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.

Key words： superhydrophilicity; superoleophobicity; oil--water separation; sponge; water collection; anti-fouling property

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.

References

1 Schrope M. Oil spill: Deep wounds. Nature, 2011, 472(7342): 152–154

PMID

2 Wang B, Liang W, Guo Z, . Biomimetic super-lyophobic and super-lyophilic materials applied for oil/water separation: a new strategy beyond nature. Chemical Society Reviews, 2015, 44(1): 336–361

PMID

3 Ge J, Zhao H Y, Zhu H W, . Advanced sorbents for oil-spill cleanup: recent advances and future perspectives. Advanced Materials, 2016, 28(47): 10459–10490

PMID

4 Nordvik A B, Simmons J L, Bitting K R, . Oil and water separation in marine oil spill clean-up operations. Spill Science & Technology Bulletin, 1996, 3(3): 107–122

5 Chu Z, Feng Y, Seeger S. Oil/water separation with selective superantiwetting/superwetting surface materials. Angewandte Chemie International Edition, 2015, 54(8): 2328–2338

PMID

6 Peng Y B, Guo Z G. Recent advances in biomimetic thin membranes applied in emulsified oil/water separation. Journal of Materials Chemistry A: Materials for Energy and Sustainability, 2016, 4(41): 15749–15770

7 Ma Q, Cheng H, Fane A G, . Recent development of advanced materials with special wettability for selective oil/water separation. Small, 2016, 12(16): 2186–2202

PMID

8 Ge B, Zhang Z, Zhu X, . A graphene coated cotton for oil/water separation. Composites Science and Technology, 2014, 102: 100–105

9 Zhu X, Zhang Z, Ge B, . A versatile approach to produce superhydrophobic materials used for oil–water separation. Journal of Colloid and Interface Science, 2014, 432: 105–108

PMID

10 Li J, Kang R, Zhang Y, . Facile fabrication of superhydrophobic meshes with different water adhesion and their influence on oil/water separation. RSC Advances, 2016, 6(93): 90824–90830

11 Ren G, Song Y, Li X, . A superhydrophobic copper mesh as an advanced platform for oil–water separation. Applied Surface Science, 2018, 428: 520–525

12 Guan H, Cheng Z, Wang X. Highly compressible wood sponges with a spring-like lamellar structure as effective and reusable oil absorbents. ACS Nano, 2018, 12(10): 10365–10373

PMID

13 Yu T L, Lu S X, Xu W G. A reliable filter for oil–water separation: Bismuth coated superhydrophobic/superoleophilic iron mesh. Journal of Alloys and Compounds, 2018, 769: 576–587

14 Xue Z, Wang S, Lin L, . A novel superhydrophilic and underwater superoleophobic hydrogel-coated mesh for oil/water separation. Advanced Materials, 2011, 23(37): 4270–4273

PMID

15 Kota A K, Kwon G, Choi W, . Hygro-responsive membranes for effective oil–water separation. Nature Communications, 2012, 3(1): 1025

PMID

16 He K, Duan H, Chen G Y, . Cleaning of oil fouling with water enabled by zwitterionic polyelectrolyte coatings: overcoming the imperative challenge of oil–water separation membranes. ACS Nano, 2015, 9(9): 9188–9198

PMID

17 Yang R, Moni P, Gleason K K. Ultrathin zwitter ionic coatings for roughness-independent underwater superoleophobicity and gravity-driven oil–water separation. Advanced Materials Interfaces, 2015, 2(2): 1400489

18 Gao S, Sun J, Liu P, . A robust polyionized hydrogel with an unprecedented underwater anti-crude-oil-adhesion property. Advanced Materials, 2016, 28(26): 5307–5314

PMID

19 Zhang S, Jiang G, Gao S, . Cupric phosphate nanosheets-wrapped inorganic membranes with superhydrophilic and outstanding anticrude oil-fouling property for oil/water separation. ACS Nano, 2018, 12(1): 795–803

PMID

20 Yang H C, Xie Y, Chan H, . Crude-oil-repellent membranes by atomic layer deposition: oxide interface engineering. ACS Nano, 2018, 12(8): 8678–8685

PMID

21 Wenzel R N. Resistance of solid surfaces to wetting by water. Industrial & Engineering Chemistry, 1936, 28(8): 988–994

22 Jung Y C, Bhushan B. Wetting behavior of water and oil droplets in three-phase interfaces for hydrophobicity/philicity and oleophobicity/philicity. Langmuir, 2009, 25(24): 14165–14173

PMID

23 Yang J, Zhang Z, Xu X, . Superhydrophilic–superoleophobic coatings. Journal of Materials Chemistry, 2012, 22(7): 2834– 2837

24 Xu Z, Zhao Y, Wang H, . A superamphiphobic coating with an ammonia-triggered transition to superhydrophilic and superoleophobic for oil–water separation. Angewandte Chemie International Edition, 2015, 54(15): 4527–4530

PMID

25 Zhu Q, Tao F, Pan Q. Fast and selective removal of oils from water surface via highly hydrophobic core–shell Fe₂O₃@C nanoparticles under magnetic field. ACS Applied Materials & Interfaces, 2010, 2(11): 3141–3146

PMID

26 Calcagnile P, Fragouli D, Bayer I S, . Magnetically driven floating foams for the removal of oil contaminants from water. ACS Nano, 2012, 6(6): 5413–5419

PMID

27 Chen N, Pan Q. Versatile fabrication of ultralight magnetic foams and application for oil–water separation. ACS Nano, 2013, 7(8): 6875–6883

PMID

28 Fowkes F M. Attractive force at interface. Industrial & Engineering Chemistry, 1964, 56(12): 40–52

29 Owens D, Wendt R. Estimation of the surface free energy of polymers. Journal of Applied Polymer Science, 1969, 13(8): 1741–1747

30 Wang Y, Di J, Wang L, . Infused-liquid-switchable porous nanofibrous membranes for multiphase liquid separation. Nature Communications, 2017, 8(1): 575

31 Tian X, Verho T, Ras R H A. Moving superhydrophobic surfaces toward real-world applications. Science, 2016, 352(6282): 142–143

PMID