화학공학소재연구정보센터
Macromolecules, Vol.29, No.1, 320-325, 1996
Wetting Kinetics of Polymer-Solutions - Experimental-Observations
It is known that the spreading rates of small liquid drops over a solid surface exhibit a strong dependence on the viscosity of the liquid. These observations have led us to study the spreading behavior of polymer solutions on high- and low-energy substrates to determine what role complex theology plays in wetting kinetics. We did not observe any effects of non-Newtonian (nonlinear) behavior, nor were any obvious signs of viscoelasticity (memory) visible. Instead, we observed a most intriguing phenomenon that polymer solutions, despite having low surface energies, do not wet high-energy substrates. In addition, nonwetting drops spread to an equilibrium configuration by either one of two distinct mechanisms. In the first case, they spread as a wetting Newtonian liquid and then stopped, that is, equilibrated, abruptly. In the second, they equilibrated continuously. We offer some possible molecular and continuum arguments to explain the differences between these two mechanisms.