| 초록 |
We produce droplets and shells from cholesteric liquid crystal mixtures using a coaxial microfluidic set-up, and collect the droplets/shells in the sample plane, such that they form a 2D colloidal crystal at high volume fraction. Planar director alignment is achieved by using polyvinylalcohol (PVA) in the aqueous continuous phase. In case of shells also the internal aqueous phase contains PVA for the same purpose as stabilizer. This alignment ensures a radial helix orientation and thus selective reflection in all directions from the droplet. We presently investigate the influence of the character of the PVA solution (concentration, molecular weight, degree of hydrolysis) and on the geometrical features of the droplets/shells on the optical properties. Apart from the interesting fundamental optics issues, they also hold considerable potential for application in self-assembled tunable omnidirectional lasers. |
