Triton X-100 Aqueous Solution Research Articles

Microemulsion Extraction of Monascus Pigments from Nonionic Surfactant using High Polarity of Diethyl Ether as Excess Oil Phase

Stripping of organic compound from nonionic surfactant micelle aqueous solution is indispensable for many industrial processes. In this paper, a relatively high polarity diethyl ether was screened for forming Winsor I microemulsion, which was used for stripping of organic compound from nonionic surfactant. Setting up extractive fermentation of Monascus pigments in Triton X-100 aqueous solution as a model, cloud point extraction of Monascus pigments from fermentation broth, and back-extraction of Monascus pigments from the coacervate phase of cloud point system by Winsor I microemulsion were conducted. Monascus pigments were successfully separated from nonionic surfactant into the excess diethyl ether phase.

Water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid-liquid microextraction for the determination of fungicides in wine.

A sample preparation method, dispersive liquid-liquid microextraction assisted by an emulsion with low concentration of a surfactant in water and dispersed solvent coupled with gas chromatography-mass spectrometry, was developed for the analysis of the fungicides cyprodinil, procymidone, fludioxonil, flusilazole, benalaxyl, and tebuconazole in wine. A microsyringe was used to withdraw and discharge a mixture of extraction solvent and 240 μL of an aqueous solution of Triton X-100 (the dispersed agent) four times within 10 s to form a cloudy emulsion in the syringe. This emulsion was then injected into a 5 mL wine sample spiked with all of the above fungicides. The total extraction time was approximately 0.5 min. Under optimum conditions using 1-octanol (12 μL) as extraction solvent, the linear range of the method in analysis of all six fungicides was 0.05-100 μg L(-1), and the limit of detection ranged from 0.013 to 0.155 μg L(-1). The absolute recoveries (n = 3) and relative recoveries (n = 3) were 30-83 and 81-108% for white wine at 0.5, 5, and 5 μg L(-1), and 30-92 and 81-110% for red wine, respectively. The intraday (n = 7) and interday (n = 6) relative standard deviations ranged from 4.4 to 8.8% and from 4.3 to 11.2% at 0.5 μg L(-1), respectively. The method achieved high enrichment factors. It is an alternative sample preparation technique with good performance.

Dilute Triton X-100 in water as a reference liquid for hydrometer calibration using Cuckow’s method

We propose a 200 parts in 106 by volume solution of the surfactant Triton X-100 in water as a reference liquid for hydrometer calibration using Cuckow’s method. This liquid has advantages over traditional hydrocarbon fluids such as nonane and tridecane; it is safer, less expensive, and the density can be determined with sufficient accuracy from the mixing ratio. Previous researchers have used about 70 parts in 106 by volume Triton X-100 in water. Here we report measurements on the surface tension behaviour of aqueous Triton X-100 solutions with concentrations in the range (39–301) parts in 106 by volume. These measurements indicate that a 200 parts in 106 mixture is a suitable compromise between surface tension behaviour and accuracy of calculation of the liquid density from the mixing ratio of Triton X-100 to water. Performance tests to confirm the suitability of this liquid are given.

Preparation, characterization, viscosity, and thermal conductivity of nitrogen-doped graphene aqueous nanofluids

Nanofluids perform a crucial role in the development of newer technologies ideal for industrial purposes. In this study, Nitrogen-doped graphene (NDG) nanofluids, with varying concentrations of nanoparticles (0.01, 0.02, 0.04, and 0.06 wt%) were prepared using the two-step method in a 0.025 wt% Triton X-100 (as a surfactant) aqueous solution as a base. Stability, zeta potential, thermal conductivity, viscosity, specific heat, and electrical conductivity of nanofluids containing NDG particles were studied. The stability of the nanofluids was investigated by UV–vis over a time span of 6 months and concentrations remain relatively constant while the maximum relative concentration reduction was 20 %. The thermal conductivity of nanofluids was increased with the particle concentration and temperature, while the maximum enhancement was about 36.78 % for a nanoparticle loading of 0.06 wt%. These experimental results compared with some theoretical models including Maxwell and Nan’s models and observed a good agreement between Nan’s model and the experimental results. Study of the rheological properties of NDG nanofluids reveals that it followed the Newtonian behaviors, where viscosity decreased linearly with the rise of temperature. It has been observed that the specific heat of NDG nanofluid reduced gradually with the increase of concentration of nanoparticles and temperature. The electrical conductivity of the NDG nanofluids enhanced significantly due to the dispersion of NDG in the base fluid. This novel type of fluids demonstrates an outstanding potential for use as innovative heat transfer fluids in medium-temperature systems such as solar collectors.

Identification of phase boundaries in surfactant solutions via Compton spectrum quenching.

The critical micelle concentration and the phase boundary between isolated surfactant molecules and aggregates are probed via fluorescence spectroscopy and a Compton spectrum quenching technique for aqueous and toluenic solutions of Triton X-100 (TX-100). The internal fluorophore of TX-100 provides a convenient probe for the fluorescence measurements, and the appearance of redder bands in the fluorescence spectra and their relationship with aggregation (clustering of TX-100) phenomena is addressed. The Compton spectrum quenching approach makes use of quench indicating parameters (QIPs) commonly measured in liquid scintillation counting experiments. Phase boundaries identified by the QIP-based approach are in excellent accord with the fluorescence-based approach.

Behavior of cetyltrimethylammonium bromide and Triton X-100 mixture at solution–air interface in presence of short-chain alcohols

Surface tension measurements of the aqueous solutions of cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX-100) mixture with methanol or propanol in the whole range of alcohol concentration and in the range of surfactant mixture concentration from 1×10−6 to 1×10−3M were carried out. Based on the obtained results, the surface excess concentration values of this mixture and alcohols were calculated from the equation of Gibbs adsorption isotherm as well as from the Guggenheim-Adam one. Applying these surface excess concentration values, the composition of the mixed surface layer was established and compared with the hypothetic monolayer determined from the surface excess concentration values of the surfactant mixture and alcohols on the assumption that their adsorption was independent. The composition of the TX-100 and CTAB mixture was also calculated from the Rosen et al. concept on the assumption that water+alcohol was a mixed solvent and compared to the composition of the mixed monolayer formed from the independent adsorption of TX-100 and CTAB. From this comparison it results that there is a synergism in the reduction of the water surface tension at a certain composition of the surfactant mixture in the presence of alcohols. This synergism was confirmed by the standard free energy of the surfactant mixture adsorption calculated from both the Langmuir equation and the excess Gibbs free energy of TX-100 and CTAB mixing in the monolayer in the presence of methanol or propanol.

Synthesis and Association of Ag(0) Nanoparticles in Aqueous Nonionic Surfactant Triton X-100 Solution: A Facile Approach for Antibacterial Application

Synthesis and Association of Ag(0) Nanoparticles in Aqueous Nonionic Surfactant Triton X-100 Solution: A Facile Approach for Antibacterial Application

Self-aggregation of a synthetic zinc chlorophyll derivative possessing a 131-dicyanomethylene group as a light-harvesting antenna model

Zinc methyl 3-hydroxymethyl-131-dicyanomethylene-pyropheophorbide-a, one of the bacteriochlorophyll-d analogs, was prepared by modifying chlorophyll-a. The semi-synthetic compound self-aggregated in an aqueous Triton X-100 solution to give large oligomers with red-shifted and broadened electronic absorption bands. The J-aggregates were similar to self-aggregates of bacteriochlorophyll-d molecules in natural light-harvesting antennas of green photosynthetic bacteria. The strongly electron-withdrawing dicyanomethylene group was an alternative functional moiety of the hydrogen-bond accepting 131-oxo group which had been necessary for such self-aggregation.

Interactions of dipeptides with Triton X-100 in aqueous solution: A volumetric and spectroscopic study

The interactions of dipeptides with Triton X-100 in aqueous solution have been investigated by means of density, fluorescence spectroscopy and UV–vis spectroscopy. The standard partial molar volume (V2,ϕo), standard partial molar volume of transfer for dipeptide from water to aqueous Triton X-100 solution (ΔtVo) and partial molar expansibility (Eϕo) have been calculated from density data. Fluorescence spectroscopy was used to estimate the critical micellar concentration (ccmc) and micelle aggregation number of Triton X-100 in aqueous dipeptide solutions. Effects of temperature and hydrocarbon chain length of dipeptides on the volumetric properties of dipeptide and critical micelle concentration (ccmc) of Triton X-100 were examined. The pyrene fluorescence spectra were also used to study the change of micropolarity produced by the interactions of Triton X-100 with dipeptides. From the results of UV–vis absorption spectra, the binding constant between dipeptide and Triton X-100 above the ccmc was determined. The results have been interpreted in terms of solute–solvent interactions and structural changes in the mixed solutions.

Self-aggregation of Synthetic Zinc Hydroxylated Chlorophyll Derivatives inside Aqueous Micelles: Neighboring Effect of Additional O-Functional Groups

Abstract Zinc methyl bacteriopheophorbide-d possessing a 1-hydroxyethyl group at the 3-position self-aggregated in an aqueous Triton X-100 solution to afford a red-shifted Qy band, but the substitution of hydroxy and acetoxy groups at its 32-position completely disturbed their self-aggregation. Their neighboring groups intramolecularly interacted with the 31-hydroxy group to prevent them from producing chlorosomal J-aggregates.

The effect of temperature induced phase transitions in aqueous solutions of triblock copolymers and Triton X-100 on the EPR, magnetic relaxation and luminescent characteristics of Gd(III) and Eu(III) ions

The present report is inspired by the idea to develop novel spectroscopy based techniques to detect the phase transitions in solutions of triblock copolymers with the use of Gd(III) and Eu(III) ions as probes. The choice of (PEO)13(PPO)30(PEO)13 (L64), (PPO)14(PEO)24(PPO)14 (17R4), (PPO)8(PEO)22(PPO)8 (10R5) and Triton X-100 is conditioned by their phase transitions occurring in mild conditions. The cloud point extraction (CPE) data reveal the conditions (pH and chelating agent) where the binding of lanthanides with surfactant rich phase of triblock copolymers and Triton X-100 occurs. The effect of phase transitions in solutions of triblock copolymers on the temperature resolved line widths in EPR spectra of Gd(III) aqua ions and transverse relaxation rates of Gd(III) inner-sphere water protons depends on the architecture of triblock copolymers and pH conditions. The steady state luminescence of Eu(III) complexes with phosphine oxide in aqueous solutions of triblock copolymers and TX-100 is influenced by the temperature induced aggregation and phase separation in solutions of reverse triblock copolymers 17R4 and 10R5, while the effect of the aggregation is insignificant for L64.

Dye exchange in micellar solutions. Quantitative analysis of bulk and single molecule fluorescence titrations

A quantitative empirical model is presented, which relates the total surfactant concentration with the fluorescence intensity and the mean translational diffusion coefficient of dyes in micellar solutions, as determined by Fluorescence Correlation Spectroscopy (FCS). Based on this model a systematic data analysis method is defined for the precise determination of the dye binding equilibrium constant, the critical micelle concentration, the translational diffusion coefficients, and the hydrodynamic radii of dyes and micelles and related properties. The method can be used for the routine and automatic determination of the cmc of surfactant solutions. The model is applied to dyes with very different hydrophobicity in aqueous solutions of the non-ionic surfactant Triton X-100. As a reference the cmc of Triton X-100 is also determined directly from changes in the absorbance of its phenyl-ring applying a ratiometric method.

Synthesis of Ag@SiO2 hybrid nanoparticles templated by a Triton X-100)/1-hexanol/cyclohexane/H2O water-in-oil microemulsion

A water-in-oil microemulsion was prepared by using nonionic surfactant Triton X-100, 1-hexanol, cyclohexane and AgNO3 aqueous solution with a concentration of 0.2 mol L−1. Successive addition of sodium borohydride (NaBH4), ammonium hydroxide (NH3·H2O) and tetraethyl orthosilicate (TEOS) to this microemulsion leads to the formation of hierarchically-organized Ag@SiO2 hybrid nanoparticles with Ag nanocrystals randomly distributed inside amorphous SiO2, as proved by transmission electron microscopy (TEM) and high-resolution electron microscopy (HRTEM) observations. In many cases, H2 gas bubbles, which were produced during the reduction of Ag+, were found to influence the structures of Ag nanocrystals. The morphologies of the hybrid nanoparticles and the H2-induced cavities can be easily tuned by the molar ratio of AgNO3 to NaBH4 and the volume ratio of AgNO3 aqueous solution to TEOS. Embedded in amorphous SiO2, the Ag nanoparticles are highly stable, while the unprotected Ag nanocrystals underwent fast aggregation. The inner Ag nanocrystals have dominant (111) planes and are optically active, as shown by X-ray powder diffraction (XRD) and UV-vis measurement, respectively. These properties make these Ag@SiO2 hybrid nanoparticles fascinating candidates for a variety of applications in catalysis and life science.

Mutual influence of cetyltrimethylammonium bromide and Triton X-100 on their adsorption at the water–air interface

On the basis of surface tension values of the aqueous solution of cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX-100) mixtures measured at 293K as a function of CTAB or TX-100 concentration at constant TX-100 or CTAB concentration, respectively, the real surface area occupied by these surfactants at the water–air interface was established which is inaccessible in the literature. It appeared that at the concentration of the CTAB and TX-100 mixture in the bulk phase corresponding to the unsaturated monolayer at the water air-interface this area is the same as in the monolayer formed by the single surfactant at the same concentration as in the mixture. In the saturated mixed monolayer at this interface the area occupied by both surfactants is lower than that in the single surfactant monolayer corresponding to the same concentration in the aqueous solution. However, the decrease of the CTAB adsorption is lower than that of TX-100 and the total area occupied by the mixture of surfactants is also lower than that of the single one. The area of particular surfactants in the mixed saturated monolayer changes as a function of TX-100 and CTAB mixture concentration and at the concentrations close to CMC or higher the area occupied by both surfactants is the same. The changes of the composition of the mixed surface monolayer are connected with the synergetic effect in the reduction of the water surface tension by the adsorption of CTAB and TX-100 at the water–air interface. This effect was confirmed by the values of the standard Gibbs free energy of adsorption of both individual surfactants and their mixtures with different compositions in the bulk phase determined by using the Langmuir equation if RT instead of nRT was applied in this equation.

Export of intracellular Monascus pigments by two-stage microbial fermentation in nonionic surfactant micelle aqueous solution

Microbial fermentation of intracellular product is usually limited by high intracellular product concentration inhibition and complex downstream product processing. Perstractive fermentation of intracellular Monascus pigments in the nonionic surfactant Triton X-100 aqueous solution was studied in the present work, in which the intracellular product was exported from the intracellular to the extracellular aqueous solution and consecutively extracted into the nonionic surfactant micelles. After the second stage perstractive fermentation in the two-stage operation mode, biomass increased from 5 to 24g/l DCW. The corresponding extracellular concentrations of yellow, orange, and red pigments were 60, 49 and 26AU. The increase of cell density and the final pigment concentration were difficult to occur in a conventional aqueous medium using the two-stage fermentation. This positive effect of perstractive fermentation was ascribed to low intracellular pigment density, which eliminated the product inhibition and prevented the product from further degradation. The high efficiency of perstractive fermentation was further confirmed by fed-batch operation mode, in which the final biomass reached 28g/l DCW and the corresponding extracellular concentrations of yellow, orange, and red pigments were 130, 84 and 47AU.

Phenol induced growth in Triton X-100 micelles: Effect of pH and phenols’ hydrophobicity

Cloud point, viscosity and dynamic light scattering data on aqueous micellar solutions of a nonionic surfactant Triton X-100 in the presence of several phenolic solutes are reported. These additives alter the surfactant's solution behavior depending on their hydrophobicity and pH of the solution. α-Naphthol, p-cresol and phenol induced micellar growth whereas more hydrophilic catechol, quinol, resorcinol did not show any significant change in micelle size. Increase in p-cresol concentration, decrease in pH and increase in temperature favored micelle growth. NMR results show that at lower concentration (10mM) p-cresol resides in the shell region while at higher concentration (40mM) both in shell region and core/shell interface. Quinol resides at micelle–water interface even at high concentration (40mM).

Wettability, adhesion, adsorption and interface tension in the polymer/surfactant aqueous solution system: II. Work of adhesion and adsorption of surfactant at polymer–solution and solution–air interfaces

The values of the surface tension of aqueous solutions of Triton X-100, Triton X-114, Triton X-165, sodium dodecylsulfate, sodium hexadecylsulfonate, cetyltrimethylammonium bromide, cetylpyridinium bromide, sodium N-lauryl sarcosinate, dodecyldimethyethylammonium bromide, tetradecyltrimethylammonium bromide and benzyldimethyldodecylammonium bromide and those of contact angle measured in the polytetrafluoroethylene (polymethyl methacrylate, nylon 6)–solution–air system were applied for the studies of correlation between the adsorption of surfactants at the solution–air and polymer–solution interfaces, critical surface tension of polymer wetting and work of adhesion of aqueous solutions of these surfactants to the above mentioned polymer surfaces. On the basis of the surface tension of aqueous solutions of surfactants studied and polymer–solution interface tension the Gibbs surface excess concentration at the polymer–solution interface was calculated and compared to that at the solution–air one. Using the Gibbs surface excess concentration data the molar fraction of surfactants at the polymer–solution interface was determined and compared to that at the solution–air one. The values of the activity of surfactants at the polymer–solution interface obtained from the Sprow and Prausnitz equation were also compared to those at the solution–air one and next used for calculations of the work of adhesion of solution to the polymer surface. The obtained values were compared to those determined from the Young–Dupree equation.

Wettability, adhesion, adsorption and interface tension in the polymer/surfactant aqueous solution system. I. Critical surface tension of polymer wetting and its surface tension

The contact angle of aqueous solutions of Triton X-100, Triton X-114, Triton X-165, sodium dodecylsulfate, sodium hexadecylsulfonate, cetyltrimethylammonium bromide, cetylpyridinium bromide, sodium N-lauryl sarcosinate, dodecyldimethyethylammonium bromide, tetradecyltrimethylammonium bromide and benzyldimethyldodecylammonium bromide on polytetrafluoroethylene, polymethyl methacrylate and nylon 6 was studied. The contact angle values were used in the Young equation for the polymer–solution interface tension calculation and for the determination of the critical surface tension of polymer wetting. The critical surface tension of polymer wetting was obtained on the basis of the relationship between the cosine of contact angle and/or the adhesion tension as a function of the surface tension of aqueous solution of studied surfactants and then was discussed in relation to the Lifshitz–van der Waals components and electron-acceptor and electron-donor parameters of polytetrafluoroethylene, polymethyl methacrylate and nylon 6 surface tension. The role of the parameter of interfacial interactions in the relationship between the critical surface tension of polymer wetting and the surface tension was also considered. This parameter was calculated by using the polymer–solution interface tension as well as the polymer and aqueous solutions of surfactant surface tension.

Enzymatic measurement of phosphatidylserine in cultured cells

Phosphatidylserine (PS) is a quantitatively minor membrane phospholipid involved in diverse cellular functions. In this study, we developed a new fluorometric method for measuring PS using combinations of specific enzymes and Amplex Red. The calibration curve for PS measurement was linear and hyperbolic at low (0-50 µM) and high (50-1000 µM) concentrations, respectively, and the detection limit was 5 µM (50 pmol in the reaction mixture). This assay quantified PS regardless of the chain length and the number of double bonds. We applied this new method to the determination of PS content in HEK293 cells, which was validated by a recovery study and comparison with TLC-phosphorus assay. We showed that the PS content was high in sparse cells. The overexpression of PS synthase 1 elevated not only the cellular PS content but also the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) contents, suggesting the conversion of PS into PE and the enhancement of PC production. This new assay for PS measurement is simple, specific, sensitive, and high throughput, and it will be useful to clarify the metabolism and biological functions of PS.

Activity and thermodynamic parameters of some surfactants adsorption at the water–air interface

Measurements of the surface tension of aqueous solutions of Triton X-100, Triton X-114, Triton X-165, sodium dodecylsulfate, sodium hexadecylsulfonate, cetyltrimethylammonium bromide, cetylpyridinium bromide, sodium N-lauryl sarcosinate, dodecyldimethylethylammonium bromide, tetradecyltrimethylammonium bromide and benzyldimethyldodecylammonium bromide were made at different temperatures. On the basis of the obtained results the activity of the surfactants at the water–air interface was determined and discussed based on the intermolecular interactions. The surfactant activity at the water–air interface was taken into account for determination of thermodynamic parameters of surfactant adsorption using the Langmuir method and the Szyszkowski equation. The thermodynamic parameters were also determined by means of the Rosen and Aronson, Gamboa and Olea methods as well that based on the changes of tail–water interface tension to that of tail–air.