Synergistic effect of nano-silica and eco-friendly hydrogel for the cost-effective and highly efficient oil-water separation

Reported herein is a novel eco-friendly and low-cost oil-water separation mesh that can achieve a high separation efficiency up to 99%, while the prepared mesh maintained excellent performance even after immersion in salty water for 5 days, or cycle use for 20 times. The superhydrophilic and underwater superoleophobic mesh was modified with a layer of rough nano silica by soot template method firstly, and then the mesh was covered with the calcium alginate hydrogel coating via a simple dip-coating method. The synergistic effect of the low-cost nano-silica and environmentally friendly calcium alginate hydrogel not only endowed the mesh with outstanding oil-water separation performance but also overcame the shortcoming of high-cost and pollutive in the fabrication of oil-water separation materials. The prepared mesh maintained excellent oil-water separation efficiency and water permeation flux, even after treatment in various harsh environments. The cost-effective and eco-friendly oil-water separation mesh holds great potential in the treatment of industrial and domestic waste oil.