Advancing thermoregulatory textiles through inorganic phase change materials: Integration strategies, performance, and future pathways

Thermoregulatory textiles are increasingly needed to provide thermal comfort and safety in extreme environmental, occupational, and wearable technology applications. This review aims to critically review recent developments in the functionalization of inorganic phase change materials, such as salt hydrates, metallic PCMs, and eutectic composites, into textiles, with special emphasis on performance enhancement and commercialization potential. A systematic review of reported literature is carried out to compare encapsulation, incorporation, surface treatment, and multi-layer laminate structures in terms of thermophysical performance and durability. Inorganic PCMs have latent heat storage values of 120–350 J g⁻¹ and phase change temperatures between 15–60 °C, which are appropriate for wearable textile applications. Despite these advances, some of the major drawbacks in the field include phase segregation, mechanical brittleness, density-induced weight gains, and recyclability limitations. This review is unique in the sense that it correlates the composition and integration of the materials and their thermal performance metrics, thus providing a pathway for scalability. It also discusses some of the future directions in the field of multifunctional smart textiles, sustainable PCM composites, and standardization guidelines, which can take this technology from the laboratory scale to the commercial scale.