Measurement of polymer shear modulus using thickness shear acoustic waves

다국어 초록 (Multilingual Abstract)

This work describes a series of experiments on the measurement of the viscoelastic properties of thin lms in contact with thicknesslayer from a measurement of the impedance spectrum of the resonator around the series resonance point. This method is applied to thecharacterisation and comparison of the properties of polyethylene oxide (PEO) and polydimethyl siloxane (PDMS) polymer layers. Thevalues for the shear moduli of these two layers clearly indicates that, at room temperature, the PEO layer is in the glassy state, while thePDMS is in the rubbery state. Cooling of the PDMS layer to temperatures below. 60 .C induces a transition to the glassy state and thislms during the in-diusion of organic vapours are also studied with this technique. This produces the dramatic result that in the case ofPDMS the induced frequency shift is not dominated by the mass loading of the vapour molecules, but rather by changes in the shearmodulus of the polymer. In this case the frequency shift is not a negative shift, as conventionally predicted by the Sauerbrey equation,but a positive shift due to the softening of the polymer by the organic vapours.

참고문헌 (Reference)

1 "Surface-Launched Acoustic Wave Sensors" John Wiley and Sons Inc 1997

2 "Acoustic Wave Sensors" Academic Press 1997