Fabrication and characterization of 1 D Fe₃ O₄/P(NIPAM–MAA– MBA) nanochains with thermo-and pH-responsive shell for controlled release for phenolphthalein

One-dimensional (1D) Fe₃O₄/poly(N-iso-propylacrylamide-methacrylic acid-N,N⁰ -methylenebis-acrylamide)(Fe₃O₄/P(NIPAM–MAA–MBA)) peapod-like nanochains have been successfully synthesized by magnetic field-induced precipitation polymerization. Fe₃O₄ microspheres modified with vinyl groups can be arranged with the direction of the external magnetic field in a line and linked permanently via P(NIPAM–MAA–MBA) coating during precipitation polymerization. The properties of 1D Fe₃O₄/ P(NIPAM–MAA–MBA) were characterized by transmission electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), vibrating sample magnetometry, X-ray photoelectron spectroscopy, and UV–Vis spectrophotometer. Magnetic measurement revealed that these 1D peapod-like nanochains showed highly magnetic sensitivity. The thermal-and pH- response of 1D magnetic Fe₃O₄/P(NIPAM–MAA– MBA) nanochains was investigated by the temperature/pH dependence of hydrodynamic radius of Fe₃O₄/P(NIPAM– MAA–MBA) microspheres. The release behavior of phenolphthalein from 1D magnetic Fe₃O₄/P(NIPAM–MAA–MBA) nanochains could be effectively controlled by changing the temperature/pH values.