Research For The Performance Of Micro-nano Composites Solid-solid Phase Change Material

A kind of form-stable polyethylene glycol(PEG)/halloysite(HNT) composite phase change materials (PCMs) were prepared by physical blending method with PEG as phase change material and HNT with nano-tubular structure as the matrix material. The influence of the Fe3O4nanoparticles on the thermodynamic properties of PEG/HNT solid-solid phase change polymer nano-composite materials for energy storage was also discussed. And then the microcapsule phase change material (MPCM) with polyaniline (PANI) as shell and n-octadecane(ODE) as core were synthesized by emulsion polymerization method. The samples were characterized by X-ray diffraction Analysis (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and infrared spectrometric analyzer (FT-IR). The specific content was given as follows:(1) A kind of form-stable PEG/HNT composite PCMs were prepared by physical blending method with PEG as phase change material and HNT with nano-tubular structure as the matrix material. The results showed that HNT could adsorb large numbers of PEG, not only because of its special tubular structures, but also with hydrogen bonding occurs between the PEG and HNT. There are only physical adsorptions, not chemical reaction between PEG and HNT for the complex system. The enthalpy increased with the content of PEG increased, but the phase transition temperature is unchanged. The appropriate content of PEG should be65%in phase change material. There is a clear leakage when the content of PEG exceeded65%, because PEG can not be completely adsorbed by HNT.(2) A kind of form-stable PEG/HNT/Fe3O4composite phase change materials (PCMs) was prepared by the physical blending method. PEG as phase change material, HNT with nano-tubular structure as the matrix material and Fe3O4as the third phase, respectively. The results showed that there are only physical adsorption, not chemical reaction between PEG, HNT and Fe3O4. The enthalpy phase and the phase transition temperature of the HNT/PEG/Fe3O4composite phase change materials has increased compared with pure PEG and PEG/HNT composite. When the content of Fe3O4nanoparticles and PEG are6%and60%, the enthalpy phase and the phase transition temperature are105J/g and 63.1℃respectively.(3) The microcapsule phase change material (MPCM) with PANI as shell and ODE as core were synthesized by emulsion polymerization. The results showed that the MPCM with a complete core-shell structure because core was encapsulated well by shell. There is no chemical reaction between ODE and aniline during the polymerization. The molecular structure and the crystallization of ODE is no change in the MPCM. The enthalpy and phase transition temperature are149.5J/g and30.2℃, respectively. When the temperature exceeds the ODE phase transition temperature the composite can maintain macro-solid phase.