Efficient oil-water separation and iodine adsorption using fluorine-enriched conjugated microporous polymer-coated sponge

A one-pot Sonogashira-Hagihara coupling procedure was employed to develop a fluorine-enriched conjugated microporous polymer-coated sponge (CMP-F@sponge), which exhibited superhydrophobicity with a water contact angle of 154.8 degrees. The oil-water separation capacity and iodine capture capacity of the CMP-F@sponge were assessed. Incorporating fluoroalkyl chains reduced the material's surface energy, and increasing its hydrophobic properties. These sponges showed remarkable oil-water separation capabilities, achieving 99.2 % separation efficiency, demonstrating suitability for separating emulsified oils. CMP-F@sponge could adsorb a variety of oils up to 125 times its own weight and maintained high performance after 10 adsorption-desorption cycles. Remarkably, the superhydrophobic sponges achieved a separation efficiency of 99.3 % using a vacuum pump system, which imparted them with a continuous-oil-collection ability, effectively addressing large-scale oil spills. Furthermore, CMP-F@sponge could efficiently adsorb iodine from a cyclohexane solution with an adsorption efficiency of 84 %. The DFT and ESP calculations show that the structural units in the CMP-F contribute greatly to its iodine adsorption capacity. The presence of C-F, C=O, and it-conjugated systems created high-affinity binding sites for Lewis acidic iodine molecules, leading to the formation of polyiodides I3- and I5- . The higher mechanical stability makes the CMP-F@sponge as a promising candidate for industrial oil spill treatment and iodine removal applications from organic waste liquid.