Guanidinium based ionic porous organic polymer as a propitious material for inordinate uptake of permanganate ions from water

Abstract

Metal based oxo anions remains as one of the major contributor towards fresh water contamination. The bioaccumulation and biomagnification through food chain poses threat to the sustainability of environment. We introduce a novel guanidinium based cationic porous organic polymer which was designed aiming to the fast and efficient removal of permanganate via electrostatic interaction between cationic polymer and the anionic pollutant permanganate. The polymer unveiled exceptionally high uptake of 9.4 g/g for permanganate ions. This is far superior than the existing literature reports. The material exhibited fast sorption kinetics and a removal efficiency of 100 %. Moreover, selectivity, pH and recyclability experiments were also evaluated to confirm the practical applicability of the material. Additionally, we have employed two distinct strategies for the synthesis of guanidinium based cationic porous organic polymer: solvothermal and mechanochemical. Both the polymers were characterized using CPMAS 13C NMR, FT-IR, Powder-XRD, N2 sorption analysis, TGA and FE-SEM. The physicochemical properties of both the polymers were compared. Further, the polymers showed 100 % removal efficiency for permanganate from aqueous solution. Since the mechanochemical method does not involve energy consumption, long time duration or involvement of any toxic organic solvents, the process is environmentally benign and economically viable. Whilst the solvothermal method consumed more energy and time. Hence, mechanochemical method was found to be more efficient, cost-effective and environmentally sustainable method in the fabrication of a highly efficient guanidinium based polymeric adsorbent material for permanganate removal from aqueous solution