Interfacial heat conduction enhancement mechanism between CNTs encapsulated with LCC

The unique hollow structure of carbon nanotubes (CNTs) allows for the synthesis and preservation of linear carbon chain (LCC), while the LCC inside tube can cause the performance changes on CNT. Since the interfacial heat transfer conductance between CNTs dominate the thermal performance of assembly structure, the core-shell structure of LCC encapsulated in CNTs (LCC@CNT) is expected to improve the thermal conductivity of CNT assembles. In this work, the enhancement mechanism is explored by heat transfer process parameters (such as heat flow, temperature distribution) and phonon mode (such as phonon density of states, overlap energy, similarity index) based on molecular dynamics simulation. The LCC affects interfacial heat conduction by the combination of low frequency phonons excitation and additional heat transfer path. The LCC also shows significantly weak temperature dependence, especially for the CNT with smaller diameters. The enhancement on partially overlapping is limited while the temperature dependence is further weakened. This work provides a new strategy to improve heat conduction at CNTs interface, offer data support for thermal design of CNT assembles, and also explore a new idea for the LCC application with its unstable characteristic. • Investigate thermal enhancement mechanism of encapsuled LCC for CNT interface. • Analyze the LCC effect difference on partially and fully overlap CNTs interface. • Explore the variation of LCC effect as a function of diameter and temperature.