The Effect of the Liquid-Crystalline Order on Releasing Dye Molecules from Liquid-Crystalline Nano-Emulsions

Abstract

We fabricated dye-containing liquid-crystalline nano-emulsions (LCNEs) dispersed in water, and studied the controllability of releasingdye molecules from the coreof LCNEs into water. We estimated the concentration of the dye molecules held in the core of LCNEs from transmission spectrum. As a result, it was revealed that the dye molecules are released from the core of LCNEs below the characteristic release-temperature on cooling. Moreover, the depolarized static light scattering measurement was performed to estimate the Isotropic-Nematic(I-N) phase transition temperature of low molecular weight liquid crystals in the core of LCNEs. By controlling mixing ratio of binary liquid crystalline mixture, we tuned theI-N phase transition temperature. The release-temperature completely corresponds to the I-N phase transition temperature in the coreof LCNEswithin the whole mixing ratio. Thus, we confirmed that the emergence of the liquid-crystalline order in the core of LCNEs plays a principal role in releasing the dye molecules from LCNEs.