Study of thermal effusivity variations in water solutions of polyethylene glycol 200 using photoacoustic method

A photoacoustic open cell with microphone registration has been used to determine thermal effusivity of liquids. Modification of the method has been proposed and tested. Application of the method for the investigation of structural changes in water solutions of polyethylene glycol 200 (PEG) is presented. The dependence of thermal effusivity of the solution on the PEG concentration has been compared with these obtained for density and adiabatic compressibility. It has been shown, that the determination of effusivity can complement and verify information obtained by other methods of studying concentration dependent structural changes in liquid mixtures.