Novel Natural Composite Phase Change Materials for Efficient Thermal Energy Storage in Low Carbon Buildings

Abstract

The development of bio-based Natural Composite Phase Change Materials newline(NCPCM) offers a sustainable solution for enhancing the energy efficiency of low-carbon newlinebuildings by utilizing natural and readily available resources. In this study, a novel biobased newlineNCPCM was synthesized from a combination of natural materials, including Lac, newlineRosin, Flowers of silk cotton, red ochre, Cinnabar, Beeswax, and Butter. This NCPCM newlinedisplayed promising thermal properties, with a peak phase transition temperature of newline75 °C and a latent heat capacity of 194 J/g. To integrate the NCPCM into building newlinematerials, three different compositions (2%, 3%, and 5% by weight of the binder) were newlineincorporated directly into a natural hydraulic lime matrix, forming lime mortar specimens newlinethat were further tested for their physical, mechanical, and thermal characteristics. newlineThe results showed substantial improvements in compressive strength, newlineparticularly for the NCPCM2 and NCPCM3 formulations, which demonstrated increases newlineof 22.64% and 47.42%, respectively, after 28 days of curing. X-ray diffraction (XRD) newlineanalysis revealed enhanced calcium carbonate formation due to the presence of lac and newlinerosin, which contain carboxylic acid esters of fatty acids that contribute to this process. newlineFurthermore, Fourier-transform infrared spectroscopy (FTIR) and Scanning electron newlinemicroscopy (SEM) analyses confirmed the chemical stability of the bio-additives and newlinedemonstrated that the morphology of these additives was successfully retained within the newlinelime matrix newline