Multifunctional Flexible Wearable Kevlar Aerogel Membranes with Breathable and Unidirectional Liquid Penetration Properties for Personal Thermal Management Application

Heat preservation, breathability, and unidirectional liquid penetration properties of wearable materials are vital for wearable Kevlar aerogel membranes with breathable and unidirectional liquid penetration properties were fabricated by underwater protection spraying of PDMS-trichlorotoluene onto one side of a Kevlar aerogel membrane and magnetron sputtering of Al nanoparticles on the other side of a Kevlar aerogel membrane PDMS (Al-KAM-PDMS). The results indicated that the PDMS side played an important role in improving the unidirectional liquid penetration property due to the asymmetric wettability property and an aerogel structure. To simulate unidirectional liquid penetration, simulated sweat can be penetrated from the PDMS side to the Al side of Al-KAM-PDMS within 14.4 s, implying excellent permeability. The Al side with high infrared reflectivity (72.77%) demonstrates that infrared radiation can be reflected back to the human body to achieve passive heating. An infrared image shows that Al-KAM-PDMS enables a simulated skin temperature decrease of 5 degrees C under a low temperature environment as compared to the Kevlar aerogel. The introduction of PDMS into Al-KAM-PDMS endows the membrane with high tensile stress of 5.60 MPa. In addition, Al-KAM-PDMS also possesses excellent breathability, showing its potential in wearable materials. Because of the exceptional unidirectional liquid penetration, breathability, and radiant heat insulation ability, Al-KAM-PDMS is a promising wearable material to help maintain a comfortable microclimate for individuals in outdoor environments.