Tailor-made synthesis of an melamine-based aminal hydrophobic polymer for selective adsorption of toxic organic pollutants: an initiative towards wastewater purification

A cost-effective melamine-based polyaminal covalent polymer (CPCMERI-2) has been prepared by a facile synthetic approach using the solvothermal condensation reaction and characterized by solid-state analytical tools like C-13 NMR, PXRD, N-2 sorption isotherm and FT-IR. The electron-rich moieties in the skeletal backbone induce hydrophobicity in the polymer with an appreciable water contact angle of 130 degrees. AFM study establishes the plausible reason for the hydrophobicity. On account of its high thermal and chemical stability, the polymer CPCMERI-2 has been projected as a next-generation sorbent material for oil-like materials, and executed liquid-phase adsorption of kerosene over water surface. CPCMERI-2 selectively adsorbs kerosene and has a feeble adsorption affinity towards diesel and some other organic solvents like chloroform, benzene, nitrobenzene, and toluene. To improve the bio-compatibility and cost effectiveness of the material, a bio-waste material like the peel of Citrus limetta is used in the composite material, and it unveils a new avenue towards exploring the use of naturally abundant bio-material peels as low-cost sorbent materials. Additionally, CPCMERI-2 has gained attention due to its enormous potential in wastewater purification, which has also been tested in a lab-scale experimental setup. We expect that this material (CPCMERI-2) will harbinger a new type of composite polymer, wherein naturally abundant waste bio-materials could be used as precursors to explore its usefulness as an adsorbent for the removal of oils and organic pollutants.