(88d) Controlled Nucleation From Solution Using Polymer Microgels with Tunable Structure

It is essential to control crystallization in many areas of science and technology, and nucleation is the crucial step in controlling the crystallization process. However, nucleation behavior remains largely unpredictable, due to the presence of container surfaces, dust, dirt and other impurities that can provide heterogeneous nucleation sites thus making the control and scale-up of processes that depend on primary nucleation difficult. Furthermore, mechanistic understanding of the role of interfaces in nucleation from solution is limited. In this study, we demonstrated a new method to control nucleation with polymer microgels synthesized by Stop-Flow Lithography (SFL). The microstructure of the polymer microgels was systematically tuned to vary the degree of nanoscopic confinement on nucleation. We found the polymer microstructure has a tremendous impact on nucleation kinetics. Moreover, there exhibited an optimum polymer mesh size at which nucleation was dramatically enhanced, the degree of which depends on the extent of polymer-solute interactions. With easily tunable microstructure and chemistry, polymer microgels offer a promising approach to rationally design materials for controlling nucleation from solution.