Fast transfer process of pyrene between oil-in-water miniemulsion droplets

Recently phase formation mechanisms have been estimated by using various fl uorescent probes. In this report, the mixing process between internal phase s of oil-in-water miniemulsions is discussed for two-dimensional color grap hics data (two-dimensional fluorescence images) based on the excimer format ion of pyrene as a hydrophobic fluorescent probe. Just after miniemulsion s olution B (water, oil, and nonionic surfactant) was gradually added to mini emulsion A (water, oil, surfactant, and trace amount of pyrene) with gentle and careful stirring, the fluorescence spectra and the two-dimensional ima ge of pyrene were measured. The decreasing of the excimer peak of pyrene wa s observed as soon as miniemulsion solution B was added. The result showed that pyrene initially located in miniemulsion droplets was smoothly diluted by the addition of miniemulsion droplets which contain only oil in the int ernal phase. The internal phases of miniemulsion droplets are miscible with out changing the droplet diameter, and it is declared that pyrene transfers smoothly to the interface between droplets stabilized by the nonionic surf actant because the droplet diameter showed no significant difference throug hout this mixing process.