(196e) Nucleation of Colloidal Crystals Via Emulsion Crystallization

Emulsion droplets containing gel particles of a thermo-responsive polymer, poly-N-isopropylacrylamide (PNIPAM), were used as an experimental model system for the study of nucleation. Using independent droplets, we can isolate the interactions between crystallites. Also, emulsion crystallization is proved to be capable of eliminating heterogeneous crystallization in atomic systems. Therefore, we are able to carry accurate measurements of the nucleation rate of colloidal crystals. Temperature was used to fine-tune the volume fraction of the PNIPAM suspensions. The droplet sizes were varied with flow rates in microfluidic emulsification to tune the nucleation volume. Measurements of UV-Vis spectroscopy, light scattering and polarized microscopy offer complimentary information of crystallization from reciprocal space (UV-Vis and light scattering) and real space (polarized microscopy).