A photochromic long persistent luminescent polyurethane based on a colour conversion process

A photochromic long persistent luminescent polyurethane (PLPLPU) is prepared via incorporating amino-functionalized phosphors (NH2-SrAl2O4:Eu2+,Dy3+) and the red fluorescer 1-[(2-hydrocyethly)amino]anthraquinone (HAA) based on a colour conversion process. X-ray Diffraction (XRD), UV-vis absorption spectroscopy (UV), thermogravimetric analysis (TG), a fluorescence spectrophotometer and an afterglow brightness tester as well as the percentage of the migration test were utilized to characterize the structure and properties of the resultant samples. The photoluminescence emission spectrum of phosphors is overlapped with the excitation spectrum of HAA, which demonstrates that HAA can be selected as a colour conversion agent and can be excited by phosphors in the dark. PLPLPU shows red emission in daylight and yellow in the dark, exhibiting a pleasant photochromic long persistent luminescence effect. Furthermore, HAA in PLPLPU was confirmed to have a better thermal migration stability than the blend samples due to the chemical combination.