Determination of the size of macromolecules by hydrodynamic tests in turbulent flow

A method of estimating the size of macromolecules by measuring a decrease i n their hydrodynamic resistance in the turbulent flow regime (the Thoms eff ect) is described. The motion of macromolecular coils in a viscous sublayer is considered as a continuous sequence of deformations-rotations, and a qu antitative relationship is derived between the macromolecular coil volume a nd the drop in resistance. Experimental data obtained for two PB samples in toluene and poly(actyl methacrylate) in a theta-solvent show a good agreem ent between the coil size calculated by the Flory formula and that determin ed from the results of the hydrodynamic tests.