Interpretation of Mechanochemical Properties of Lipid Bilayer Vesicles from the Equation of State or Pressure−Area Measurement of the Monolayer at the Air−Water or Oil−Water Interface

Langmuir ◽  
1999 ◽  
Vol 15 (4) ◽  
pp. 998-1010 ◽  
Author(s):  
Si-shen Feng
Keyword(s):  
Equation Of State ◽  
Lipid Bilayer ◽  
Area Measurement ◽  
Water Interface ◽  
Pressure Area ◽  
Oil Water ◽  
Lipid Bilayer Vesicles

Dynamical formation of lipid bilayer vesicles from lipid-coated droplets across a planar monolayer at an oil/water interface

Soft Matter ◽  
2013 ◽  
Vol 9 (40) ◽  
pp. 9539 ◽  
Author(s):  
Hiroaki Ito ◽  
Toru Yamanaka ◽  
Shou Kato ◽  
Tsutomu Hamada ◽  
Masahiro Takagi ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Water Interface ◽  
Oil Water ◽  
Lipid Bilayer Vesicles

Applicability of the Langmuir Equation of State for Asphaltene Adsorption at the Oil–Water Interface: Coal-Derived, Petroleum, and Synthetic Asphaltenes

2015 ◽  
Vol 29 (6) ◽  
pp. 3584-3590 ◽  
Author(s):  
Jayant P. Rane ◽  
Sharli Zarkar ◽  
Vincent Pauchard ◽  
Oliver C. Mullins ◽  
Dane Christie ◽  
...  
Keyword(s):  
Equation Of State ◽  
Langmuir Equation ◽  
Water Interface ◽  
Oil Water

Neutral molecules and a simplified treatment for ions

1960 ◽  
Vol 252 (1009) ◽  
pp. 225-248 ◽  
Keyword(s):  
Equation Of State ◽  
Activity Coefficients ◽  
Specific Interaction ◽  
Electrical Potential ◽  
Electrical Energy ◽  
Water Interface ◽  
Free Energy Of Adsorption ◽  
Counter Ions ◽  
Surface Active ◽  
Oil Water

Films of neutral substances adsorbed at the oil/water interface obey the equation of state and the adsorption isotherm which are derived assuming complete mobility of the molecules in the interface. The equations are obeyed down to areas of ~ 30A 2 per molecule; deviations which occur below this value result from interactions between the adsorbed molecules. Adsorbed films of completely ionized sodium alkyl sulphates and quaternary am m onium compounds also obey these equations when allowance is m ade for the electrical contribution to the adsorption energy and for electrical interaction between the ions in the aqueous bulk phase. The activity coefficients cannot be neglected in these systems at concentrations exceeding 0.001 m. In the range 0.001 to 0.09m the ‘complete’ Debye-Huckel equation is used to calculate these coefficients; at the higher concentrations (for sodium decyl and octyl sulphates) the activity coefficients thus calculated are suspect. The electrical energy is given exactly by a modified Gouy equation, when allowance is made for the film ions being situated a finite equilibrium distance from the interface and for the fact that counter-ions will be present above the head groups. This modified equation yields linear plots for the isotherm and leads to consistent values for the free energy of adsorption of the molecules. It also ( a ) demonstrates th at the electrical potential at the phase boundary (jrd) differs from that in the plane for the film ions (i/r0) and th at the true jr0 is lower than th at calculated from the simple Gouy equation; from the m easured surface potentials (AF) interpreted by the equation of Schulm an & Hughes (1932), it is shown th at the calculated is experim entally confirmed; ( b ) predicts much more accurately than the simple equation the relation between the observed surface pressure (17) and area per molecule (equation of state). Deviations from the equations occur for short-chain compounds (C8 and C 10) in w ater at high concentrations, and for all surface-active agents in high electrolyte concentrations (> m/100), especially where A < 70A 2 . It is concluded that these deviations result m ainly from a neglect of ionic size in the theoretical treatm ent. There is no evidence in any of the systems for any specific interaction between counter ions and adsorbed film ions. The experimental results are inconsistent with the view that appreciable energy changes associated with dehydration of the surface-active ions occur as they approach the oil/water interface.

Interfacial equation of state for ionized surfactants at oil/water interfaces

Soft Matter ◽  
2015 ◽  
Vol 11 (32) ◽  
pp. 6482-6491 ◽  
Author(s):  
Alireza Bahramian ◽  
Ali Zarbakhsh
Keyword(s):  
Equation Of State ◽  
Interfacial Tension ◽  
Water Interface ◽  
Oil Water

Predicted and experimental interfacial tension isotherms at the oil/water interface as a function of SDS and C10TAB concentration.

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