(118f) Microfluidic Synthesis for Monodisperse PNIPAm Core/Shell Microcapsules

We present a microfluidic approach for the in situ preparation of monodisperse core/shell microcapsules. Using flow-focusing method, droplets of monomer solution were continuously generated by an immiscible oil phase. Hydrophobic photoinitiator in oil phase are diffused into the interface between continuous phase and disperse phase, and then polymerized by UV exposure. The PNIPAM microcapsules are core/shell microcapsules consists of thin polymeric shell and core containing water. Microfluidic systems produce highly monodisperse hollow microcapsule having below 1.1% coefficient of variation (CV) and rapid response to temperature. In addition, the size of microcapsules can be controlled by the flow rate of the oil or monomer phase and different concentrations of surfactant (Span80) to control interfacial tension between oil phase and NIPAm phase. Furthermore, we demonstrate this approach enables the fabrication of uniform microcapsules to have the potential to encapsulate various materials such as proteins and nanoparticles.