A FLUORESCENCE STUDY OF NAPHTHALENE TAGGED POLYVINYLALCOHOL ASSEMBLED IN LANGMUIR-BLODGETT-FILMS MIXED WITH STEARIC-ACID

Naphthalene labelled polyvinylalcohol (NAPVA) was synthesised and Langmuir-Biodgett (LB) films of NAPVA mixed with stearic acid (SA) were deposited on glass slides. Excellent uniform and homogeneous films with very high transfer ratios were obtained, A comparative study of the absorption spectra of NAPVA in ethanol, cast film and LB films revealed that the NA chromophores in LB films were preferentially oriented. Emission spectra of NAPVA in ethanol and in cast film show a broad band at 370 nm which corresponds to the second excimer emission of naphthalene which arises due to partial overlap of the NA chromophores. In LB films the NA monomer fluorescence emission as well as the partial excimer emission is observed. Normal sandwich excimer is observed in a turbid ethanol solution and in the bulk material, Our results suggest a uniform distribution of monomeric and partial excimeric NA fluorophores in such LB films.