Superhydrophobic DTMS/rGO-nanocomposites modified polyurethane sponge for efficient oil–water separation

ABSTRACT

Dodecyltrimethoxysilane (DTMS)-modified reduced graphene oxide (rGO) nanocomposites were incorporated into polyurethane (PU) sponges by a combination of dip-coating and thermal curing reduction reaction to obtain a novel superhydrophobic DTMS-rGO-PU sponge for effective oil/water separation. The reaction conditions, such as the dip-coating solution concentration, the thermal curing reduction temperature, and the reaction time were demonstrated to be key factors in forming hierarchical DTMS-rGO nanocomposites, which significantly affected the surface wettability of the PU sponge. The resulting DTMS-rGO-PU sponge with a static water contact angle (WCA) of 152.2° displayed superior superhydrophobicity, and achieved an oil–water separation efficiency of 99.89% for various oil/water mixtures. This superhydrophobic sponge also showed minimal deterioration in its high oil adsorption capacity after 100 recycled adsorption operations. Furthermore, the as-prepared DTMS-rGO-PU sponge was proven to be physically and chemically stable and durable in harsh environmental conditions, suggesting its potential for industrial applications in oil spillage management.

KEYWORDS:

• Superhydrophobic
• sponge
• graphene
• mixture
• separation

Acknowledgements

The authors express their appreciation to Dr Yingming Zhu from the New Energy and Low Carbon Technology of Sichuan University for the SEM and XRD spectra measurements, Dr Xiang Lin, Mr Pan Wu, and Dr Jie Wei from the Engineering Teaching Centre, School of Chemical Engineering, Sichuan University for the FTIR and Raman spectra measurements, and Mr Jingshui Liu from Shiyanjia Lab (www.shiyanjia.com) for the XPS analysis. These invaluable contributions to the research are gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number 21978182]; Sichuan Province Science and Technology Support Program [grant number 2021YFH0045].