Synthesis of a Novel Nanoencapsulated n-Eicosane Phase Change Material with Inorganic Silica Shell Material for Enhanced Thermal Properties through Sol-Gel Route

Abstract

A novel nanoencapsulated phase change material (PCM) based on an n-eicosane core and an inorganic silica shell was synthesized through sol-gel route by using tetraethyl-orthosilicate (TEOS) and sodium silicate as an inorganic silica-precursor at different conditions for enhanced thermal stability and phase change properties. Fourier transform infrared spectra confirm the chemical composition of synthesized nanocapsules. Scanning electronic microscopic images show that the nanocapsules consist of spherical morphology. Furthermore, nanocapsules present different particle size range between 250-550 nm with respect to their pH values; the optimum pH for n-eicosane/TEOS nanocapsules is 2.20, and 2.94 for n-eicosane/sodium silicate, respectively. In addition to this, capsules synthesized by using TEOS show small particle size distributions as compared to the ones integrated by using sodium silicate as a silica-precursor. Differential scanning calorimetry suggests that by controlling the acidity of the reaction solution nanoencapsulated n-eicosane/silica can achieve good phase change properties and high encapsulation efficiency. Thermogravimetric analysis (TGA) shows that silica-nanocapsules have good thermal stability and phase change performance. Synthesis of nanoencapsulated n-eicosane (PCM) with the silica shell material through sol-gel process can be a perspective technique to prepare the nano-PCMs with enhanced thermal transfer and phase change properties for potential applications to thermal-regulating textiles and fibers.