Heterogeneous wettable cotton based superhydrophobic Janus biofabric engineered with PLA/functionalized-organoclay microfibers for efficient oil-water separation

The recent requirement for superwettable materials for efficient absorption of heavy oils and waste organic solvents has led to the advancement of various functional materials, where the disposal and non-degradation of their constituents in the environment is a threat, contributing to global warming. In the present work, we report an in situ fabricated, heterogeneous wettable, and biodegradable PLA Janus fabric based on a cellulosic-substrate, functionalized with surface-modified nanoclay. The developed Janus fabric, which is fabricated via an efficacious electrospinning technique, possesses superhydrophobicity (WCA ∼ 152°)/superoleophilicity (OCA ∼ 0°) and low ice-adhesion, owing to its hierarchical textured morphology, as revealed by FE-SEM analysis, along with an excellent oil-water separation efficiency of 99.16%, which is maintained for 30 reusable washing cycles, and a maximum permeation flux of around 65000 l m-2 h-1 for n-hexane from a solvent-water mixture. More importantly, the reported Janus fabric demonstrates microbial and hydrolytic biodegradation with 78% weight loss in 28 days, at a rate of 2.79 ± 0.5% per day at room temperature, under an in-house developed biotic system constituted of decompost slurry. The FESEM analysis of the biodegraded samples revealed the presence of Gram-positive Bacillus polymyxa bacteria. Moreover, the engineered Janus fabric retains its inherent properties under various acidic and basic conditions (pH = 1 to 10), hyper-saline solutions (10% to 30%), mild-detergent solution, UV-radiation (254 nm), and sub-zero temperatures (-20 °C to 0 °C). The successive results demonstrate that the developed Janus fabric can be effectively used as a proficient biodegradable material for the efficient absorption of heavy oils/waste organic solvents in comparison with non-degradable synthetic materials.