Inkjet printing of nanocellulose–silver ink onto nanocellulose coated cardboard
Cellulose nanocrystals (CNC) have recently been used in the field of flexible electronics. The present work proposes to evaluate the contribution of CNC in the inkjet printing of silver conductive tracks. The potential of CNC to enhance both ink and substrate properties for printed electronics application was evaluated. First, CNC potential to be used as a scaffold for silver nanoparticles production in a compatible silver inkjet ink was evaluated. It has been found that the CNC dispersing properties, combined to their nanometrical rod-shape, allowed producing conductive suspensions at very low silver content comparing to classical silver ink. Inkjet printing of the CNC–silver suspension was then investigated on several substrates. Among these substrates, CNC coated cardboard has been studied to propose a new alternative for the printing of conductive tracks onto a porous substrate like cardboard. It appears that the CNC coating significantly limits the ink diffusion into the porous substrate by modification of the ink drop absorption kinetics, leading to the printing of well-defined conductive patterns. By using CNC in both ink formulation and substrate pre-treatment, the produced conductive patterns are nearly only composed of cellulosic material, offering new prospects in the development sustainable electronics.