In this study, a novel microencapsulated phase change material (palmitic acid@AlOOH) was prepared using an in situ emulsion interfacial poly-condensation method. The resulting colloidal-sphere microcapsules, with diameter around 200 nm, are of core-shell microstructures. Characteristic peaks of both palmitic acid and AlOOH can be observed during their IR spectrum characterization. According to the TGA examinations, the encapsulated ratios of palmitic acid (PA) to PA@AlOOH are 52%, 57% and 69%. The DSC results indicate that melting temperatures of the microencapsulated PCMs are remarkably 50 degrees C lower than those of pristine PA, which might originate from the strong interface interactions between the core and shell of PA@AlOOH. The thermal storage capabilities of the microcapsules are also tested. The method and mechanism of this study can be extended to design other organics@inorganics PCMs with different core-shell structured compositions. (C) 2011 Elsevier B.V. All rights reserved.