Research on passive cooling of electronic chips based on PCM: A review

A Roadmap for Biomass-Driven Development of Sustainable Phase Change Materials

While the world remains dependent on fossil fuels in nearly every aspect of life, unused biomass is piling up as waste, despite its significant potential for valuable applications-a critical missed opportunity for sustainable innovation. Phase change materials (PCMs) have emerged as a pivotal technology in the urgent transition toward carbon neutrality, especially considering that heating and cooling consume nearly half of global energy expenditure. This comprehensive review advances the scientific understanding of sustainability and circularity in PCM fabrication by providing a strategic framework for developing composites from renewable resources. This framework involves the introduction of a novel classification system (types 0-3) for biomass-derived PCMs based on their levels of modification, enabling a comparison of material sources, performance metrics, and environmental impacts. By showing recent innovative developments in PCM shape stabilization, thermal conductivity enhancement, and leakage protection, it critically highlights the opportunities to replace conventional materials with innovative biomass-derived alternatives, such as biomass-derived carbons and polymers. Furthermore, the study integrates tools aligned with the Principles of Green Chemistry to aid the fabrication of truly sustainable materials, helping to guide researchers through material selection, process optimization, and the comprehensive evaluation of the environmental impact associated with their use and disposal.

Graphene-based polymer composites in thermal management: materials, structures and applications

Graphene, with its high thermal conductivity (k), excellent mechanical properties, and thermal stability, is an ideal filler for developing advanced high k and heat dissipation materials. However, creating graphene-based polymer nanocomposites (GPNs) with high k remains a significant challenge to meet the demand for efficient heat dissipation. Here, the effects of graphene material and structure on thermal properties are investigated from both microscopic and macroscopic perspectives. Initially, it briefly introduces the influence of graphene structural parameters on its intrinsic k, along with summarizing methods to adjust these parameters. Various techniques for establishing different thermal conductivity pathways at the macroscopic scale (including filler hybridization, 3D networks, horizontal alignment, and vertical alignment) are reviewed, along with their respective advantages and disadvantages. Furthermore, we discuss the applications of GPNs as thermal interface materials (TIMs), phase change materials (PCMs), and smart responsive thermal management materials in the field of thermal management. Finally, the current challenges and future perspectives of GPN research are discussed. This review offers researchers a comprehensive overview of recent advancements in GPNs for thermal management and guidance for developing the next generation of thermally conductive polymer composites.

Carbon-Enhanced Hydrated Salt Phase Change Materials for Thermal Management Applications

Inorganic hydrated salt phase change materials (PCMs) hold promise for improving the energy conversion efficiency of thermal systems and facilitating the exploration of renewable thermal energy. Hydrated salts, however, often suffer from low thermal conductivity, supercooling, phase separation, leakage and poor solar absorptance. In recent years, compounding hydrated salts with functional carbon materials has emerged as a promising way to overcome these shortcomings and meet the application demands. This work reviews the recent progress in preparing carbon-enhanced hydrated salt phase change composites for thermal management applications. The intrinsic properties of hydrated salts and their shortcomings are firstly introduced. Then, the advantages of various carbon materials and general approaches for preparing carbon-enhanced hydrated salt PCM composites are briefly described. By introducing representative PCM composites loaded with carbon nanotubes, carbon fibers, graphene oxide, graphene, expanded graphite, biochar, activated carbon and multifunctional carbon, the ways that one-dimensional, two-dimensional, three-dimensional and hybrid carbon materials enhance the comprehensive thermophysical properties of hydrated salts and affect their phase change behavior is systematically discussed. Through analyzing the enhancement effects of different carbon fillers, the rationale for achieving the optimal performance of the PCM composites, including both thermal conductivity and phase change stability, is summarized. Regarding the applications of carbon-enhanced hydrate salt composites, their use for the thermal management of electronic devices, buildings and the human body is highlighted. Finally, research challenges for further improving the overall thermophysical properties of carbon-enhanced hydrated salt PCMs and pushing towards practical applications and potential research directions are discussed. It is expected that this timely review could provide valuable guidelines for the further development of carbon-enhanced hydrated salt composites and stimulate concerted research efforts from diverse communities to promote the widespread applications of high-performance PCM composites.