Preparation and characterization of emulsion-templated porous polymers containing modified aluminum-silicate nanoparticles for thermal energy storage applications

Phase change materials (PCMs) absorb heat as endothermic during their melting, they release the heat as exothermic during their solidification. These materials can store thermal energy as latent heat through phase change at constant temperature and thanks to their high latent heat storage capacity, they can be used in many engineering fields. In this thesis study, emulsion-templated porous polymers containing modified aluminum silicate-based nanoparticles were prepared to be used in thermal energy storage systems, and the materials obtained were used as support material for the preparation of paraffin-based form-stable phase change materials. Kaolinite clay with aluminum silicate structure as nano-filler and n-nonadecane, a 19-carbon paraffin, as phase change material were selected. In this thesis study, first of all, the hydrophilic kaolinite clays were modified with Cetyl Trimethyl Ammonium Bromide (CTAB), a cationic modification agent, in order to harmonize with the high internal phase emulsion system and to keep the emulsion stabilization. With the modification process, the hydrophilicity of kaolinite was reduced and a hydrophobic surface compatible with the high internal phase emulsion system was obtained. Modified kaolinite clay has been used in the preparation of porous support materials required for the production of shape- stablized PCMs containing n-nonadecane. In the prepared composite materials, it was observed that the hierarchical porous structure was obtained, the pore morphology improved with the increase of aluminum silicate-based modified kaolinite fillers, and the porous composite containing 1% filler had the highest thermal stability and surface area. All synthesized porous composite materials were loaded with n-nonadecane as a phase change material by one step impregnation method and shape-stabilized composite PCMs were produced. According to the results of the analysis, the peak melting temperature of PHPK1.0 composite PCM was determined as T peak-melting =36.37°C, thermal energy storage capacity ΔH melting =132.3 J/g and n-nonadecane content was calculated as 52.5%. It has been determined that all form-stable PCMs containing n-nonadecane produced using porous composites as support materials have high thermal energy storage capacity (ranging between 92-142 J/g) and display leakage-proof property for thermal energy storage applications.