Binding of metal ions by polyethylenimine and its derivatives

Abstract

Measurements have been made of the binding of divalent metal ions, Cu2+, Ni2+, Co2+, and Zn2+ ions, by polyethylenimine (PEI) and its acetyl or alkyl derivatives by the equilibriumdialysis technique. These metal ions, in particular the Cu2+ ion, exhibited tremendously remarkable binding affinity toward PEI. The extent of complexation of the polymer with the metal ions was decreased markedly by acetylation or alkylation of the polymer. PEI with no primary amine showed an appreciable decrease in its affinity for the metal ion. These results indicate the participation of the primary amine of the polymer in the formation of the complex. A cooperative binding isotherm was observed in PEI–metal ion complex formation, suggesting swelling or conformational change of the polymer induced by this coordination process. Binding of the Cu2+ ion by PEI was found to be essentially independent of temperature over the range 5–35°C.

Effects of divalent cations, seawater, and formation brine on positively charged polyethylenimine/dextran sulfate/chromium(III) polyelectrolyte complexes and partially hydrolyzed polyacrylamide/chromium(III) gelation

“…2) became bimodal, and this suggested that growth was by the agglomeration of particles rather than by a simple expansion of individual nanoparticles. This was consistent with the known affinity of primary amines (which account for about 25% of the amines in PEI for divalent cations) 32…”

Polymer assisted deposition of epitaxial oxide thin films

“…The ratio -NH 2 :-NH-:-N= can be measured experimentally by 13 C-NMR (see Figure 3a), and varies typically between 39:37:24 and 32:30:39 for most of the samples analyzed from different suppliers. 43 These functional groups can bind directly to a large number of ions in water solution, 61,62 , and for optimum results -NH-:-N= should be kept between ≈1.1-1.5. On the other hand, although water solutions of PEI present a very high pH, -NH 2 and -NH-protonate below pH≈10 and pH≈6, respectively (see Figure 3b).…”

Environment-Friendly Approach in the Synthesis of Metal/ Polymeric Nanocomposite Particles and Their Catalytic Activities on the Reduction of p-Nitrophenol to p-Aminophenol

“…This ligand role property results in some advantages of the composite material such as water solubility, high capacity for metal uptake, easy separation of polymer complexes, high flexibility of the molecular conformation, and good chemical and physical stability [69][70][71].…”