Preparation of polyhipe composites containing modified magnetic nanoparticles and thermal energy storage applications

Phase Change Materials (PCMs) are materials that can be used for thermal energy storage and provide the continuity of thermal comfort by taking the heat from the environment with a constant temperature or giving it to the environment. Since these materials transform from solid to liquid or from liquid to solid during the phase transition, they are not suitable for direct use in energy conversion processes due to leakage, contamination problems and large volume changes. Although PCMs have high energy storage capacity, their performance is significantly restricted due to leakage problems and low thermal conductivity encountered in practice. For this reason, the approach used in recent years is to form shape stabilized PCMs by trapping these materials in the appropriate support material. In this way, it is possible to improve many properties of these materials such as thermal conductivity, chemical stability, flame resistance etc. This thesis study based on design, preparation and characterization of polymerized high internal phase emulsion (polyHIPE) foams as support materials containing iron oxide (Fe3O4) nanoparticles for impregnation of n-heptadecane as phase change material (PCM). The Fe3O4 nanoparticles were synthesized mechanically assisted co-precipitation method and modified for harmonization with the emulsion system. Fe3O4 nanoparticles doped support materials were prepared via emulsion-templated strategy, and the produced polymeric foams used for preparation of shape-stabilized n-heptadecane based composite PCMs. The total latent heat of produced composite PCM was determined as 99.6 J/g by differential scanning calorimetry (DSC) analysis, while the impregnation ratio of n-heptadecane was found to be 67%. The performance of composite PCM was also investigated via leakage and thermal behaviour tests. Based on the analysis result, it was determined that shape-stabilized n-heptadecane based composite PCMs are promising energy materials for low temperature latent heat storage applications.