Synthesis And Properties Of Dual Responsive Microgel Complexes

Microgels were synthesized by precipitation copolymerization of N-isopropylacrylamide, methacrylic acid (MAA) and poly(ethylene glycol mono-methacrylic acid) (PEGMA), using N,N'-methyenediacrylamide and potassium persulfate as crosslinker and initiator respectively. The morphology of the microgels were characterised by Transmission Electron Microscope (TEM). The structure of microgels were proved by infra-red spectroscopy (IR). The thermosensitivity of microgels were investigated by light scattering method and the pH-sensitivity was investigated by turbidity. The results indicate that these microgels have good pH and temperature sensitivity and obvious volume phase transition temperature. Another series of microgels were synthesized by precipitation copolymerization of vinyl caprolactam (Vcl) and MAA, using N,N'-methyenediacrylamide and potassium persulfate as crosslinker and initiator respectively. The morphology of microgels were characterised by TEM. The structure of the final product was proved by IR. IR result indicates that the prepared microgels are copolymers of Vcl and MAA. The thermo-sensitivity of microgels was investigated by light scattering method and the pH-sensitivity was investigated by turbidity. The results indicate that these microgels have good pH and temperature sensitivity and obvious volume phase transition temperature.Hybrid microgels which include magnetic nanoparticles (Fe3O4) in their net work were synthesized. The morphology of hybrid microgels were characterised by TEM. The results show that hybrid microgels have magnetic property and good stability.