Nonsteady Effects Due to a Small Surface Pressure Perturbation in an Elastic Insoluble Monolayer

Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears

“…Therefore, the SQ/hMGS interaction is relevant to study. Control experiments with axisymmetric drop shape analysis (as previously described in [ 48 ]) of SQ/whole tear samples revealed an identical trend. SQ spread on the surface of tear drops at 0.2 µg/cm 2 (the maximum surface concentration of SQ in the SQ/hMGS pseudo-binary films) did not affect the interfacial properties of whole tears (data not shown).…”

“…As the melting temperature of SQ is −75 °C, SQ is in a disordered state at physiological temperature. It is known that in disordered lipid films, the contribution of the elastic processes to the rheology properties decreases, while the one of the viscous processes increases [ 48 ]. Viscoelasticity of meibum was also found to decrease when the lipid became more disordered [ 10 , 47 ].…”

“…Then the relaxation of the surface pressure (see Figure 8 for details) was registered; for the samples studied, it usually took ≤500 s for complete relaxation. The surface pressure relaxation kinetics is described by the following equation [ 48 ]: where π( t ) is the surface pressure at a given time t ; π max is the maximal surface pressure at the start of the relaxation, immediately after the compression is performed; π ∞ is the equilibrium surface pressure after completion of the relaxation; τ fast and τ slow are relaxation times for rapid and slow processes which take part in the total relaxation process; А fast and А slow are constants which reflect the contribution of the fast and slow relaxation times, respectively, to the total surface pressure change.…”

Emulsions stability, from dilute to dense emulsions — Role of drops deformation

“…Theoretical development based on a cooperative effect in the electric field is in agreement with experimental observations [204,205]. Relaxation processes in insoluble monolayers during twodimensional phase transitions were also remarkably analyzed by Panaiotov and Bois [196] and applications to liposomes spread at a surface merit also reading [206].…”

“…Let us mention here that the influence of desorption controlled interchange on dynamic surface tension and calculation of desorption kinetic constant has been published by Panayotov et al [195] already in the year 1983. Surface dilational elasticity and relaxation processes were also studied by Panayotov [196] et al [196,197], both theoretically and experimentally; they obtained very interesting results on fundamental properties of spread and adsorbed monolayers.…”