4‐Vinylpyridine derived physically crosslinked hydrogel as efficient mercury indicator

Abstract

AbstractHere, we report a photoclicked crystalline monomer DiPy which forms polymeric hydrogel Polym‐DiPyC3. The monomer DiPy and polymer Polym‐DiPyC3 are well characterized using spectroscopic and analytical techniques. The rheometric curve revealed the hydrogel Polym‐DiPyC3 to exhibit viscoelasticity with a damping factor (tanδ) in the range between 0 and 1. The considered hydrogel film on exposure to mercury concentration ≥2 ppm showed a loss of transparency and swellability. Energy dispersive x‐ray and mapping confirmed the mercury presence on the surface of Polym‐DiPyC3. The material behaves as a naked‐eye indicator due to gain in opacity and loss of swellability. The DFT parameter supported the soft Lewis acid Hg2+ to guest onto the soft thioether site of the polymer film Polym‐DiPyC3.Highlights The monomer DiPy was synthesized via thiol‐alkene photoclick reaction. The ionic polymer Polym‐DiPyC3 is physically crosslinked. The polymer Polym‐DiPyC3 exhibits viscoelastic property. The mercury presence causes Polym‐DiPyC3 to lose its hydrogel property. The observed affinity of mercury for sulfur was well supported with DFT.