Microcapsules composed of stearic acid core and polyethylene glycol‐based shell as a microcapsule phase change material

Abstract

The shell materials of the existing microcapsule phase change materials (PCMs) are always not PCMs, so the enthalpy change (ΔH) in the phase transition processes of these microcapsule PCMs is much smaller compared with the pure encapsulated PCMs (the core materials), reducing the storage ability for thermal energy of the microcapsules. Herein, we prepared microcapsules composed of stearic acid (SA) core and polyethylene glycol (PEG)-based shell as a microcapsule PCM. The PEG-based shell is a solid-solid PCM with cross-linked network, which is in solid state even at 80 C, avoiding the leakage and lose of the whole microcapsule PCM. Additionally, the microcapsule PCM has high ΔH of 113.4 and 115.3 J g −1 during their solidification and melting procedures respectively, displaying outstanding storage capacity for thermal energy. The microcapsule PCM shows dual temperature range in the melting/solidification process resulting in a wide effective temperature range, and has better thermal stability than pure SA. Moreover, the thermal property of the microcapsules changes a little after 100 times of thermal cycling, indicating high thermal reliability of the material.

A form-stable phase change material based on intermolecular hydrogen bonding with a high chemical recycling rate

“…[1][2][3] Small temperature change and high thermal energy density during their endothermic and exothermic processes are the distinguishing features of PCMs. [4][5][6] Because of their high thermal energy storage capacity, negligible temperature variation in phase change procedures, low cost and wide range of sources, [7][8][9] PCMs have been employed in many important fields, such as solar thermal energy storage, 10 off-peak electricity storage 11 and thermal management for batteries 12 and buildings. 13 The forms of PCMs include solid-solid, solid-liquid, liquid-gas and solid-gas.…”

Versatile Fabrication of Polymer Microcapsules with Controlled Shell Composition and Tunable Performance via Photopolymerization

“…Until now, poly­(methyl methacrylate) (PMMA), , polyurethane (PU), , melamine formaldehyde (MF), , and other polymers , have been widely used as microcapsule shells. However, the limited diversity of microcapsule shells makes it difficult to regulate the properties of microcapsules.…”

Fabrication and performance of phase change microcapsules with fatty acid monoglyceride based waterborne polyurethane as the shell

“…The melting enthalpy of microcapsules was 76 J g À1 . However, most of the waterborne polyurethane shell materials in PU-PCMs were obtained by the reaction of polyether polyol 31,32 or polyester polyol 33 with isocyanate compounds and this kind of waterborne polyurethane showed low affinity with phase transfer materials (mainly paraffin) which is one of the reasons for the low encapsulation efficiency of the prepared microcapsules. On the other hand, most of the reported PU-PCMs are fabricated in the size of micro-meter scale, which limits their application in semi-or transparent temperature-regulating films.…”