The effect of ionic strength on the shape asymmetry of high-molecular-massflexible polyions in dilute aqueous-saline solutions

The aqueous-saline dilute solutions of high-molecular-mass flexible polyele ctrolytes, salts of poly(2-methacryloyloxyethyltrimethyl ammonium) (M-w = 9 .6 x 10(6)) and 2-acrylamido-2-methylpropanesulfonic acid copolymer with ac rylamide (M-w = 6 x 10(6)) were studied by flow birefringence, viscometry, and light scattering. It was found that, in the region of moderate ionic st rengths I, the shape asymmetry of polyions p varies from 2.0-2.5 at I = 1 m ol/l (a Gaussian coil) to similar to 4-4.5 at I = 0.05 mol/l (an extended a symmetric coil). The experimental evidence is compared with the results fro m the theoretical and experimental studies of p as a function of I.