Aliphatic hydrocarbons, effect solubilization

For nonionic POE surfactants, on the other hand, the effect of temperature increase appears to depend on the nature of the solubilizate. Nonpolar materials, such as aliphatic hydrocarbons and alkyl halides, which are solubilized in the inner core of the micelle, appear to show increased solubility as the temperature is raised, the increase becoming very rapid as the cloud point (Section IIIB below) of the surfactant is approached (Saito, 1967). 

Since the PIT of a hydrocarbon-water emulsion stabilized with a POE nonionic surfactant is, as might be expected, related to the cloud point of an aqueous solution of the nonionic saturated with that hydrocarbon (Chapter 4), these effects on the PIT of emulsions stabilized by POE nonionics are readily understood. As mentioned in the discussion (Chapter 4, Section IIIB) of the effect of solubilizate on the cloud points of POE nonionics, long-chain aliphatic hydrocarbons that are solubilized in the inner core of the micelle increase the cloud point, whereas short-chain aromatic hydrocarbons and polar materials that are solubilized between the POE chains decrease it. They have the same effect on the PIT long-chain aliphatic hydrocarbons increase the PIT and therefore tend to form stable O/W emulsions, whereas short-chain aromatics and polar additives decrease it and tend to form stable W/O emulsions (Shinoda, 1964). An increase in the length of the POE chain increases the cloud point and the PIT and consequently increases the tendency to form O/Wemulsions, consistent with the generalization that the more water-soluble the emulsifier, the greater its tendency to form O/W emulsions. 

Toernblom, M. and Henriksson, U. (1997) Effect of solubilization of aliphatic hydrocarbons on size and shape of rodlike Cl 6TABR micelles studied by 2H NMR relaxation. /. Phys. Chem. B, 101, 6028-6035. 

Tomblom, M. and U. Henriksson. 1997. Effect of solubilization of aliphatic hydrocarbons on size and shape of rodlike C(16)TABr micelles studied by H-2 NMR relaxation. J. Phys. Chem. B 101 (31) 6028-6035. Jana, N. R., L. Gearheart, and C. J. Murphy. 2001. Wet chemical synthesis of high aspect ratio cylindrical gold nanorods. J. Phys. Chem. B 105 (19) 4065-4067. 

The difference in properties when the aliphatic chain of amine oxide contains more than 14 carbons is attributed to the mismatch of the hydrophobic chain with that of the SDS. The extra terminal segment results in a disruptive effect on the packing of the surface active molecules. The observed association behavior in the case of 0 2 C14-DAO with SDS is then also due to the maximum cohesive interaction between hydrocarbon chains in addition to the reduced electrostatic repulsion in the head groups. Solubilization of the 1 1 association is also determined by this chain length compatibility effect which may contribute to the absence of visible precipitation in C12/C12 and C2 2/ -14 mixtures. Chain length compatibility effects in different systems have been discussed by other investigators (24,25,26). 

In nonpolar aprotic solvents, such as the aliphatic and aromatic hydrocarbons and symmetrical halogenated hydrocarbons, or in polar solvents, such as aldehydes, ethers, and asymmetric halogenated hydrocarbons, the cathodic process can be the reduction of oxygen, which is quite soluble in hydrocarbons, or the reduction of protons allowed by the presence of halogen acid resulting from the hydrolysis of halogenated hydrocarbons. The polar behavior of the solvent favors the solvating effect of metal ions, the solubilization of the corrosion products of the corrosion process. 

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