Synthesis of superhydrophobic ultralight aerogels from nanofibrillated cellulose isolated from natural reed for high-performance adsorbents

Reed is one of the widely available aquatic plant resources, and its applications are generally limited to some traditional areas like papermaking and animals' fodder. Besides, most of reed is wasted or directly burned every year causing serious air pollution (like atmospheric haze). Therefore, it is worth to further develop new forms of high-value applications of reed. Herein, natural reed was collected to fabricate ultralight adsorbents namely nanofibrillated cellulose (NFC) aerogels via an easily operated method, which includes chemical purification, ultrasonication, and freeze drying. The NFC aerogels with an ultra-low density of 4.9 mg cm(-3) were characterized by scanning electron microscopy, energy-dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. For acquiring good hydrophobicity, the NFC aerogels were subjected to a hydrophobic treatment by methyltrichlorosilane. The superhydrophobic NFC aerogels with contact angles of as high as 151 degrees-155 degrees have excellent adsorption efficiency (53-93 g g(-1)) for various organic solvents and waste oil. More importantly, the aerogels also exhibit favorable adsorption recyclability, which can maintain more than 80 % of the initial adsorption efficiency after the five cycles.