Salt induced doping and swelling: Thin films with tunable elastic modulus

POLY 294

Jad A Jaber, jjaber@chem.fsu.edu, Department of Chemistry and Biochemistry, Center for Materials Reserach and Technology (MARTECH), The Florida State University, Dittmer Research Building, Tallahassee, FL 32306 and Joseph B. Schlenoff, schlen@chem.fsu.edu, Department of Chemistry and Biochemistry, Center for Materials Research and Technology (MARTECH), The Florida State University, Tallahassee, FL 32306.
The advent of polyelectrolyte multilayers, PEMU, provided dynamic bio-interfaces to control cell attachment, phenotype and cytoskeleton. PEMU are highly interpenetrating thin films stabilized by reversible physical crosslinks. Changing the pH or ion strength of the surrounding aqueous medium breaks some of the ion-pairing crosslinks. As a result, the “ideally” neutral glass-like multilayer becomes progressively more rubber-like. The dynamics of adhesion and differentiation of cells, anchored to the PEMU surface, will also change. Shedding light on the mechanism of this intra-extracellular feedback loop will allow the development of more effective tissue repair strategies. Results on counter-ion induced plasticization of PEMU, as an effective route to reversibly control the elastic modulus of the interface, will be presented. Classical theories of rubber elasticity were adapted to describe the dependence of modulus on solution ion strength, and illuminate the topology of chains within PEMU.
 

General Papers: Polymers and Biology
1:00 PM-4:20 PM, Monday, 11 September 2006 San Francisco Marriott -- Salon 12/13, Oral

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006