Surface modification of Ag nano-powder synthesized by DC arc plasma evaporation

The silver nano-powder, synthesized by DC arc plasma evaporation in vacuum, were surface modified with appropriate surfactant to improve its dispersion and adhesion at the Ag/substrate interface when used as the conductive paste. The Ag nano-powder were characterized with X-ray diffraction, X-ray fluorescence spectroscopy, and transmission electron microscopy. The impacts of the surface modification conditions, including the type and concentration of surfactant and ultrasonic time, on the stability of its dispersion in ethanol solvent were evaluated by means of pH-Zeta potential analysis. The spherical, polycrystalline, cubic-phased Ag nano-powder has a purity of 99.92% (wt), with a narrow size distribution. The Ag powder in alcohol displayed better dispersion, after surface modification under the conditions: the composite surfactant consisting of 2.5% triethanolamine and 2.5% polyvinylpyrrolidone, for a ultrasonic time of 70 min, and at a pH of 8.