1 research outputs found
Scaling Equation for Viscosity of Polymer Mixtures in Solutions with Application to Diffusion of Molecular Probes
We measured macroscopic viscosity
as well as nanoviscosity experienced
by molecular probes diffusing in solutions containing two polymer
species vastly differing in the molecular weight. On this basis we
postulated a scaling equation for viscosity of complex liquids characterized
by two distinct length-scales. As an experimental model, we used aqueous
solutions of low-polydispersity poly(ethylene glycol) and poly(ethylene
oxide) with molecular weight ranging from 6 to 1000 kg/mol, polymer
concentrations from 0.25% up to 50%, and viscosity up to 500 mPa·s.
The proposed model distinguishes between the contributions to the
total viscosity stemming from the mesoscopic structure of the complex
liquid and from the magnitude of interactions dictated by the chemical
nature of its constituents. It allows to predict diffusion rates of
nanoscaled probes in polymer solution mixtures and can be adapted
to various multilength-scale complex systems