LANGMUIR-BLODGETT-FILMS OF SURFACE-ACTIVE AZODYE - INVESTIGATION BY ATOMIC-FORCE MICROSCOPY

Langmuir-Blodgett (LB) films of surface-active azodye, YOPE, were prep ared at different surface pressures and observed by atomic force micro scopy. The surface structure was compared with that of LB films of the arachidic acid/YOPE hybrid. The two-dimensional phase separation was observed in hybrid LB films. The molecular arrangement of YOPE on Lang muir films was inferred from the AFM observation of LB films and the s urface pressure-area (pi-A) isotherms. At lower surface pressures, the dye chromophores of YOPE molecules were lying along the air-water int erface. The arithmetic additivity of pi-A isotherms was substantiated for hybrids.