Thermodynamics and dynamics of polymer nanocomposites

COLL 370

Michael Rubinstein, mr@unc.edu, Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290 and Andrey V. Dobrynin, avd@ims.uconn.edu, Polymer Program, Institute of Materials Science and Department of Physics, University of Connecticut, 97 North Eagleville Road, Storrs, CT 06269-3136.
We discuss thermodynamics principles determining the stability of nanoparticles-polymer mixtures taking into account the effect of geometric asymmetry on the entropy and the energy of mixing. A molecular model of nanoparticle mobility in a polymer matrix is developed and the mean square displacement of a nanoparticle in polymer solutions and melts is calculated. We demonstrate that dynamics of these small particles is influenced by only a subset of relaxation modes with shorter relaxation times and find that polymer adsorption on particles significantly reduces their mobility and can potentially lead to gelation and formation of a reversible network.
 

Polymer-Nanoparticle Systems: Theory, Simulation, Experiments
9:00 AM-12:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 227, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008