A luminescence thermometer: temperature sensitive paint based on rare earth complexes and polymethyl methacrylate

Well-defined probes based on rare earth complexes were prepared by using europium oxide (Eu2O3), gadolinium oxide (Gd2O3), 2-thenoyl trifluoroacetone (TTA), and 1,10-phenanthroline monohydrochloride monohydricrate (phen) as raw materials. Fluorescence spectroscopy was used to determine that 1:1 is the optimal ratio of Eu3+ and Gd3+. So a Eu0.5Gd0.5(TTA)3phen/PMMA temperature sensitive paint was prepared composed of rare earth complexes Eu0.5Gd0.5(TTA)3phen as probe molecules and polymethyl methacrylate (PMMA) as the matrix. The as-prepared Eu0.5Gd0.5(TTA)3phen/PMMA exhibits a strong emission at 617 nm and has fine temperature quenching properties in the range of 20 °C–90 °C. Furthermore, the rate of change of luminescence and temperature sensitivity are enhanced due to doping of Gd3+, illustrating a synergistic effect between Gd3+ and Eu3+.