High stability of photoinduced merocyanine in naphthopyran-doped polyvinylpyrrolidone electrospun nanofibers

Highly stable merocyanines (MCs) of naphthopyrans based on polyvinylpyrrolidone (PVP) nanofibers have been developed by electrospinning mixtures of PVP and naphthopyran derivatives. The surface and internal features of the electrospun fibers were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The naphthopyrans displayed normal photochromic performance in the polymeric fibers and presented high-stability MC forms. The one-dimensional structure of the nanofibers and hydrogen bonds between PVP and MC structures of naphthopyran were responsible for the high degree of stability. The absorption intensities of the most highly stable MC form were 77% compared with the initial intensity after fading for three days. © 2014 Society of Chemical Industry