A functionalized nano-structured cellulosic sorbent aerogel for oil spill cleanup: Synthesis and characterization

A new synthesis strategy was adopted to convert cellulose to a biodegradable sorbent with properties of very high oil absorption and retention capacities, excellent oil-water selectivity, good mechanical strength and recycling ability. The sorbent in form of a hydrophobic/oleophilic nano-structured aerogel was prepared through functionalizing cotton cellulose with low surface energy moieties followed by dissolving and chemically cross-linking the product in an organic medium (DMSO), and freeze-drying. High absorption capacities of 40.7, 57.1, and 47.3 g/g were achieved for three different light crude oils at 25 °C which is comparable with most synthetic oil sorbents. Washburn's model was utilized to describe the wicking dynamics and fluid flow through the pores and to evaluate the effects of all important factors on the sorption process. Via comparing the experimental data with the predictions made by the model, it was revealed that unlike other cellulose-based oil sorbents reported in the literature, the swelling of fibrous network in the synthesized aerogel plays an important role in the absorption process besides the capillary pressure, resulting in a very good oil retention capacity and at the same time lowering the absorption rate, especially for viscose organic liquids.