Metal Ion Removal from Aqueous Solution by Liquid Phase Polymer‐Based Retention Technique

Summary: Water‐soluble poly[3‐(dimethylamino)propylacrylate] is synthesized by radical polymerization with a yield of 87%. The polymer structure is confirmed by FT‐IR and 1 H‐NMR spectroscopies. The polymer lost only 3% of weight up to 100 °C. The narrowest molecular weight distribution is observed with the fraction between 3,000 and 10,000 Da. P(DAPA) presents a high affinity for the metal ions Pb 2+ and Cu 2+ , while the other metal ions are not significantly retained. By increasing the filtration factor, Z, metal ion affinity decreases, indicating a very weak ligand‐metal interaction and the possibility of its destruction when washed with water at the filtration cell's pH. For Z = 10, the retention values of Pb 2+ and Cu 2+ at pH 5 are 76.5% and 48.5%, respectively, while the values for Cu 2+ and Cd 2+ at pH 7 are 89.5% and 40.4%, respectively.