Porous sulfur-rich polymers from spirobifluorene-derivatives via inverse vulcanization for efficient Hg2+ capture

Abstract

There is a critical need for nanoporous materials for gas storage, molecular separations, and environmental remediation. However, generating porosity directly in as-made inverse vulcanized polymers has remained an unresolved and persistent challenge. Here we report the direct synthesis of porous, sulfur-rich polymers via inverse vulcanization in a single-step process that affords high specific surface area (up to 214 m² g⁻¹), a hierarchical micro-mesoporous structure, and sulfur content as high as 35 wt%. This is demonstrated by reacting a molecularly rigid and contorted three dimensional monomer (spirobifluorene derivative-2,2′,7,7′-tetraethynyl-9,9′-spirobi[fluorene], TEF) promoting the formation of porosity in an inverse vulcanization process to ensure high sulfur contents. The approach makes the resulting TEF-S polymers highly promising for Hg²⁺ capture in wastewater treatment applications, and they maintain their performance even in the presence of competing ions. As a result, TEF-S highlights the potential of rigid olefinic molecules in designing porous inverse-vulcanized functional materials, paving the way for future innovation in this field.