Preparation of hyperbranched polysiloxane containing terminal amino group and research on their luminescence properties

Abstract

In order to obtain a polymer with good biocompatibility and aggregation induced luminescence, amino group was introduced into hyperbranched polysiloxane (HBPSi) structure by one-step transesterification, and two HBPSi containing terminal amino group (HBPSi-NH₂) were prepared. It was worth noting that both of them exhibit good luminescence characteristics. To further study the relationship between their structure and luminescence intensities, the structure and molecular weight distribution of these two HBPSi-NH₂ were studied by nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (FTIR) and gel permeation chromatography (GPC), the luminescence properties of the prepared NH₂-HBPSi were characterized by fluorescence spectroscopy (PL). The results showed that the luminescence intensity of HBPSi-NH₂ was affected by the molecular weight and dispersion. HBPSi-NH₂ with high molecular weight can emit strong fluorescence, and in the good solvent (tetrahydrofuran, THF), the HBPSi-NH₂ exhibit strong dispersion and leads to the weakest luminescence performance, while in bad solvent, it can lead to the weak dispersion and the strongest luminescence performance.