Unified theory for photoinduced molecular movement in azobenzene containing polymer films

PHYS 128

Mathieu Juan, mathieu.juan@utt.fr1, Jérôme Plain, jerome.plain@utt.fr1, Renaud Bachelot1, Pascal Royer1, Gary P. Wiederrecht, wiederrecht@anl.gov2, and Stephen K. Gray, gray@tcg.anl.gov3. (1) LNIO - Institut Charles Delaunay - University of Tehcnologie of Troyes, LNIO, 12 rue Marie Curie, Troyes, 10010, France, (2) Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, (3) Chemistry Division, Argonne National Laboratory, Argonne, IL, Argonne, IL 60439
Azobenzene molecules exhibit interesting properties for photo-induced modifications of polymer films, such as for nanoscale optical imaging or molecular manipulation with light. Yet dynamic is quite complex and shows different sensitivity to the polarization of the electromagnetic field. Although numerous models have been proposed, they are restricted to specific experimental configurations. Indeed, no unified theory has been developed yet which allows a complete description. We report on a statistical model for topographic modifications. Our Monte Carlo approach relies on two points. First, based on the worm-like translation model initially proposed by Fiorini et al., molecules are assumed to move along their axis after a photo-induced isomerization. Second, the absorption probability is described through the molecular dipole and the incident field. The Monte Carlo model shows good agreement with far-field and near-field observation. Using complex calculated electromagnetic field, we mimic the experimentally obtained topography showing the predictive aspect of our model.
 

Spectroscopy, Chemistry, and Imaging through Nanophotonics
8:20 AM-12:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 340/341, Oral

Division of Physical Chemistry

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