Incorporating polyethylene glycol grafted epoxy and porous polyvinylidene fluoride for efficient advanced phase-change passive radiative cooling materials

초록

This study presents novel phase-change (PC) passive radiative cooling (PRC) materials using polyethylene glycol (PEG) grafted epoxy (EP) resin and etched polyvinylidene fluoride (EPVDF). In addition, PRC composites with enhanced optical properties are developed via the synthesis and integration of micro-sized expanded graphite (EG) into the phase-change material (PCM) matrix. After that, the thermally conductive PCM is bonded with the PRC layer by epoxy curing. The as-synthesized EPVDF/PEGEP/EG-OH (EPPE) exhibits an endothermic reaction at 25–42°C. As a result, the PEGEP/EG-OH achieves a high thermal conductivity of 2.99 W/mK and a total latent heat of 78.5 J/g. Field tests demonstrate that the EPPE maintains the lowest temperature during daylight, thereby confirming its superior cooling efficiency relative to the pure PVDF. Additionally, theoretical calculations using MATLAB indicate that the cooling capacity of the EPPE reaches 107.34 W/m2, representing a substantial improvement over pure PVDF and robustly validating the proposed nanoparticle assembly strategy. These results highlight the potential of structurally controlled particles to revolutionize PRC technologies, thereby offering a pathway toward more energy-efficient and environmentally friendly cooling solutions.

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