Cross-Linked Organic Polymer with Amine/Dithiocarbamate Backbone: A Multipurpose Adsorbent for Removal of Dyes, Iodine, and Hg2+/Pb2+ from Wastewater

The contamination of freshwater by industrial pollutants poses significant health risks, highlighting the urgent need for cost-effective, multifunctional materials to remove diverse environmental pollutants. Motivated by the pressing need, we have developed a class of tertiary amine-centered dithiocarbamate (DTC)-based cross-linked polymers (CPs) for fast and efficient removal of diverse pollutants from the environment. Furthermore, subsequent to the synthesis, the tunability of the side chain was achieved by integrating two different types of functional groups: CP-1, which contains a benzyl (aromatic) group, and CP-2, which incorporates a methyl (aliphatic) group. The synthesized polymers were characterized via various techniques including solid-state C-13 NMR, FT-IR, TG-DTA, SEM, EDAX, and DSC. Furthermore, the polymeric materials were employed for the removal of dyes, radioactive iodine, and heavy metals including toxic mercury and lead ions. CPs have removed the radioactive iodine from water as well as air with an inordinate uptake capacity of >6.5 g/g from the vapor phase, demonstrating very high uptake. In line, the benzyl-containing CP has removed various azo dyes within 5 s with high uptake capacities, i.e., 2315.46, 1138.01, and 588.23 mg/g for Eriochrome Black T, Congo Red, and Methyl Orange, respectively. Moreover, the polymeric material effectively eliminated heavy metals, mercury (Hg2+) and lead (Pb2+), from water with uptake capacities of 316.56 and 98.70 mg/g, respectively. The CPs have also been successfully employed in the column chromatographic purification of contaminated water for practical application. Overall, the tertiary amine-centered DTC-based cross-linked polymers are versatile multifunctional materials, which showed facile synthesis, tunability with both aliphatic and aromatic moieties, and thermal stability and were able to remove diverse pollutants from water within a few seconds followed by column chromatographic purification for practical implementation.