Bifunctional aerogel-encapsulated ZIF-8@PEG hybrid architectures: Synergistic integration of thermal insulation and flame retardancy

Thermal-insulating and flame-retardant materials, as a class of functional materials with unique properties, play a pivotal role in various fields. The study utilized silica aerogel as the thermal-insulating base material and incorporated ZIF-8-encapsulated polyethylene glycol-based shape-stabilized phase change materials (ZIF-8@PEG) to fabricate silica aerogel-based ZIF-8@PEG composites (ZP-SA) via a sol-gel method. The microstructure, thermal stability, and molecular architecture of the composite phase change materials were characterized through scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The experimental results demonstrated that the prepared ZP-SA exhibited a three-dimensional skeletal structure, with a phase change enthalpy of 80.98 J/g and phase transition temperatures of 53.18 °C (melting) and 26.89 °C (solidification). The material displayed excellent thermal stability during heating-cooling cyclic tests. In terms of flame retardancy, ZP-SA achieved a limiting oxygen index (LOI) value of 30.2 %. These findings confirm that the incorporation of ZIF-8@PEG effectively enhances the thermal-insulating and flame-retardant performance of the composite material. The research provides a novel theoretical framework and practical insight for the design of advanced thermal-insulating and flame-retardant composite materials, demonstrating significant academic and applied value.