Encapsulation Study of Persistent Luminescent Pigment of Alkaline Earth Aluminate

Silica encapsulation was studied on the particle surface of aluminate-based luminescent pigment by using TEOS as the raw materials. The encapsulated particles were analyzed by SEM, diameter testing, BET surface area measurement and XPS, a dense SiO2 film formed on particle surface with the thickness of 14nm. The anti-water property and luminescent characteristics measurement show that encapsulated particles have a better anti-water performance and similar luminescent properties to non-encapsulated particles. Moreover, the encapsulation procedure was analyzed and the process parameters' effect on coating film was also researched. The results show that the encapsulation procedure is actually a kind of sol-gel procedure of SiO2·nH2O on the surface of particles and its process is optimized as following: pH of encapsulation solvent is about 10, encapsulation temperature is at 80℃ and reaction time is about 3.0.