Structural, luminescent and thermal properties of blue SrAl2O4:Eu2+, Dy3+ phosphor filled low-density polyethylene composites

The performance of nanophase luminophors is usually compromised by environmentally induced degradation. In this study, composites of low density polyethylene (LDPE) with various concentrations of the blue-emitting europium and dysprosium co-doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) phosphor were investigated. The blue long-lasting phosphorescence of the composites was observed in the dark after removal of the excitation light. X-ray diffraction analysis revealed the presence of the SrAl2O4 phase in the composites. PL spectra of the composites have two sets of peaks, major broad bands peaking at about 4855 angstrom and minor ones at wavelengths between 4115 and 4175 angstrom, attributed to the 4f-5d transition of Eu2+. DSC and TGA results show that the introduction of the phosphor in LDPE matrix caused a slight reduction in the crystallinity of LDPE but a significant increase in the stability of the composites. (C) 2009 Elsevier B.V. All rights reserved.