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.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Reversible Crosslinking in Ultrathin FilmsJoe Schlenoff, Florida State University, DMR-0309441
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)
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.