Improving solubilization in microemulsions with additives. 2. Long chain alcohols as lipophilic linkers

Graciaa, A.; Lachaise, J.; Cucuphat, C.; Bourrel, M.; Salager, Jean-Louis

doi:10.1021/la00036a008

Cited by 121 publications

(133 citation statements)

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“…A very small amount of lipophilic linker in oil (say, 1%) can more than duplicate the solubilization with very little compensation change on the water side of the interface. Very lipophilic amphiphiles, which are generally referred to as polar oils, were found to behave as lipophilic linkers: long chain (>C 10 ) n-alcohols, phenols, fatty esters, and the like (86). It is worth noting that such molecules may occur naturally in an oil phase, as "polar" impurities at the 1% level.…”

Section: Solubilization Enhancement With Multiple Amphihilic Speciesmentioning

confidence: 99%

Enhancing solubilization in microemulsions—State of the art and current trends

Salager

Antón

Sabatini

et al. 2005

J Surfact & Detergents

225

198

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Along a formulation scan, solubilization is maximal when a bicontinuous microemulsion is in equilibrium with both oil and water excess phases in a so-called Winsor III system. The logical way to enhance solubilization is to increase the interaction of the surfactant for both the oil and water phases, which can be easily attained by increasing the size of both the head and tail groups. However, this approach is limited by solubility constraints. Additional solubilization enhancement can be attained by introducing a molecule(s) that bridge the bulk phase and the adsorbed surfactant layer; this can be accomplished by using the so-called lipophilic and hydrophilic "linker effect" or by using block copolymer additives. In either case, the goal is to modify an extended zone in the oil and water domains close to their boundary. The intramolecular grafting of a linker group between the hydrophilic and lipophilic moieties in a surfactant results in a so-called "extended" surfactant structure, which produces enhanced solubilization, as does the surfactant/linker combination, but with the added benefit that the self-contained extended surfactant structure does not undergo selective partitioning. We conclude that an improvement in solubilization is directly related to the presence of a smooth, blurred, and expanded transition across the interfacial region from polar to apolar bulk phases.KEY WORDS: Extended surfactants, future trends, interfacial tension, lipophilic and hydrophilic linkers, microemulsions, solubilization, state of the art.

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Section: Solubilization Enhancement With Multiple Amphihilic Speciesmentioning

confidence: 99%

Enhancing solubilization in microemulsions—State of the art and current trends

Salager

Antón

Sabatini

et al. 2005

J Surfact & Detergents

225

198

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“…n-Alcohols have been found to be effective co-surfactants in crude oil-in-water emulsions [16]. Short-chain alcohols improve oil-in-water emulsion stability [17]. In addition, the emulsion-stabilizing effect is stressed by increasing the alkyl chain size of the alcohol [18].…”

Section: Introductionmentioning

confidence: 99%

Effects of Short-Chain n-Alcohols on the Properties of Asphaltenes at Toluene/Air and Toluene/Water Interfaces

Martins

Santos

2018

Colloids and Interfaces

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Abstract:Crude oil asphaltenes contain a wide series of chemical species, which includes the most polar compounds and interfacially active agents from the petroleum. Asphaltenes have been considered to be implicated in foam and emulsion formation during the petroleum recovery and production process. In this work, the interfacial activity of organic solutions containing asphaltene and n-alcohols was investigated. Asphaltene extraction from a 28 • API crude oil produced 2.5 wt % of n-pentane precipitated asphaltene (C5I). Dynamic surface and interfacial tensions of asphaltene solutions were assessed by the pendant drop method. Asphaltene films were evaluated at the air-water interface using a Langmuir trough. Results were expressed by means of the interfacial tension time-dependence. Interfacial tension measurements showed alcohols reduce the toluene/water interfacial tension of asphaltene solutions. The interfacial tension was reduced from 23 mN/m to 15.5 mN/m for a 2 g/L solution of asphaltene plus n-butanol. Higher asphaltene concentrations did not affect the toluene/air surface tension. The effects of n-alcohols on the asphaltene surface activity was dependent on the asphaltene aggregation state. n-Alcohols modify the asphaltene film elasticity and the film phase behavior.

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“…Considerable debate has occurred as to whether the alcohol enhances oil solubilization in microemulsions by acting as a cosurfactant or as a cosolvent (6,9,10). Oil solubilization is linearly related to surfactant micelle concentration (11,12).…”

Section: Introductionmentioning

confidence: 99%