An unusual superhydrophilic/superoleophobic sponge for oil--water separation

Abstract

Development of porous materials with anti-fouling and remote control- lability is highly desired for oil–water separation application yet still challenging. Herein, to address this challenge, a sponge with unusual superhydrophilicity/superoleophobicity and magnetic property was fabricated through a dip-coating process. To exploit its superhydrophilic/superoleophobic property, the obtained sponge was used as a reusable water sorbent scaffold to collect water from bulk oils without absorbing any oil. Owing to its magnetic property, the sponge was manipulated remotely by a magnet without touching it directly during the whole water collection process, which could potentially lower the cost of the water collection process. Apart from acting as a water-absorbing material, the sponge can also be used as affiliation material to separate water from oil–water mixture and oil in water emulsion selectively, when fixed into a cone funnel. This research provides a key addition to the field of oil–water separation materials.

Keywords

superhydrophilicity / superoleophobicity / oil--water separation / sponge / water collection / anti-fouling property

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Disclosure of potential conflicts of interests

The authors declare no potential conflicts of interests.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 11704321) and the Natural Science Foundation of Shandong Province (ZR2016JL020 and ZR2019MEM044), and the Yantai Science and Technology Plan Projects (2019XDHZ087).

Appendix

The video found at https://doi.org/10.1007/s11706-020-0516-6 shows application of the obtained sponge in collection of water from bulk oil with the assistance of a magnet.

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