finally, do some research on the anti-UV performance of the pyrophyllite doped with ZnO. It indicates that the best calcination temperature is400℃, but the performance is much lower comparing with pyrophyllite coated with titanium dioxide composite powders.