Optically transparent bionanofiber composites with low sensitivity to refractive index of the polymer matrix

Transparent polymers were reinforced by bacterial cellulose (BC) nanofibers, which are 10x50 nm ribbon-shaped fibers. They exhibited high luminous transmittance at a fiber content as high as 60 wt%, and low sensitivity to a variety of refractive indices of matrix resins. Due to the nanofiber size effect, high transparency was obtained against a wider distribution of refractive index of resins from 1.492 to 1.636 at 20 degrees C. The optical transparency was also surprisingly insensitive to temperature increases up to 80 degrees C. As such, BC nanofibers appear to be viable candidates for optically transparent reinforcement. (c) 2005 American Institute of Physics.