Bilayer Nanoporous Polyethylene Membrane with Anisotropic Wettability for Rapid Water Transportation/Evaporation and Radiative Cooling

Abstract

Both sweat drainage and evaporation play important roles in achieving personal moisture and thermal management during sweat-producing exercises. However, it remains a great challenge to simultaneously realize thermal management through radiative cooling for human body without perspiration. Herein, we report a bilayer nanoporous polyethylene membrane with anisotropic wettability, which possesses superior radiative cooling ability (∼2.6 °C lower than that of cotton) without perspiration. Meanwhile, it realizes efficient sweat drainage and good evaporation cooling property (∼1.0 °C lower than that of cotton) in perspiration to avoid sticky and hot sensation. In addition, it can also block water and fine particulate matter owing to the hydrophobic nanoporous structure. By virtue of the outstanding personal thermal and moisture management performance, it is expected that this study provides inspiration for designing new clothing and medical protective suits with more comfortable microclimates and reducing energy consumption for global sustainability.

Ordered-Porous-Array Polymethyl Methacrylate Films for Radiative Cooling

“…The optical properties of PMMA are discussed in this section before and after pore-forming. The extinction coefficient ( k ) is an important parameter that reflects the emission performance of the material in the infrared spectral band. , The reflection index ( n ) and extinction coefficient ( k ) are both shown in Figure a,b, respectively, based on refs and. It was shown that the multiple extinction peaks of PMMA were found in the transparent window band of the atmosphere.…”

Gradient monolayered porous membrane for liquid manipulation: from fabrication to application

“… 59 And Zhao's group reported a porous polyethylene membrane with anisotropic wettability, which could possess superior radiative cooling ability without perspiration. 102 …”

Janus Membrane Decorated by MXene Multilayered Nanoflakes for Wet–Thermal Management

“…Perspiration evaporation plays an indispensable role in human wet regulation. Avoiding increased sweat or moisture on the skin becomes the focus of wet management . Traditional textiles, such as cotton and silk fabric, − show excellent water adsorption capacity resulting from their wicking behavior and drain out sweat or moisture from the human skin effectively, alleviating the sense of wettedness quickly .…”

“…Avoiding increased sweat or moisture on the skin becomes the focus of wet management. 1 Traditional textiles, such as cotton 2 and silk fabric, 3−5 show excellent water adsorption capacity resulting from their wicking behavior and drain out sweat or moisture from the human skin effectively, alleviating the sense of wettedness quickly. 6 However, such a wicking behavior shows the so-called bidirectional property, that is, sweat or moisture can be transported from the human skin to the environment as well as in the reverse direction.…”