In a groundbreaking study aimed at revolutionizing building insulation, researchers have successfully enhanced the efficiency of composite phase change materials (PCMs) using oleophobic-modified biochar. The study focuses on a novel strategy for preparing high-performance composite PCMs, which are crucial for reducing building energy consumption and contributing to energy conservation and carbon reduction.

The oleophobic modification of white pine biochar, labeled Zn-WPC-A, proved to be a game-changer. This modified material exhibited outstanding support for paraffin wax (PW)/biochar composite PCMs, showcasing an impressive 84.26% loading rate of PW and an encapsulation efficiency of 82.26%. The oleophobic biochar effectively prevented PW leakage, addressing a critical challenge in solid-liquid phase change PCMs.

The research also highlighted a significant 40% reduction in temperature variation within a simulated house, showcasing the potential of composite PCM in regulating indoor temperatures. Additionally, the inclusion of biochar increased the thermal conductivity of PW by an impressive 227.54%, demonstrating excellent thermal responsiveness.

The study’s eco-friendly approach involved utilizing waste white pine for biochar preparation through high-temperature carbonization and ZnCl2 activation. The activation process, combined with oleophobic modification using perfluorooctanoic acid (PFOA), resulted in a perfluorooctanoic acid zinc oleophobic coating on the biochar’s surface. This not only enhanced the biochar’s supporting performance but also contributed to its stability.

The findings hold promise for the widespread application of biochar in composite PCMs, addressing issues such as leakage and low thermal conductivity. By transforming waste materials into high-performance insulation, the research takes a significant step towards sustainable and energy-efficient building solutions.