Characterization of Monoolein Langmuir Monolayers Spread at The Salt Solution/Air Interface

Abstract

The Langmuir monolayer is commonly described at interfaces for an insoluble homogenous single molecular layer. Langmuir monolayers have demonstrated various issues regarding soft matters and complex fluids by forming ideal uniform two-dimensional structures over the air-water interface. This monolayer has advantages for evaluating physicochemical properties at interfaces and, for the insoluble molecules, can be applied simultaneously to the different interaction occurrences at interfaces. For this experiment, monoolein lipid was used as a spreading solvent to create a Langmuir monolayer, and five different types of salt sub-phases were applied for the physicochemical properties’ interaction studies. On the air-water interface, the surface properties of monoolein lipids were investigated for interfacial phase behaviors, using the Wilhelmy plate pressure sensor technique compression isotherm (π-A). Data and analysis were also contributed to the correspondent, precise verification of physical state behavior with the surface pressure measurements on the interfaces through the compressibility modulus and the elasticity modulus parameters on the surface. In the experiments, the interfacial activity of the monoolein lipids was found to be stable on the aqueous sub-phase, while the area per molecule over the interface did not have much impact as a sub-phase with a change in salts. The repeatability and reproducibility of tests were affirmed by the difference in the Langmuir monolayer’s particular phase transition orientation behavior and the stability of colloidal lipid dispersion. However, Langmuir monolayer formation contributes to several special groups being restructured and is found to be a more remarkable natural process for their attractive organic dynamic structural properties over the interface, but the interfacial molecular dynamics have proven to be difficult to calculate.