Ultralight and hydrophobic nanofibrillated cellulose aerogels from coconut shell with ultrastrong adsorption properties

Ultralight aerogels based on nanofibrillated cellulose (NFC) isolated from coconut shell were successfully prepared via a mild fast method, which included chemical pretreatment, ultrasonic isolation, solvent exchange, and tert-butanol freeze drying. The as-prepared NFC aerogels with complex three-dimensional fibrillar networks had a low bulk density of 0.84 mg/cm(3) (specific surface area=9.1 m(2)/g and pore volume=0.025 cm(3)/g), maintained a cellulose I crystal structure, and showed more superior thermal stability than the coconut shell raw materials. After the hydrophobic modification by methyl trichlorosilane (MTCS), the NFC aerogels exhibited high water repellency properties, an ultrastrong oil-adsorption capacity (542 times that of the original dry weight of diesel oil), and superior oil-water separation performance. Moreover, the absorption capabilities of the MTCS-treated NFC aerogels were as high as 296-669 times their own weights for various organic solvents and oil. Thus, this class of high-performance adsorbing materials might be useful for dealing with chemical leaks and oil spills. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42037.