Effect of oil chain length on the

Figure 11. Effect of Oil Chain Length on the Oil/Alcohol Titration Plots for Microemulsions.

The effect of oil chain length on the partition coefficient of surfactant in the oil/brine system is explained in Figure 4. 

Fig. 19. Effect of oil chain length on the interfacial tension in high and low surfactant concentration systems.

Lipase potassium dodecanoate -several oils Effect of oU chain length on the trigliceride synthesis [28]... 

Figure 10. Schematic Illustration of the Effect of Increasing Oil Chain Length on the Partitioning of Alcohol in the Water, Oil and Interfacial Region.

In a petroleum sulfonate/isobutanol/dodecane/brine system, there are two regions of ultralow interfacial tension (IFT), one at low surfactant concentrations (0.1-0.2%) and the other at higher surfactant concentrations (4 to 10%). In the low concentration range, the oil/brine/surfactant/alcohol system is a two-phase system, whereas at high surfactant concentrations, it becomes a three-phase system in which a middle phase microemulsion is in equilibrium with excess brine and oil. For low surfactant concentration systems, we have shown that the ultralow IFT minimum corresponds to the onset of micellization and partition coefficient of surfactant near unity. This correlation was observed for the effect of surfactant concentration, salt concentration and oil chain length on the interfacial tension. The minimum in interfacial tension corresponds to a maximum electrophoretic mobility of oil droplets. This correlation was also observed for the effect of caustic on several crude oils. 

FIG. 8 Effect of chain length on the CMC concentration at 35°C [86]. (Reprinted with permission of American Oil Chemists Society.)... 

The effect of chain length on the pseudo rate constant is shown in Fig. 18. Clearly, the optimum chain length for AOS is 16 carbon atoms. However, at this optimum the rate of oil solubilization for AOS is still below that observed for the reference compound DOBS 103, a sodium alkylbenzenesulfonate with 10-13 carbon atoms in the alkyl chain. Increasing the chain length of IOS subjected to an aging step before hydrolysis with NaOH (IOSa in Fig. 18) leads to a continuously increasing rate of oil solubilization. The highest rate was... 

Schick and Fowkes (11) studied the effect of alkyl chain length of surfactants on critical micelle concentration (CMC). The maximum lowering of CMC occurred when both the anionic and nonionic surfactants had the same chain length. It was also reported that the coefficient of friction between polymeric surfaces reaches a minimum as the chain length of paraffinic oils approached that of stearic acid (12). In order to delineate the effect of chain length of fatty acids on lubrication, the scuff load was measured by Cameron and Crouch (13). The maximum scuff load was observed when both hydrocarbon oil and fatty acid had the same chain length. Similar results of the effect of chain length compatibility on dielectric absorption, surface viscosity and rust prevention have been reported in the literature (14-16). 

The sensory effects of volatile compounds depend on the chain length, type of functional group, and positional and geometric isomerism. The same aldehyde can produce different odors and flavors in aqueous and oil solutions, the threshold being much lower in the former medium. In oil-in-water emulsions such as mayonnaise, the oil-water partition coefficient (Pq/ ) of a given compound affects its sensory impact on the emulsion (Jacobsen, 1999). 

A further step in the direction of a more detailed and realistic description of the amphiphile is taken by models in which the amphiphile is modeled by a polymer-like chain of subunits that are water-like at one end and oil-like at the other end [23]. Such models have been studied both in the continuum [24-26] and on a lattice [27 -31]. The advantage of these models is that they allow a calculation of the effect of the amphiphile chain length on the properties of microemulsions. These models have been studied mostly by computer simulations. 

In order to emphasize the role of the inter facial films and to highlight the most recent viewpoints on the stability of microemulsions, sponge phases, and dilute lamellar phases, some of the experimental facts about phase behavior of microemulsion systems containing alcohol are reviewed in this chapter. The systems investigated consist of water, oil, alcohol, and sodium dodecylsulfate (SDS). In the next section, the theoretical aspects of the stability of surfactant phases are briefly discussed. Then in Secs. Ill and IV the effects of varying alcohol and oil chain lengths and the addition of a water-soluble polymer are examined. The examination of multiphase regions provides the location of lines of critical points or critical endpoints. This chapter also deals with the study of several physical properties in the vicinity of critical points. 

H., Effect of Hydrophilic Chain Length of Amphiphilic Silicone Oil (Copolymer) on the Nonionic Surfactant-Layer Curvature. J. Phys. Chem. B 2004,108, 12736-12743. 

The effect of added oil on the phase behavior of the Ci2(EO) -water system was investigated as a function of EO chain length at 25°C [296]. When decane is added to the system Ci2(EO)3-water, the lamellar to reverse hexagonal Hu transition takes place, while in the system decane-Ci2(EO)7 water, the normal hexagonal Hi to hydrophilic discrete cubic Ii transition occurs. These phenomena may be interpreted by considering the two ways in which oil may affect the system [296] ... 

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