News Coatings Technologies
Wood-based phase-change composites regulate indoor temperature
Researchers demonstrate how vacuum impregnation of n-octadecane into delignified wood, combined with strategic surface coatings, produces bio-based phase-change composites for intelligent thermal management. Wood wax oil coatings increase phase change enthalpy while polyurethane coatings reduce it significantly.
Delignified wood (DLW) is increasingly investigated as a sustainable scaffold for phase-change materials (PCMs), because its hierarchically porous structure provides both mechanical robustness and space for embedding functional media. A recent study designs a multifunctional wood-based composite by vacuum-impregnating n-octadecane into DLW and delignified-hemicellulose wood (DHLW) matrices, followed by surface coating with either wood wax oil or polyurethane. The approach aims to combine the natural benefits of wood substrates with the latent heat storage capability of PCMs for temperature regulation in the human comfort range.
The n-octadecane/DLW composite achieved a phase change enthalpy of 165 J/g with a transition temperature between 25 °C and 30 °C, well within the human comfort zone. Removal of hemicellulose, however, compromised the structural integrity of the wood scaffold, resulting in a 19 % reduction in latent heat, underlining the role of native wood components in preserving PCM loading capacity.
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Coating type strongly influences thermal performance
Surface coating proved decisive in modulating the thermal performance of the composites. A wood wax oil coating increased the phase change enthalpy by 20 %, reaching 197.2 J/g, an effect attributed to a hydrophobic sealing action that limits leakage and preserves the PCM in the pore network. In contrast, a polyurethane coating led to a 39 % reduction in enthalpy, which the authors attribute to spatial hindrance introduced by the polymer layer.
Thermal stability analysis confirmed the reliability of the composites for practical applications, with decomposition temperatures exceeding 220 °C. The study elucidates the synergistic relationship between substrate, PCM component and interface treatment in bio-based PCM systems. According to the authors, the findings offer a new paradigm for developing intelligent temperature-regulating wood and sustainable thermal management materials, of potential interest for functional coatings on wood-based building products.
Source: Zhu, X. et al., Interfacial engineering of delignified wood phase-change composites: synergy between vacuum impregnation and surface coating for intelligent thermal management. Journal of Coatings Technology and Research 23, 2753–2762 (2026).
