In order to obtain stable phase change composites with a high PEG load and enthalpy, a series of polyethylene glycol (PEG) based phase change composites with different mesoporous materials (active carbon and silica molecular sieves) were prepared by a simple approach. Various characterization techniques were carried out to investigate the properties of the composites. It was observed that both the porous characteristics and surface properties of the mesoporous stabilizers combined affected the crystallinity and phase change behavior of PEG. Among the various composites, PEG/AC PCMs with 80 wt% of PEG had the largest latent heat, a relatively low melting point, the least supercooling and a higher heat storage efficiency. This study will provide insight into the fabrication of stabilized polymer based high performance phase change systems for heat storage application. (C) 2011 Elsevier B.V. All rights reserved.