Synthesis Of Titanate Red Persistence Materials By Hydrothermal Synthesis Method And The Applications In The Ceramic Glaze

According to the basic theory of color-light, it is known that random color-light can be obtained under mixing definite ratio of red, green and blue long persistent materials. Green and blue phosphors have been commercialized, however, red phosphors has not yet because its starting brightness and afterglow time have not achieved practical application requirements. Therefore, it becomes the focus of researchers in the recent years.Nowadays, titanate red persistence materials, as a good luminescent materials matrix for its ideal color purity, excellent chemical stability, great weathering ability and high quantum efficiency, have attracted much attention in the research about red long persistence materials. The traditional solid-state method for preparing titanate powders has some inherent drawbacks, such as high sintering temperature, large product size and product lack of homogeneity, While the preparation of pure Ca2Zn4Ti16O38:Pr3+(shorted:CZT:Pr) by sol-gel method needs21h at950℃.Therefore, the optimization of synthesis conditions is exigent to be solved. In this thesis, titanate red long persistent materials was prepared by hydrothermal synthesis method, the synthesis conditions、 luminescent properties、crystalline structure、micromorphology were also studied systematically. Furthermore, ceramic glaze was coated in the surface of spherical pottery base by mixing Ca0.8Zn0.2Ti03:Pr3+red persistent powder and base glaze, the surface of luminescent glaze is smooth and glossy.Firstly, CaTiO3:Pr3+powders were prepared by hydrothermal method in this thesis. The influences of the concentration of CO(NH2)2and citric acid on the luminescent properties were investigated, the effects of hydrothermal temperature、hydrothermal time、sintering temperature were also studied. The results show that when the mole ratios of CO(NH2)2to metal ions and citric acid to Ti(OC4H9)4equal to2:1, hydrothermal conditions is heating at200℃for2h, the product with the best performance can be obtained. The luminescent properties can be further improved by calcining at1050℃o The excitation spectra of the samples exhibited broad band with peaking at about330nm, while the emission spectra is612nm.Secondly, Zn2+doped multi-titanate was also prepared by hydrothermal method and the luminescent properties of Ca0.8Zn0.2TiO3:Pr3+phosphors were obvious superior to that of CaTiO3: Pr3+. CaTiO3, ZnTiO3and Ca2Zn4Ti16O38phases coexisted in the samples. The excitation spectrum located at330and380nm and the emission line centered at612nm. Likewise, the effects of the concentration of CO(NH2)2and citric acid, the hydrothermal temperature and time, calcination temperature and time on the luminescence properties were investigated. The result showed that the optimal sample was obtained when the mole ratios of CO(NH2)2to metal ions and citric acid to Ti(OC4H9)4equal to1:1, which was kept at200℃for8h during hydrothermal process and then calcined at1050℃for4h.Thirdly, the effects of the sintering temperature of vitreous glaze and the content of photoluminescence powder in the totality photoluminescence ceramic glaze powders on the properties of photoluminescence ceramic glaze were investigated. Explore the technology of preparation to improve the ceramic surface continued, and got the red long afterglow photoluminescence ceramic, which have a glossy surface and well photoluminescence capability, was prepared by the best raw material proportion.