Wasted Poly (ethylene terephthalate) Derived Composite Xerogel with Enhanced Electromagnetic Interference Shielding and Photothermal Conversion

The wasted poly(ethylene terephthalate) recycling (rPET) presents a critical worldwide challenge requiring optimization of processing economics and material performance. This study demonstrates the synthesis of hybrid xerogels through thermoreversible gelation using rPET matrices combined with nickel-decorated carbon nanotubes (Ni@CNTs). Investigations focused on the gel formation dynamics within rPET/Ni@CNT systems and structural transformations during xerogel formation. The engineered xerogels displayed hierarchical macroporous architectures supported by interconnected nanofibrous networks, achieving enhanced thermal resilience and mechanical strength. To functionalize these scaffolds, polyethylene glycol (PEG) was chemically grafted to fabricate phase-change composites (PCCs) with multifunctional capabilities. Optimized PCC formulations exhibited synergistic performance metrics: enhanced heat transfer kinetics (1.3±0.32 W/(m·K)), substantial energy storage capacity (125.6 J/g), and reliable thermal cycling stability (zero leakage through 20 meltfreeze cycles). Furthermore, the PCCs exhibited a considerable solar-thermal conversion efficiency (73.4%) and a significative electromagnetic shielding capacity (30.4 dB). This methodology estab lishes a viable pathway for valorizing post-consumer PET waste into high-performance engineering materials, aligning with circular economy objectives.