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Wood is a great natural material with good energy storage and temperature adjustment for the energy crisis. In this study, wood was delignified, and the PEG-based eutectic polymer (PGMA) was impregnated into the delignified wood, and styrene (SM) grafted AlN was selected as thermal conductive filler to synthesize a stable phase change heat storage wood. The result shows that the styrene (SM) polymerized on the surface of AlN to form polystyrene (PS), and the dispersion of AlN was enhanced. The thermal stability and loss resistance of PCES-Wood are improved for the penetration of PS-AlN into the cavities, which is attributed to the PS-AlN playing a "limiting" role in the crystallization of PGMA. When the content of PS-AlN is 6%, the thermal conductivity of PCES-Wood reaches 0.5148 W/(m·K). 4% PS-AlN-PCES@Balsa has the lowest undercooling and heat loss rate, and the melting enthalpy and solidification enthalpy reach 125.60 J/g and 120.30 J/g, respectively. The phase change temperature range is between 19.59 and 33.87 °C, which is in the comfortable temperature range for humans. Under the illumination of the simulated solar light source, the surface temperature of PS-AlN-PCES@Balsa rises rapidly and shows a lasting heat storage capacity at low temperatures compared with the original wood. After 200 cold and hot cycle tests, the phase change enthalpy of PS-AlN-PCES@Balsa is still high, and there is a slight leakage phenomenon. The phase change wood prepared in this study shows that it is a potential material to store and release solar energy in practical applications. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) with high heat recovery and high energy density were introduced to the wood-plastic composites (WPCs) to regulate the indoor temperature, achieving the purpose of reducing building energy consumption. However, the interface compatibility between PCMs and WPCs seriously restricts its applications. To improve the utilization efficiency and expand the application fields, novel thermal storage wood-plastic composites (WPCs) were synthesized based on poly (ethylene glycol) (PEG) encapsulated by organic montmorillonite (OMMT) and WPC matrix. The leakage of PEG in PCMs were effectively solved. WPCs were successfully prepared since the peaks of the C–O bond and Si–O bond in WPC-3 are significantly more intense than WPC-0. The phase change temperature range of WPCs (17–26 °C) was similar to PCM3 (17–23 °C), which was caused by the restriction on crystal arrangement and orientation of PEG molecular chains in the wood-plastic matrix. The value of latent heat for PCM3 was 108.97 J/g, while the enthalpy value of WPCs reached 47.53 J/g when the loading percentage of PCM3 was 40%. Based on the good thermal properties, both PCMs and WPCs could effectively regulate the indoor temperature. The results of TG show that the fabrication of the organic network enhanced the thermal stability of PCMs, and the high-temperature resistance of the MMT reduced the degradation rate of WPCs. The thermal storage WPCs possess excellent thermal reliability and stability, good interface interaction and combustion performance, which are potential in the application of building energy-saving and indoor air-conditioning systems. [ABSTRACT FROM AUTHOR]

It is of great value to create new bio based green energy-saving and temperature regulating materials under the background of carbon peak and carbon neutralization. In this study, balsa wood was prepared by delignification as encapsulation materials to combine with polyethylene glycol based phase change materials (PCMs) to make phase change energy storage wood (PCES-Wood). In order to improve the thermal conductivity of PCES-Wood, the carbon black grafted with octadecyl isocyanate(aCB)was impregnated into the wood to obtain a thermally enhanced phase change energy storage wood (aCB-PCES@Balsa). The results show that aCB exhibited superior dispersibility and formed thermal conduction pathways in the wood. When the aCB content is 4%, the degree of supercooling of aCB-PCES@Balsa is the smallest, and the melting enthalpy and solidification enthalpy reach 100.34 J/g and 91.10 J/g, respectively. The 4% aCB-PCES@Balsa also exhibits strong hydrophobicity and full-optical-segment absorption. Under the irradiation of a simulated solar light source, the surface temperature of 4% aCB-PCES@Balsa rises rapidly to 28 °C and exhibits long-lasting heat storage capacity at low temperatures. After 200 cycles of cooling and heating, the phase change energy storage wood still maintains a high phase change enthalpy value, indicating that the aCB-PCES@Balsa has a good durability. This study provides a new approach for green heat storage in biomass composites. • Modified wood has greater porosity. • Synthetic phase change energy storage material prevents the leakage of polyethylene glycol. • Phase change energy storage wood has high phase change enthalpy. • Phase change energy storage wood has faster heat transfer capacity. • Phase change energy storage wood has strong water swelling resistance. [ABSTRACT FROM AUTHOR]