INTERACTION AND DYNAMICS OF POLYMER-SOLUTIONS AT THE AIR LIQUID INTERFACE BY LASER-LIGHT SCATTERING/

The viscoelastic property of the underlying polymer solution is shown to have an effect on the propagating behavior of surface modes. The pr opagation of the surface modes is affected by the interaction of the c apillary wave and the viscoelastic response of the underlying liquid. The surface laser light scattering (SLLS) spectrum of the viscoelastic liquid is shown to exhibit in general a two-peak structure. A central peak appears as the solution viscoelasticity increases. It is shown t hat in the viscoelastic regime, the capillary wave component is suppre ssed by the increase of the surface dilational modulus. However, the e ffect of the dilational modulus is not pronounced in solutions with a large amplitude of shear modulus, despite the fact that in the same ty pe of viscoelastic solutions, the decrease in the surface tension give s rise to an effect. (C) 1998 Published by Elsevier Science B.V. All r ights reserved.