Novel Multifunctional Composites by Functionally Dispersed Carbon Nanotubes Throughout the Matrix of Carbon/Carbon Composites

Recently, increasing demands for smarter and smaller products calls for the development of multifunctional composites. These materials are used not only as structural materials but also satisfy the needs for additional functionalities such as thermal, electrical, magnetic, optical, chemical, biological, etc. In this research, a novel carbon nanotubes dispersion approach leads to a new generation of multifunctional composites with additionally novel thermal functionality, we called it heat-directed functionality. These distinctive composites have unique capability which can conduct the majority of the transferred heat by conduction to the preferred area or direction of the thermal structure. This unique heat-directed property can be attained by varying the in-plane thermal conductivity. Varying the in-plane thermal conductivity of the composites functionally is achieved by dispersing highly heat-conductive materials such as carbon nanotubes throughout the matrix functionally, not uniformly. Therefore, in this research three phase carbon/carbon composites have been fabricated with functionally dispersed carbon nanotubes throughout the carbon matrix of continuously plain woven carbon fiber fabrics in order to attain this useful property. The fabricated heat-directed carbon/carbon composites have been examined experimentally and numerically. The in-situ full-field infrared measurements and finite element analysis of the designed composites showed that the heat transfer direction can be substantially controlled by just functionally dispersed a few percentages of carbon nanotubes through the matrix of traditional long carbon fiber-reinforced carbon matrix composites. This exceptional property can play a significant performance improvement in heat transfer process along the in-plane of the materials as well as helping to decrease the heating up of the Earth, global warming, due to the escaped heat of many engineering applications. In other words, the efficient heat energy management or heat energy saving via using the introduced multifunctional carbon/carbon composites with heat-directed functionality can significantly help with both sides of the equation of efficient energy consumption and friendly-environment applications.