Sol–Gel Transition in Gelatin Observed with Surface Waves

Surface wave velocity and absorption were measured in the frequency range 250–750 Hz in gelatin solution at around the sol–gel transition temperature. We propose a dispersion relation for surface wave propagation on gel, which takes surface tension and viscoelasticity into account. The results obtained using the dispersion relation provide the shear elasticity and viscosity in the gelation process. The shear elasticity and viscosity were interpreted within the framework of the percolation theory. The critical exponents obtained experimentallyt=1.7–2.2 ands=0.7–0.8 are in good agreement with the percolation theory.