Flexible and transparent optically anisotropic films based on oriented assembly of nanofibers

Abstract

Nanofibers are characterized with unique electronic, magnetic and optical properties, due to their extremely high aspect ratio and large specific surface area. Assembly of nanofibers with predesigned macro architectures is a key step toward practical applications. Herein, we demonstrate the scalable oriented assembly of nanofibers based on electrospinning, and explore their potential application in constructing optically anisotropic films. By the post soaking-and-drying approach, the nonwoven films assembled by oriented polymer nanofibers can be readily converted to flexible films with high transparency, which show optical transmission contrast exceeding 0.9 in the visible to near infrared region. The method for preparation of optically anisotropic films proposed here circumvents the sophisticated dye-doping and thermal drawing processes which are inevitable in conventional approaches. Considering the scalability potential of the electrospinning technique, the method demonstrated here is promising for industrial production of film polarizers.