title: Hydrodynamic characteristics and equilibrium rigidity of pullulan molecules.
abstract: The hydrodynamic characteristics of the polysaccharide pullulan (polymaltotriose) in water have been investigated and its molecular characteristics have been determined. Experimental values varied over the following ranges: velocity sedimentation coefficient (S): 0.9 < S < 11.2, translational diffusion coefficient (10(7) cm2 s-1): 1.1 < D < 14.7 and intrinsic velocity (cm3 g-1): 6.7 < [eta] < 164, which corresponds to a change in molecular weight (x 10(3)) in the range 3.9 < MSD < 644. On the basis of analysis of the literature and our experimental data, excluded volume effects have been shown to have a prevailing influence on the chain length of these polysaccharides. The equilibrium rigidity and hydrodynamic chain diameter of pullulan were evaluated on the basis of the theory of hydrodynamic properties of a wormlike necklace, taking into account excluded volume effects. At low M (< 30 x 10(3)) the translation friction data (in contrast to viscometric data) cannot be described in the framework of the theory of linear molecules.
authors.affiliation: Institute of Physics, St Petersburg State University, Russia.
authors.forename: G M
authors.initials: GM
authors.lastname: Pavlov
authors.forename: E V
authors.initials: EV
authors.lastname: Korneeva
authors.forename: N P
authors.initials: NP
authors.lastname: Yevlampieva
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004058:Diffusion; D017276:Friction; D005936:Glucans / Q000737:chemistry*; D008970:Molecular Weight; D014783:Viscosity
chemical_list: D005936:Glucans; C009109:pullulan