Designing polymeric microgels with star-like architecture

We modified the synthesis of poly(N-isopropylacrylamide) (pNIPAM) microgels by using ethylene glycol-dimethacrylate (EGDMA) as crosslinker to produce thermoresponsive microgels with customized properties. The far higher reactivity of EGDMA than that of NIPAM results in the formation of microgels with unique, star-like architecture. Our hypothesis is that the improved properties (sharper volume phase transition, higher swelling degree) arise from such structure. We aim to verify this hypothesis and to gain strict control over the synthesis of star-like microgels. To this end, we will measure form factors of particles produced with varying synthesis parameters and combine their analysis with numerical simulations, to reach in-depth understanding of the relationship between synthesis protocol and structure and key features of the microgels. The gained insights will enable rational design and easy synthesis of microgels with star-like architecture.