THE MONOLAYER BEHAVIORS AND INSITU UV-IRRADIATED POLYMERIZATIONS OF 2,4-HEXADECADIENOIC ACID AT THE AIR-WATER-INTERFACE

Abstract

The monolayer behaviors of 2,4-hexadecadienoic acid were investigated using a Langmuir trough with a constant perimeter barrier at 24-degrees-C in terms of the characteristics of pi-A isotherms and the UV-irradiated polymerizations of the monolayer films at the air/water interface . The spread film on the pure water dissolved into the subphase, but not on the acid subphase of pH 2.8. The monolayer isotherms were reproducible below the collapse pressure of ca. 20dyn/cm near the molecular area of 30 angstrom2, and no phase transitions between the expanded and the condensed state[C(s)-1(max): ca. 60 dyn/cm] were observed. When monolayers were irradiated by a UV lamp(lambda(max): 252.1 nm), monolayer films were readily polymerized in situ within a few minute for all the applied surface pressures(ie., 5dyn/cm, 10dyn/cm and 15dyn/cm), and the resulting polymer were shown very stable.