Evaluation of an Ionic Porous Organic Polymer for Water Remediation

The targeted synthesis of a novel ionic porous organic polymer (iPOP) was reported. The compound (denoted as QUST-iPOP-1) was built up through a quaternization reaction of tris(4-imidazolylphenyl)amine and cyanuric chloride, and then benzyl bromide was added to complete the quaternization of the total imidazolyl units. It featured a special exchangeable Cl^-/Br^--rich structure with high permanent porosity and wide pore size distribution, enabling it to rapidly and effectively remove environmentally toxic oxo-anions including Cr₂O₇^2-, MnO₄^-, and ReO₄^- and anionic organic dyes with different sizes including methyl blue, Congo red, and methyl orange from water. Notably, QUST-iPOP-1 showed ultra-high capacity values for radioactive TcO₄^- surrogate anions (MnO₄^- and ReO₄^-), Cr₂O₇^2-, methyl blue, and Congo red, and these were comparable to some reported compounds of exhaustive research. Furthermore, the relative removal rate was high even when other concurrent anions existed.