Nanofibers with an Adjustable Core-Sheath Structure Constructed from Hyperbranched Polyester for Efficient Loading of ZnO Nanoparticles

Loading nanoparticles is a valuable way to constructfunctionalfiber materials, yet the lack of homogeneity and easy agglomerationhinder its functional effect. Hyper-branched polyester (HBPE) hasbeen identified as the ideal delivery vehicle for nanoparticles. Itsapplication in nanofibers can be a promising approach to enhancingthe loading efficiency. In this study, adjustable core-sheath structuredpolyacrylonitrile (PAN)/HBPE nanofibers were fabricated owing to thephase separation of two components during centrifugal spinning, andzinc oxide nanoparticles (ZnO NPs) were further introduced into thesheath. Scanning electron microscopy, transmission electron microscopy,energy-dispersive spectroscopy, and so forth were utilized to characterizethe morphology of the obtained nanofibers. Results indicated thatthe thickness of sheath in PAN/HBPE nanofibers could expand from 33.33to 57.14% as the mass ratio of PAN/HBPE decreased from 8:2 to 5:5.Additionally, the ZnO NPs were encapsulated and dispersed by HBPEand successfully delivered to the sheath layer of the nanofibers.Therefore, the Zn content on the surface of PAN/HBPE/ZnO NP nanofiberscan reach 17.86 wt % with only 6 wt % ZnO NPs doped, representinga 90% increase compared with HBPE-free nanofibers. Besides, the PAN/HBPE/ZnONP nanofibers exhibited excellent air permeability and qualified biocompatibility,as well as outstanding functional release. The antibacterial ratesagainst Escherichia coli and Staphylococcus aureus reached 96.62 +/- 0.34 and99.55 +/- 0.78%, respectively. This facile processing strategysubtly combines the advantages of material and structure, providinginsights to better achieve efficient loading of nanoparticles on nanofibers,enabling more researchers to customize functional materials.