The UCR researchers have now found that composites containing the “wonder material” graphene can block EM radiation while dissipating excess heat. “Surprisingly, we discovered that the graphene composites can block EM energy even below the so-called percolation threshold, and remain electrically insulating (which is an important property for a thermal interface material).” Electrical percolation is the term used to describe composites in which electrically conductive filler particles form a continuous network, allowing for electrical current to flow. Team members Fariborz Kargar and Zahra Barani of the UCR Phonon Optimized Engineered Materials (POEM) Center, led by Balandin, prepared epoxy-resin composites containing a high loading fraction of few-layer graphene fillers (FLG). They processed the material in their lab to determine the optimum aspect ratio, lateral dimensions, and thickness of the fillers. For EM shielding applications, for example, fillers with high aspect ratios are best, and for thermal applications optimum lateral dimensions and thickness are required, says Balandin. Read More…
