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

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