Preparation Of Nano-micron Photochromic Fibers And Study Of Their Properties

With the development of society,the demand for different types of textiles is growing in the daily life,different colors of textile products also allow people to live more colorful.In this paper,the photochromic properties and mechanism of N-hydroxyethyl-3,3-dimethyl-6-nitroindoline spiropyran were studied.Four kinds of novel materials containing spiropyran structural units were prepared by atom transfer radical polymerization method.Photochromic nanofibers were prepared by electrospinning technology and their photochromic luminescent properties were studied.Firstly,two kinds of new polymers were synthesized by atom transfer radicalpolymerization,one is polymethylmethacrylate with spiropyran photochromic units at the end of molecular chains,and the other is a block copolymer including repetitive architectural units of vinyl spiropyran(SPMA)and methyl methyl acrylate.The spinning solution was prepared by doping with rare earth terbium(?)complex,and nanocomposite photochromic luminescent fibers were prepared by electrospinning.FTIR and 1H NMR results indicated that the target product had been successfully prepared.Field emission scanning electron microscopy(SEM)and transmission electron microscopy(TEM)showed that the prepared nanofibers had a smooth surface and uniform diameter distribution.UV and fluorescence test results showed that the prepared nanofibers had better photochromic luminescent properties.Secondly,the organic/inorganic nanocomposites with spiropyran photochromic units and polymethyl methacrylate were prepared by atom transfer radical polymerization initiated on the surface of nano-silica.The nanocomposites were mixed into polyester spinning liquid,then nano-micron fibers were prepared by electrospinning technology.The results of FTIR showed that nano-silica has been successfully modified,and the morphologies changes before and after modifying were observed by SEM and TEM.The thermogravimetric analysis showed that the prepared nanocomposite particles had good thermal stability.The luminescent discoloration of the samples was confirmed by UV and fluorescence analysis.Finally,cellulose non-woven fabric with photochromic properties was obtained by surface modification.The FTIR results showed that the target product had been successfully prepared.The morphology of the nonwoven fabric before and after grafting was observed by SEM.The surface of the nonwoven fabric was smooth before grafting,and the surface became rough after grafting.The photochromism and luminescence properties were characterized by UV and fluorescence spectra.The results showed that the modified cellulose fabrics had better photochromic and luminescent properties.Based on the study of spiropyran photochromic materials,we found that it has good color changing luminescence behavior,and it has broad prospects in textile application.