Microencapsulation of n‐Eicosane as Energy Storage Material

Abstract

AbstractFor heat energy storage application, polyurea microcapsules containing phase change material, n‐eicosane, were synthesized by using interfacial polymerization method with toluene‐2,4‐diisocyanate (TDI) and diethylenetriamine (DETA) as monomers in an emulsion system. Poly(ethylene glycol)octyl‐phenyl ether (OP), a nonionic surfactant, was the emulsifier for the system. The experimental result indicates that TDI was reacted with DETA in a mass ratio of 3 to 1. FT‐IR spectra confirm the formation of wall material, polyurea, from the two monomers, TDI and DETA. Encapsulation efficiency of n‐eicosane is about 75%. Microcapsule of n‐eicosane melts at a temperature close to that of n‐eicosane, while its stored heat energy varies with core material n‐eicosane when wall material fixed. Thermo‐gravimetric analysis shows that core material n‐eicosane, micro‐n‐eicosane and wall material polyurea can withstand temperatures up to 130, 170 and 250 °C, respectively.