Polymerization And Application Of Functional Copolymers With Stimulation-responsive Luminescence

The phenomenon of aggregation-induced emission(AIE)has drawn extensive attention from the scientific community because it is completely opposite to the aggregation-induced quenching(ACQ)phenomenon of traditional organic dyes.At present,many AIE compounds with different structures and different luminescence mechanisms have been discovered.Researchers have used these compounds to synthesize AIE polymers.AIE polymers can not only overcome the shortcomings of low mechanical strength and difficulty in processing of small molecule systems,but also have good film-forming property and coordination amplification effect.They can meet more diverse application needs,and have potential application prospects in the fields of chemical/biosensing,biomarkers,electroluminescence,and logic gate devices.In this paper,AIE monomer 4-((4-vinylbenzyl)oxy)tetraphenylethylene(VBO-TPE)was synthesized.RAFT polymerization method was used to conduct ternary copolymerization with styrene(St)and maleic anhydride(MAH).A series of terpolymer with different value of([VBO-TPE]+[St]+[MAH])/[CTA]and different monomer ratios were prepared.On this basis,the anhydride groups on the copolymer were hydrolyzed,acidified and grafted,and the fluorescence properties of the reaction products,including pH responsiveness and ionic responsiveness,were studied.The details are as follows:1.In the mixed solution of THF/H2O,the fluorescence intensity of the terpolymer increases with the increase of H2O content in the solution,and the peak fluorescence intensity can be increased by up to 347 times,which are not affected by the value of([VBO-TPE]+[St]+[MAH])/[CTA]and monomer ratio of the copolymer.2.The fluorescence performance of the copolymer hydrolysate(NaPTSM)is pH responsive.The fluorescence intensity will gradually increase with the decrease of pH value,and the peak fluorescence intensity under acidic conditions can be up to 4 to 5 times of the value under alkaline conditions.3.The fluorescence intensity of poly carboxylic acid structure(HPTSM)obtained after NaPTSM acidification is metal ion responsive,and fluorescence quenching occurs in the presence of Fe3+.The detection limit(LOD)of Fe3+ is 3.3×10-6 mol/L.4.The fluorescence performance of the copolymer grafted with PEG-NH2 is also pH responsive.The fluorescence intensity under acidic conditions is significantly enhanced when compared with that under alkaline conditions,and the difference in fluorescence intensity under different pH values is more obvious.In summary,we have synthesized a type of ternary copolymer with AIE characteristics,and its fluorescence behavior after modification shows pH responsiveness and metal ion responsiveness.It may find potential application as Fe3+ fluorescent probe.