Fluorine-Free Oil Absorbents Made from Cellulose Nanofibril Aerogels

Abstract

Aerogels based on cellulose nanofibrils (CNFs) have been of great interest as absorbents due to their high absorption capacity, low density, biodegradability, and large surface area. Hydrophobic aerogels have been designed to give excellent oil absorption tendency from water. Herein, we present an in situ method for CNF surface modification and hydrophobic aerogel preparation. Neither solvent exchange nor fluorine chemical is used in aerogel preparations. The as-prepared hydrophobic aerogels exhibit low density (23.2 mg/cm(-3)), high porosity (98.5%), good flexibility, and solvent-induced shape recovery property. Successful surface modification was confirmed through field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and water contact angle measurements. The hydrophobic aerogels show high absorption capacities for various oils, depending on liquid density, up to 47× their original weight but with low water uptake (<0.5 g/g aerogel).

Superhydrophobic hBN-Regulated Sponges with Excellent Absorbency Fabricated Using a Green and Facile Method

“…Absorption of chloroform is almost two times as much as that of the pure sponge. Absorption capacity is obviously higher than many recent reported sorbents (Table 1), such as nitrogen-rich carbon aerogel10, CNT/PDMS coated PU sponge27, highly hydrophobic, fire-resistant (UHF) sponge30, cellulose nanofibril aerogels45 and micro-wrinkled reduced GO46. The capacity of hBN coated sponge is also higher than that of melamine sponge coated with exfoliated graphene (165 g.g −1 , or 153 g.g −1 )1523, reduced graphene (99 g.g −1 )24 and MoS 2 (159 g.g −1 )26.…”

Nanofibrillated cellulose composites and wood derived scaffolds for functional materials

“…An alternative strategy is to modify the NFC dispersions prior to the freeze or supercritical drying process. [108][109][110][111][112] In this way, the entire cellulose aerogel could be functionalized. For instance, Zhang et al 108 reported a facile process to prepare hydrophobic, exible, and low-density (#17.3 mg cm À3 ) cellulose aerogels by freeze-drying aqueous NFC suspensions with methyltrimethoxysilane (MTMS) as a silylating agent.…”

Micro–Nanocomposites in Environmental Management

“…It can be obtained from wood pulp, cotton, hemp, and some species of bacteria. In recent years, cellulose nanofibrils (CNFs) extracted from cellulose pulp have become a promising candidate for environmental applications because of their high surface areas, high aspect ratios, and biodegradability . For example, Chin et al prepared CNFs from kenaf core .…”