Abstract:

The aggregation-induced emission (AIE) molecules are novel organic fluorescent materials that present distinct photophysical properties in contrast to conventional aggregation-caused quenching fluorescent dyes. In virtue of their unique properties, they can be widely used in many fields such as chemical/biological sensing, biological probing and imaging, diagnosis and treatment integration and optoelectronic devices. In this paper, based on innovative experimental competition, tetraphenylethylene (TPE) side-chain polyacrylate AIE polymers have been synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization. With the optimization and exploration of the experimental conditions, the initiator of 2, 2'-azobis-2, 4-dimethylvaleronitrile (ABVN) with shorter half-life and higher activity was adopted to replace the conventional azobisisobutyronitrile (AIBN). As a result, the frontier scientific research experiment, which would have required more than 12 hours reaction, was adapted into a shorter polymerization time of 3-5 hours with moderate yields and good polymer product quality. Thus, the research experiment was remoulded as an experiment suitable for undergraduate laboratory teaching. A range of modern laboratory techniques, such as the anhydrous oxygen-free operation, the column chromatography separation and purification operation, the RAFT controlled polymerization, the gel-permeation chromatography molecular characterization, FTIR, NMR, UV-Vis, and fluorescence emission spectroscopy, have been involved and practised. The photophysical properties of the synthesized TPE side-chain AIE polymers were investigated, with the relative fluorescence quantum yield in the THF/water mixture solution of high water fraction reached a high value of 17%.

Key words: Tetraphenylethylene (TPE), AIE polymer, RAFT controlled polymerization, Photophysical properties, Innovation experiment