Thermodynamics of solubilization

Mallikarjun, Ramesh; Dadyburjor, Dady B.

doi:10.1016/0021-9797(81)90261-7

Cited by 18 publications

(5 citation statements)

References 7 publications

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“…The above volume fraction was estimated assuming that excess volumes from nonideal molecular interactions are negligible. The specific volume of one alkyl chain in the micellar core of Triton X-100 was reported to be 363 Å 3 (21), which leads to a hydrophobic (alkyl) volume of 0.22 L/mol of surfactant. The liquid molar volumes of naphthalene, phenanthrene, and pyrene were taken from Daubert and Danner (24) as 0.13, 0.16, and 0.17 L/mol, respectively.…”

Section: Effect Of Solubilites On the Micellar Sizementioning

confidence: 99%

“…In the process of polyoxyethylene surfactants aggregation to form micelles, the net free energy of aggregation has contributions from the following: (i) transfer of hydrophobic moieties from water to a hydrophobic core; (ii) formation of an interface between the hydrophobic core and water; (iii) conformational free energy of the hydrophobic moieties due to constrained location of the headgroups at the aggregate surface; (iv) deformation and mixing free energy of the polyoxyethylene chains; and (v) steric interaction between the headgroups at the aggregate surface ( − ). The magnitudes of the first two contributions are generally much larger than those of the others.…”

Section: Introductionmentioning

confidence: 99%

“…The magnitudes of the first two contributions are generally much larger than those of the others. Molecular structure of the hydrophobic tail determines physical properties of the liquid-hydrocarbon-like core, including the interfacial tension at the core−water interface ( , ). This interfacial tension limits the curvature of the core−water interface that can be supported and, thus, the size of the micelle ( − ).…”

Section: Introductionmentioning

confidence: 99%

“…Molecular structure of the hydrophobic tail determines physical properties of the liquid-hydrocarbon-like core, including the interfacial tension at the core−water interface ( , ). This interfacial tension limits the curvature of the core−water interface that can be supported and, thus, the size of the micelle ( − ). A higher curvature and larger interface can be supported by the same free energy change if the interfacial tension is decreased, which can occur by the presence of certain types of solutes at the interface.…”

Section: Introductionmentioning

confidence: 99%

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Solubilization of PAH Mixtures by a Nonionic Surfactant

Guha

Jaffé

Peters

1998

Environ. Sci. Technol.

126

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Enhanced solubilization of naphthalene, phenanthrene, and pyrene in micellar solutions of Triton X-100 was studied for single compounds and their binary and ternary mixtures. Experimental results were obtained for the following conditions: (i) naphthalene, phenanthrene, and pyrene as single compounds at saturation; (ii) naphthalene, phenanthrene, and pyrene as binary and ternary mixtures at satura tion; (iii) phenanthrene at saturation in a range of naphthalene concentrations; (iv) pyrene at saturation in a range of naphthalene concentrations. The solubility enhancement of naphthalene was slightly reduced in the presence of phenanthrene and/or pyrene. A synergistic effect on the solubilization of phenanthrene was observed in the presence of different amounts of naphthalene. The solubility of phenanthrene was greatly enhanced in both binary mixtures and in the ternary mixture. The solubility of pyrene was slightly reduced in the presence of naphthalene, remained unaffected in the presence of phenanthrene, and increased significantly in the ternary mixture. The increase in the partition coefficient values is explained by the partitioning of the solubilzate at the micellar core−water interface, which changes the interfacial free energy and effectively increases the volume of the core leading to a higher solubilization potential.

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Section: Effect Of Solubilites On the Micellar Sizementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Solubilization of PAH Mixtures by a Nonionic Surfactant

Guha

Jaffé

Peters

1998

Environ. Sci. Technol.

126

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“…This assumption is reasonable when the contaminant concentration is less than 1% of the surfactant concentration ( , ), as is the case for the results discussed here. When the surfactant and solute concentrations are comparable, a mixed micelle system will be formed with different micellar dynamics than for the pure surfactant system ( , ).…”

Section: Formulation Of Biodegradation Kinetics Of a Hydrophobic Subs...mentioning

confidence: 99%

Bioavailability of Hydrophobic Compounds Partitioned into the Micellar Phase of Nonionic Surfactants

Guha

Jaffé

1996

Environ. Sci. Technol.

151

119

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The apparent solubility of polycyclic aromatic hydrocarbon compounds such as phenanthrene can be increased in the presence of surfactants above their critical micelle concentration. A fraction of the phenanthrene partitioned into the micellar phase of some nonionic surfactants can be directly bioavailable to phenanthrene-degrading microorganisms. A model describing the biodegradation of the directly bioavailable micellar-phase substrate is presented. The hypothesis on which the model is based considers the following steps: (a) the contaminant is transported by filled micelles from the bulk solution to the proximity of the cells; (b) the exchange of the filled micelle with the hemimicellar layer around the cell delivers the contaminant to the cell; (c) the contaminant diffuses into the cell and is biodegraded. The biodegradation kinetics were explained in terms of a series of mass-transfer processes, which lead to a similar equation as the Monod kinetics. The theoretically derived expression, describing the micellarphase substrate that is directly bioavailable, includes a series of surfactant dynamics and mass transfer rate parameters that are not readily available or easily determined. A simplified formulation, which can be used to estimate the direct bioavailability of the micellar-phase substrate was therefore obtained and was used to explain experimental observations. The bioavailable fraction of the micellar-phase substrate was independent of the biomass concentration and was a function of the surfactant concentration, the polyoxyethylene chain length of the surfactant, and the biomass surface characteristics.

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Detergency

Lynn¹

2000

Kirk-Othmer Encyclopedia of Chemical Technology

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Many factors determine the ultimate effectiveness of a cleaning system. Knowledge of the substrate to be cleaned, the soil to be removed, the nature of the bath, and the detergent formulation is required to adequately describe the cleaning process. Home laundering, for example, involves removal of particulate or oily soils from textiles of varying compositions in an aqueous bath. Formulated detergents, added to the bath or fabric, significantly affect this process. Hard surface cleaning involves the removal of soil from a nonporous substrate, normally assisted by a detergent formulation. Detergent formulations differ in complexity, depending on the particular application for which they are designed and the variability in conditions under which they are expected to perform. Laundry detergents can require high water softening capability and therefore significant levels of water softeners. The replacement of phosphate has led to much research and development activity and increased numbers of choices in determining the most suitable formulations for a given purpose. The type and concentration of surfactant is another primary factor in determining the formulation. Measurement of cleaning efficacy can be done by several methods, ranging from the subjective (panelists rating) to more objective ones, such as reflectometry. Performance profiles are then used to determine more efficient formulations. Once the formulation is identified and deemed ready for commercialization, it must be manufactured. Liquids can be mixed simply by addition of the ingredients to water. The historic method of mixing ingredients for powders is to blend in a crutcher and spray dry in a hot tower. The resulting particle typically dissolves easily because of its porous structure. The formulations also must meet or surpass existing/potential health, safety, and environmental issues. With an understanding of all the appropriate factors involved in detergency, the formulator can more quickly and efficiently determine the optimum formulations to meet the specified objectives.

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Thermodynamics of solubilization

Cited by 18 publications

References 7 publications

Solubilization of PAH Mixtures by a Nonionic Surfactant

Solubilization of PAH Mixtures by a Nonionic Surfactant

Bioavailability of Hydrophobic Compounds Partitioned into the Micellar Phase of Nonionic Surfactants

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