Regulation of Non-Traditional Intrinsic Luminescence (NTIL) in
Hyperbranched Polysiloxanes by Adjusting Alkane Chain Lengths:
mechanism, film fabrication and chemical sensing
Abstract
Biocompatible polymers with non-traditional intrinsic luminescence
possess the advantages of environmental friendliness and facile
structural regulation, however, it is challenging to regulate the
emission property. In this work, five kinds of hyperbranched
polysiloxanes (HBPSi) with different alkane chain lengths are
synthesized. Optical investigation shows that the emission wavelength of
HBPSi is closely related to the alkane chain lengths, namely, short
alkane chains will generate relative long-wavelength emission.
Electronic communication among functional groups is responsible for the
emission. HBPSi molecules aggregate together due to the strong hydrogen
bond and amphiphilicity, the functional groups in the aggregate are so
close that their electron clouds are overlapped and generate spatial
electronic delocalizations. HBPSi with shorter alkane chains will
generate larger electronic delocalizations and emit longer-wavelength
emissions. Moreover, these polymers show excellent application in the
fabrication of fluorescent films and chemical sensing. This work could
provide a strategy for regulating the emission wavelength of
unconventional fluorescent polymers.