Generalized concentration dependence of makromolecule selfdiffusion coefficients in polyethyleneoxide solutions

Self-diffusion of polystyrene in solution 1. Experimental results of the NMR pulsed field gradient technique

“…The -3 exponent is in agreement with scaling theory for P-solvents and is the maximum negative slope expected in the semidilute solution. No prolonged region with a slope of -1.75 was found in accordance with literature data [9]. Nearly identical master curves to those in Fig.…”

“…Nearly identical master curves to those in Fig. 4 are also observed for polystyrene in cyclohexane, benzene, carbon tetrachloride and PEO in water and organic solvents [8,9,25,26]. where the solution should be uniformly filled with blobs of the length equal to the Flory-radius RF of the shorter chains in the mixture.…”

“…As discussed by Callaghan and Pinder [21] and calculated by Fleischer and Straube [7] the blob concept, combined with the reptation mechanism and the assumption of a concentration independent monomeric friction coefficient, is able to explain the concentration dependence of the self-diffusion coefficient in good solvents, e. g. 9 The line in Fig. i is theoretically calculated as described in Ref.…”

“…As in Ref. [9], low molar mass fractions of polystyrene were used to obtain the T2 (c) dependence to diminish the influence of the large-scale modes of motion.…”