FLUORESCENCE QUENCHING BEHAVIOUR OF HYPERBRANCHED POLYMER TO THE NITRO- COMPOUNDS

摘要

Fluorescence quenching behaviour of hyperbranched polymer film to various aromatic nitro-compounds is presented. The quenching efficiency of 1% and 1 ppm polymer solution in ethanol is 80% and 40%, respectively, for the nitro aromatic compounds. It has been established that aromatic structure and numbers of nitro groups have almost no effect on the quenching properties. The quenching is concentration dependent. The quenching for the vapour of nitro compounds is fast and related to the vapour pressure. The quenching mechanism was attributed to the strong electron-withdrawing property of the nitro groups. Presence of an electron-donating group showed fluorescence enhancement to hyperbranched polymer. Molecular simulation of the polymer structure has shown that the hyperbranched conjugated polymer has a well-developed network structure, with cavities being large enough for the nitro aromatic molecule to penetrate and interact with the polymer linkage.