Dynamics of drop formation and characterization of additive manufactured CS/AgNP/PVA composite membranes

Abstract

AbstractThis study investigated the dynamics of drop formation and the printability of chitosan/silver nanoparticles composite fluid (CS/AgNP) modified with polyvinyl alcohol (PVA) using an inkjet 3D printer. It specifically investigated the relationship between rheological properties and fluid mechanical properties in determining the minimum drop velocity for 3D printing of modified CS ink. Proper matching of modified CS fluid rheological properties to the established physical parameters generated adequate droplets on glass substrates and formed membrane composites. The dynamic viscosity of the CS ink decreased with an increase in the concentration of PVA, which resulted in the disruption of existing molecular forces within the CS/AgNP polymer chains, suggesting that the solvent (PVA) was responsible for reducing the shear stress, surface tension, and viscosity of the composite membranes and subsequently improving the flow rates of the CS matrix at the nozzle orifice. Optimized drop velocity of 1.77 m/s yielded adequate formation of the CS/AgNP/PVA membrane composite with enhanced surface morphology, while an increase in drop velocity to 2.5 m/s brought about the formation of satellite droplets with irregular surface structures in printed CS composites. Therefore, adherence to minimum fluid drop velocity is fundamental to effective inkjet printing of composite membranes.