Thermoresponsive Luminescent Electrospun Fibers Prepared From Poly(DMAEMA-co-SA-co-StF1) Multifunctional Random Copolymers

摘要

We report novel thermoresponsive electrospun (ES) fibers prepared from multifunctional random copolymers oF poiy((2-(dimethylamino)ethylme[hacrylate)-co-(stearylacrylate)-co-(9,9-dihexyl-2-(4-vinylpenyl)-9H-fluorene)) tpoly(DMAEMA-co-SA-co-StFl)). The moieties oF DMAEMA, SA. and StFl were designed to exhibit the thermoresponsive. physical cross-linking, and Fluorescent Functionality, respectively. The eFFects of the copolymer compositions on the morphology and photoluminescence of the prepared ES fibers were explored. The prepared P4 copolymer with the DMAEMA/SA/StFI mole ratio oF 92/3/5 showed the lower critical solution temperature (LCST) of 32.5 °C. A significant temperature-dependent swelling and de-swelling behavior was found in the P4 ES fibers, which had the diameter of 753 ± 1.74 nm and 5-10 nm StFI aggregated domain. Accompanied with volume-changing on the P4 ES fibers, a reversible photoluminescence (PL) quenching was also observed during the heating and cooling cycle between 40 and 60 °C. Such reversible switching of the "on-off" PL intensity was probably due to the light absorption ability of the StFl moiety, resulted from the extended/compact structural transformation on the PDMAEMA moiety. Furthermore, the high surFace/volume ratio of the ES fibers led a much better temperature response compared with the corresponding spin-coated film. The present study demonstrated that the ES fibers prepared from multifunctional copolymers exhibited the thermoreversible variation on both volume and photoluminescence intensity.