PDMS/ZrO_(2)/SiO_(2)超疏水辐射制冷薄膜的制备及性能

Preparation and properties of PDMS/ZrO_(2)/SiO_(2)superhydrophobic radiative cooling film

被动日间辐射制冷(PDRC)技术由于不需要外部能源、绿色清洁无污染而受到广泛关注。将聚二甲基硅氧烷(PDMS)和ZrO_(2)粒子混合形成分散液,再将其浇铸成膜后得到PDMS/ZrO_(2)辐射制冷薄膜,然后通过喷涂PDMS/SiO_(2)分散液对其进行疏水化处理制备了一种PDMS/ZrO_(2)/SiO_(2)超疏水辐射制冷薄膜。对ZrO_(2)粒径和喷涂液中SiO_(2)用量进行了优化。结果表明,当ZrO_(2)为500 nm,SiO_(2)用量为3.0%(以乙酸乙酯质量计)时,制得的PDMS/ZrO_(2)/SiO_(2)薄膜的表面接触角可达156°±2°,滚动角为0.3°±0.1°,表现出优异的自清洁性能。其太阳光反射率高达95.3%,红外发射率>90%。在太阳光直射下,薄膜可实现平均低于环境温度9.99℃的降温效果。薄膜的自清洁性能使其表面不受泥土污染,从而具有稳定持久的辐射降温功能。此外,薄膜具有优异的机械性能、耐摩擦性能以及耐酸/碱溶液和紫外光照稳定性。

Passive daytime radiative cooling(PDRC)technology has attracted a lot of attention due to its external-energy-free and environmentally benign properties.Herein,polydimethylsiloxane(PDMS)/ZrO_(2)/SiO_(2)superhydrophobic radiative cooling film was synthesized by spraying hydrophobic PDMS/SiO_(2)dispersion solution onto PDMS/ZrO_(2)radiative cooling film obtained from casting and drying of PDMS/ZrO_(2)dispersion solution,during which optimization of ZrO_(2)particle size and SiO_(2)dosage in spraying solution were conducted.The results showed that the PDMS/ZrO_(2)/SiO_(2)film with optimal ZrO_(2)particles size of 500 nm and SiO_(2)dosage of 3.0%(based on the mass of ethyl acetate)had a surface contact angle of 156°±2°and a rolling angle of 0.3°±0.1°,exhibiting excellent self-cleaning activity.Moreover,its sunlight reflectance reached up to 95.3%with infrared emissivity>90%.The average film cooling was efficient,9.99℃lower than ambient temperature under direct sunlight.The self-cleaning property could keep the film from soil contamination and maintain the cooling performance.Furthermore,the film displayed good mechanical properties,friction resistance,and stability against acid/alkali solutions and UV light.