Dodecyl Mercaptan Functionalized Copper Mesh for Water Repellence and Oil-water Separation

Yanling Tian,Jiekai Feng,Zexin Cai,Yuxiao Cui,Faze Chen,Jiaqi Chao,Dawei Zhang

doi:10.1007/s42235-021-0062-7

Abstract

Reckless discharge of industrial wastewater and domestic sewage as well as frequent leakage of crude oil have caused serious environmental problems and posed severe threat to human survival. Various nature inspired superhy-drophobic surfaces have been successfully applied in oily water remediation. However, further improvements are still urgently needed for practical application in terms of facile synthesis process and long-term durability towards harsh environment. Herein, we propose a simple one-step dodecyl mercaptan functionalization method to fabricate Super-hydrophobic-Superoleophilic Copper Mesh (SSCM). The prepared SSCM possesses excellent water repellence and oil affinity, enabling it to successfully separate various oil-water mixtures with high separation efficiency (e.g., > 99% for hexadecane-water mixture). The SSCM retains high separating ability when hot water and strong corrosive aqueous solutions are used to simulate oil-water mixtures, indicating remarkable chemical durability of the dodecyl mercaptan functionalized copper mesh. Additionally, the efficiency can be well maintained during 50 cycles of separation, and the water repellence is even stable after storage in air for 120 days, demonstrating the reusability and long-term stability of the SSCM. Furthermore, the functionalized mesh also shows good mechanical robustness towards abrasion by sandpaper, and oil-water separation efficiency of > 96% can be obtained after 10 cycles of abrasion. The reported one-step dodecyl mercaptan functionalization could be a simple method for increasing the water repellence of copper mesh, and thereby be a great candidate for treating large-scale oily wastewater in harsh environments.

Highlights

Frequent occurrence of oil spills, and massive discharge of industrial and domestic oily wastewater make the problem of oil and water pollution increasingly serious, causing great harm to the ecological environment[1,2,3,4]
When the CM was immersed into dodecyl mercaptan ethanol solution, a direct adsorption chemical reaction occurred on the surface, which was accompanied by oxidative addition to the surface bonds of the CM and the reduction of hydrogen elimination[46]: 2CH3 CH2 10 CH2SH 2Cu
The micro/nano structures and the low surface energy of the self-assembled monolayers enabled the CM to be superhydrophobic by this one-step adsorption reaction

Summary

Introduction

Frequent occurrence of oil spills, and massive discharge of industrial and domestic oily wastewater make the problem of oil and water pollution increasingly serious, causing great harm to the ecological environment[1,2,3,4]. Ansah et al prepared various morphologies of Cu(OH) and CuO on CM, such as needle-shaped, hair-shaped and arch-shaped structures, which were further modified with fluorosilanes to obtain superhydrophobic surfaces[44] Those universal synthesis methods are relatively complex and environmentally-unfriendly, often requires two steps consisting of building micro-nanostructures and low surface energy material modification, and the direct construction of superhydrophobic surfaces by a one-step method with good durability towards harsh environments (e.g., corrosive aqueous solutions) remains a great challenge[45]. It is of great relevance and urgency to develop a robust superhydrophobic interface with simple preparation process and high environmental adaptability

Methods

Results

Conclusion