Pengembangan Komposit Phase Change Materials (PCM) dan Magnetit (Fe3O4) sebagai Beton Penyimpan Termal

Abstract

This study aims to develop a phase change material (PCM) composite based on paraffin wax and polyethylene glycol (PEG6000), reinforced with magnetite (Fe3O4) nanoparticles, to enhance the thermal conductivity of concrete used as a thermal energy storage (TES) material. Composite fabrications were first carried out with ultrasonication of magnetite (37 kHz for 30 minutes at 80°C). Then, the magnetite varied into 15%, 25%, 35%, and 45% were encapsulated within vertically and horizontally arranged copper tubes embedded in concrete. Characterizations included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy with energy- dispersive X-ray spectroscopy (SEM-EDX), vibrating sample magnetometry (VSM), as well as thermal conductivity and heat distribution tests were conducted to evaluate the thermal, physical, and magnetic properties of the composites. Our DSC’s findings indicated a reduction in the latent heat but improved thermal conductivity with a rise in the magnetite content. The paraffin–magnetite composite with 35% magnetite achieved an optimal thermal conductivity of 0.52 W/m·K, while the PEG–magnetite composite reached 0.624 W/m·K. TGA analysis demonstrated enhanced thermal stability, with degradation temperatures reaching up to 450°C. XRD patterns confirmed the formation of physical composites without the emergence of new chemical phases, and SEM-EDX analysis revealed a uniform dispersion of Fe particles within the PCM matrix. VSM analysis indicated superparamagnetic behavior, with maximum saturation magnetization values of 34.96 emu/g for the paraffin–magnetite composite and 29.84 emu/g for the PEG–magnetite composite. Overall, the incorporation of magnetite (Fe3O4) effectively enhanced the thermal conductivity, stability, and energy storage capacity of PCM-embedded concrete. The developed PCM–magnetite composite, encapsulated in concrete, demonstrates significant potential as an efficient and sustainable passive thermal energy storage material for energy-saving building applications.