Magnetic thermally sensitive interpenetrating polymer network (IPN) nanogels: IPN-pNIPAm@Fe₂O₃-SiO₂

In this paper, iron oxide-silica@poly(acrylamide-co-N,N-diethylacrylamide)/poly(N,N-diethylacrylamide) interpenetrating polymer network (IPN-pNIPAm@Fe2O3-SiO2) nanogels, possessing both magnetic and thermo-sensitive properties were successfully prepared. The preparation approach involved two steps, consisting of nanoparticle self-assembly and in situ polymerization with monomers. The structural combination of interpenetrating polymer networks (IPNs) with the Fe2O3-SiO2 nanoparticles led to a synergistic property enhancement of both IPNs and nanoparticles, which could increase the mechanical strength of hydrogels and decrease the aggregation of nanoparticles. The synergistic effect was induced by the compatibility of these two individual components. Furthermore, the swelling and shrinking behaviors of the IPN-pNIPAm@Fe2O3-SiO2 nanogels revealed the reversible thermo-responsive properties of IPN nanogels. This fabrication approach for IPN-pNIPAm@Fe2O3-SiO2 nanogels can provide a facile route for manufacturing smart nanocomposites with stability in aqueous solution and reversible swelling/deswelling stimuli-responsive properties to achieve multifunctional tasks in clinical therapy.