Correlation of particles size with mixed current (im) in electroless deposition of nano silver metal onto polyurethane catheter surface

Abstract

ABSTRACTElectroless deposition of nano-size silver metal onto polyurethane (PU) catheter is investigated. Grain size of the deposit is regulated by monitoring mixed potential, Em that indicates the deposition mechanism and mixed current, im which determines the deposition rate. It is demonstrated that these two parameters can be regulated through [Ag+] and/or [N2H4]. At relatively higher [Ag+] rate is under anodic control, whereas, at a lower [Ag+], diffusion of Ag+ controls the process (cathodic control). Lower the value of im, lower is the size of deposit, achieved under cathodic diffusion control mechanism. Size of the deposit lowers further by reducing deposition time. Silver particles of 48 nm are achieved within 5 min of deposition time at 0.1 M [N2H4] and 0.0001 M [AgNO3]. Average crystallite size measured from the XRD is around 13 nm and there are uniformly spread agglomerated spherical particles with some distributed cubic ones observed in the SEM.