Fabrication of Transparent Cellulose Fiber Paper by Sequential Treatment of Cationic Cellulose Nanofibers and Polyvinylpyrrolidone

Paper-based material is receiving more and more attention as an alternative of plastics in flexible electronics. However, conventional paper made of cellulose fibers is opaque owing to its micron-sized void space among fibers. Herein, cellulose fiber paper was changed into transparent paper by sequentially coating cationic cellulose nanofibers (CNFs) and polyvinylpyrrolidone (PVP). The morphology, transparency, thermal and mechanical properties were analyzed. The results show that the coating of CNFs reduces the micron-sized void space in the cellulose fiber paper, favoring the further improvement on the transparency of paper by coating PVP. By optimizing the coating amount of CNFs and PVP, a transparent paper with a transmittance of 88.5 % at 550 nm is obtained. The as-prepared transparent paper also shows improved thermal stability, slightly increased tensile strength and significantly enhanced deformation resistance. It was a potential candidate of flexible electronic substrates.