ELECTROMAGNETIC NANOCOMPOSITES AND METHODS OF MANUFACTURE

摘要

Nanocomposites of magnetic nanoparticles in a polymer matrix which has been heat treated is shown to have good giant magnetoresistance characteristics and structural integrity. The flexible nanocomposites were fabricated using a surface-initiated-polymerization (SIP) method. The uniformly distributed nanoparticles within the polymer matrix favor a continuous carbon matrix formation after heat treatment, rendering the transition from insulating to conductive composites. The coercive forces reflect strong particle loading and matrix dependent magnetic properties. One obtained nanocomposites possess fairly good giant magnetoresistance (MR), with a MR of 7.3 % at room temperature and 14 % at 130 K. Furthermore, the formed carbon matrix had a 7 wt.% argon adsorption potential for fuel cell applications. As an example, the method utilizing physicochemical adsorption of an initiator onto the iron-oxide (Fe2O3) nanoparticle surface was used for urethane polymerization in a tetrahydrofuran (THF) solution.