(59b) Magnetic Epoxy Resin Nanocomposites Reinforced with Fe@C Nanoparticles

Magnetic epoxy nanocomposites comprising carbon coated iron (Fe@C) nanoparticles have been produced in this work. Fe@C nanoparticles were suspended in epoxy resin monomer to investigate the rheological properties and the corresponding cured epoxy nanocomposites are fabricated with a heating treatment. Effects of particle loading on the rheological properties, including complex viscosity, storage modulus and loss modulus are systematically investigated. Unique rheological phenomena “a decreased viscosity with a better dispersion” are observed and explained in terms of the improved filler dispersion quality. Meanwhile, significant increased storage modulus in cured nanocomposites is observed and related to the better dispersion and strong interfacial interaction between NPs and epoxy matrix as revealed by SEM imaging. The Fe@C nanoparticles become magnetically harder after dispersing in epoxy than that of pure Fe@C nanoparticles due to the decreased interparticle dipolar interaction, which arises from the enlarged NP spacer distance for the single domain nanoparticles. Finally, electrical resistivity measurements indicate a threshold percolation of the nanoparticles between the loading of 5 wt% and 10 wt%, where a significant reduction of resistivity is observed.