Influence of d -glucose as additive on thermodynamics and physical properties of aqueous surfactant two-phase systems for the continuous micellar extraction

Ritter, Eric; Racheva, Ralena; Jakobtorweihen, Sven; Смирнова, Ирина

doi:10.1016/j.cherd.2017.02.032

Cited by 11 publications

(10 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The water solubility of compounds can be enhanced in micellar solutions by their favorable partitioning in the micelles compared to water. − This property is highly influenced by the charge of the surfactant headgroup. Because of this solubilization effect, surfactant-based systems find applications in cosmetics, detergents, and extraction processes. − The partition equilibria of a solubilized molecule (solute), defined as the partition coefficient ( K i = c i micelle / c i water ), is a decisive factor regarding the efficiency of extraction processes. In practical applications, mostly mixtures of surfactants are used because they have improved characteristics compared to those of single surfactants solutions. − For example, mixed micelles from block copolymers are promising vehicles for drug delivery as a result of improved physical stability and enhanced loading capacities compared to those of conventional polymeric micelles for drug delivery .…”

Section: Introductionmentioning

confidence: 99%

Micellization and Partition Equilibria in Mixed Nonionic/Ionic Micellar Systems: Predictions with Molecular Models

et al. 2017

View full text Add to dashboard Cite

In practical applications, surfactant solutions are mostly used in mixtures of nonionic and ionic surfactants because they have improved characteristics compared to those of single surfactant solutions. By adjusting the composition of the micelles and the pH value, the solubilization of solutes can be enhanced. Nevertheless, the partitioning of solutes between nonionic/ionic mixed micelles and the aqueous phase is studied to a much lesser extent than for single surfactant solutions. Theoretical methods to predict partition equilibria in mixed micelles are of interest for screening studies. For those, the composition of the mixed micelle has to be known. Here we investigate mixtures of TX-114 (Triton X-114), Brij35 (C12E23), SDS (sodium dodecyl sulfate), and CTAB (cetyltrimethylammonium bromide). First, to investigate the surfactant compositions in the micelles, molecular dynamics (MD) self-assembly simulations were applied. Thereafter, the predictive COSMO-RS model, which applies the pseudophase approach, and its extension to anisotropic systems termed COSMOmic were compared for the prediction of partition equilibria in mixed micelles, where various molar ratios of the surfactants were considered. It could be demonstrated that both methods are applicable and lead to reasonable predictions for neutral molecules. However, taking into account the three-dimensional structure of the micelle is beneficial because the calculations with COSMOmic are in better agreement with experimental results. Because the partitioning behavior of ionizable molecules in mixed micelles is of particular interest, the partitioning of ionized isovanillin in mixed Brij35/CTAB micelles at different micelle compositions was calculated with COSMOmic. Using a thermodynamic cycle, the position-dependent pK of isovanillin within the micelle is calculated on the basis of COSMOmic free energy profiles. As a result, the protolytic equilibrium of isovanillin within the micelles can be taken into account, which is crucial for the reliable prediction of partition coefficients.

show abstract

Section: Introductionmentioning

confidence: 99%

Micellization and Partition Equilibria in Mixed Nonionic/Ionic Micellar Systems: Predictions with Molecular Models

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Moreover, no stable phase boundary during experiments in the continuous extraction column could be observed at 40 °C. Comparable effects were described in the literature for the nonionic surfactant Tergitol 15-S-7 (ρ Tergitol 15‑S‑7 < ρ water ) . Thus, the simple decrease of the temperature does not solve the given extraction problem.…”

Section: Resultsmentioning

confidence: 99%

“…Comparable effects were described in the literature for the nonionic surfactant Tergitol 15-S-7 (ρ Tergitol 15-S-7 < ρ water ). 22 Thus, the simple decrease of the temperature does not solve the given extraction problem. Therefore, additives were tested to tune the liquid−liquid equilibrium and density differences of water/ROKAnol NL5 and to enable the extraction under these conditions.…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

“…22 This led to a successful implementation of a system water/Tergitol 15-S-7/D-glucose in a stirred extraction column. 22 However, the addition of sugars to microalgae cultures could lead to a contamination by bacteria or other microorganisms in an open fermentation process. Moreover, the overall mass of D-glucose required for an industrial process would be immense.…”

Section: Mpmentioning

confidence: 99%

See 1 more Smart Citation

Long-Chain Alcohol-Modified Micellar Systems and Their Application in a Continuous Extraction Process

Fellechner

Rotzolk

Смирнова

2019

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

The integration of an in situ extraction into biocatalytic processes is often limited by the toxicity of organic solvents. Therefore, it is desirable to use water-based extraction systems (for example, aqueous micellar two-phase systems). They can be used, for instance, for the extraction of valuable products from microalgae cultures. Recently, the nonionic surfactant ROKAnol NL5 was identified as a suitable surfactant for this purpose, since it forms an upper micellar phase, enabling an easy separation of whole-cell biocatalysts. However, its application at temperatures below 45 °C is limited by unstable phase boundaries, whereas the maximal temperature to ensure the vitality of the most microalgae cultures is ∼40 °C. To overcome this problem, the addition of long-chain alcohols to the surfactant–water mixture during extraction is suggested in this work. Using 1-hexanol, a continuous extraction process with the model solute trans-cinnamic acid at 40 °C in a stirred column could be realized. The results of a new suggested water/ROKAnol NL5/1-hexanol system at 40 °C (extraction yield, Y cont = 97.67% ± 0.14%; enrichment factor, log10 T CA = 2.42 ± 0.03; number of theoretical stages, N theo = 4.45 ± 0.16) are comparable to those of the water/ROKAnol NL5 system at 45 °C (Y cont = 99.26% ± 0.24%, log10 T CA = 2.60 ± 0.10, N theo = 5.88 ± 0.67), ensuring, however, no damage of microalgae.

show abstract

“…In cosmetics, water-insoluble compounds are dissolved using the solubility in micelles. − In pharmacy, surfactants are often added to drugs to improve the dispersion within the human body and are used as drug delivery agents. ,, Furthermore, micellar solubilization is used for extraction and purification of membrane proteins. − Zwitterionic micelles are used to mimic biological membranes due to their structural similarity to phospholipids and their easier preparation compared to liposomes. − Nonionic surfactants find application in environmental analytical chemistry to enrich and extract nanoparticles . In chemical engineering, nonionic surfactants are used in cloud point extractions (CPE). − …”

Section: Introductionmentioning

confidence: 99%

Solute Partitioning in Micelles: Combining Molecular Dynamics Simulations, COSMOmic, and Experiments

et al. 2017

View full text Add to dashboard Cite

The partition equilibria of solutes between micelles and an aqueous phase is a key factor in many applications. Depending on the task, many micelle-solute combinations are possible. Therefore, theoretical methods to predict the partition behavior in micellar systems are needed. Here, two predictive methods are evaluated and compared. First, it is shown how molecular dynamics simulations (MD) with the umbrella sampling method can be used to calculate free energy profiles in micellar systems. The second applied method is an extension of the COSMO-RS theory to anisotropic systems termed COSMOmic. Both methods are compared by means of free energy profiles and experimental micelle/water partition coefficients. A particular focus is on the partitioning of ionized solutes. As experimental data for partitioning in micelles especially for charged solutes is rare, partition coefficients were also determined experimentally. To get a general understanding of micelles examples of all micelle classes (classified by headgroup charge) are studied: nonionic Triton X-114 (TX114), zwitterionic miltefosine (HePC), anionic sodium dodecyl sulfate (SDS), and cationic cetyltrimethylammonium bromid (CTAB). The free energy profiles of neutral solutes obtained from MD simulations and COSMOmic are in an overall good agreement, and partition coefficients from both methods are in good agreement with experimental data. Depending on the system, the results for charged solutes show some deviations between the methods and experimental data.

show abstract

Influence of d -glucose as additive on thermodynamics and physical properties of aqueous surfactant two-phase systems for the continuous micellar extraction

Cited by 11 publications

References 50 publications

Micellization and Partition Equilibria in Mixed Nonionic/Ionic Micellar Systems: Predictions with Molecular Models

Micellization and Partition Equilibria in Mixed Nonionic/Ionic Micellar Systems: Predictions with Molecular Models

Long-Chain Alcohol-Modified Micellar Systems and Their Application in a Continuous Extraction Process

Solute Partitioning in Micelles: Combining Molecular Dynamics Simulations, COSMOmic, and Experiments

Contact Info

Product

Resources

About