Experimental study on a functional microencapsulated phase change material for thermal management

Phase change materials play a vital role in the field of thermal management field, in particular for the microencapsulated protocols owing to its large specific area, enhanced thermal stability and controlled volume variation. However, its sophisticated preparation process associated with complex chemical or physical events still heavily hinders the advance application. Herein, microencapsulation of phase change materials through an facile in-situ copolymerization of N-(tert-butyl)acrylamide, divinylbenzene and para-quaternary ammonium functionalized styrene has been studied. The ratio of core/shell, oil/water ratio and the different monomers were investigated towards the encapsulation efficiency and morphology of the as prepared microcapsules. Chemical composition, morphology of the microcapsules were analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction instrument, thermal gravimetric analysis, scanning electron microscopy and transmission electron microscopy. Thermo-physical characteristics, such as leakage-proof performance, latent heat capacity and phase change temperature were also studied. This study, for the first time, using a quaternary ammonium functionalized styrene based amphipathic monomer, which was designed to be able to stay at the interface of oil and water, as one of the shell materials with the purpose of attaining a high encapsulation rate. As a result, the encapsulation efficiency of our protocol can achieve to 84.50% without observation of any PCMs leakage. Additionally, it was noteworthy that this study offers a facile way to construct PCMs microcapsule, which only needs a simple and rough mixing and filtration, thanks to the self-assembly characteristic of this amphipathic monomer.