Magnetic CNT microfibrillated cellulose of sugarcane bagasse (mCNT-MFCSCB) foam as oil sorbent

Adsorption/absorption methods are among the popular approaches to clean oil contaminants on water surfaces due to their simplicity, efficiency, and low cost. To date, there is still ongoing research to develop oil sorbent material with high oil selectivity and, thus, high sorption capacity using environmentally friendly approaches. Herein, we proposed the development of a new oil sorbent in the form of porous carbon foam prepared from plant- based microcellulose fiber that is eco-friendly, non-toxic, reasonably cheap, and efficient, thereby promising a potential industry-adaptable approach. Three-dimensional (3D) crosslinked microfibrillated cellulose of sugarcane bagasse (MFCSCB) foams were first prepared as a base material, and magnetic ferrite nanoparticles (Fe3O4) and carbon nanotubes (CNTs) were further mixed into the structure of MFCSCB foam to impose hydrophobic property and introduce magnetic behaviour required as a good oil sorbent material. The foam comprises a 3D interconnected structure of cellulose microfiber with high porosity embedded with CNT/Fe3O4 nanocomposite. Maximum oil sorption efficiency is achieved using Design Expert Software, where the response surface method (RSM) with a three-level, three-factor full factorial design was used. Independent factors selected in the preparation of the mCNT-MFC composite foams were the percentage of CNTs, freezing temperature, and sonication time. The sample with the highest oil sorption performance (5.05 ± 0.5 g/g) was obtained at 0.75% CNT, -140 ℃ freezing time, and a sonication time of 20minutes. Data inserted for the oil sorption optimization was the average value of triplicate samples with an average standard deviation of 0.5. The optimum sample was further characterized in detail using FESEM, FTIR, and XRD to understand the mechanism of oil sorption. The recyclability potential and oil sorption kinetics of the sample were also investigated. The mCNT-MFCs can selectively remove the oil from the oil/water interface with good oil sorption efficiency due to the presence of a highly porous structure and hydrophobic properties possessed by the composite, as well as easy oil recovery by a solvent removal approach.