I-Corps: High thermal conductivity polymers and phase change materials based on graphene

The broader impact/commercial potential of this I-Corps project is the development of high thermal conductivity polymers and phase change materials. The proposed high thermal conductivity polymers may replace metals in wide range of thermal management technologies leading to advantages including ease of processing, corrosion resistance, lower weight, and lower carbon footprint as polymers require less energy to process compared to metals. These polymers may improve thermal management in mobile electronics such as laptops and mobile phones, in high brightness light emitting diodes (LEDs), in automobiles and aerospace applications, and in offshore heat exchangers where such polymers, due to their corrosion resistance, would be able to replace expensive metals like titanium. Similarly high thermal conductivity phase change materials may enable superior thermal management in batteries, by absorbing thermal energy generated during charging process, mitigating the increase in temperature during these periods, thus improving the life of the battery. Batteries with improved thermal management are essential to the successful design and development of next-generation electric vehicles. High thermal conductivity phase change materials also have tremendous potential as next generation energy storage materials, key to the efficient utilization of renewable sources of energy. This I-Corps project is based on the development of high thermal conductivity polymers and phase change materials through use of optimally prepared expanded graphite. Intercalating agents used in preparing expanded graphite have been shown to have a significant impact on thermal conductivity of resulting polymer-graphite composites. Further, different intercalating agents lead to different degrees of oxidation of graphite, thus impacting the oxidative damage to graphite, which in turn results in different graphite thermal conductivities. The effect of different intercalating agents results in different thermal conductivities of the polymer composites and phase change materials. Overall, the use of an optimum intercalating agent leads to a maximum enhancement in thermal conductivity. In addition, this leads to a decrease in the amount of graphite needed for achieving a desired enhancement in thermal conductivity, which may lower the cost of the composite. These composites also are found to impact thermal conductivity of phase change materials where the optimum intercalating agent may result in 50 to 60% higher thermal conductivity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.