Solution-based Sulfur-Polymer Coating on Nanofibrillar Films for Immobilization of Aqueous Mercury Ions

Abstract

Herein, we report the solution-based method for coating sulfur polymers on various substrate materials. First, sulfur polymers were synthesized by reacting elemental sulfur and 1,3-diisopropenylbenzene and dissolved in various organic solvents to search for solvents with good solubility. Next, the trend in film thickness of sulfur-polymer coating was systematically examined using the sulfur-polymer solutions in dichlorobenzene (DCB) and various materials with different surface energy. The nanofibrillar film made of the poly(vinyl alcohol) and poly(acrylic acid) (PVA-PAA) blend exhibited the most uniform/conformal deposition of sulfur polymer via dipping-coating, indicating that the DCB solution is most suitable for the well-controlled deposition of sulfur polymer on nanostructured materials with higher surface energy than 40 mN/m. Finally, the resultant sulfur polymer-coated nanofibrillar film showed high mercury ion uptake capacity (26 mg/g with 50 ppm Hg solution) even with a small amount of sulfur-based adsorbent (20 mg) loading on the film (40 mg). Our study suggests that the sulfur polymer solution can introduce the crucial properties of elemental sulfur on the surface of any conventional materials even with mechanical flexibility and nano/microscale structural complexity.