Jung Jung-Yeul, Kim Young Won, Yoo Jung Yul
Institute of Advanced Machinery and Design, Seoul National University, Seoul 151-744, Korea.
Anal Chem. 2009 Oct 1;81(19):8256-9. doi: 10.1021/ac901247c.
It is well-known that the liquid and the nanoparticles in an evaporating colloid droplet on a hydrophilic surface move radially outward for the contact line to maintain its position. However, the motion of micro/nanoparticles in an evaporating didisperse colloid droplet has not been reported to date. In this study, an experiment on an evaporating didisperse colloid droplet on the hydrophilic surface is carried out. It is found that nanoparticles move radially outward and remain at the contact line while microparticles move inward toward the center of the droplet. Furthermore, the mechanism of the microparticles moving toward the center of the droplet is found to be due to the surface tension force of the liquid.
