Anionic Surfactant Sodium Dodecyl Benzene Research Articles

Determination of bovine serum albumin using resonance light scattering technique with sodium dodecylbenzene sulphonate–cetyltrimethylammonium bromide probe

In this paper, the anionic surfactant sodium dodecylbenzene sulphonate (SDBS) and cationic surfactant cetyltrimethylammonium bromide (CTMAB) were used as resonance light scattering (RLS) probe to determine bovine serum albumin (BSA). Based on the weak RLS intensity of SDBS–CTMAB probe and the enhancement of RLS intensity of BSA in the presence of the probe, a simple assay for BSA was developed. The experimental results showed that the formation of three component complex BSA–SDBS–CTMAB is the main reason for the enhancement of RLS intensity of BSA, in which SDBS as a bridge can interact with both BSA and CTMAB. The effects of pH value, incubation time, concentrations of SDBS and CTMAB on the enhanced RLS intensity of BSA were investigated. Under the optimum conditions, the enhanced RLS intensity is proportional to the concentration of BSA in the range from 2.5 × 10 −8 to 2.0 × 10 −6 mol L −1. The detection limit is 9.7 × 10 −9 mol L −1 for BSA. The study of foreign substance effect on the determination of BSA indicated that most of metal ions have little effect on the determination of BSA. The results of assay for BSA in synthetic samples were satisfactory.

Miniemulsion polymerization initiated by L‐ascorbic acid and sulfonate/sulfate surfactants

AbstractStyrene miniemulsions that were stabilized by common anionic surfactants (sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, and disulfonated alkyl diphenyl oxide sodium salt) polymerized at 25 °C in the presence of L‐ascorbic acid without the addition of a free‐radical initiator. The polymerizations exhibited high rates and molecular weights, with conversions greater than 70% achieved in less than 1 h and weight‐average molecular weights greater than 1 × 106 g/mol. Polymers did not form in the absence of L‐ascorbic acid. Although the final conversion was only slightly independent on the L‐ascorbic acid concentration, it was dependent on the surfactant concentration. The rate and final conversion were also strongly dependent on the surfactant type. Moreover, it was possible to initiate polymerizations with a monomer‐soluble derivative of L‐ascorbic acid (L‐ascorbic acid 6‐palmitate), although the rates were dramatically reduced compared with those when water‐soluble L‐ascorbic acid was used. High yields and high‐molecular‐weight polymers were also produced with butyl acrylate and methyl methacrylate with L‐ascorbic acid in the presence of sodium dodecyl benzene sulfonate. The initiation was attributed to an interaction between the surfactant and L‐ascorbic acid, which formed a redox initiation system that generated radicals capable of adding monomer. These results are of particular significance for redox‐initiated emulsion/miniemulsion polymerizations with L‐ascorbic acid as the reducing agent and with sulfate or sulfonate surfactants. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 69–80, 2007

Response of Surface‐Plasmon Resonance Sensor Based on Gold Surfaces Modified by Self‐Assembled Monolayer to Nonionic Surfactants

A chemical sensor for the determination of nonionic surfactants (NISs) based on surface‐plasmon resonance (SPR) phenomenon was fabricated using a gold thin film, the surface of which was modified with a self‐assembled monolayer (SAM). Stearylmercaptan was used for the SAM constituent. The magnitude of the angle shift of SPR sensor to NISs increases in this order: Triton X‐100<heptaethyleneglycol dodecyl ether (HEEG)<hexaethyleneglycol dodecyl ether (HEG)<pentaethyleneglycol dodecyl ether (PEG). This order of magnitude of angle shift is in accord with the sequence of the hydrophobicity of the NISs. The linear relationships between Δθ (the change in the resonance angle relative to the baseline value) and the concentration of NISs were obtained in the concentration range from 2×10−6 M to 1×10−5 M. The coexistence of common inorganic cations and anions at 100 times excess to the Triton X‐100 gives only a positive error less than ca. +5%. The coexistence of an anionic surfactant (sodium dodecylbenzene sulfonate) at 10 times excess to the Triton X‐100 gives a very serious positive error of ca. +320%. This serious positive error was completely eliminated by using the flow system with an anion‐exchange resin column.

Changes in air saturation and air–water interfacial area during surfactant-enhanced air sparging in saturated sand

Reduction in the surface tension of groundwater, prior to air sparging for removal of volatile organic contaminant from aquifer, can greatly enhance the air content and the extent of influence when air sparging is implemented. However, detailed information on the functional relationship between water saturation, air–water contact area induced by air sparging and the surface tension of water has not been available. In this study, the influence of adding water-soluble anionic surfactant (sodium dodecyl benzene sulfonate) into groundwater before air sparging on the air–water interfacial area and water saturation was investigated using a laboratory-scale sand packed column. It was found that water saturation decreases with decreasing surface tension of water until it reaches a point where this trend is reversed so that water saturation increases with further decrease in the surface tension. The lowest water saturation of 0.58 was achieved at a surface tension of 45.4 dyn/cm, which is considered as the optimum surface tension for maximum de-saturation for the initially water-saturated sand used in this study. The air–water contact area generated in the sand column due to air sparging was measured using a gaseous interfacial tracer, n-decane, and was found to monotonically increase with decreasing water saturation. The results of this study provide useful design information for surfactant-enhanced air sparging removal of volatile contaminants from aquifers.

Improvement of the acridine orange–protein–surfactant system for protein estimation based on aromatic ring stacking effect of sodium dodecyl benzene sulphonate

The fluorescence of acridine orange (AO) is greatly quenched by the anionic surfactant sodium dodecyl benzene sulphonate (SDBS), but when protein is added into the AO-SDBS system, the fluorescence intensity of the latter is enhanced again. Based on this, a new fluorimetric method of determination of protein was developed. Under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of protein, such as bovine serum albumin (BSA), human serum albumin (HSA) and egg albumin (EA), over a wide range with detection limits at the 10(-9) g/mL level. This method has been satisfactorily used for the determination of protein in samples. We compared results using 280 nm and 490 nm excitation wavelengths and the mechanism of the assay.

Study on the formation and depolymerization of acridine orange dimer in acridine orange–sodium dodecyl benzene sulfonate–protein system

Experiment indicates that the fluorescence of acridine orange (AO) can be greatly quenched by anionic surfactant sodium dodecyl benzene sulfonate (SDBS), but when protein is added into the AO–SDBS system, the fluorescence intensity of the latter is enhanced. It is considered that SDBS can promote the formation of AO dimer, resulting in the quenching of the fluorescence of AO. When bovine serum albumin (BSA) is added into AO–SDBS system, BSA and SDBS can interact and form negative micelle-like cluster complex with “aromatic ring stacking,” which destroys the formation conditions of AO dimer and makes some AO dimers turn into monomer, resulting in the fluorescence enhancement of AO–SDBS system. Whereas the positive AO and residual AO dimer are dissolved in the negative BSA–SDBS cluster through electrostatic and hydrophobic forces and form a large association. Here, the fluorescence enhancement of AO–SDBS is considered to originate from the hydrophobic microenvironment provided by BSA and SDBS, the depolymerization of AO dimer and intermolecular energy transfer between BSA and AO.

Electropolymerisation of pyrrole onto aluminium from alkaline solutions containing a surfactant

Polypyrrole films have been successfully electrodeposited on aluminium substrates from alkaline solutions containing an anionic surfactant (sodium dodecyl sulphate or sodium dodecylbenzene sulfonate). Homogeneous and adherent films were formed under potentiostatic, galvanostatic and potentiodynamic control. The electrochemical response was compared to that obtained with vitreous carbon as a substrate. Studies performed in monomer-free solutions showed that both OH− and Na+ play an important role in the redox process. Scanning electron microscopy and atomic force microscopy studies indicated that the presence of surfactants influences the morphology of the polymer producing more homogeneous and less rough films than those formed in absence of surfactants.

The array and interfacial activity of sodium dodecyl benzene sulfonate and sodium oleate at the oil/water interface

There is a close correlation between the interfacial activity and the adsorption of the surfactant at the interface, but the detailed molecular standard information was scarce. The interfacial activity of two traditional anionic surfactants sodium dodecyl benzene sulfonate (SDBS) and sodium oleate (OAS) were studied by experimental and computer simulation methods. With the spinning drop method and the suspension drop method, the interfacial tension of oil/aqueous surfactant systems was measured, and the influence of surfactant concentration and salinity on the interfacial tension was investigated. The dissipative particle dynamics (DPD) method was used to simulate the adsorption of SDBS and OAS at the oil/water interface. It was shown that it is beneficial to decrease interfacial tension if the hydrophobic chains of the surfactant and the oil have similar structure. The accession of inorganic salts causes surfactant molecules to form more compact and ordered arrangements and helps to decrease the interfacial tension. There is an osculation relation between interfacial density and interfacial activity. The interfacial density calculated by molecular simulation is an effective parameter to exhibit the interfacial activity.

Ostwald ripening and solubilization in alkane in water emulsions stabilized by different surfactants

The Ostwald ripening (OR) and the solubilization of alkanes in water emulsions stabilized by the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and the non-ionic surfactants hexaoxyethylene glycol n-dodecyl ether (C12E6) and polyoxyethylene (20) sorbitan monolaurate (Tween20) were investigated. For the emulsions stabilized by the anionic SDBS the mass transport in both OR and solubilization is molecular diffusion of the oil through the continuous phase and no contribution of a micellar mediated transport is observed. For the emulsions stabilized by the non-ionic surfactants three different situations occur. For emulsions prepared in one single step under the high shear conditions of a microfluidizer, the mass transport is also mainly molecular diffusion. For already prepared emulsions to which extra surfactant is added, there is, besides molecular diffusion, a small contribution by a micellar mediated mechanism. Finally, in the solubilization studies the mass transport is a fusion–fission mechanism rather than molecular diffusion.

Adsorption mechanism of surfactants on nonwoven fabrics

AbstractFor improved surface properties, nonwoven fabrics of polypropylene and poly(ethylene terephthalate) were treated with several kinds of surfactants, including anionic, cationic, and nonionic types. The adsorption isotherms of the anionic, cationic, and nonionic surfactants on the nonwoven fabrics were different. The adsorption isotherm of the cationic surfactant (dodecyl dimethylbenzyl/ammonium chloride) exhibited a maximum. The adsorption isotherm of the anionic surfactant (sodium dodecylbenzene sulfonate) was in the shape of the fifth Brunauer adsorption isotherm, and that of the nonionic surfactant (alkylphenol/ethylene oxide condensate) was similar to the fourth Brunauer adsorption isotherm. The time of the adsorption equilibrium was constant for the same types of adsorbate and adsorbent, and it was not related to the initial concentration. The specific surface resistance of the nonwoven fabrics decreased substantially after the adsorption of ionic surfactants. The nonwoven fabrics with the surfactants were characterized with scanning electron microscopy and X‐ray photoelectron spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3210–3215, 2003

Ostwald Ripening of Alkane in Water Emulsions Stabilized by Sodium Dodecyl Benzene Sulfonate

The Ostwald ripening of alkane in water emulsions stabilized by the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) was investigated. For emulsions prepared under high-shear conditions in a microfluidizer, ripening rates do not depend on the micellar surfactant concentration. The aging process is due to the molecular transport of alkane through the continuous phase, and there is no significant contribution from a transport mechanism by the micelles. When micellar surfactant solutions are added to an already formed emulsion, the Ostwald ripening process is not affected, confirming the fact that the micelles do not contribute to the transport of alkane molecules.

Effect of the Nature of the Templating Surfactant on the Synthesis and Structure of Mesoporous V−Mg−O

The mesostructured V−Mg−O was synthesized at room temperature using vanadium acetylacetonate and magnesium chloride as source materials. The effects of a number of factors, such as the nature of the surfactant, the pH, and the vanadium/magnesium molar ratio in the formation of mesoporous V−Mg−O phases were investigated for a fixed molar concentration of surfactant. The synthesized samples were examined by X-ray diffraction, Brunauer−Emmett−Teller analysis, transmission electron microscopy, and energy dispersive spectroscopy. The anionic surfactants sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) generated amorphous structures, while the cationic surfactant cetyltrimethylammonium bromide (CTAB) generated lamellar mesoporous structures with various degrees of crystallinity. Equimolar mixtures of an anionic surfactant, SDS, and a cationic surfactant (dodecyltrimethylammonium bromide (DTAB), myristyltrimethylammonium bromide (MTAB), cetylpyridium bromide (CPB), and cetyltrimethylammonium bromide (CTAB)), particularly the mixture SDS + CTAB, generated ordered lamellar structures with high crystallinity. It was found that the ordered arrangement (“crystallinity”) of the pores was strongly dependent on the vanadium/magnesium molar ratios in the initial batches; too large or too small ratios were unfavorable to the crystallinity and generated distorted hexagonal (wormlike) mesostructures. The optimum vanadium/magnesium molar ratio regarding the crystallinity was found to be in the range 1:1 to 1:1.5, and the mesoporous phase had a lamellar structure. For both the single and the mixtures of anionic and cationic surfactants, the higher the pH, the more favorable was the formation of a lamellar-structured mesoporous V−Mg−O phase.

ENHANCED ANIMAL WASTE MANAGEMENT THROUGH APPLICATION OF SURFACTANTS TO SOIL MATERIAL: LABORATORY FEASIBILITY TESTING

Laboratory testing was conducted to determine the feasibility of using surfactants to enhance soil performancewith regard to animal waste management at feedlot and dairy sites. Three surfactants, one anionic (sodium dodecyl benzenesulfonate) and two cationic (polyoxypropylene methyl diethyl ammonium chloride and tetradecyl trimethyl ammoniumbromide), were tested on a sandy loam. The best surfactants are those capable of substantially reducing the amount of leachingunder saturated and unsaturated flow conditions. Maintaining acceptable mechanical compaction characteristics, and ifpossible, limiting nitrate mobility are also important. The experimental program therefore focused on three areas: (1)Surfactant influence on leaching as indicated by effects on soil hydraulic properties (saturated hydraulic conductivity, soilmoisture diffusivity, and unsaturated soil wetting front penetration); (2) Surfactant effects on mechanical compaction; and(3) Nitrate transport in surfactantmodified soil.Saturated hydraulic conductivity was measured using fallinghead permeability tests. Transient unsaturated horizontalcolumn experiments provided information concerning surfactant influence on soil moisture diffusivity and wetting frontpenetration. Standard Proctor methods were applied in the study of surfactant effects on mechanical compaction. Adsorptionbatch tests gauged nitrate mobility in surfactanttreated soilThe anionic surfactant (sodium dodecyl benzene sulfonate) and one of the two cationic surfactants (polyoxypropylenemethyl diethyl ammonium chloride) produced considerable reductions in saturated hydraulic conductivity, soil moisturediffusivity, and unsaturated soil wetting front penetration. With regard to mechanical compaction, the anionic surfactant andthe other cationic surfactant (tetradecyl trimethyl ammonium bromide) affected decreases in the optimum moisture contentcorresponding to maximum dry bulk density. The moisture content range between optimum and the wet value correspondingto 90% or 95% maximum dry bulk density is also much narrower for these two surfactants, thereby increasing the difficultyof field compaction. Interestingly, the cationic surfactant having the greatest influence on soil hydraulic properties was notthe same one having the most substantial effect on mechanical compaction. Adsorption batch tests indicate nitrate mobilityin the sandy loam is not significantly altered by soil treatment with any of the three surfactants. The polyoxypropylene methyldiethyl ammonium chloride test results (no adverse effects on mechanical compaction and reduced hydraulic conductivity,diffusivity, and wetting front penetration) are alone enough to suggest the feasibility of using surfactants to enhance soilperformance for animal waste management. However, more investigation is needed with a greater variety of surfactants ona number of different soils, particularly with regard to hydraulic property testing using leachate typically generated at animalfeedlot and dairy facilities.

Small-Angle X-ray Scattering Study of Platinum-Containing Hydrogel/Surfactant Complexes

Size distributions of platinum nanoparticles embedded in nanostructured hybrid matrixes and the internal structure of these systems were studied by anomalous and conventional small-angle X-ray scattering. The complexes of polyelectrolyte gels with oppositely charged surfactants were employed as nanostructured matrixes. Two complexes of a cationic gel of poly(diallyldimethylammonium chloride) with anionic surfactants sodium dodecyl sulfate and sodium dodecylbenzene sulfonate were charged with platinum compounds (PtCl4, Na2PtCl6, (NH4)2PtCl4, and H2PtCl6) and reduced with NaBH4 and N2H4×H2O. Fast reduction with NaBH4 yields mostly small Pt nanoparticles with radii about 2 to 3 nm, whereas for N2H4×H2O, a significant amount of large (up to 40 nm) particles is found. The pH of the reaction medium and the Pt ion geometry were found to influence particle nucleation and growth. The internal ordering in gel/surfactant complexes during the nanoparticle formation was characterized from the Bragg peaks in the scatte...

Fouling of electrodialysis membranes by organic substances

In this investigation, the influence of various kinds of organic solutes on the fouling of an anion and a cation selective ED membrane was studied. Fouling by adsorption of organic matter onto the membrane was measured as an increase in the membrane resistance with time. Experiments were performed with a fatty acid (octanoic acid), two anionic surfactants (sodium octanoate and sodium dodecylbenzene sulphonate) and an alkaline bleach plant filtrate from a sulphate pulp mill. A marked difference was observed between the increase in the membrane resistance of the anion selective membrane and that of the cation selective membrane. The cation selective membrane was slightly fouled by the bleach plant filtrate, but was only marginally affected by the other organic solutes. The anion selective membrane, on the other hand, was markedly fouled by all solutes.

Enhanced transport of bacteria through a soil matrix using colloidal gas aphron suspensions

The influence of an anionic surfactant sodium dodecylbenzene sulfonate (DDBS) in the form of either an aqueous solution or microgas dispersion known as colloidal gas aphron (CGA) on the transport of a Psendomonas psendoalcaligenes, strain through a saturated soil matrix was examined. The experiments were conducted in 30‐cm‐long and 6.35 cm internal diameter stainless steel columns packed with a sandy clay loam. A 10‐ml pulse (0.033 pore volumes) of a bacterial suspension containing 1010 colony forming units (cfu) per ml was injected, and the column was eluted with either deionized water, a solution of DDBS, or a CGA suspension at a surface loading rate of 0.16 cm/min. The bacterial distributions within the column were similar after the passage of the water and surfactant solutions; however, the distribution of bacteria in the columns and effluent after the passage of the CGA suspension was markedly enhanced. The bacterial concentration in the lower half of the column after the passage of the CGA suspension was 2 to 3 orders of magnitude higher than that observed for either the surfactant or water solutions under similar experimental conditions. The final bacterial density in the effluent after the passage of the surfactant solution was one‐half order of magnitude greater than that in the effluent produced by passage of water. After the passage of the CGA suspension, the total number of bacteria in the effluent was at least 2 or 3 orders of magnitude greater than that obtained by passage of either surfactant or water as the eluting agent, respectively. The results of the study suggests that CGA suspensions can transport bacteria more efficiently than conventional surfactant solutions or water.

Photodegradation of dyes with poor solubility in an aqueous surfactant/TiO2 dispersion under visible light irradiation

The photodegradation of a cationic dye, Malachite Green (MG), is examined both in an anionic surfactant sodium dodecylbenzene sulfonate (DBS)/TiO2 dispersion and in a cationic surfactant hexadecytrimethylammonium bromide (HTAB)/TiO2 dispersion under visible irradiation (λ>470 nm). In the absence of surfactants, MG is difficult to degrade in aqueous TiO2 dispersion, owing to its poor solubility in water and low adsorption on the surface of TiO2 particles. Addition of surfactants enhances the solubility and adsorption ability of MG and hence accelerates significantly the MG degradation rate in aqueous TiO2 dispersions. The MG degradation rate reaches a maximum when the concentration of DBS added is at its c.m.c. According to the adsorption characteristics of the ionic surfactant molecules, the degradation rate of MG decreases with increases in the pH of DBS/TiO2 dispersions, while the degradation of MG is more rapid at higher pH ranges in HTAB/TiO2 dispersions. These results confirm and reinforce that the adsorption of dyes molecules upon the TiO2 particle surface is a prerequisite for TiO2-assisted photodegradation under visible irradiation and the degradation takes place at the TiO2 particle surface, rather than in the bulk solution. The photodegradation kinetics of the dyes in surfactant/TiO2 dispersions under visible irradiation obeys the Langmuir–Hinshelwood model. Evidence for the generation of active OH radicals is obtained using spin-trapping (DMPO) EPR spectroscopy.

Water solubility enhancement of pyrene in the presence of humic substances, by S. Tanaka et al.: comments

The ability of the anionic surfactant sodium dodecylbenzene sulfonate to significantly enhance the solubility of pyrene in aqueous solution when added at a concentration below the cmc was not confirmed. Possible reasons for the discrepancy are revealed.

Hydrophobic layered double hydroxides (LDHs): Selective adsorbents for liquid mixtures

The external and internal surface area of the calcium aluminum double hydroxide [Ca2Al(OH)6] NO3 · 2H2O were hydrophobized by the anionic surfactants sodium dodecylsulfate and sodium dodecylbenzene sulfonate. The adsorption behavior towards liquid mixtures (benzene/n-heptane and n-propanol/toluene) was studied by determining the surface excess adsorption isotherms, the heats of immersion in these liquids, and the basal spacing, i.e. the expansion of the interlayer space. Both hydrophobic layered double hydroxides (LDHs) adsorbed n-heptane, benzene, toluene, and n-propanol between the layers with considerable increase of the basal spacing. Interlamellar swelling of the hydrophobizised LDHs in n-heptane was fundamentally different to the behavior of hydrophobized 2:1 clay minerals (smectites, vermiculites). The surface excess isotherms for benzene/heptane mixtures were U-shaped and indicate preferential adsorption of benzene. Dodecylbenzene sulfonate double hydroxide preferentially adsorbed propanol from n-propanol/toluene mixtures but the dodecylsulfate derivative adsorbed both compounds.

The effect of an anionic surfactant on the rheology and stability of high volume fraction O/W emulsion stabilized by PVA

The effect of the addition of an anionic surfactant (sodium dodecyl benzene sulphonate) on the rheology and storage stability of concentrated O/W emulsions stabilized by poly (vinyl alcohol) is reported. It was found that the surfactant markedly reduced the magnitudes of the storage modulii of the emulsions. This could be attributed to a reduction in the interfacial tension resulting from the formation of polyelectrolyte type complexes between the PVA and NaDBS at the O/W interface. The results were compared to the equation (given by Princen) relating concentrated emulsion rheology to the interfacial tension and droplet size. Reasonable agreement was found, though there was a small difference in the constants in the equation given by Princen and those found here. The agreement suggested that the emulsions were deforming above a critical volume fraction and that the rheological properties were dominated by the dilation of the interface during shear. Microelectrophoresis measurements showed that the addition of the surfactant conferred a charge onto the PVA stabilized droplets as a result of the formation of the polyelectrolyte complex. The NaDBS was found to reduce the long-term stability of the emulsions compared to emulsions containing PVA alone.