Adsorption studies of some inorganic and organic salts on new zwitterionic ion exchangers with carboxybetaine moieties

The synthesis and characterization of two structures of crosslinked polyzwitterionic carboxybetaines based on the 4-vinylpyridine: divinylbenzene macromolecular supports of gel and porous type as well as the evaluation of their retention property of organic and inorganic salts are reported. Ion exchange capacity values, pK(a), FT-IR spectroscopy and ESEM images of their polymeric precursors proved the content of ionic groups, the selectivity for hydrogen atom and the morphology structure of the zwitterionic ion exchangers with positive and negative charges located in the same structural unit and bound by one or two methylene groups. The yielded compounds exhibited retention capacities for divalent and trivalent heavy metals as well as for cefotaxime from aqueous solutions. The values are related to their chemical and morphological structures. The highest retention capacity values of the heavy metals and cefotaxime were obtained when the zwitterionic ion exchanger with two methylene groups as the spacer between the opposite charges and porous structures was used in the investigation studies. (C) 2010 Elsevier B.V. All rights reserved.