Hexagonal Boron Nitride-Induced Lamellar-Structured Flexible Phase Change Film for Temperature-Controlled Information Storage and Wearable Thermal Regulation

The development of multifunctional composite phase change materials has emerged as a popular research field to achieve efficient thermal energy storage and management across diverse application scenarios. Herein, a novel flexible reversible thermochromic phase change film (TC-PCMs/nBN/OBC) has been proposed. The film comprises a thermochromic compound, hexagonal boron nitride (h-BN), and olefin block copolymers (OBC), and features a layered structure with h-BN embedded laterally in OBC. This design enhances thermal conductivity and confers reversible thermochromic ability, as well as excellent flexibility. The TC-PCMs/nBN/OBC film can perform multiple functions, including thermal storage, light-to-thermal conversion, and temperature-controlled information storage. Additionally, a sandwich-like structure of the multifunctional smart flexible device (TC-PCMs/10BN/OBC-CC) is fabricated using TC-PCMs/10BN/OBC and conductive cloth via easy layer-by-layer assembly. This flexible device is simple to prepare, retains the excellent comprehensive properties of TC-PCMs/nBN/OBC, and possesses high electric-to-thermal conversion efficiency (86.5%). Overall, the results demonstrate that TC-PCMs/10BN/OBC can meet diverse application requirements.