Facile Preparation of Calcium Stearoyl Lactylate as Solid–Liquid Phase Change Materials with Improved Form Stability and Adjustable Phase Transition Temperature for Thermal Comfort

Abstract

In this study, a homologous series of calcium stearoyl lactylates (CSLs) with adjustable phase transition temperature were synthesized as solid–liquid phase change materials (PCMs) by esterification between stearic acid (SA) and lactic acid (LA), combining with the self‐esterification of LA, and neutralization with calcium hydroxide (Ca(OH)2). The chemical structures of CSLs were confirmed by Fourier transform infrared spectroscopy (FT‐IR) and 1H nuclear magnetic resonance spectrum (1H NMR). X‐ray diffraction (XRD) was applied to study the crystalline structure of solid–liquid PCMs. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) were carried out to determine the phase change properties and thermal stability of prepared CSLs. Research results show that calcium ions (Ca2+) have positive effects on improving form stability of synthesized PCMs. The melting temperatures in the range of 40.45°C–25.47°C could be tailored by varying the molar ratio of SA to LA from 1:1 to 1:4. The thermal storage capabilities reach about 53% with the latent heat of fusion in the range of 84.5–55.50 J/g. The PCMs show acceptable thermal reliability and reusability after thermal cycles for 100 times. Suitable phase transition temperatures make CSLs potential for thermal comfort, and the mechanism of temperature regulation would provide reference for design of more PCMs used in different situations. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13136, 2019

Thermal energy storage properties and lab‐scale thermal performance in cementitious plaster of composite phase change material for energy efficiency of buildings

“…5,6 The latent heat thermal energy storage (LHTES) based on phase change materials (PCMs) is one of mostly preferred TES methods because it allows harvesting/retrieving high amount of latent heat per unit mass of PCM at an almost constant temperature and small volume variation. [7][8][9][10] Paraffins are promising organic solid-liquid PCMs for TES systems due to their appropriate phase change temperature, LHTES capacity, good thermal stability/reliability, little supercooling degree, etc. 11,12 However, such a type PCM requires storage container owing to the leakage issue observed through its solid-liquid phase change.…”

“…In addition to the active thermal systems, thermal energy storage (TES) has been implemented as passive technique in buildings 5,6 . The latent heat thermal energy storage (LHTES) based on phase change materials (PCMs) is one of mostly preferred TES methods because it allows harvesting/retrieving high amount of latent heat per unit mass of PCM at an almost constant temperature and small volume variation 7‐10 …”