Hydrocarbon alkanes, solubilized

Structural Considerations of Lamellar Liquid Crystals Containing Large Quantities of Solubilized Hydrocarbon Alkanes... 

Low angle X-ray data alone cannot provide an unambiguous answer to the question of location and order of the hydrocarbon chains. We considered direct determinations of the order parameters of the solubilized hydrocarbon chains to be useful information. A preliminary NMR investigation (3) of alkane solubilized in the lamellar phases formed by and water provided tentative support for the... 

The main features of gas and alkane solubilization suggest that they are solubilized in a hydrocarbon-like environment, with the amount solubilized dependent on the volume of hydrocarbon available, and they are only moderately influenced by the environment outside the micellar core. 

Enhanced bacterial growth rate and increased rate of n-alkane consumption Surfactant solubilization increases aqueous solubility of hydrocarbon 24... 

A neutral molecule solubilized in the micelle can be located in several positions or microenvironments. As early as the 1930s it was suggested by Lawrence that the site of a solubilized molecule would be dependent on the hydrophobic/hydrophilic composition of the solubilizate. Two extremes are easily identified the core of the micelle providing a hydrocarbon-like microenvironment, and the palisade layer providing an aqueous or water-rich interfacial environment. It seems logical to assume, then, that nonpolar solutes like alkanes would prefer the micellar core and that polar molecules would be anchored at the surface. However, this is an oversimplification available data tend to contradict it. First, the solubility of alkanes in micelles is significantly lower than expected if compared to solubility in hydrocarbon solvents. Second, the size of a micelle is normally such that part of the solute would be close to the surface at any time. Sepulveda et al. state that for SDS micelles at least half of the solute will be within 4 to 5 A of the surface. We should also consider the timescale of the experiments, as the timescale for intramicellar migration is short. The rate constants of entry and exit of molecules to and from micelles is of the order 1(F and... 

In early work. Hartley suggested that the hydrocarbon interior of the micelle must be liquidlike if one is to understand its extensive solubilization properties. Very little has happened that would alter that view. Since alkanes with structures analogous to the hydrocarbon tails found in surfactants exhibit freezing points generally much lower than the temperatures at which micelles are studied, the liquidlike nature of the core is to be expected. 

Recently, fluorous chemistry has been used to solubilize and phase-transfer nanocrystals of metals (Au) and chalcogenides (CdS) as well as inorganic nanorods (ZnO) [551]. Here, a fluorous label (e.g. fluorinated alkane thiol) is attached to the nanostructures which are then readily extracted by a fluorocarbon from aquous or hydrocarbon solutions, due to fluorine-fluorine interaction. This method not only enables the purification of the nanostructures, but also helps one to study them in the most-nonpolar medium possible, the refractive index of fluorocarbon being around 1.2. 

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