Paraffin/Diatomaceous Earth/Zinc Oxide Phase Change Energy Storage Materials and the Cooling Performance in Pdms Coatings

Abstract

It is of great significance to construct low-cost functional paraffin/diatomaceous earth phase change energy storage materials by simple methods to expand its application in thermal management coatings. Here, paraffin/diatomaceous earth/zinc oxide (PA/F-DE/ZnO) composite phase change materials (PCMs) were prepared by a simple melt blending method with diatomaceous earth as the carrier and paraffin as phase change material. The effect of the ratio of paraffin to diatomaceous earth and the content of ZnO in the PA/F-DE/ZnO on the properties of the composite PCMs were investigated. XRD, FTIR, DSC and SEM were used to characterize the heat storage performance and the structure of the composite PCMs. The results indicated that the comprehensive properties such as leakage rate of the composite PCMs were better when the mass ratio of paraffin to diatomaceous earth was 1:1. Then, nano-ZnO was introduced to the 1:1 of paraffin/diatomaceous earth system to improve the thermal conductivity and leakage rate of PA/F-DE/ZnO, and also endowed the UV absorption performance of the composite PCMs. The PA1/F-DE/ZnO10 composite PCMs with 10 wt% of ZnO showed the best UV absorption performance, and retained the heat storage performance well. 5 wt% of PA1/F-DE/ZnO10 was combined with Polydimethylsiloxane (PDMS) to form a PDMS-PA1/F-DE/ZnO10 composite film. The temperature of PDMS-PA1/F-DE/ZnO10 film surface was 5~6 ℃ lower than that of PDMS film in the heating temperature range from room temperature to 60 ℃, indicating a cooling performance and good thermal stability. The prepared PDMS-PA1/F-DE/ZnO10 showed an outstanding cooling effect when applied in computer and phone cooling.

Keywords: Diatomaceous earth, Paraffin, Zinc oxide, Phase change energy storage, Cooling coating