Tunable Electrical Resistivity of Carbon Nanotube Filled Phase Change Material Via Solid-solid Phase Transitions

Thermo-responsive materials can be used in temperature sensing systems. In this study, we demonstrated a carbon nanotube (CNT) incorporated form-stable phase change material (FSPCM) that exhibits variation of electrical resistivity in over three orders of magnitude during phase transition. The electrical resistivity was manipulated by the volume change induced by the thermal energy due to the phase transformation. The phase change material (PCM) was encapsulated by polyaniline (PANI) and the solid state of the microcapsule was maintained during the melting and cooling processes. The form-stable microcapsules underwent volume expansion and shrinkage with respect to the temperature. Thus, the thermal expansion coefficient is related to the temperature variation and volume change of PCM capsules. The CNT embedded phase change material (PCM) showed remarkable electrical reversibility and thermal stability in the melting/cooling cycles. We expect that the CNT/PCM nanocomposite can be successfully applied to flexible electronics and thermal sensing probes in the future.