Preparation of Superhydrophobic PU@CuS via Electroless Plating and Its Application on Photothermal-Assisted Separation of High-Viscosity Crude Oil from Water
Yunpeng Liu, Enyu He, Sanjay S. Latthe, Rajaram S. Sutar, Ruimin Xing, Renbao Zhao, Xuesong Huang, Shanhu Liu
Abstract
Crude oil spills pose serious challenges due to low fluidity and high viscosity. Researchers are exploring a range of sustainable cleanup solutions, such as using heating components to reduce oil viscosity. Herein, an electroless plating technique was adopted for depositing copper sulfide (CuS) on a polyurethane (PU) sponge by a coordination strategy. Subsequently, a layer of octadecyltrichlorosilane (OTS) was deposited to enhance the surface oil absorption ability. The PU@OTS-CuS sponge has demonstrated superhydrophobicity and remarkable oil absorption capability ranging from 11.5 to 47 g/g for oils with diverse viscosities. Moreover, it has sustained its 22.5 g/g oil absorption capacity for lubricant oils and separation efficiency of over 97% for the n -hexane and dichloromethane–water mixture even after undergoing 10 cycles. The surface temperature of the modified sponge was increased to 74 °C within 180 s under 1 sun irradiation and a sustained crude oil absorption capacity of 20 g/g even after 10 cycles. In continuous crude oil remediation, the modified sponge collected 3.257 g within 15 min at a rate of 0.542 g/min. Additionally, the modified sponge revealed superior stability against immersion in seawater and different pH solutions, exposure to UV light, sand abrasion, mechanical compression, and cyclic photothermal performance. This research presents a new strategy for depositing a photothermal component on sponge surfaces to improve crude oil cleanup.