Concentration Of Surfactant Sodium Dodecylbenzenesulfonate Research Articles

Green Surfactant Assisted-Solidified Floating Organic Drop Micro-Extraction (SA-SFODME) for the Preconcentration of Trace Lead with Determination by Flame Atomic Absorption Spectrometry (FAAS)

Determination of trace lead from environmental samples was carried out by solidified floating organic drop microextraction for preconcentration before analysis by flame atomic absorption spectrometry. The determination of lead from environmental samples, even at trace levels, was possible with an ordinary flame atomic absorption spectrometer (FAAS). The lead formed a hydrophobic complex with the anionic surfactant sodium dodecyl benzene sulfonate (SDBS), and this hydrophobic complex was extracted into the 1-dodecanol drop. Parameters affecting analytical performance have been studied. The optimum pH value was 3.5. The optimum sample volume, SDBS concentration, and extraction solvent volume were 75 mL, 50 mM in dodecanol, and 75 µL, respectively. The optimum extraction time was determined as 30 min, the optimum extraction temperature was 45 °C, the optimum mixing speed was 650 rpm and the ideal extraction phase volume was 0.50 mL. Methanol has been shown to be effective when used as a diluent. Using the optimum conditions, the enhancement factor was 106, and the limit of detection (3s) and precision were 3.3 ng/mL and 2.3% (n = 9,15 ng/mL), respectively. The limit of quantification (LOQ) (10s) was 10 ng/mL and the linear working range was 15-100 ng/mL. The accuracy was evaluated by certified reference material analysis. The optimized method was applied to the determination of Pb(II) from environmental water samples. This method follows the principles of green analytical chemistry.

Effect of solution pH on removal of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) from model wastewater using nanoscale zero-valent iron (nZVI)

Batch experiments for removal of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) from model wastewater using nanoscale zero-valent iron (nZVI) were conducted to elucidate mechanisms of SDBS removal by nZVI. To clarify the effects of solution pH on removal of SDBS by nZVI, the concentration profiles of Fe ions and dissolved oxygen (DO) were measured besides the concentrations of SDBS and total organic carbon (TOC) at pH of 3, 5, 7 and 9. The SDBS concentration rapidly decreased to less than 4% of the SDBS loadings within 40 min at pH 3, 7 and 9. However, TOC decreases were rather slow and the maximum TOC removal of 62% after 240 min was obtained at pH 7. The XRD patterns confirmed that the main corrosion product was lepidocrocite at pH 5 and 7 while magnetite was dominant at pH 9. The maximum removal of SDBS by nZVI at pH 7 was attributed mainly to the ionic adsorption of anionic SDBS onto the positively charged nZVI surface. The novel kinetic model for dynamic linkage of SDBS removal with concentrations of total eluted iron ions and DO via the formation of iron oxide/hydroxide layer on nZVI surface could simulate the experimental results with the average correlation coefficient of 0.952. The mechanisms of SDBS removal by nZVI at different pH values were clarified and quantified by the proposed kinetic model.

Development and application of modified lye for treating hydrogen sulphide in coal mine

To improve the absorption efficiency of alkaline liquor treated with hydrogen sulphide in coal mines, a single sodium carbonate lye was taken as the basic raw material to modify the absorption of lye by adding the surfactant sodium dodecyl benzene sulfonate (SDBS) and the oxidant hydrogen peroxide. Respectively, the effects of different concentrations of surfactants and oxidants in sodium carbonate solution on the removal of hydrogen sulphide gas were investigated. The results show that the concentration of sodium carbonate solution is positively correlated with the removal rate of hydrogen sulphide. When the concentration of sodium carbonate solution increases to 2%, the initial removal rate of hydrogen sulphide is close to 100%, however, the problem of secondary dissipation of hydrogen sulphide is more significant after vibration. With the increase of SDBS and hydrogen peroxide concentration, the removal rate of hydrogen sulphide from sodium carbonate solution respectively increases to 93.1% and 86.2%. Finally, through experimental analysis and in situ measurements, the optimal ratio of the modified lye in the hydrogen sulphide treatment of this experiment is as follows: the concentration of sodium carbonate solution is shown to be 2%, the concentration of surfactant is 0.4%, and the concentration of oxidant is 0.6%. On this basis, by comparing the 40,201 working face of Xiaozhuang Coal Mine with the 40,202 working face, it is concluded that the average removal rate of the modified lye is 93.5%, and the treatment effect of removing hydrogen sulphide is significant.

In Situ Measurement of Depletion Caused by SDBS Micelles on the Surface of Silica Particles Using Optical Tweezers

Dual-trap optical tweezers have been used to directly measure the interaction forces between two silica particles upon controlling the concentration of the ionic surfactant sodium dodecylbenzenesulfonate (SDBS). By capturing two silica particles in one spot optical trap and one linear optical trap and controlling the linear trap to bring one particle to approach another sufficiently closer, the interaction forces between these two particles can be measured as the separation distance changes. Results showed that with increasing concentrations of SDBS, the interaction force between the two silica particles emerges at closer surface distance between two silica particles. Only repulsive force exists between silica particles below the critical micelle concentration (cmc) of SDBS and it could be well-fitted using the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. However, the depletion attraction force appears above the cmc of SDBS which is induced by the generation of SDBS micelles. By in situ measurement of the interaction force between two silica particles in the presence of different concentrations of SDBS, the depletion force can be quantitatively calculated.

A Specific Turn-On Fluorescent Sensing for Ultrasensitive and Selective Detection of Phosphate in Environmental Samples Based on Antenna Effect-Improved FRET by Surfactant.

Phosphate is not only an important indicator for aquatic ecosystems, but also plays vital roles in biosystems. A new strategy for ultrasensitive and selective detection of phosphate is fabricated based on a new insight found in this paper, in which a lower concentration of surfactant sodium dodecylbenzenesulfonate (SDBS) can greatly induce fluorescence resonance energy transfer (FRET) from ciprofloxacin (CIP) to Eu3+ in the CIP-Eu3+ complex. Surfactant SDBS does not act as a sensitizer for enhancing the fluorescence intensity of the system, but acts as a sensitizer of FRET and makes the native fluorescence of CIP quenched completely (switch off). Eu3+ ions can coordinate with the oxygen-donor atoms of phosphate, which weakens FRET from CIP to Eu3+ and results in the fluorescence recovery of CIP (turn on). The multicomplex of the CIP-Eu3+-phosphate has more sensitive fluorescent response than that of the reported coordination nanoparticle-based fluorescent probes. The LOD (S/N = 3) of this sensing system can attain 4.3 nM. The possible interferential substances existing in environmental samples, such as 17 common metal ions, 11 anions, and fulvic acid investigated, do not interfere with the phosphate detection. This sensing system has been successfully applied for phosphate detection in environmental samples such as wastewater, surface water, and atmospheric particulates. This work not only develops a fluorescent probe for the phosphate detection, but also provides a new strategy for designing fluorescent probes based on FRET or coordination nanoparticles.

Fluorescent Polyion Complex for the Detection of Sodium Dodecylbenzenesulfonate.

Polyion complexes have been known about for decades, with their applications mainly restricted to drug and gene delivery. In this study, we show that by the introduction of fluorescent charged molecules into a polyion complex, it can be used as a specific detection system for surfactants. The fluorescence of 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) is quenched in the ionic complex, while it can be recovered with the addition of the surfactant sodium dodecylbenzenesulfonate (SDBS), due to the stronger interaction between SDBS and the polyelectrolyte. This leads to a drastic color change of the solution, and a recovery of the strong emission of HPTS. Specifically, the fluorescence is linearly proportional to the concentration of SDBS, thus it can be used for the qualitative detection of SDBS. Furthermore, the detection limit for SDBS can be up to the order of 10−10 M. We believe that competitive dissociation of the ionic complex can be used as a general approach for the construction of new functional materials.

Aggregation Behavior and Electron‐Transfer Reaction of Dendritic Perylene Bisimide, Accompanied by the Formation of Highly Stable Anionic Radical Species

AbstractA polyethylene‐glycol‐functionalized perylene bisimide (PEPBI) was synthesized. Its concentration‐, solvent‐ and temperature‐dependent visible spectra were measured and its aggregation states were analyzed. PEPBI exists as an aggregate dimer in aqueous solution or predominantly as a monomer in organic solvents. The anionic surfactant sodium dodecylbenzenesulfonate (SDBS) can disperse PEPBI as a monomer in aqueous solution. The fluorescence of these solutions depends on the concentration of PEPBI and SDBS. The reduction of aggregated PEPBI with Na2S is slow and the monoanion radical as well as dianion species are the main forms of monomer. PEPBI exists predominantly as monomers in DMF and reacts with Na2S much faster. Interestingly, the anionic radical species exist in H‐aggregate form at low PEPBI concentrations and J‐aggregation occurs at high concentration. The dianion species is EPR‐silent and its color highly depends on its concentration in DMF.

Modeling the steady-shear rheological behavior of dilute to highly concentrated oil-in-water (o/w) emulsions: Effect of temperature, oil volume fraction and anionic surfactant concentration

Oil-in-water (o/w) emulsions having different internal phase concentrations have been encountered in the petroleum industry during production, transportation and storage operations. The present study deals with the rheological behavior of o/w emulsions of varying internal phase (oil) concentrations (10–80%) at different temperatures (25–50 °C). A controlled stress rotational viscometer was used with shear rates ranging from 1 to 100 s−1. The emulsions were prepared with an anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and the concentration of the surfactant was varied from 0.5 to 2 w/v %. The emulsions exhibited typical shear thinning behavior and described well by the power law relationship between shear stress and shear rate. Different viscosity models were tested and fitted with the experimental rheological data using rigorous-linear regression analysis. The emulsion viscosity and pseudoplasticity were found to increase with an increase in oil concentration and decrease with an increase in temperature. Droplet size distribution and surface tension (SFT) measurements showed that both droplet size and SFT of emulsions decreased with an increase in the oil concentration, which significantly influenced the emulsion rheology. The effect of oil concentration on the apparent viscosity of emulsions was correlated by an exponential and a polynomial model. Further, a correlation was proposed for the combined effect of volume fraction and temperature on viscosity of emulsions. At higher concentrations of SDBS, the emulsion showed yield stress to flow. The Herschel–Bulkley model described the rheological data significantly well.

The Effect of Sodium Dodecylbenzenesulfonate (SDBS) Micelles on a BelousovZhabotinsky Oscillating System Catalyzed with a Tetraazamacrocyclic Copper(II) Complex

AbstractThis article deals with the influence of micelles of the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on the BelousovZhabotinsky (BZ) oscillating reaction catalyzed by a tetraazamacrocyclic copper(II) complex [CuL](ClO4)2, an enzyme‐like catalyst (L=5,7,7,12,14,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene). Unlike the classical BZ oscillator in which malonic acid is usually used as a substrate, malic acid (an intermediate in the Krebs cycle) is involved in this oscillating system. Experiments reveal that formation of the SDBS micelles markedly affects the behavior of the oscillating reaction. It is found that there is a linear relationship between the change in the oscillation amplitude (ΔA) and the concentration of SDBS, whereas the change in the oscillation period (ΔT) is linearly proportional to the SDBS concentration. The most likely mechanism that involves the formation of the SDBS micelles and the effects of the micelles on the oscillating chemical system can be rationalized by assuming that the SDBS micelles are so negatively charged that they attract more [CuL]3+ than [CuL]2+. This hypothesis was confirmed by UV/VIS spectrophotometric measurements of a constant concentration of [CuL](ClO4)2 in different concentrations of SDBS; as the SDBS concentration increased, the absorbance of [CuL](ClO4)2 increased, while the maximum absorption wavelength for [CuL](ClO4)2 remained at 502 nm.

Adsorption of SDBS and Its Effect on Rheology of Preformed Particle Gels

The adsorption of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) onto preformed particle gels (PPGs) and the effect of SDBS on the swelling ratio and rheology of PPGs were investigated. SDBS molecules can adsorb onto PPGs because of the hydrophobic association with the chain of PPGs at low concentration and the association of the SDBS micelles with the chains of PPGs at high concentration. PPGs contract and the shear stress of PPGs decreases after adsorption of SDBS. In addition, the storage modulus decreases first and then increases with increasing SDBS concentration.

Investigation on the Effect of an Divalent Electrolyte on the Flocculation of SDBS with Al<sup>3+</sup>

The effect of an divalent electrolyte Ca2+ on the flocculation of two different concentrations of anionic surfactant Sodium Dodecylbenzenesulfonate (SDBS) with Al3+ has been investigated at different molar ratios Al3+ to SDBS at 298.15 K. The results showed that the flocculation characteristics of 0.01 mol•L-1 SDBS (above the critical micelle concentration CMC) and 0.001 mol•L-1 SDBS (below the CMC) were obviously different with an increase of dosages of Al3+. The z-average size of flocculate of 0.01 mol•L-1 SDBS with Al3+ decreased particularly with the pre-addition of Ca2+，It suggested the formation of the complexion Ca(SDBS)2. At optimization flocculation areas at 298.15K, pH values were all around 3.5 in the flocculation systems SDBS/Al3+ and Ca2+/SDBS/Al3+ whether the SDBS concentration above or below the CMC. The pre-addition of Ca2+ slightly affected other flocculation parameters of SDBS/Al3+ systems such as zeta potential, surface tension, conductivity and pH.

Effect of SDBS on interfacial electron transfer at the liquid/liquid interface by thin layer method

The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on electron transfer (ET) reaction between ferricyanide aqueous solution and decamethylferrocene (DMFc) located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer ( k et) increased monotonically as the SDBS concentrations increased from 0 to 200 μmol/L. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer.

Structure transition from aragonite to vaterite and calcite by the assistance of SDBS

Structure transition from aragonite to vaterite and calcite with the help of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) was investigated, respectively, by a hydrothermal method. When the experimental temperature was controlled at 90 °C, aragonite of crystal calcium carbonate was transformed into vaterite with the assistance of SDBS. Pure vaterite was obtained as the concentration of SDBS reaches to 2.5 mM. When the experimental temperature was controlled at 120 and 150 °C, respectively, aragonite was transformed into calcite, and pure calcite was obtained as the concentrations of SDBS were equal to 1.0 and 2.5 mM, respectively. Possible formation mechanism of different CaCO 3 polymorphs was proposed based on the obtained experimental results.

Role of sodium dodecylbenzenesulfonate in 2,2,6,6‐tetramethy‐1‐piperidinyloxy‐mediated styrene miniemulsion polymerization

AbstractIn studying 2,2,6,6‐tetramethy‐1‐piperidinyloxy (TEMPO)‐mediated styrene miniemulsions, we have observed that the surfactant sodium dodecylbenzenesulfonate (SDBS) not only provides colloidal stability but also influences the rate of polymerization. Increasing the SDBS concentration results in higher polymerization rates, although the molecular weight distribution and particle size distribution are not significantly impacted. We have also examined another common sulfonate surfactant, DOWFAX 8390. In contrast to SDBS, DOWFAX 8390 does not affect the polymerization rate. Furthermore, DOWFAX‐stabilized polymerizations are slower than SDBS‐stabilized polymerizations. TEMPO‐mediated bulk styrene polymerizations are also accelerated significantly in the presence of SDBS. Although the mechanism for the rate acceleration is unknown, the experimental evidence suggests that SDBS is participating in the generation of radicals capable of propagating, thereby reducing the TEMPO concentration within the particles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5974–5986, 2006

Spectrophotometric Method for the Direct Determination of Anionic Surfactant Sodium Dodecyl Benzenesulfonate (SDBS) Using a Hydrophobic Near‐Infrared (NIR) Cationic Cyanine Dye Without Solvent Extraction

A new hydrophobic near‐infrared (NIR) cationic cyanine dye was synthesized and evaluated as a new reagent for the determination of anionic surfactant sodium dodecyl benzenesulfonate (SDBS). The cyanine dye with an absorption maximum at 770 nm reacted with SDBS, causing significant hypochromism. Under the optimal conditions, the decreased absorption is proportional to the concentration of SDBS over the range 2.9 × 10−7–1 × 10−5 mol/L. The detection limit was 1.9 × 10−7 mol/L. The relative standard deviation for 1.43 × 10−6 mol/L SDBS was 1.3% (n = 9). The proposed method was applied to determination of anionic surfactant in the river with 93–106% recovery levels. Preliminary research shows that the hypochromism is due to the formation of dye aggregate facilitated by SDBS.

Mixed adsorption of poly(vinylpyrrolidone) and sodium dodecylbenzenesulfonate on kaolinite

The mixed adsorption of the nonionic polymer poly(vinylpyrrolidone) (PVP) and the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) on kaolinite has been studied. Both components adsorb from their mixture onto the clay mineral. The overall adsorption process is sensitive to the pH, the electrolyte concentration, and the amounts of polymer and surfactant. Interpretation of the experimental data addresses also the patchwise heterogeneous nature of the clay surface. In the absence of PVP, SDBS adsorbs on kaolinite by electrostatic and hydrophobic interactions. However, when PVP is present, surfactant adsorption at 10 −2 M NaCl is mainly driven by charge compensation of the edges. The adsorption of PVP from the mixture shows similar behavior under different conditions. Three regions can be distinguished based on the changing charge of polymer–surfactant complexes in solutions with increasing SDBS concentration. At low surfactant content, PVP adsorbs by hydrogen bonding and hydrophobic interactions, whereas electrostatic interactions dominate at higher surfactant concentrations. Over the entire surfactant concentration range, polymer–surfactant aggregates are present at the edges. The composition of these surface complexes differs from that in solution and is controlled by the surface charge.

Forces between surfaces in the presence of a cationic polyelectrolyte and an anionic surfactant

An atomic force microscope has been used to investigate the interaction forces between a mica surface and a colloidal glass sphere in the presence of a high molecular weight cationic polyelectrolyte, and the anionic surfactant sodium dodecylbenzenesulfonate (SDbS). The effect of addition of SDbS on the interaction forces between the polyelectrolyte coated surfaces was investigated. At low concentrations of SDbS the electrostatic repulsion initially present was progressively neutralized as a function of increasing surfactant concentration. Neutralization resulted in a strong attraction between the surfaces. As the SDbS concentration was increased further, additional surfactant association took place and the surfaces were recharged. At these surfactant concentrations the surfaces became less attractive at small separations. At high SDbS concentrations the interaction profile became purely repulsive as the surfaces were recharged. Diffuse double layer potentials derived from the direct force measurement data correlated well with zeta-potential measurements of silica particles treated with the polyelectrolyte and surfactant. Particulate stability behaviour was also seen to compare well with the force measurement and electrostatic potential data.