Effect of water resistant SiO2 coated SrAl2O4: Eu2+ Dy3+ persistent luminescence phosphor on the properties of Portland cement pastes

The present study investigates the effect of water-resistant SiO2 coated SrAl2O4: Eu2+, Dy3+ (SSA) phosphor on the properties of Portland cement pastes. In order to investigate it, firstly, SrAl2O4: Eu2+, Dy3+ phosphor was coated with SiO2 using heterogeneous precipitation method. Afterward, coated phosphor was admixed with Portland cement in varying proportions to prepare cement pastes. The setting time, hydration reaction, compressive strength, and luminescence intensity analysis were carried out. Moreover, water resistance performance of SSA phosphor based cement pastes was assessed in terms of afterglow test. Based on the results of setting time and hydration studies, it was deduced that SSA phosphor has set acceleration effect on cement pastes. Use of SSA phosphor improved the compressive strength of cement pastes due to the greater degree of hydration. Moreover, the afterglow study results confirmed the hydrolysis stability of SSA phosphor in water cured cement pastes. The XRD, SEM, EDX, TG-DTG, and FTIR analyses confirmed the formation of excessive amount of hydration products in SSA phosphor based cement pastes. Based on the results obtained, it is concluded that using SSA phosphor could be a promising approach for producing water-resistant persistent luminescence light emitting cement composites. (C) 2019 Elsevier Ltd. All rights reserved.