In Situ Radical Polymerization of N-isopropylacrylamide in Electrospun Anisotropic Nanofiber of Poly (Ethylene Oxide)

: We designed a new approach to realize in situ radical polymerization of monomers without liquid solvent to obtain gel fibers using electrospinning. Poly ( N -isopropylacrylamide) (PNIPAM) is one of the most studied thermo-sensitive polymers. The N -isopropylacrylamide (NIPAM) monomer was electrospun in conjugation with poly (ethylene oxide) (PEO) as a polymerization matrix. NIPAM in the electrospun nanofibers was polymerized via irradiation with UV light in the presence of a photoinitiator. The polymerization was confirmed by chemical analysis with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and morphological observation of scanning electron microscopy (SEM) after removing monomers through washing. The anisotropy of PNIPAM fibers was controlled by the rotation speed of the collector. This approach would be useful for the medical and biological application of anisotropic PNIPAM hydrogel nanofibers, as well as in other polymers.