An environmentally friendly method to fabricate superhydrophobic cellulose fiber for oil absorption

The complex preparation process, high cost, and use of non-renewable materials limit the marketization of most synthetic superhydrophobic oil-absorbing sponges. This work provides a preparation method of superhydrophobic and nontoxic oil absorbents by surface modification of pulp cellulose fibers. A simple hydrothermal method was used to in situ grow micron-scale petal-like γ-AlOOH layers on the surface of cellulose fibers pretreated with ultrasonication and swelled with urea, and then modified with low surface energy to prepare superhydrophobic cellulose fibers. The obtained cellulose fibers have high oil absorption property, fast absorption speed and high recyclability. The fibers exhibit excellent superhydrophobic stability in boiling water, various corrosive solutions and even high-temperature combustion environments, proving that it has the ability to absorb oil in harsh environments. In addition, after being connected to a vacuum filtration device, the as-prepared fibers can continuously separate the n-hexane solution of 200 quilts of its own weight within 15 s. And in the experiment of simulating turbulent water flow, they can still effectively remove oil from oil-water mixture. More importantly, the fiber can separate micro-nano scale oil droplets from the oil (n-hexane)-in-water emulsion with a separation rate up to 93.15% (solution transparency). All these excellent properties show that the prepared fibers have high application value in the fields of marine oil spill absorption and oil-water separation.