The blue fluorescence luminescence properties of hyperbranched polysiloxane containing halogen atom

Abstract

In order to obtain a new class of aggregation‐induced emission (AIE) polymers without common conjugated chromophores in their structures, hyperbranched polysiloxanes (HBPSi) containing halogen elements were obtained by introducing chlorine and bromine atoms into HBPSi (Cl‐HBPSi, Br‐HBPSi) through one‐step polycondensation reaction. The relationship between the chemical structure and fluorescence properties of the two types of HBPSi was studied. The results show that both Cl‐HBPSi and Br‐HBPSi prepared in this study can emit bright blue light under a UV lamp of 365 nm wavelength, and appropriate ratio of raw materials can endow the halogenated HBPSi with moderate degree of polymerization, and give it strong excitation intensity and emission intensity. Meanwhile, Br‐HBPSi exhibits a higher fluorescence intensity, which is due to the ‘heavy atom effect’ of halogen atoms. In addition, for different concentrations of tetrahydrofuran (THF) solutions with the same addition of HBPSi, the luminescence intensity increases gradually with the decrease of THF concentration. These results indicate that the emission intensity is affected by the molecular weight and concentration of polymers, and that the AIE properties of halogenated HBPSi are related to the ‘impurity atomic clusters’ formed by halogenated atoms and the hydroxyl groups formed by the heterogeneity of HBPSi. © 2023 Society of Industrial Chemistry.