Clearly Transparent Nanopaper from Highly Concentrated Cellulose Nanofiber Dispersion Using Dilution and Sonication

Abstract

Nanopaper prepared from holocellulose pulp is one of the best substrates for flexible electronics because of its high thermal resistance and high clear transparency. However, the clearness of nanopaper decreases with increasing concentration of the starting cellulose nanofiber dispersion—with the use of a 2.2 wt % dispersion, for example—resulting in translucent nanopaper with a high haze of 44%. To overcome this problem, we show that the dilution of this high-concentration dispersion with water followed by sonication for 10 s reduces the haze to less than 10% while maintaining the high thermal resistance of the nanopaper. Furthermore, the combination of water dilution and a short sonication treatment improves the clearness of the nanopaper, which would translate into cost savings for the transportation and storage of this highly concentrated cellulose nanofiber dispersion. Finally, we demonstrate the improvement of the electrical conductivity of clear transparent nanopaper prepared from an initially high-concentration dispersion by dropping and heating silver nanowire ink on the nanopaper. These achievements will pave the way toward the realization of the mass production of nanofiber-based flexible devices.

Characterization of aqueous cellulose nanofiber dispersions from microscopy movie data of Brownian particles by trajectory analysis

“…33,38,39 Even the initial concentration of CNFs can affect the transparency of the nanopaper. 12 Many hydrogen bonds between the laments of CNFs are formed during the drying of the aqueous dispersion. This stage determines the nal structure of CNF-based materials such as nanopapers.…”

Effect of p -TsOH pretreatment on separation of bagasse components and preparation of nanocellulose filaments

“…Nanocellulose is a typical example of high-value utilization of cellulose [ 7 ]. As one of the main types of nanocellulose, nanocellulose filaments (CNFs) have low density, high aspect ratio, high mechanical strength, good hydrophobicity, good biocompatibility and biodegradability [ 8 ]. The preparation and application of CNFs have attracted wide attention in academia and industry [ 9 , 10 ].…”

Cellulose transparent conductive film and its feasible use in perovskite solar cells

“…High transparency is a relatively simple task for preparation cellulose based lm. Films or nanopapers prepared from regenerated cellulose, 12,13 rational mixture of NCC and ber, 4 NFC, 14 cellulose-CMC composite 15 and TEMPO-oxidized nanocrystalline cellulose 16 are always transparent. Whereas, the two mutually opposing properties of conductivity and transparency combined in one material is a challenging task for fabricating electronic and optoelectronic devices.…”