ISSN:
1042-7147
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Stable monomolecular layers of a liquid-crystalline homopolymer bearing azobenzene chromophores in the mesogenic side groups could be prepared at the water-air interface by slow compression at room temperature. From the area per monomer unit of A0≈0.25 nm2 a structural model with tightly packed azobenzene groups oriented nearly parallel to the surface normal was deduced. After transfer to a solid support in a Y-type mode the obtained Langmuir-Blodgett-Kuhn (LBK) multilayer assemblies of varying thicknesses (from a double layer to a thick film of d = 238 nm, capable of guiding optical modes) were prepared and analyzed by X-ray reflection and optical evanescent wave techniques. A monolayer thickness of d0 = 2.52 nm, as well as the anisotropic index of refraction of these layers, could thus be evaluated.Photo-isomerization by UV-irradiation (at λ = (360±30)nm) was examined by UV-VIS absorption spectroscopy. X-ray reflectivity data of samples illuminated for 30 min showed a complete loss of the layered structure of the LBK samples. As a result strongly light-scattering films were obtained. Surface plasmon microscopy was used to demonstrate the usefulness of this photo-induced order-disorder transition for optical information storage.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pat.1991.220020304
