Tuesday, March 11, 2014
Mechanochemical Remodeling: From New Reactions to Adaptive Materials
Materials Chemistry Materials Seminar
4:00 PM - 5:00 PM
Speaker: Stephen Craig, Duke University
Abstract: The forces typical of the macroscopic world (for example, those between a baby's fingers) are many orders of magnitude larger than the forces between the individual atoms of a molecule. It has been known for decades, in fact, that breaking a piece of plastic or shearing a polymer solution can lead to homolytic carbon-carbon bond scission along the main chain of an organic polymer and a concomitant reduction in molecular weight. The magnitude of macroscopic forces, in combination with the fact that they are directional, creates a spectacular opportunity to direct chemistry that might otherwise be effectively impossible.
This talk will present studies of reactions under large, directional forces, and their applications in studies of fundamental reactivity and new classes of stress-responsive polymers. Specific outcomes include the ability to trap transition states for extended periods of time and molecules that get shorter in response to being pulled. Materials applications include new classes of self-healing polymers and mechanochemical devices.