Structural Properties of Mixed Langmuir‐Blodgett Films of 11‐(9‐Carbazolyl)undecanoic Acid and Palmitic Acid Deposited from Compressed Monolayers

Abstract

The surface pressure‐molecular area isotherms for various mixtures of 11‐(9‐carbazolyl)undecanoic acid (CUA) and palmitic acid (PA) showed plateau at about 13 mN · m−1 at 15°C. The width of plateau increased with the molar fraction of CUA. A bilayer structure due to the squeezing‐out of CUA from mixed monolayers at the air/water interface was suggested from π‐A isotherms and the limiting area. The structure of Langmuir‐Blodgett (LB) films of a 1:2.7 mixture of CUA and PA deposited at 15°C and 20 mN · m−1 by a vertical dipping method was studied by the small‐angle X‐ray scattering, absorption, and capacitance measurements These results showed that LB films deposited at 20 mN · m−1 were usual Y‐type composed of a monolayer unit. It was strongly suggested that CUA partially squeezed‐out at the air/water interface was reorganized to mixed monolayers during a transfer process.

Interlayer Energy Transfer between Carbazole and Two 9-Anthroyloxy Derivatives in Langmuir−Blodgett Films

“…According to previous studies, 41,42 11-CU in fatty acid matrix LB film is oriented with its chromophore long and short axes at an average of 35°with respect to the substrate surface. This orientation can differ slightly with the deposition conditions such as surface pressure, subphase, and matrix compound.…”