Morphology and Dynamics of Polymers in the Rubbery State at Interfaces

Mesfin Tsige

Department of Polymer Science, University of Akron, Akron, Ohio

Ahmed E. Ismail, Gary S. Grest, D. R. Heine, and Mark J. Stevens

Sandia National Laboratories, Albuquerque, New Mexico

The surface and interfacial properties of polymers play a key role in many technological applications ranging from telecommunication to biotechnology. Most of the intended applications strongly depend on wetting and adhesion phenomena. Understanding the structure and thermodynamic properties of polymers at interfaces is an area of fundamental and current technological interest. Although excellent experimental progress has been made over the years in understanding the molecular structure of polymers in contact with various environments, the quantitative analysis has been more difficult. In the past few years, computer simulations have made significant contributions by providing the details that are lacking in the experimental data.

In this talk, I will explain how we use computer simulations to study the structure and dynamics of molecules at buried interfaces. I will mainly focus on two very important problems in the study of interfaces: surface tension and chain orientation at interfaces. Surface tension is a property that represents changes in molecular interaction at the interface and could thus be used as a means of understanding interfacial properties. As a specific example, I will discuss the interfacial properties of polydimethylsiloxane (PDMS) as well as its interaction with water and polystyrene studied by using molecular dynamics simulations.