Model-Based Optimization of Microgel Synthesis in the μm Size Range

Microgels are functional polymer colloids with diverse applications, for example, in medicine, engineering, or agriculture. Some applications require large microgels in the size range of μm, which could previously only be synthesized using microfluidics or a synthesis procedure involving a fed-batch reaction with a temperature ramp. We use dynamic optimization to determine a simpler synthesis recipe that allows us to synthesize microgels in the μm range using a batch procedure. First, a sensitivity analysis shows that the microgel size is sensitive to the initial concentration of initiator and the reactor temperature. Second, the dynamic optimization yields a batch recipe that provides microgels of the desired μm size range. The recipe uses a low initial initiator concentration and a low reactor temperature. The respective recipe is validated experimentally; model simulation results and experimental measurements of the hydrodynamic diameter show good agreement.