Magnetic epoxy resin nanocomposites reinforced with core - Shell structured Fe@FeO nanoparticles: Fabrication and property analysis

Epoxy resin nanocomposites reinforced with various loadings of core-shell structured nanoparticles (Fe@FeO) are prepared using a surface wetting method. Nanoparticle loading effect on the viscosity of epoxy monomers is well-correlated to Cross'rheological model. Dynamic mechanical analysis (DMA) results reveal that the glass transition temperature is increased by 10 °C with the addition of nanoparticles, which is surprisingly independent of the particle loadings. The saturation magnetization (M_s) of the 20 wt % Fe@FeO/epoxy nanocomposites is 17.03 emu/g, which is about 15.8% of that of the pure nanoparticles. Meanwhile, the coercivity increases from 62.33 to 202.13 Oe after the nanoparticles are dispersed in the epoxy matrix. The electrical conductivity percolation is found to be around 5-10 wt %, where the resistance of the nanocomposites sharply decreases by 6 orders of magnitude. Thermal stability and tensile properties of the pristine epoxy and nanocomposites are also investigated in this work.