Down Fiber Reinforced Cellulose Nanofiber Aerogel toward Thermal Insulation and Pollutant Removal

Abstract

Cellulose nanofiber (CNF) aerogels have the advantages of being eco-friendly, hydrophilic, and biocompatible and of having high porosity and large surface area. but low mechanical durability is a main challenge. In this regard, we proposed to fabricate a DF-x/CNF-y composite aerogel through a directional freeze-drying method using down fiber (DF) as the reinforcing filler and 1,2,3,4-butanetetracarboxylic acid (BTCA) as the cross-linking agent. Due to the good compatibility between DF and CNF, DF could effectively improve the strength of a composite aerogel by dispersing stress along the pore wall. The DF-x/CNF-y composite aerogel had significant longitudinal and transversal mechanical properties. The presence of DF in the matrix promoted crystal nucleation and provided a large surface area for crystal growth, which improved thermal stability and thermal insulation performances of the composite aerogel. The capillary effect of hollow DF and the interaction between DF and CNF significantly enhanced the DF-x/CNF-y composite aerogel adsorption performance. Methylene blue (MB) was chosen as a model pollutant. The removal rate of MB correlated well with the pseudo-second-order kinetics and Langmuir model (R2 [0.9999]), its maximum adsorption capacity for MB reached up to ∼250.21 mg/g. This work provides a strategy for the fabrication of a composite aerogel, which might have potential application prospects such as space, infrared stealth, water purification, and chemical contaminant remediation.