Synthesis of Schiff base polymer/black talc nanocomposites based on m-phenylendiamine with enhanced separation performance for lead adsorption

In this study, we have developed a facile in-situ hydrothermal oxidative polymerization method to synthesize poly N,N(1,3-phenylene)dimethanimine/KH550-black talc (PNPD/KH550-BT) nanocomposites for efficient removal of lead (II) (Pb2+) in wastewater. This method employed eco-friendly solvent, offered a simple and cost-effective preparation procedure and resulted in a nanocomposite complex that displayed exceptional resistance to dissolve in various organic solvents, simplifying the separation process. Through the hydrothermal oxidative polymerization process, polymerization was promoted to generate spherical flower-like structures, effectively improving the dispersion of polymers on black talc nanosheets. Substantial concentration of sturdy lead-complexing groups was created, including N–H, –CN, and –NH2, which heightened the attraction to Pb2+ ions and maximized the effective utilization of lead binding sites. Compared with KH550-BT and PNPD, the adsorption performance of PNPD/KH550-BT composites on Pb2+ was significantly enhanced, and the largest adsorption capacity of lead (II) on PNPD/KH550-BT nanocomposites reached 867.1 mg/g. Moreover, the prepared nanocomposites had satisfactory adsorption potential after undergoing 10 cycles, showing good stability during adsorption. This work not only provides a new strategy to control the microstructure of polymer-based composite adsorbent but also presents various promising functionalized nanocomposites based on different polymers and minerals for application in vast fields.