Morphological and Interaction Characteristics of Surface-Active Ionic Liquids and Palmitic Acid in Mixed Monolayers.

A series of water soluble, surface-active ionic liquids (SAILs), namely, 1-alkyl-3-methyl imidazolium chlorides ([C -mim]Cl) and their mixtures with palmitic acid (PA) are investigated in Langmuir monolayers and Langmuir-Blodgett films. It is inferred from the surface pressure-area isotherms that C -mim-IL mixes non-ideally with PA and stabilizes the binary mixed films. In addition, the residence of mim-IL at the water surface is enhanced as a function of the increasing alkyl side chain length.