Zahra Emami Meybodi - Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O.Box: ۱۴۹۶۵/۱۱۵,Tehran, Iran.
Mohammad Imani - Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O.Box: ۱۴۹۶۵/۱۱۵,Tehran, Iran.
Mohammad Atai - Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O.Box: ۱۴۹۶۵/۱۱۵,Tehran, Iran.

Dextran chain conformation and its crosslinking reaction kinetics in dilute aqueous solutions was investigaed as a function of the solution alkalinity. To this end, aqueous solutions of dextran were prepared in the presence of different concentrations of sodium hydroxide. According to the results,the intrinsic viscosity and hydrodynamic coil radius were increased and overlap concentration decreased with increasing in dextran solution pH. Data were interpreted considering the effects ofincreasing in the solution pH on a corresponding increment in quality of solvent for dextranchains. Finally, the effects of adding a crosslinking agent i.e., epichlorohydrin on the relative viscosity of dextran solutions was investigated. As the solutions were under their critical overlapconcentration, viscosity decrement was attributed to the formation of intramolecular crosslinking and the resulting microgels

Dextran, Dilute solution, pH effect, Chain conformation, Intramolecular crosslinking