Interfaces, organic liquid

Good local mixing of the interface organic liquid with the bulk of liquid organic phase. 

Jarvis, N.L. and Zisman, W.A. "Surface Activity of Fluorinated Organic Compounds at Organic-Liquid/Air Interfaces Part II. Surface Tension vs Concentration Curves, Adsorption Isotherms, and Force-Area Isotherms for Partially Fluorinated Carboxylic Esters," Naval Research Labs Report 5364, Surface Chemistry Branch, Chemistry Division, October 8, 1959. 

At about the same time, Matsushita et al. reported a study of quasi-two-dimensional deposition in a thin layer of electrolyte solution [3], A binary zinc sulfate solution was confined within a planar disk, 17 cm in diameter, bounded on the bottom by a glass plate and on the top by a layer of immiscible organic liquid. Cell potentials of several volts were applied, and the deposits grew along the liquid-liquid interface. In this cell, the depth of solution was 10 cm, but the deposit formed only along the interface between the electrolyte solution and the organic layer. Since a... 

The rheological properties of a fluid interface may be characterized by four parameters surface shear viscosity and elasticity, and surface dilational viscosity and elasticity. When polymer monolayers are present at such interfaces, viscoelastic behavior has been observed (1,2), but theoretical progress has been slow. The adsorption of amphiphilic polymers at the interface in liquid emulsions stabilizes the particles mainly through osmotic pressure developed upon close approach. This has become known as steric stabilization (3,4.5). In this paper, the dynamic behavior of amphiphilic, hydrophobically modified hydroxyethyl celluloses (HM-HEC), was studied. In previous studies HM-HEC s were found to greatly reduce liquid/liquid interfacial tensions even at very low polymer concentrations, and were extremely effective emulsifiers for organic liquids in water (6). 

Sow spreading coefficient of organic liquid at air-water table interface (dyn/cm)... 

Donahue, DJ. andBartell, F.E. The boundary tension at water-organic liquid interfaces. / Phys. Chem., 56(4) 480-484,1952. 

Gronwald O, Snip E, Shinkai S. Gelators for organic liquids based on self-assembly a new facet of supramolecular and combinatorial chemistry. Curr Opin CoUoid Interface Sci 2002 7 148-156. 

When water-immiscible liquids are used, three quite different classes of inactivation mechanism must be distinguished. First, in some cases inactivation is related to removal of water from the molecular environment of the enzyme rather than any direct effect of the solvent itself. A second possibility is that individual molecules of the organic species dissolved in an aqueous phase around the enzyme may interact with it. Third, contact of the enzyme molecules with the bulk organic liquid at the phase interface may be involved. There is evidence that in many cases interfacial effects provide the dominant mechanism. 

Obviously, the transfer between the pure organic liquid and the air must be air-phase controlled. Since the MCF concentrations at the interface are expressed in terms of the concentrations in the air, apply Eq. 20-9a, where the pure MCF takes over the role of the water ... 

The diimide synthesis takes place at the interface between liquid ammonia and the organic solvent in which the SiCl4 is dissolved. The product must be washed and calcined to remove the NH4Cl. At high temperatures (1300-1500 °C) the crystallisation to an a-rich powder takes place [220]. Temperatures above 1500 °C cause an increase of /I and grain size [221]. A very fine /1-rich powder can be obtained, when the crystallisation of an amorphous Si3N4 powder takes place at 1300-1450 °C in presence of an oxide nitride liquid in which the amorphous phase can be dissolved and reprecipitated mainly as /I [219]. 

Most of these aspects of water-sorption equilibrium correspond to the equality of chemical potentials of water in the medium and in the polymer. The consequences of this principle are illustrated by the experiment of Fig. 14.2, where an interface is created between water and a nonmiscible liquid (oil, hydrocarbon, etc.), and a polymer sample is immersed into the organic liquid. It can be observed that, despite the hydrophobic character of the surrounding medium, the sample reaches the same level of water saturation as in direct water immersion or in a saturated atmosphere. What controls the water concentration in the polymer is the ratio C/Cs of water concentrations in the organic phase, where Cs is the equilibrium concentration, which can be very low but not zero. In other words, hydrophobic surface treatments can delay the time to reach sorption equilibrium but they cannot avoid the water absorption by the substrate. 

Table 39—Displacement Pressures for Organic Liquid-Water-Solid Interface Systems. (Bartell and Osterhof, 1927)...

Fig. 8. Raman microscope for the measurement of SERS spectra of liquid-liquid interface organic phase 250 pi and aqueous phase 250 pi.

In Eq. (48), y is the coefficient of surface tension, g is gravitational acceleration and Apm is the difference in mass densities between the aqueous and organic liquids. The interface position z = (r) and the deflection t(r) = — of the interface from its unperturbed position are shown schematically in Fig. 6. Nondimensionalization of Eq. (48) leads to two dimensionless groups that relate electrostatic and gravitational stresses to surface tension. These groups are called the electrostatic and gravitational bond numbers, and are given by [25]... 

We will describe two mesoscale, self-assembling systems in which the interactions between objects are based on capillary forces. The first is based on polyhedral polydimethylsiloxane (PDMS) objects at a perfluorodecalin (PFD)/H20 interface. These objects have their faces patterned to be either hydrophobic or hydrophilic, and they assemble via lateral capillary forces that originate from interactions between these faces (Fig. 4. la). The second system uses polyhedral objects that are suspended in water and have selected faces covered with a water-insoluble liquid - either a hydrophobic organic liquid or a liquid metal solder these objects assemble via capillary forces into three-dimensional (3D) structures (Fig. 4.1b). 

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