A Supercritical CO2 Promoted Electroless Ni-P Plating on Silk and Their Fundamental Characteristics Investigations

Abstract

This study demonstrated a promising method to integrate flexible silk textiles and conductive Ni-P metal coatings for the increasing interest in wearable devices. Electroless plating with supercritical carbon dioxide (sc-CO2) was utilized to combine the two distinct materials together conformally. Ni-P was chosen for its electrical conductivity and high corrosion resistance while silk was chosen as the substrate for its flexibility. Sc-CO2 was used as a promoter in the catalyzation to enhance the compatibility between the Ni-P with the silk. This technique allows simplification of the electroless plating by excluding the pretreatments while the substrate remains undamaged after the catalyzation step. In addition, the sc-CO2 leads to an environmental friendly process by cutting down the usage of corrosive chemicals in the catalyzation step. This study therefore demonstrates a series of palladium (II) acetylacetonate catalyzation followed by Ni-P deposition on the silk. The lowest electrical resistance at 1.02 Ω was achieved at 4 min of the Ni-P plating time. Corrosion resistance of the Ni-P/silk in a solution simulating the human sweat was evaluated. Reliability of the Ni-P/silk composite material was revealed by comparing the electrical resistances and corrosion resistances before and after an adhesive test.