Emulsion templated dual crosslinked core-sheath fibrous matrices for efficient oil/water separation

Oil-contaminated water and its purification is a major challenge and efforts in this direction have accumulated immensely over past decades as the depletion of freshwater resources is also seen in parallel. Electrospun fibrous matrices used for this purpose offer several attractive features including porous nature, high surface area, ease of fabrication and functionalization. However, poor mechanical strength and separation capacity of electmspun matrices have restricted their use. In this report, fabrication of robust, dual crosslinked fibrous matrices via emulsion electrospinning is presented. A unique near-gel resin based oil-in-water emulsion was developed as the precursor for electrospinning. Fibres had uniform core-sheath morphology formed by crosslinked polystyrene as core and crosslinked polyvinyl alcohol as sheath, thereby having distinct domains to selectively adsorb oil and water. Post-electrospinning crosslinking was optimized to achieve matrices of excellent dimensional stability, selective wettability, and hydration ability. The dual crosslinked structure of the nanofibres was responsible for not only high oil adsorption (approximate to 3305%) but also efficient oil/water emulsion separation with 99% separation efficiency and a flux up to 3000 L m(-2) h(-1). The matrices were successfully used up to 10 separation cycles without any structural disintegration or decline in separation performance, thereby reflecting their suitability for oil/water separation.

Automated summary

This study presents the fabrication of robust, dual crosslinked fibrous matrices via emulsion electrospinning, which exhibit excellent oil adsorption and oil/water emulsion separation efficiency, along with good durability and performance stability.