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Reversible Crosslinking in Ultrathin Films Joe Schlenoff, Florida State University, DMR-0309441

Reversible Crosslinking in Ultrathin Films Joe Schlenoff, Florida State University, DMR-0309441. PSS. Na+. NaCl. Ion-pair. Cl-. PDADMA. An ultrathin film made from two charged polymers. When salt is added, it beaks some of the ion pairs between the positive and negative polymers.

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Reversible Crosslinking in Ultrathin Films Joe Schlenoff, Florida State University, DMR-0309441

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  1. Reversible Crosslinking in Ultrathin FilmsJoe Schlenoff, Florida State University, DMR-0309441 PSS Na+ NaCl Ion-pair Cl- PDADMA An ultrathin film made from two charged polymers. When salt is added, it beaks some of the ion pairs between the positive and negative polymers. This is like breaking crosslinks, so the film becomes much softer. When salt is removed, the film becomes stiffer (modulus, E, increases). See the graph. The control in mechanical properties is reversible. Our theoretical analysis shows the polymer crosslinks are a mixture between “ladder” and “network” type. As shown in the diagram. J. Am. Chem. Soc.128, 2940 (2006)

  2. DMR-0309441, Joe Schlenoff, Florida State University, Education & Collaborations: With partial support from this grant, six students have completed their Ph.D degrees: Hassan Rmaile is now at Hercules Inc., Zhijie Sui (Wisconsin, postdoc) and David Salloum (P&G) finished in August 2004, and Houssam Jomaa (Intel) and Jad Jaber in 2005. Undergraduate students Mark Wang and Claudiu Bucur participated in the project. Claudiu joined, along with Rana Jisr as a Ph.D student currently bringing the DMR projects forward. We have enjoyed collaborations with Biology colleagues Tom Keller and Bryant Chase, and access to the neutron source at NIST for structural studies of our thin films.

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