Low-Cost Hyperelastic Fuller-Dome-Structured Nanocellulose Aerogels by Dual Templates for Personal Thermal Management

It is critically important to maintain the body's thermal comfort for human beings in extremely cold environments. Cellulose nanofibers (CNF)-based aerogels represent a promising sustainable material for body's heat retention because of their renewability and low thermal conductivity. However, CNF-based aerogels often suffer high production costs due to expensive CNF, poor elasticity and/or unsatisfactory thermal insulation owing to improper microstructure design. Here, a facile dual-template strategy is reported to prepare a low-cost, hyperelastic, superhydrophobic Fuller-dome-structured CNF aerogel (CNF@PU) with low thermal conductivity. The combination of air template by foaming process and ice template enables the formation of a dome-like microstructure of CNF@PU aerogel, in which CNF serves as rope bars while inexpensive polyurethane (PU) acts as joints. The aerogel combines ultra-elasticity, low thermal conductivity (24 mW m^-1 K^-1), and low costs. The as-prepared CNF@PU aerogel demonstrates much better heat retention than commercial thermal retention fillers (e.g., Flannelette and goose down), promising its great commercial potential for massively producing warming garments. This work provides a facile approach for creating high-performance aerogels with tailored microstructure for effective personal thermal management.