Self-Healing\nof Core–Shell Magnetic Polystyrene\nNanocomposites

Abstract

High\nheat generation is reported in core–shell magnetic\nnanoparticle polystyrene (PS) nanocomposites (3.5, 10 wt %) when they\nare placed in a high-frequency ac magnetic field. These magnetic nanoparticles\nwith cobalt iron oxide core and manganese iron oxide shell were synthesized\nand characterized by wide-angle X-ray scattering (WAX), thermal gravimetric\nanalysis (TGA), transmission electron microscopy (TEM), and ac field\ngradient magnetometery. When placed in a high-frequency ac magnetic\nfield, the thermal energy generated in the magnetic polystyrene nanocomposites\nresulted in a surface temperature increase. The heat generation is\nattributed to the contribution of Néel relaxation and hysteresis\nof the core–shell magnetic nanoparticles in the solid state.\nThe maximum surface temperature increased with increasing nanoparticle\ncontent and resulted in melting of the magnetic polystyrene nanocomposite.