A SPECTRAL STUDY OF AGGREGATES OF CHRYSENE IN AN ETHANOL-WATER MIXTURE AND IN LANGMUIR-BLODGETT-FILMS

Mono- and multilayers of chrysene mixed with stearic acid have been incorporated into Langmuir-Blodgett (LB) films. This is itself of interest due to the nonamphiphilic nature of chrysene. Repulsive interaction between chrysene and the fatty acid have been observed. Absorption spectra of chrysene films have been compared with that of solution. A striking similarity between emission spectra of chrysene in LB film and in an ethanol-water mixture has been observed and compared with chrysene microcrystal emission spectra. The repulsive interaction along with the spectroscopic studies have been discussed in the framework of aggregates or two-dimensional crystals of chrysene in LB films. :The possibility of any structural phase transition has been ruled out from the excitation spectra.