Preparation and Properties of a Cellulose-based Flexible Film with Conductive Stability

Dopamine molecules were introduced onto the surface of cellulose nanofibers(CNF) through amidation reaction, resulting in dopamine-modified cellulose nanofibers(DCF). High-transparency DCF/montmorillonite(MMT) film materials were prepared by combining DCF with MMT. Silver nanowires(AgNWs) and graphene oxide(GO) were further deposited on the film through vacuum filtration to prepare cellulose-based transparent conductive films. The test results showed that the grafting of dopamine molecules did not affect the morphology and crystalline structure of CNF. The prepared DCF/MMT film maintained a high transmittance(82.4%) and exhibited a tensile strength of 49.5 MPa at a relative humidity of 100%, which was a 64% improvement compared to that of CNF/MMT film. The conductive films assembled with this material exhibited good transparency, conductivity, and electrical stability. The DCF/MMT/AgNWs/GO (DMAG) film demonstrated stable high conductivity after water immersion or exposure to high humidity(relative humidity of 90%), with the sheet resistances of 32 and 38 Ω, respectively. The preparation of this conductive film provides a new approach for the assembly of transparent electronic devices.