Braun Group People
Austin Pickett
Graduate Student in Materials Science and Engineering
B.S. in Chemistry from Mississippi State University (2008)
There are many possible applications for self-healing materials, some of which include coatings, adhesives, and structural components. Furthermore, a material with this ability would have a much longer lifetime and increased durability, resulting in reduced overall cost. Much of the work in this field has been performed here at the University of Illinois with the use of encapsulated healing agents [1]. However, this approach has certain limitations. The encapsulation procedure can be quite time-consuming, requiring multiple steps. Also, the capsules can be difficult to disperse in the matrix of bulk polymeric materials.
A new area of interest for potential self-healing use is mechanochemistry [2]. This is the use of mechanical energy to alter the structure of a molecule. These “stress-sensitive” molecules, or mechanophores, can be incorporated, in one or more locations, into a polymer chain [3].
The goal of my research is to design a new mechanophore that can trap a metal ion. So far a spiropyran-based mechanophore [4] appears particularly promising since its mechanical behavior has been heavily investigated by the Autonomous Materials Systems (AMS) Group at the Beckman Institute here at Illinois. These mechanophore-ion complexes would then be incorporated into a polymer chain and, eventually, into a bulk polymeric material. Upon application of mechanical stress, the metal ion(s) would be released from the mechanophore(s). The metal ion(s) could then proceed to catalyze repairing reactions that would heal any polymer chains broken by the initial application of stress.
Autonomous Materials Systems Webpage
[1] White et al. Nature 409, 794-797 (2001)
[2] Hickenboth et al. Nature 446, 423-427 (2007)
[3] Potisek et al. J. Am. Chem. Soc. 129, 13808-13809 (2007)
[4] Davis et al. “Mechanochemical Transduction in Polymeric Materials”. accepted, Nature (2009)
Professor Paul Braun • Phone: +1.217.244.7293 • Fax: +1.217.333.2736 • Email: pbraun@illinois.edu
Department of Materials Science and Engineering • University of Illinois at Urbana-Champaign