Preparation of chitosan–ethylenediaminetetraacetate-enwrapped magnetic CoFe2O4 nanoparticles via zero-length emulsion crosslinking method

A kind of magnetic multiple functional groups nanocomposites, chitosan–ethylenediaminetetraacetate (EDTA)-enwrapped CoFe2O4 nanoparticles, i.e. CoFe2O4@chitosan–EDTA nanocomposites were synthesized by a facile zero-length emulsion crosslinking process. In this method, CoFe2O4 was used as magnetic core, and 1-ethyl-3-(3-dimethylminopropyl) carbodiimide hydrochloride (EDAC) was used as a crosslinker, integrating amino group of chitosan and carboxyl group of EDTA. Determination of amino groups in chitosan modified by EDAC-activated EDTA was carried out through the trinitrobenzenesulfonic acid (TNBS) method. The as-prepared magnetic nanocomposites were characterized by XRD, FT-IR, XPS, SEM, EDS, TEM, SAED and vibrating sample magnetometer (VSM), and the results showed that the as-prepared CoFe2O4@chitosan–EDTA nanocomposites have good dispersibility, spherical shape and enough magnetization. The method proposed can be extended to fabricate other magnetic nanocomposites possessed amino and carboxyl groups.