共焦点顕微鏡を用いた液滴蒸発過程におけるマイクロ粒子の時空間分布計測

抄録

In order to investigate complex behaviors of suspended particles in liquid, we have constructed a confocal microscope system that enables us to measure the spatio-temporal distribution of micro particles. Three-dimensional visualizations of densely-suspended particles have been performed for an evaporating droplet on a glass substrate. In a droplet of water 99.9% and particle 0.1%, it is found that the particles mostly move along the substrate surface and assemble at the contact line. For a droplet of 33.3% aqueous ethanol solution, particles migrate along not only the substrate surface, but also the air-liquid interface. This implies that the flow inside a water droplet is induced by evaporation, while the flow inside a droplet of aqueous ethanol solution is strongly influence by the Marangoni effect.