Magnetic nanocellulose-magnetite aerogel for easy oil adsorption

Hypothesis: Cellulose aerogels are a new category of high-efficiency adsorbents for treating oil spills and water pollution. However, the hydrophilic properties and recyclability of aerogels after adsorption hamper developments and applications. Combining both hydrophobic and magnetic properties are expected to improve their adsorption capacity and functionality. Experiments: In this study, the effect of oleic acid (OA) and nanomagnetite on the preparation of magnetic nanocellulose aerogels (called as NCA/OA/Fe3O4) by a mechanical mixing combined with freeze-drying method have been investigated. Findings: It has been found that the optimal condition for fabricating this NCA/OA/Fe3O4 aerogel is 0.4 wt % nanocellulose, 3 mg mL(-1) OA and 0.5 wt% Fe3O4 in the aqueous solution. This aerogel has a very low density of 9.2 mg cm(-3) and demonstrates a high adsorption capacity of 68.06 g g(-1) for cyclohexane. In addition, this aerogel adsorbent demonstrates an excellent magnetic responsivity and can be easily recycled by a permanent magnet after adsorption. As a consequence, this hydrophobic magnetic NCA/OA/Fe3O4 aerogel is promising not only for easy oil and organic solvent adsorption but also potentially for other magnetic related applications. (C) 2019 Elsevier Inc. All rights reserved.