One-pot synthesis of hyper-cross-linked polymers chemically modified with pyrrole, furan, and thiophene for phenol adsorption from aqueous solution

Pyrrole, furan, and thiophene modified hyper-cross-linked polymers (HCPs) were prepared in one-pot method by two successive Friedel-Crafts reactions, and they were assessed by phenol adsorption from aqueous solution. The results indicated that the three chemically modified polymers had lower Brunauer-Emmett-Teller surface area and pore volume than the common HCPs, while the phenol adsorption on the pyrrole and thiophene modified polymers was relatively enhanced due to the introduction of the heteroatoms on the surface. Notably, the enthalpy changes of HCP-Py, HCP-Fu, and HCP-Th were greater than the HCPs, and the introduced heteroatoms provide greater interaction with phenol through dipole-dipole interaction. More importantly, the kinetic adsorption revealed that the required equilibrium time on the three chemically modified polymers (about 45 min) was shorter than the HCPs (about 75 min), and the pseudo-second-order rate equation described the kinetic data very well. The micropore diffusion model was suitable for characterizing the adsorption on the HCPs, but it could not account for the kinetic data on the chemically modified polymers.