Sustainable 3D Nanofiber Aerogel Monoliths from Short Jute Fiber for Thermal Insulation

Abstract

Natural fiber-based sustainable aerogels have huge potential applications due to their low density, porous nanostructure, and high specific surface area. Here, the novel nanoporous three-dimensional (3D) jute nanofiber aerogel monoliths were successfully developed by a sol–gel–aerogel process, which were then analyzed and their potential application as thermal insulators evaluated. Acetone, an antisolvent, is used to regenerate short jute fiber (Corchorus capsularis) dissolved in dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride hydrate (TBAF) mixed solvents into wet gels. Wet gels are then dried by supercritical carbon dioxide (scCO₂) to obtain the jute nanofiber aerogels (JNAs). The gelation process, porosity, pore size, micromorphology, mechanical property, Brunauer–Emmett–Teller (BET) analysis (nitrogen gas adsorption), and thermal properties are carefully characterized. The findings indicate that the percentage of the fiber content in sols is related to the density of the nanofibrous structure, specific surface area, nanopore size, compressive modulus, and other properties as well. The aerogels have a very high specific surface area (172–1253 m² g^–1), very low density (0.0074–0.0490 g cm^–3), high compressive modulus (0.07–4.52 MPa), and high porosity (96.62–99.49%). Furthermore, attenuated total reflectance-Fourier transform infrared spectroscopy is used to confirm the possible existence of strong hydrogen bonds between the cellulose monomers. These nanostructures are an important factor to achieve the thermal insulation properties of JNAs, which make them suitable for a thermal insulator beneath metal roofing application.