Synthesis of anthracene-based polyaminal polymer for CO2 capture and lead (II) removal from water waste

Abstract

In response to the rising interest in reducing atmospheric CO2 levels and heavy metals in water, new polyaminal-linked polymer networks were effectively synthesized using a one-pot polycondensation reaction of melamine and 9-anthracenecarboxaldehyde (PAN-AN). The polyaminal porosity parameter was investigated and applied for CO2 adsorption and heavy metal removal. Fourier transform infrared spectroscopy, solid-state ¹³C NMR, and X-ray diffraction were used to confirm the formation of the polymer structure. The porous material structure was determined using a scanning electron microscope and N2 adsorption–desorption methods at 77 K. The polyaminal has a Brunauer–Emmett–Teller surface area of ∼ 230.42 m2/g and a high CO2 uptake of 30.08 cm3/g. PAN-AN was used to investigate the adsorption behavior of several metal cations and showed high sensitivity for Pb(II). The pH, adsorbent dose, initial concentration, and contact time were used to evaluate the synthesized polymer as an adsorbent against the Pb(II) ion. At pH 5.5 and 20 mg of dosage, PAN-AN had a high capability in removing 90.05% of Pb(II). Furthermore, the Freundlich model fits the adsorption isotherm data well, whereas the adsorption kinetics followed the pseudo-second-order kinetic model. The results revealed that the porosity (PAN-AN) influences CO2 adsorption and heavy metal adsorption.