Relationship between Liquid-water Penetration Behavior and Internal Structure in Porous Layer of Copper Nanoparticles

Abstract

In this study, the penetration behavior of pure water into a porous layer of copper nanoparticles which was formed on a copper substrate by a thermal treatment was experimentally investigated. The amount of liquid-water penetrating into the porous layer was calculated by measuring the volume change of pure water dropped on the surface of porous layer using a high-speed camera. For the penetration behavior of liquid-water in the porous layer, the Lucas-Washburn equation, Darcy's law, and Kozeny-Carman equation were used to estimate the effective pore radius, penetration coefficient, and specific surface area, respectively. Furthermore, observational study was conducted by a scanning electron microscopy to investigate the surface structure of nanoparticles in detail. As a result, it was confirmed that the thermal treatment not only changed the size of the nanoparticles aggregates, but also created new nanostructures on the surface of copper nanoparticles. The experimental results showed that the newly formed nanostructures on the nanoparticles’ surface also affected the penetration behavior of liquid-water.