吸水性树脂在固态上转换材料中的应用研究

Application of water absorbent resin in solid upconversion materials

采用5,10,15,20-四苯基卟啉钯(PdTPP)作光敏剂,9,10-二苯基蒽(DPA)作发光剂,二者溶于有机溶剂后再分散到含表面活性剂吐温20(Tween-20)的水溶液中制得水包油(O/W)型微乳液,具有三维网状多孔结构的聚丙烯酸钠吸水性树脂可高效吸附该微乳液,得到固态上转换树脂。对该上转换树脂进行了光物理性能研究,荧光光谱显示其上转换发光峰位于447 nm处,并观察到肉眼可见的上转换蓝色光。随着温度变化,树脂中含有的微乳液由O/W型可逆转化为W/O型微乳液,该相转变可促进上转换体系中的三线态-三线态能量传递(TTET)和三线态-三线态湮灭(TTA)过程,使上转换效率提高。聚丙烯酸钠吸水性树脂作为一种新型TTA上转换载体,制备方法简单,可在有氧环境下获得高效稳定的上转换发光,在光电材料中具有广泛的应用前景。

A type of solid upconversion material is reported. Sodium polyacrylate absorbent resin absorbed efficiently the oil-in-water (O/W) microemulsion containing photosensitizer (5,10,15,20-tetraphenylporphyrin palladium,PdTPP),emitter (9,10-diphenylanthracene,DPA) and surfactant (Tween-20) and the upconversion resin was formed. The surface structure and optical properties of the upconversion resin were studied. In the fluorescence spectra,the upconversion luminescence locates at 400 nm^530 nm and the maximum emission peak appears at 447 nm. The green-to-blue upconversion fluorescence is visible to naked eyes. As the temperature increases,the O/W microemulsion can be reversibly converted into water-in-oil (W/O) microemulsion. This phase transformation can effectively facilitate the triplet-triplet-energy-transfer (TTET) and triplet-triplet annihilation (TTA) process,and then the upconversion intensity of the resin is highly enhanced. The sodium polyacrylate absorbent resin is a novel medium for TTA-upconversion materials and reveals excellent performance in ambient air. It has great application potential in photoelectric materials.