Water-Soluble Ionic Liquid-Containing Sulfur Polymers for Mercury Capture, Demulsification, and Antibacterial Activity

Sulfur polymers, prepared by inverse vulcanization using elemental sulfur and vinylic monomers, are emerging functional materials of current research interest; however, sulfur polymers suffer from limited water solubility due to the hydrophobic nature of conventional comonomers and sulfur. Herein, the preparation of ionic liquid (IL)-containing sulfur polymers are reported using the hydrophilic ionic liquid, 1-allyl-3-vinylimidazolium chloride (AVImCl) as a comonomer. The introduction of IL significantly enhances the hydrophilicity of sulfur polymers, enabling them to dissolve in water. Benefiting from the thorough contact with aqueous mercury ions, the resultant sulfur polymer possesses high uptake capacity (436 mg g⁻¹). After binding mercury, a coordination complex is formed and precipitated. The charged sulfur polymers gain a new application in demulsification. The polymer quickly breaks oil-in-water (O/W) emulsions through anion exchange between Cl⁻ of the polymer and dodecylbenzenesulfonate (DBS⁻) of the surfactant. In addition, the polymer has a growth inhibitory effect against Staphylococcus aureus. The integration of IL and elemental sulfur provides a novel approach to modifying the wettability of sulfur polymers. Also, this novel water-soluble IL-containing sulfur polymer, with mercury capture, demulsification, and antibacterial activity, can be considered as a multifunctional material in practical water purification.