Enhancing paraffin wax crystallization and investigating thermo-physical properties of ethylene-propylene-diene monomer/paraffin wax/silica phase change system: The influence of silica nanoparticles

Abstract

Nowadays, phase change systems play a crucial role in thermal energy storage applications. However, key challenges persist in these systems, namely achieving a higher phase change enthalpy while minimizing leakage of the phase change materials (PCMs). This study focuses on investigating the thermo-physical properties of a phase change composite comprising Paraffin Wax (PW) and silica nanoparticles. The objective is to enhance the thermal efficiency of an ethylene-propylene-diene monomer (EPDM) rubber/PW PCM/silica composite by utilizing silica nanoparticles as nucleating agents to promote the crystallinity of PW PCM. The results demonstrate that the incorporation of 0.4 wt% silica nanoparticles maximizes the crystallinity of PW PCM, coinciding with the threshold for particle aggregation within the PW PCM matrix. Furthermore, a lower crosslink density in the rubber matrix facilitates a higher loading of PW PCM (197 %) and mitigates leakage (1.36 %). Thermo-physical analysis of the composite materials reveals that the presence of silica nanoparticles significantly reduces the melting kinetics and enhances the crystallinity of PW PCM. Moreover, the inclusion of silica nanoparticles elevates the energy storage capacity of the EPDM/PW PCM/silica composite by augmenting the heat capacity and substantially reducing the melting and freezing kinetics of PW PCM.