Electrospun rubber nanofibrous membranes with thiol functionalization for heavy metal removal and detection

This work presents a sustainable strategy for fabricating thiol-functionalized electrospun nanofibrous membranes (ENMs) for heavy metal removal and detection in water. The membranes are produced via green electrospinning of an aqueous styrene–butadiene rubber (SBR)/poly(ethylene oxide) (PEO) dispersion, followed by UV irradiation that simultaneously induces thiol-ene crosslinking and surface functionalization. This process stabilizes the nanofibrous structure while enabling precise control of the surface density of accessible thiol (-SH) groups through stoichiometric tuning, reaching values of approximately 180 μmol/g. The resulting ENMs exhibit effective interaction with multiple heavy metal ions (i.e., Cu(II), Pb(II), Hg(II), and Ag(I)), combining adsorption capability with colorimetric detection in aqueous media. A distinct response toward Cu(II) allows detection down to 3 mg/L. The nanofibrous architecture enhances functional group accessibility compared to dense materials, while maintaining mechanical robustness and favorable wettability for operation in aqueous environments. This solvent-free, low-energy approach provides a scalable and environmentally benign route to multifunctional nanofibrous membranes with tunable surface chemistry and dual detection–removal functionality, highlighting their potential for advanced water treatment and monitoring applications.