Continuous Preparation of Homogeneous Crosslinked PDMS Microgel Particles through Photoinduced Reversible Addition-Fragmentation Chain Transfer Polymerization

As one of the most widely used silicone polymers, polydimethylsiloxane (PDMS) microgel particles have broad application prospects in the fields of sensors, polymer toughening agents, bioengineering, and drug delivery. Here, we reported the continuous preparation of homogeneous crosslinked PDMS microgel particles through photoinduced reversible addition-fragmentation chain transfer (photoRAFT) polymerization. Based on the design of methacrylate-functionalized PDMS, the introduction of photoRAFT polymerization allows the formation of microgel particles with homogeneous networks, which were more regular and have better swelling behavior than networks prepared by conventional free radical polymerization processes. Moreover, the dormant polymer chain could be reactivated and lead to the postmodification of PDMS microgel particles. The crosslinking RAFT polymerization was continuously carried out in a flow photoreactor. Uniform PDMS microgel particles with high colloidal stability could be achieved in a short time (0.5–10 min), and the crosslinking densities can be easily tuned by changing the residence time which has less effect on the final particle size.