Dilute solution properties and degree of chain branching for dextran

Abstract

Abstract Hydrodynamic volume, radius of gyration, and viscometric constants, K and a , for dextran, with a wide molecular weight range were calculated using experimental reported average-molecular weights ( M n , M w ), and intrinsic viscosity, [ η ], data in water and 0.05 M Na 2 SO 4 . Degree of chain branching for dextran was also determined using different procedures. This study demonstrated that hydrodynamic volume and radius of gyration of a dextran sample with M w M w are almost identical, whereas the latter parameters for a dextran sample with M w > 20 kDa was smaller than that of its linear counterpart. Values of 0.506 in water and 0.512, 0.425 and 0.273 in 0.05 M Na 2 SO 4 for the exponent a were obtained. A smaller value for a was obtained for a larger M w range. Molecular weights of desirable nano-particles for various branches of nanotechnology can be estimated from a derived radius of gyration–molecular weight relationship.