title: Viscoelastic properties of low-viscosity liquids studied with thickness-shear mode resonators.
abstract: The network analysis method was applied to AT cut quartz blanks (f(0) = 10 MHz), which were loaded with liquids of low and medium viscosity (water, methanol, ethanol, 1-propanol, 1-butanol, glycerol solutions). The shift of the resonance frequency Δf could be separated into a term due to rigidly coupled mass Δf(rig) and a term due to viscous damping Δf - Δf(rig). From the difference Δf - Δf(rig) and the broadening of the resonance curve, the complex shear modulus G = G' + iωη(L) was calculated. The viscosity coefficients η(L) are in good agreement with literature data. As G' > 0, it can be concluded that the examined fluids also reveal elasticity at shear frequencies in the MHz range. For the low-viscosity liquids, elastic contributions resulting from collective interactions of molecules are measurable but small and neglectable in most applications. The medium viscous liquid glycerol (98%) begins to exhibit considerable elasticity, resulting from the relaxation of separate molecules.
authors.affiliation: Universität des Saarlandes, Physikalische Chemie, Im Stadtwald Geb. 9.2, D-66123 Saarbrücken, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bund
authors.forename: G
authors.initials: G
authors.lastname: Schwitzgebel