Durable silver nanowire transparent electrodes enabled by biorenewable nanocoating using chitin and cellulose nanofibers for flexible electronics

The protection of silver nanowire (AgNW) networks is crucial for enhancing their durability and applicability to flexible electronics. In this study, we present a sustainable and efficient strategy to protect AgNW-based flexible transparent electrodes (FTEs) using a layer-by-layer (LBL) assembly of biorenewable chitin and cellulose nanofibers (Chi and Cell). These uniform LBL-assembled thin films were successfully fabricated on AgNW FTEs due to their opposite surface charges. The resulting (Chi/Cell)_n bilayers, where n is the number of bilayers, did not degrade the optoelectrical properties of AgNW FTEs and significantly enhanced their stability under various harsh conditions. The optimized (Chi/Cell)₁₀@Al-AgNW FTEs exhibited comprehensive stability against UV/O₃ treatment for 40 min, thermal treatment at 250 °C for 350 min, Na₂S (1%), HCl (10%), and NH₃ (30%) treatments for 3, 30, and 105 min, respectively, sonication for 300 min, and 10 000 cycles of bending test. Therefore, the (Chi/Cell)₁₀@Al-AgNW FTEs were successfully applied to transparent heaters (TH) and pressure sensors with remarkably improved applicability, durability, and performance compared to pristine AgNW FTEs, providing a reassuring solution to the stability issues of AgNW-based FTEs.