Enhancing negative differential thermal resistance effect at the solid-fluid interface by using surfactant: A molecular dynamics study

Abstract

The negative differential thermal resistance (NDTR) effect has received a lot of attention for its potential applications in thermal switching and thermal management. Therefore, it is crucial to explore and develop new ways to improve the NDTR performance. In this work, the influence of the surfactant on NDTR effect in the solid-liquid system has been investigated by using molecular dynamics simulation. It is found that the NDTR window and the maximum heat flux through the system can be extended significantly by using surfactant. With increasing temperature differences, the surfactant molecules are deported from the high-temperature interface and adsorbed on the low-temperature interface. The wettability transition of the high-temperature interface from hydrophilic to superhydrophobic is responsible for the enhanced NDTR effect. In addition, the effect of surfactant concentration and solid-surfactant coupling strength on the NDTR effect is also examined. The results show that there is an optimal surfactant concentration and solid-surfactant coupling strength for an optimized NDTR effect. The results in this paper provide a new idea for the design of thermal thermistor.