Sulfoethylated polyethylenimine: synthesis in gel and sorption properties

Using the gel synthesis approach of polymer-analogous transformations, N-sulfoethylation of polyethylenimine was carried out by treating the polymer with sodium vinyl sulfonate. The compositions and structures of the products were characterized by elemental analysis, FT-IR spectroscopy, and ¹H NMR spectroscopy. At pH 3.0–4.5 sulfoethylated polyethylenimine can selectively extract Ag^I and Cu^II from an ammonia—acetate buffer solution in the presence of a series of transition and alkaline-earth metals. At pH > 6.5 the sorbent can be used for the group extraction of a number of transition metal ions. The structural feature of the obtained derivative eliminates the selectivity of sorption of Ag^I ions compared to Cu^II ions, which has previously been revealed for the sulfoethylated derivatives of chitosan and polyaminostyrene.