Two-Dimensional Miscibility StudiesThe Analysis of Interaction between Long-Chain Alcohols and Semifluorinated Alkanes

Abstract

This work presents the results of phase behavior studies of two-dimensional (2D) binary systems involving semifluorinated alkanes (SFAs) and fatty alcohols. Four different SFAs were selected for investigations: (i) with a short and branched perfluorinated moiety (iF3H20), (ii) with a short and normal perfluorinated chain (F4H20), (iii) with a long and branched perfluorinated fragment (iF9H20), and (iv) with a long and normal perfluorinated group (F10H20). Two alcohols were selected to mix with the above-mentioned SFAs: tetradecanol and docosanol. The measurements were based on surface pressure/area isotherms in addition to Brewster angle microscope (BAM) imaging. Dependencies of the collapse surface pressure and the compression modulus vs the monolayer composition together with the excess free energy of mixing values, complemented with BAM images, enabled us to draw some general conclusions regarding the phase behavior of the investigated mixed systems. Generally, it has been noticed that the addition of docosanol into an SFA monolayer exerts a condensing effect, contrary to tetradecanol. Moreover, SFAs with a long perfluorinated segment mix to a larger extent with alcohols as compared to their analogues having a short perfluorinated moiety. The resultant phase diagrams for all the investigated eight mixtures are presented and discussed.

Synthesis and surface activities of organic solvent-soluble fluorinated surfactants

“…However, rather little work has been reported in recent decades [22][23][24][25][26][27]. NAlkyl perfluorooctanesulfonamides have been widely used in fabrics and papers, fire retardants, anticorrosion agents, and many other commercial formulations [5,28].…”

Towards understanding structure-stability and surface properties of laminin peptide YIGSR and mutants

“…The different phases in the isotherms are identified from the compressibility modulus C s − 1 defined as − A (∂π/∂A). The maximum collapse pressure, which is a measure of the surface activity of the compound, can also be determined by this parameter [30].…”

Interaction Study of Lipopeptide Biosurfactant viscosin with DPPC and Cholesterol by Langmuir Monolayer Technique

“…Fig. At lower viscosin fractions, the deviation from the ideality was minimal (41,42). This ratio provides the concept of ideality/nonideality of mixing.…”

“…4 shows the ratio between the excess area per molecule and the area per molecule of ideal mixing (A ex /A id ). They have assumed that at high pressure binary mixture may demix and segregate (42,43). When A ex = 0, ideal mixing or complete immiscibility occurs.…”