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

We reportg novel the moresponsive electrospun (ES) fibers prepared from multifunctional random copolymers of poly((2-(dimethylamino)ethyl methacrylate)-co-(stearyl acrylate-co-(9,9-dihexyl-2-(4-vinylpenyl)-9H-flurone)) (poly(DMAEMA-co-SA-co-StFl)). The moites 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 prepares ES fibres were explored. The prepared P4 copolymer with the DMAEMA/SA/StFl mole ratio of 92/3/5 showed the lower critical solution temperature (LCST) of 32.5 degrees C. A significant temperature-dependent swelling and de-swelling behavior was found in the p4 ES fibers which had the diameter of 753 +/- 17.4 nm and 5=10 nm StFl 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 degrees 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 molety. Furthermore the high surfact/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.