Hyperelastic Kevlar Nanofiber Aerogels as Robust Thermal Switches for Smart Thermal Management

Abstract

Scheme 1. Schematic of SPRG-TIC process for ultralight HEKAs and their application as on-off thermal switches.

Universal passive radiative cooling behavior of aerogels

“…Therefore, it can be observed that the chemical structures and morphologies of the six aerogels are quite different, especially the microstructure of the aerogels, which can represent almost all the reported aerogel structures. According to reported studies 17,47–51 and Fig. S2 ESI,† all the aerogels exhibit excellent mechanical properties, most of which exhibit robust flexibility.…”

“…The aerogels used in this study were synthesized according to our previous studies. 17,38,[47][48][49][50][51] The chemical structures and photo images of the aerogels are shown in Fig. 1a and b, respectively.…”

“…1a and b) were synthesized, and their PRC properties were studied. These aerogels include silica aerogel, 38 boron nitride (BN) aerogel, 47 reduced graphene oxide (GO) aerogel, 48 Kevlar aerogel, 49 poly(p-phenylene-2,6-benzobisoxazole) (PBO) aerogel, 50,51 and polyimide (PI) aerogel. 17 The above six aerogels include various chemical components (such as inorganic oxide aerogels, ceramic aerogels, carbon aerogels, and various organic polymer aerogels) and various microstructures (nanoparticles, nanoplates, and nanobers), which have been widely investigated, and their applications in thermal insulation have received extensive attention.…”

Ultrafine aramid nanofibers prepared by high-efficiency wet ball-milling-assisted deprotonation for high-performance nanopaper

“…electronegative surfaces, 6,7 show a flexible assembling ability like cellulose nanofibers (CNFs), for forming various microstructures (e.g., 2D films/papers, [8][9][10] 3D hydrogels/aerogels 11,12 ) with functional fillers (e.g., carbon nanotube, [13][14][15] graphene, 16 and MXene 17,18 ) by solution processing. Beyond CNF derivatives that are often limited by their water solubility and poor thermal stability, 19,20 ANF-based products reveal a high water-resistance and thermal stability due to their aramid backbones, and meanwhile inherit the outstanding mechanical properties from the pristine microfibers.…”

“…One-dimensional (1D) aramid nanofibers (ANFs) produced from aramid microfibers, with a nanoscale diameter (<20 nm), large aspect ratio, high specific surface area, and exposed electronegative surfaces, 6,7 show a flexible assembling ability like cellulose nanofibers (CNFs), for forming various microstructures ( e.g. , 2D films/papers, 8–10 3D hydrogels/aerogels 11,12 ) with functional fillers ( e.g. , carbon nanotube, 13–15 graphene, 16 and MXene 17,18 ) by solution processing.…”