On the estimation of the shape of macromolecules from sedimentation and viscosity measurements

摘要: Current theories for the interpretation of sedimentation and viscosity data are discussed, with particular reference to those substances where experimental uncertainties preclude application Scheraga-Mandelkern β function. Attention is directed ratio Ks (the coefficient concentration-dependence reciprocal coefficient) [η], intrinsic viscosity. This was reported by Wales Van Holde be a constant equal about 1.6 all random-coil polymers, theoretical basis this constancy derived; also fundamental importance in “porous-plug” theory Ogston polymer Yamakawa. From survey existing data, it shown here that compact spherical macromolecules give Ks/[η] values 1.6, whereas known asymmetric lower values. These observations form method distinguishing between separate contributions asymmetry expansion