The effective viscosity
in polymer solutions probed by diffusion
of nanoparticles depends on their size. It is a well-defined function
of the probe size, the radius of gyration, mesh size (correlation
length), activation energy, and its parameters. As the nanoparticle’s
size exceeds the radius of gyration of polymer coils, the effective
viscosity approaches its macroscopic limiting value. Here, we apply
the equation for effective viscosity in the macroscopic limit to the
following polymer solutions: hydroxypropyl cellulose (HPC) in water,
polymethylmethacrylate (PMMA) in toluene, and polyacrylonitrile (PAN)
in dimethyl sulfoxide (DMSO). We compare them with previous data for
PEG/PEO in water and PDMS in ethyl acetate. We determine polymer parameters
from the measurements of the macroscopic viscosity in a wide range
of average polymer molecular weights (24–300 kg/mol), temperatures
(283–303 K), and concentrations (0.005–1.000 g/cm3). In addition, the polydispersity of polymers is taken into
account in the appropriate molecular weight averaging functions. We
provide the model applicable for the study of nanoscale probe diffusion
in polymer solutions and macroscopic characterization of different
polymer materials via rheological measurements.