Polydopamine functionalized transparent conductive cellulose nanopaper with long-term durability†
Abstract
High performance transparent conductive cellulose-based nanopaper (TCCNP) with long-term durability is a predominant alternative for the upscale production of next-generation green flexible electronics. Here, dual-layered TCCNP with excellent mechanical robustness and chemical stability was successfully assembled by tight binding between the mussel-inspired polydopamine functionalized nanofibrillated cellulose (PDA@NFC) substrate and the silver nanowire (AgNW) layer. The highly adhesive PDA coatings on the NFC surface uniformly connected AgNW networks and simultaneously soldered the wire-to-wire junctions, thus dramatically increasing the overall electrical conductivity. The as-prepared TCCNP possesses exceptional optoelectronic properties with an optical transmittance of 90.93% at a wavelength of 550 nm and a sheet resistance of 14.2 Ω sq−1. Meanwhile, the TCCNP displays excellent mechanical stability with negligible changes in optoelectronic performances even after 1000 bending cycles and 100 peeling tests. Furthermore, the TCCNP exhibits outstanding air and chemical corrosion stabilities after being exposed to air for 150 days or immersed in different solutions for 180 min, and its transparent conductive performance remains constant close to its initial values, which is superior to those of NFC–AgNW TCCNP without PDA or the commercial ITO/PET transparent conductive films (TCFs). More importantly, the ease of disposal of TCCNP and its good stability can greatly contribute to its application in multifunctional electronic and photoelectric flexible devices.