具有防水透湿功能的PVDF-HFP/PMHS辐射制冷膜的制备及性能研究OA

Traditional cooling technologies are associated with high energy consumption and environmental pollution.Passive radiative cooling technology has attracted increasing attention as a promising green alternative.However,exist-ing radiative cooling materials are susceptible to environmental factors such as water vapor and pollutants in complex environments,leading to performance degradation.Poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and polymethylhydrosiloxane(PMHS)were used as raw materials to fabricate porous membranes with both waterproof breathable and radiative cooling properties via the phase separation method.The effects of PMHS addition amount on the membrane's microstructure,surface chemical properties,waterproof breathable performance,and radiative cooling properties were systematically investigated.Results show that when the mass ratio of PVDF-HFP to PMHS is 2.5∶2.2,the membrane exhibits the optimal comprehensive performance:its water contact angle reaches 136°,hydrostatic pres-sure is 14.1 kPa,and moisture vapor transmission rate is 4.22 kg·m-2·d-1,indicating excellent waterproof and breathable performance.The micro/nanoporous structure(average pore size of 1.45 µm)formed inside the membrane matches the solar wavelength range(300～2 500 nm),which significantly enhances the Mie scattering effect and results in a solar re-flectance of 91.5%.Meanwhile,the membrane has an average infrared emissivity of 96.03%in the atmospheric window band(8～13 µm).Outdoor actual measurements show that the membrane can achieve a cooling effect of 5.9 ℃ under di-rect solar irradiation.The radiative cooling material prepared in this study integrates waterproof and breathable proper-ties,weather resistance,and efficient radiative cooling performance,showing broad application prospects in the fields of building energy conservation,automotive industry,and smart textiles.