2 research outputs found
Spectroscopic characterizations of the mixed Langmuir-Blodgett (LB) films of 2,2'-biquinoline molecules: evidence of dimer formation
This communication reports the -A isotherms and spectroscopic
characterizations of mixed Langmuir and Langmuir-Blodgett (LB) films of
nonamphiphilic 2, -biquinoline (BQ) molecules, mixed with polymethyl
methacrylate (PMMA) and stearic acid (SA). The pi-A isotherms and molefraction
versus area per molecule studies indicate complete immiscibility of sample (BQ)
and matrix (PMMA or SA) molecules. This immiscibility may lead to the formation
of microcrystalline aggregates of BQ molecules in the mixed LB films. The
scanning electron micrograph gives the visual evidence of microcrystalline
aggregates of BQ molecules in the mixed LB films. UV-Vis absorption,
fluorescence and excitation spectroscopic studies reveal the nature of these
microcrystalline aggregates. LB films lifted at higher surface pressure
indicate the formation of dimer or higher order n-mers.Comment: 21 pages, 5 figure