Surface Modification of SrAl<sub>2</sub>O<sub>4</sub>:Eu<sup>2+</sup>, Dy<sup>3+</sup> Phosphors Using Silica Encapsulation

Silica encapsulated phosphors SrAl2O4:Eu2+, Dy3+ have been synthesized by non-homogeneous phase coring method, in which glycerol was firstly used as dispersion medium and hyper-dispersant was introduced as additive. IR, BET and scanning electron microscopy (SEM) demonstrated that a dense layer of silica was formed on the surface of phosphor SrAl2O4:Eu2+, Dy3+. The results showed that the encapsulated phosphors possess good properties in water-resistance, heat-resistance and dispersibility when encapsulation amount reached 8 wt. %. Moreover, the photoluminescence intensity of phosphors SrAl2O4:Eu2+, Dy3+ was improved apparently after surface modification. All results revealed that silica encapsulation would effectively improve alkaline earth aluminates phosphors’ properties and using glycerol as the dispersion medium is helpful to silica encapsulation.