Polymers in Two Dimensions: Spanning Solutions, Melts, and Glasses

Gerald G. Fuller

Chemical Engineering, Stanford University, Stanford, CA 94305-5025

Many polymers are amphiphilic and strong attach themselves to fluid/fluid interfaces. Many configurations are possible and the one explored here has the chains adsorbed in a flat configuration, executing a two-dimensional random walk on the surface. This can result in strongly nonlinear interfaces that produce non-Newtonian surface flows and a corresponding complex interfacial rheology. Experiments are offered that demonstrate that such chains produce isotherms that are independent of molecular weight and that contain a number of conformational and morphological transitions. The first transition has the chains passing from non-overlapping and compressed configurations over to multilayers. This is demonstrated by interfacial rheological measurements coupled with Monte Carlo simulations. The influences of temperature and chemical modification of the chains to systematically vary hydrophobicity are also investigated.