Determination of the frequency-dependent bulk modulus of glycerol using a piezoelectric spherical shell

Abstract

Through the coupling between the electrical capacitance of a spherical piezoceramic shell and the mechanical stiffness of a liquid contained therein, the frequency-dependent adiabatic bulk modulus Ks(ω) of the liquid can be derived. Using this method, Ks(ω) of glycerol in the range 15 Hz-15 kHz has been measured at the glass transition. The loss peak frequencies of the compressibility κs(ω)=Ks-1(ω) and the specific heat cp(ω) have the same temperature dependence, but the frequency dependences are different. © 1994 The American Physical Society.