Smart pillar[5]arene‐based PDMAEMA/PES beads for selective dye pollutants removal: design, synthesis, chemical‐physical characterization, and adsorption kinetic studies

This article reports on the synthesis of an innovative smart polymer, P5‐QPDMAEMA, opportunely developed with the aim of combining the responsiveness of PDMAEMA polymer and the host‐guest properties of covalently linked pillar[5]arenes. Thanks to a traditional Non‐Induced Phase Separation (NIPS) process performed at various coagulation pH, the blending of P5‐QPDMAEMA with polyethersulfone gave rise to the formation of functional beads for the removal of organic dyes in water. Adsorption tests are carried out on all the produced blend‐based beads, by employing two representative dyes, the cationic methylene blue (MB), and the anionic methyl orange (MO). In particular, the P5‐QPDMAEMA based beads, prepared at acidic pH, featured the best MO removal rate (i.e., 91.3% after 150 minutes starting from a 20 mg·L–1solution) and a high selectivity towards the removal of the selected anionic dye. Based on the adsorption kinetics and isotherm calculations, the pseudo‐first order and Freundlich models were shown to be the most suitable to describe the MO adsorption behavior, achieving a maximum adsorption capacity of 21.54 mg·g−1. Furthermore, zwitterionic beads are obtained by a post‐functionalization of the PDMAEMA and the P5‐QPDMAEMA based beads, to test their removal capability towards both anionic and cationic dyes, as shown.