Fabrication of new Fe-phthalocyanine oligomer–magnetite hybrid magnetic nano particles and their effects on the LCST behavior of thermo-sensitive poly(N-isopropylacrylamide-co-acrylic acid) magnetic nanocomposites

Abstract

Abstract In this paper, new thermo-sensitive poly(N-isopropylacrylamide-co-acrylic acid) magnetic nanocomposites (P(NIPAM-co-AAc)/Fe3O4/FePc) were prepared by in situ dispersion polymerization. The new Fe3O4/FePc hybrid magnetic nanoparticles were fabricated by solvent-thermal route from 4,4′-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))diphthalonitrile and FeCl3.6H2O. The morphology, structure and properties of the Fe3O4/FePc hybrid nanoparticles were investigated. The results exhibited the spherical structures of hybrid nanoprticles with diameters of 30–70 nm and superparamagnetic property. TGA results revealed that about 22.3% of the phthalocyanine oligomer was incorporated into the resulting hybrid magnetic nanoparticles. The magnetic nanocomposite hydrogels were characterized by means of Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), X-ray diffraction (XRD) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM) and differential scanning calorimetry (DSC). The lower critical solution temperatures (LCST) of the magnetic nanocompositehydrogelsin water were measured by DSC and the LCST behavior of them were studied. The results showed that the LCST of the hydrogels were influenced by the content of Fe3O4/FePc hybrid nanoparticles. The LCST of P(NIPAM-co-AAc)/Fe3O4/FePc-2% and P(NIPAM-co-AAc)/Fe3O4/FePc-4% were at about 38 and 41 °C, respectively. The results showed that an increase in Fe3O4/FePc hybrid nanoparticles content makes the LCSTs of the hydrogels increase to near the human body temperature.