Numerical Investigation of the Effect of Chirality of Carbon Nanotube on the Interfacial Thermal Resistance

Molecular dynamics simulations (MD) were performed to study the interfacial thermal resistance between a carbon nanotube (CNT) and carbonate molten salt eutectic. The carbonate salt eutectic consists of lithium carbonate (Li2CO3) and potassium carbonate (K2CO3) in 62: 38 molar ratio. Molten salt nanofluids are being explored for thermal energy storage (TES) and as coolants for energy conversion, such as, concentrated solar power (CSP) applications. The estimates for interfacial thermal resistance (also known as "Kapitza Resistance" or "Rk") between CNT and solvent (molten salt) can be used to estimate the optimum dimensions of nanoparticles for maximizing thermal properties of the mixture (such as thermal conductivity and specific heat capacity values). The interfacial thermal resistance was calculated by parametrically varying the values of chirality of single walled CNT (e.g., armchair, chiral, and zigzag). The numerical computations were performed by placing a CNT of a particular chirality and solvent molecules (of appropriate number density) in a simulation box. The system was allowed to equilibrate by imposing conservation schemes to an initial temperature. This was followed by heating the CNT to a higher temperature which was cooled by the surrounding solvent molecules that were at a lower temperature. The rate of decay of the CNT temperature was used to estimate the value of the interfacial thermal resistance. The results show that the Kapitza resistance of the CNT is dependent on the chirality of the CNT.