Preparation and Properties of Novel Superhydrophobic Cellulose Nanofiber Aerogels

The superhydrophobic cellulose nanofiber aerogels were prepared via sol-gel and subsequent freeze-drying with cellulose nanofibers as raw materials and perfluorohexyl ethyl trimethoxysilane and 3-aminopropyl trimethoxysilane as modifying monomers. The effect of volume ratio and total dosage of the two modifying monomers on the superhydrophobic properties was investigated, and the property variations of the cellulose nanofibers before and after modification were also characterized by FT-IR, XRD, TGA, SEM, XPS, and laser flash diffusivity apparatus. The results showed that the modifying monomers were successfully grafted onto cellulose nanofibers, and the prepared modified cellulose nanofiber aerogels had higher thermal stability. After modification, a micron-level arrayed three-dimensional grid superhydrophobic surface structure was constructed, and the surface energy was reduced. The prepared aerogels exhibited superhydrophobicity with a water contact angle up to 151° and excellent thermal insulation performance with a thermal conductivity of 0.035 W·m−1·K−1, which displayed promising application potential in the field of thermal insulation and waterproof materials.