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

Abstract

Heat preservation, breathability, and unidirectional liquid penetration properties of wearable materials are vital for personal thermal management applications. Herein, flexible 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 °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.

Wearable Aerogels for Personal Thermal Management and Smart Devices

“…146 Besides aerogel fibers, aerogel films are also excellent potential wearable candidates for thermal insulation in PTM. For instance, Zhang et al 147 aerogel film was a promising PTM candidate to form a comfortable microclimate in outdoor environments. 147 Table 1 summarizes the wearable aerogels for thermal insulation mentioned above and other related excellent works, as well as their corresponding thermal conductivities.…”

“…For instance, Zhang et al 147 aerogel film was a promising PTM candidate to form a comfortable microclimate in outdoor environments. 147 Table 1 summarizes the wearable aerogels for thermal insulation mentioned above and other related excellent works, as well as their corresponding thermal conductivities. The aerogels were composed of Kevlar, PI, SiC, chitosan, graphene, PVA, cellulose, etc., in the form of films, fabrics, and textiles.…”

“…Besides aerogel fibers, aerogel films are also excellent potential wearable candidates for thermal insulation in PTM. For instance, Zhang et al reported a flexible Kevlar aerogel film that featured wearability, breathability, and unidirectional liquid penetration. The aerogel film was prepared by underwater protection spraying of polydimethylsiloxane (PDMS) in trichlorotoluene onto one side of a Kevlar aerogel film and magnetron sputtering Al nanoparticles on the other side (Al-KAM-PDMS).…”

Properties and application of Kelvar and its composites

“…Yongfang Chen et al reported that Kelvar also has breathable and unidirectional liquid permeation properties, which could help designers design versatile flexible wearable Kevlar aerogels [11]. Wearable materials have become an important part of daily life and an essential requirement for individuals.…”