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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Prof. Andrew Lyon, Georgia Tech
Smoothing Out the Defects with Polymer Microspheres
This talk will discuss various aspects of the defect tolerance, self-healing, and geometry adaptation properties of hydrogel microspheres. Hydrogel microspheres (microgels) are micron- to submicron-sized particles, each composed of a cross-linked network of water soluble polymer. As a result of their large water content, which can easily exceed 99% by volume, microgels composed of flexible polymers such as poly(alkylacrylamides) have a high degree of conformational flexibility; they are exceedingly soft structures. We have found that this softness permits microgels to be extremely adaptive to geometric restrictions, resulting in defect-tolerant colloidal crystals where large "dopant" particles are assimilated into the lattice seamlessly. This adaptive nature is also illustrated by the passage of microgels through orifices at least 10-fold smaller than the equilibrium microgel diameter, which is potentially relevant in the use of microgels for injectable drug delivery formulations. Finally, the use of microgels in self-healing polymer films will be discussed, along with illustrations of the applicability of such films in reconstructive surgery.
