Integrated asymmetric cellulose aerogel membrane with triple thermal insulation and unidirectional liquid penetration for personal thermal management

With the rapid development of personal thermal management, there is an urgent need for an advanced material that can effectively integrate various thermal functions to keep body warm and cope with the cold outdoor environment. Herein, a multifunctional cellulose based asymmetric modification aerogel membrane (ACAM) encompassing thermal insulation, thermal radiation reflection, solar adsorption, and directional perspiration has been fabricated via bottom-up assembling biomass sisal fibers and pulp fibers into cellulose aerogel membrane, followed by spin-coating ionic liquid modified graphene (IGNs) and silver nanowires (AgNWs) on both sides of the cellulose aerogel membrane, respectively. The results showed that the temperature on the IGNs side is 14.2 °C higher than that of the cotton cloth after 30 s of sunlight exposure. Compared with pure cellulose aerogel membrane, the AgNWs side of ACAM has lower infrared emissivity and higher infrared reflectivity, and the temperature is reduced by 3.2 °C in indoor environment. In addition, the ACAM has asymmetric wettability, which facilitates the transfer of sweat from the hydrophobic side to the hydrophilic side and perspiration penetration was achieved in 10.6 s to obtain the comfort of wearing. The ACAM also exhibits excellent breathability, easy preparation and controllable functional structures. This work may provide a new idea for heat management and dynamic moisture to ensure maximum comfort in very harsh environments.