Heterogeneously structured conductive carbon fiber composites by using multi-scale silver particles

This paper reports a new approach to enhance the through-thickness thermal conductivity of laminated carbon fabric reinforced composites by using nanoscale and microscale silver particles in combination to create heterogeneously structured continuous through-thickness thermal conducting paths. High conductivity of 6.62 W/(m K) with a 5.1 v% silver volume fraction can be achieved by incorporating these nanoscale and microscale silver particles in EWC-300X/Epon862 composite. Silver flakes were distributed within the inter-tow area, while nanoscale silver particles penetrated into the fiber tows. The combination of different sizes of silver fillers is able to effectively form continuous through-thickness conduction paths penetrating fiber tows and bridging the large inter-tow resin rich areas. Positive hybrid effects to thermal conductivity were found in IM7/EWC300X/sliver particle hybrid composites. In addition, microscale fillers in resin rich areas showed less impact on tensile performance than nanoscale particles applied directly on fiber surface.