Title :
Maxwell-displacement current generated by cis-trans photoisomerisation in azobenzene-containing Langmuir-Blodgett films
Author :
Nordmann, I. ; Fruebing, P. ; Ruhmann, R. ; Prescher, D. ; Katholy, S. ; Knochenhauer, W. ; Rosin, C. ; Brehmer, L.
Author_Institution :
Inst. of Solid State Phys., Potsdam Univ., Germany
Abstract :
Cis-trans isomerisation induced by light irradiation in polymer Langmuir-Blodgett (LB) films is investigated using the Maxwell-displacement current method and uv-vis spectroscopy. The materials looked at are statistical copolymers of polymethacrylate with azobenzene groups incorporated in the side chains. Relaxation times for cis-to-trans as well as trans-to-cis isomerisation were determined from the Maxwell-displacement current/time plots at different temperatures. Uv-vis spectroscopy showed that the isomerisation process is almost completed after 3 minutes and that the thermal back relaxation requires less then 24 hours. From the experimental results, the change in the normal component of the dipole moment was calculated
Keywords :
Langmuir-Blodgett films; electrical conductivity; isomerisation; photochemistry; polymer blends; polymer films; ultraviolet spectra; visible spectra; 3 min to 24 h; Maxwell-displacement current; Maxwell-displacement current method; Maxwell-displacement current/time plots; azobenzene groups; azobenzene-containing Langmuir-Blodgett films; cis-to-trans isomerisation; cis-trans isomerisation; cis-trans photoisomerisation; copolymers; dipole moment; light irradiation; polymer Langmuir-Blodgett films; polymethacrylate; relaxation times; side chains; thermal back relaxation; trans-to-cis isomerisation; uv-vis spectroscopy; Biological materials; Chemical and biological sensors; Computational Intelligence Society; Optical films; Optical polymers; Optical sensors; Physics; Polymer films; Spectroscopy; Temperature;
Conference_Titel :
Electrets, 1996. (ISE 9), 9th International Symposium on
Conference_Location :
Shanghai
Print_ISBN :
0-7803-2695-4
DOI :
10.1109/ISE.1996.578179
