Structure of dextran–magnetite complex: relation between conformation of dextran chains covering core and its molecular weight

A homologous series of dextran–magnetite complex (DM) was synthesized using alkali-treated dextrans with various molecular weights from 1800 to 27 000. The structure of DM particles in water, particularly effect on molecular weight of dextran, was studied. The number of dextran chains binding to a core is possibly determined by the steric hindrance between dextran chains covering core. The conformation of dextran chains may change from a fully extended state to a random-coiled state with an increase in molecular weight.