Determination of the complex shear modulus of polymer solutions with piezoelectric resonators

The new procedure, which was worked out for the determination of complex sh ear moduli of polymer solutions, comprises an experimental setup working wi th impedance measurements at liquid covered quartz crystals (network analys is in the MHz range) and a calibration of these sensors concerning their su rface roughness and an additional damping from the coupling of shear and co mpressional waves. As an example the frequency dispersion of the viscosity and shear modulus of aqueous poly(ethylene oxide) and dextran solutions is determined. The steady state value of the viscosity, which depending on con centration (0.1-40 wt.%) lies between 1 and 20 mPa s decreases by about 50% at 90 MHz.