Designing Active Coatings and Multilayer Composites: Harnessing Mechano-chemical Transduction in Responsive Gels
Final rept. 12 Jul 2007-11 Jul 2010
PITTSBURGH UNIV PA
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With the development of the 3D GLSM simulation technique, we could now investigate the effect of a localized mechanical impact on a BZ polymer gel film. Through these studies, we isolated a unique form of mechano-chemical transduction. In particular, we found that a localized impact can drive a system that was initially in the non-oscillatory state into the oscillatory regime. The chemical waves are nucleated in the region of the local impact and propagate outwards. Within the 3D system, these variations in chemical concentration produce propagating ripples on the surface of the film. We found that these oscillations and ripples depend on the magnitude and location of the applied force. Furthermore, we isolated a remarkable case where the system continues to oscillate even after the applied force is released. Our results on these 3D systems provide the first predictions that local mechanical deformations can excite traveling chemical waves and wide-spread oscillations within BZ gels. The findings open up the possibility of harnessing BZ gels for a range of applications. Specifically, these materials could be used to create sensors that not only can transmit a signal in response to mechanical impact, but also transport reagents to address the after effects. Since the nature of the oscillations indicates the strength and location of the impact, the coatings could also provide an early warning system, indicating that the underlying components need to be checked for incipient damage.
- Physical Chemistry