Photoinduced Anisotropic Response inLayer-by-layer Ultrathin Polymer Films asProbed by Surface Plasmons

摘要

The evaluation of photoinduced anisotropic behavior in ultrathinpolymer films involves spectroscopic methods that directly probechanges in optical dielectric constants as well as the redirection ofoscillator strengths in absorbing molecular species.Azobenzene dyeshave been widely studied in the past both as bulk thin films and asmoieties in self-assembled monolayers.For ultrathin films of the orderof a few to a hundred nm, surface sensitive techniques like surfaceplasmon resonance spectroscopy and scattering methods have beenutilized to directly probe directly the changes in thickness, refractiveindex, and morphological roughness.In addition, the preparation ofhybrid liquid crystalline (LC) cells allows correlation of molecularorientation behavior in LC molecules with control of photo-orientation ofthese azobenzene dyes as new photo-alignment layers.