Polymer hybrid thin films based on rare earth ion-functionalized MOF: photoluminescence tuning and sensing as a thermometer

Abstract

A series of photofunctional polymer hybrid thin films based on rare earth ion functionalized metal organic frameworks (MOFs, 1 for zinc complexes bio-MOF-1 (Zn₈(ad)₄(BPDC)₆O·2Me₂NH₂) and 2 for rare earth complexes RE(BPDC)(Ad) (BPDC = biphenyl-4,4′-dicarboxylic acid, Ad = adenine) have been prepared via polymerization reaction of ethyl methacrylate (EMA) and 4-vinylpyridine (VPD). The as-obtained hybrid films were characterized by X-ray diffraction, FT-IR, and SEM, especially for the luminescence performance and sensing ability. These hybrid polymer thin films are dense and transparent and display multi-colors, including blue, red and blue-green. Among them, Y_0.9Tb_0.0999Eu_0.0001-2 fabricated hybrid thin film displays a white light output. More significantly and interestingly, the Tb_0.999Eu_0.001-2 fabricated hybrid thin film can be used as luminescent ratiometric thermometer based on the energy transfer from Tb³⁺ to Eu³⁺, whose color will change from blue-green to pink from 100 K to 320 K.