Preparation of two-dimensional nano montmorillonite/stearic acid energy storage composites with excellent stability and heat storage property

Abstract

Phase change energy storage materials have the ability to store thermal energy during the phase change process, and release the stored energy when desired. As a result, this technology has been extensively studied due to its potential in improving energy utilization and alleviating the problem of energy shortage. In this paper, two-dimensional montmorillonite nanosheets (2DMts) were prepared by ultrasonic method. With 2DMts as the host and energy storage molecule stearic acid (SA) as the guest, a phase change energy storage composite material (2DMt/SA) was prepared using a self-assembly approach. The d001 value of the 2DMt/SA composite was 4.08 nm, indicating that the layer of Mt. was completely peeled off. Additionally, the 2DMt/SA composite had a high latent heat storage capacity (192.4 J/g), which was nearly identical to that of SA samples. Compared with SA, the thermal stability of 2DMt/SA was significantly improved. After 50 cycles of heating and cooling, only 0.557% of the latent heat was lost. There was no liquid leakage indicating that the composite had an excellent structure stability. In addition, after nano silicon carbide (SiC) was added to the 2DMt/SA system, the thermal conductivity of the system increased by 113.7%. This self-assembly method solved the problem of liquid leakage and poor thermal stability in phase change materials. As a result, the 2DMt/SA composite can be applied to road asphalt materials for surface protection applications.