A bio-based composite material for water remediation from oily contaminants

In this work, a novel composite sorbent material for water remediation from oily contaminants, based on a cellulose three-dimensional fibrous scaffold treated with stearic acid and expanded graphite flakes, is presented. The pristine cellulose foams are inherently omniphilic, absorbing indiscriminately both water and oils. However, after being modified with stearic acid and graphite via drop casting, they become superhydrophobic (still preserving their superoleophilic characteristics). As a result, the foams start exhibiting a highly selective behaviour which permits to absorb different kinds of oils and organic solvents, while repelling water completely. Thermal and chemical characterizations reveal that the modification treatment is successfully performed, while the performed mechanical tests demonstrate a good recovery of elasticity after repeated deformations and confirm that the elasticity of the foam is preserved after the treatment. Although based on natural materials, the fabricated foams exhibit oil absorption rate, saturation time and capacity values comparable to those of some synthetic materials with the same aim, exhibiting a very important added value, as it is based on low cost, green and biodegradable materials, requiring, at the same time, low processing costs and providing excellent reusability properties.