Optically transparent nanofiber sheets by deposition of transparent materials: A concept for a roll-to-roll processing

Deposition of transparent materials on cellulose nanofiber sheets enhanced the transparency of nanofiber sheets. The coated nanofiber sheets exhibited high transparency regardless of the wide distribution of refractive indexes of the coated resins, and the loss of transparency compared with the theoretical values was less than 2.5%. The low coefficient of thermal expansion of the nanofiber sheets (8.5 ppm/K) was maintained after the coating. The continuous coating of functional transparent materials on the nanofiber sheets is a promising approach toward accomplishing a simple roll-to-roll manufacturing process.