4-Aminothiophenol/formaldehyde-based, N/S-containing amorphous porous organic polymer: Preparation from catalyst-free thiol-aldehyde-amine reaction and its application in high-performance iodine capture

Abstract

The release of radioactive iodine (129I and 131I) from nuclear industry is a serious problem to endanger the environment and public safety. It is highly important to develop materials that can effectively remove 129I and 131I from different phases. The purposive construction of N, S-containing polymers can provide effective support for the development of high-performance iodine adsorbent materials. Herein, using low-price 4-aminothiophenol and formaldehyde as the starting substrates, a polymer (P-4-AT) containing abundant N/S heteroatoms in its structure was readily prepared via catalyst-free thiol−aldehyde−amine reaction (termed as TAAR). The Characterization of chemical structure and basic properties of P-4-AT indicate that P-4-AT belongs to a novel amorphous porous organic polymer (POP). The application of P-4-AT in iodine adsorption was systematically investigated. P-4-AT can effectively capture iodine in both vapor (atmospheric pressure, 75 °C) and solution (cyclohexane and water) phases, with the equilibrium adsorption amounts up to 6.13, 2.48 and 2.74 g g−1, respectively. Experimental and theoretical analyses of the adsorption mechanism revealed that the N/S-containing groups in the structure of P-4-AT and its aromatic skeleton played crucial role in the process of adsorption of iodine.