Behavior of 1-Pyrene-Carboxaldehyde Mixed with a Polymer Matrix within the Nano-Dimensional Langmuir-Blodgett Films

ABSTRACT

Mixed films of a polycylic aromatic hydrocarbon 1-pyrene-carboxaldehyde (PyCHO) and a polymer matrix, viz. isotactic poly(methyl methacrylate) (PMMA) were studied at the air–water interface by surface pressure versus area per molecule (π-A) isotherms. The diagrams obtained by plotting the mean area per molecule as a function of the molar fraction of PyCHO showed positive deviations from ideal conditions with a small exception indicating a repulsive type of interaction between PyCHO and PMMA molecules, resulting in the formation of aggregates. Spectroscopic as well as scanning electron microscopy (SEM) studies revealed that aggregates were present when the mixed film was transferred onto quartz substrates at different mole ratios of PyCHO.

KEYWORDS:

• PyCHO
• air–water interface
• Langmuir-Blodgett films
• miscibility
• aggregate