抄録
The electrostatic potential distribution at liquid-liquid interface in a microchannel was directly measured by nano color imaging technique using two kind of fluorescent dyes and the evanescent wave. A T-shaped microchannel for an aqueous solution was attached to an I-shaped microchannel for an oil phase in order to from the liquid-liquid interface between two immiscible fluids. Two kinds of aqueous solutions at different Na^+concentrations were mixed in the T-shaped microchannel for investigating the effect of Na^+ motion on formation of electrostatic potential at the interface. The calibration curve expressing the relationship between the fluorescent intensity ratio and the electrostatic potential was prepared to convert the fluorescent intensity image into the electrostatic potential distribution. Moreover, the Na^+ concentration distribution near the interface was also measured by microscale laser induced fluorescence which comprised of a confocal microscope and an ion indicator. Formation mechanism of electrostatic potential will be examined by comparing the Na^+ concentration distribution with the electrostatic potential distribution.
