Anionic Surfactant Sodium Dodecylbenzenesulfonate Research Articles

Effect of surfactants on morphology and luminescent properties of Ca3(VO4)2:Bi, Eu3+ red phosphors

Using anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant cetyltrimethylammonium bromide (CTAB) and nonionic surfactant glyceryl monostearate (monostearin) respectively, Ca3(VO4)2:Bi, Eu3+ red phosphors were prepared by a facile reaction chemistry method and their morphology, structure and luminescent properties were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and fluorescence spectrometer. The results showed that the introduction of surfactants not only greatly influenced their morphology, but also induced a remarkable change value of I615/I592. The reason that causes the variation of these properties for Ca3(VO4)2:Bi, Eu3+ red phosphors was concluded to be related to different surfactants.

Influence of Calcium Ions on Rhamnolipid and Rhamnolipid/Anionic Surfactant Adsorption and Self-Assembly

The impact of Ca(2+) counterions on the adsorption at the air-water interface and self-assembly in aqueous solution of the rhamnolipid biosurfactant and its mixture with the anionic surfactant sodium dodecylbenzenesulfonate, LAS, has been studied using neutron reflectometry and small-angle neutron scattering. The results illustrate how rhamnolipids are calcium tolerant and how their blending with conventional anionic surfactants improves the calcium tolerance of the anionic surfactant. Ca(2+) has relatively little effect upon the adsorption and self-assembly of the monorhamnose, R1, and dirhamnose, R2, rhamnolipids, even at high pH, due to their predominantly nonionic nature. For R1/R2 mixtures the addition of Ca(2+) has little impact upon the adsorbed amount or the surface composition. For R2/LAS mixtures the addition of Ca(2+) results in an increased adsorption and a surface slightly richer in R2. The weak binding of Ca(2+) to R1 and R2 does result in a change to the degree of ionization of the micelles and especially for mixed R1/R2 micelles at R1-rich solution compositions. The stronger binding of Ca(2+) to LAS results in the addition of Ca(2+) having a much greater impact on the self-assembly of R1/LAS and R2/LAS mixtures. For R1/LAS mixtures the addition of Ca(2+) promotes the formation of more planar structures, even at low surfactant concentrations where in the absence of Ca(2+) mixed globular micelle formation dominates. In R2/LAS mixtures, where there is a greater contrast between the high and low preferred curvatures associated with R2 and LAS, the addition of Ca(2+) results in a more complex evolution in micellar aggregation and the degree of ionization of the micelles. This results in variations in Ca(2+) binding that promotes micellar structures in which a spatial segregation of the two surfactant components within the micelle occurs.

Sonication-assisted dispersion of carbon nanotubes in aqueous solutions of the anionic surfactant SDBS: The role of sonication energy

Sonication is a powerful technique to promote the dispersion of carbon nanotubes (CNTs) and enhance their solubility; this is necessary for CNT applications, especially in the biochemical and biomedical fields. In this study, batch experiments were conducted to evaluate the role of sonication energy on the dispersion of CNTs in the presence of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS). It was observed that the concentration of dispersed CNTs in the SDBS solution depended on the sonication energy, but not the sonication time or output power of the sonicator alone. The amount of dispersed CNTs was positively correlated with the concentrations of SDBS and CNTs, and the length of the CNTs. The promotion of oxygen-containing functional groups on the dispersed CNTs was observed at relatively low sonication energies. The optimal energy, i.e. the minimum energy supplied by sonication to achieve a saturated suspension of dispersed CNTs in the SDBS solution, was CNT diameter-dependent, because of the larger vdW forces between tubes of smaller diameter. An exponential decay curve was constructed for the optimal energy values as a function of the outer CNT diameter, to assist in determining the energy needed to disperse CNTs.

Kinetics of Surfactant Desorption at an Air–Solution Interface

The kinetics of re-equilibration of the anionic surfactant sodium dodecylbenzene sulfonate at the air-solution interface have been studied using neutron reflectivity. The experimental arrangement incorporates a novel flow cell in which the subphase can be exchanged (diluted) using a laminar flow while the surface region remains unaltered. The rate of the re-equilibration is relatively slow and occurs over many tens of minutes, which is comparable with the dilution time scale of approximately 10-30 min. A detailed mathematical model, in which the rate of the desorption is determined by transport through a near-surface diffusion layer into a diluted bulk solution below, is developed and provides a good description of the time-dependent adsorption data. A key parameter of the model is the ratio of the depth of the diffusion layer, H(c), to the depth of the fluid, H(f), and we find that this is related to the reduced Péclet number, Pe*, for the system, via H(c)/H(f) = C/Pe*(1/2). Although from a highly idealized experimental arrangement, the results provide an important insight into the "rinse mechanism", which is applicable to a wide variety of domestic and industrial circumstances.

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 heavy metals and surfactants on the adsorption of phenolic compounds on sediment

The effects of different heavy metals (copper and mercury), cationic surfactants cetylpyridinium chloride, anionic surfactant sodium dodecylbenzenesulfonate and the chemistry of the solution (pH value) on the adsorption of three selected phenolic compounds (2, 4-Dichlorophenol, 2, 4-Dinitro-phenol and 2, 4-Dimethyphenol) on sediment were studied. Results indicated that in the sediment-water system with phenolic compounds: (1) all of the data could be simulated by Freundlich equation; (2) the experiments studying pH effects showed that the adsorption capacity of 2, 4-Dichlorophenol and 2, 4-Dimethyphenol were quite potentia Hydrogenii dependent and increased with decrease in potentia Hydrogenii, while 2, 4-Dinitrophenol followed the different trend; (3) As the concentration increased from 0 to 0.2 mM for Cu2+, the Freundlich capacity coefficient constant varied from 62.84 to 325.1 for 2, 4-Dichlorophenol, from 13.1 to 82.179 for 2, 4-Dinitrophenol and from 29.433 to 7.976 for 2, 4-Dimethyphenol, respectively. The Freundlich capacity coefficient constant of 2, 4-Dichlorophenol, 2, 4-Dinitrophenol and 2, 4-Dimethyphenol varied from 62.84 and 421.43, 13.1 and 138.1, 29.433 and 1.381, respectively, with concentration of Hg2+ increased from 0 to 0.04 mM, respectively; (4) the adsorption of 2, 4-Dichlorophenol and 2, 4-Dimethyphenol were accentuated by cetylpyridinium chloride but suppressed by sodium dodecylbenzenesulfonate, whereas the adsorption of 2, 4-Dinitrophenol on sediment was enhanced by both cationic and anionic surfactants, effects that are consistent with electrostatic and hydrophobic interactions among ionic surfactants, phenolic compounds and sediment. The results are believed to provide a useful insight into describing the transport and fate of phenolic compounds in natural environments.

Enzymatic synthesis of conductive polyaniline in the presence of ionic liquid

Enzyme catalyzed aniline polymerization has shown notable advantages, such as benign process and good solvent solubility for polyaniline. In this study, we further explored the possibility of using anionic surfactant sodium dodecylbenzenesulfonate (SDBS) as the template for the synthesis of conductive polyaniline by horseradish peroxidise (HRP), particularly in the presence of imidazolium-based ionic liquid [bmim]OTF. We found that the use of [bmim]OTF offered the protection for HRP against the inactivation by SDBS. Meanwhile, [bmim]OTF ensured the synthesis of conductive PANI in the presence of SDBS based on UV–vis spectrophotometer analysis. The conductive PANI was further characterized by FTIR, TGA, and cyclic voltammetry. Our results demonstrated that the enzymatic synthesized PANI in the presence of both SDBS and [bmim]OTF possessed excellent electrochemical properties.

Synergetic effect of cationic surfactive ionic liquid C 12mimBr and anionic surfactant SDBS on the phase behavior and solubilization of microemulsions

Synergistic effect of the surfactant mixture of ionic liquid 1-dodecyl-3-methylimidazolium bromide (C 12mimBr) and sodium dodecyl benzene sulfonate (SDBS) on the phase behavior and the solubilization ability of the microemulsion systems was studied with ɛ– β fishlike phase diagrams. The middle-phase microemulsion appears at the range of the mole ratios of C 12mimBr to SDBS 0–0.1 and 0.7–1.0. The solubilization ability (SP*) of the mixed surfactant based microemulsion systems increased markedly compared to the pure C 12mimBr or SDBS-based microemulsion systems. The mixture of C 12mimBr and SDBS also shows preferable synergism in the solubility of the alcohol and the composition of the interfacial layer. The effects of alcohols, alkanes and NaCl concentrations on the ɛ– β fishlike phase diagrams of C 12mimBr/SDBS (molar ratio = 8:2)/alcohol/alkane/brine microemulsion systems were also investigated.

Removal of surfactant dodecylbenzenesulfonate by consecutive use of ozonation and biodegradation

AbstractSuccessful surfactant removal from wastewater is often limited by the high concentration of the surfactant. The use of advanced oxidation processes can be the key to aid biological treatment of water containing high amounts of surfactants. The present study analyzes the biodegradation of the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) and the effects of its combination with ozonation. SDBS pre‐ozonation favors the metabolism by microorganisms. Experimental results indicate that the application of a concentration of up to 60 μM of ozone for 60 min, prior to contact with microorganisms, increases the percentage of SDBS removed by biodegradation alone. These results demonstrate that the removal of SDBS and of the total organic carbon is increased by the consecutive use of ozonation and biodegradation.

Control of Rheological Behaviour with Oppositely Charged Polyelectrolyte Surfactant Mixtures

Abstract Mixtures of the cationic, cellulose based polyelectrolyte JR 400 and the anionic surfactant sodium dodecylbenzene sulfonate (LAS) have been used to control the rheological behaviour of aqueous solutions. Around charge equilibrium precipitation takes place, but both for the surfactant-rich and the polymer-rich side homogeneous solutions are formed. In these monophasic regions the rheology depends strongly on the mixing ratio between the two components and highly viscous systems can be obtained on the polyelectrolyte rich side upon the addition of relatively small amounts of surfactant. Here the viscosity increases by more than four orders of magnitude before reaching the phase boundary of precipitation. Small-angle neutron scattering (SANS) showed the formation of an interconnected network of rodlike aggregates composed of a polyelectrolyte/surfactant complex, which explains the observed high viscosity due to the high degree of interconnection by the polyelectrolyte.

Effect of Surfactants on the Adsorption of Fluazinam in Soils

Soil contamination with pesticide has caused critical environmental and health defects and increasing attention has been paid for developing innovative technology for cleaning up this contamination. In this study, the effects of cationic surfactant cetyl trimethyl ammonium bromide, anionic surfactant sodium dodecylbenzenesulfonate, and non-ionic Tween 80 on the adsorption of fluazinam at the concentration of 1/2 CMC, 1 × CMC and 2 × CMC in three soils were evaluated by using batch equilibrium experiment. The K values followed the order as: S1 > S2 > S3 in absence of surfactants. The use of a nonionic surfactant considerably weaken the fluazinam retention, while that of cationic surfactant has the reverse trend. The effects of anionic surfactant on the adsorption of fluazinam in soils is related to soil physicochemical properties and anionic surfactant concentration. These results are of practical interest in developing effective surfactant remediation technology for fluazinam contaminated soils.

Treatment of 2,4,5-trichlorophenol by MgAl–SDBS organo-layered double hydroxides: Kinetic and equilibrium studies

Clay-based adsorbents were synthesized by incorporating anionic surfactants sodium dodecylbenzenesulfonate (SDBS), into calcined magnesium aluminum layered double hydroxide (MgAl–C) via ion exchange. The sample has been characterized by powder X-ray diffraction, FT-IR spectroscopy and B.E.T measurement. The result shows that SDBS adsorption on the calcined phase is enhanced by reconstruction of a matrix hydrotalcite intercalated by the dodecylbenzenesulfonate with basal spacing of 30 Å, which is larger than that of MgAl–CO 3. The product which is an organophilic layered double hydroxide or organo-LDH (MgAl–SDBS) was examined for their ability to adsorb organic pollutant. The adsorption of 2,4,5-trichlorophenol (TCP) from aqueous solutions by MgAl–SDBS hydrotalcite was investigated in a batch mode. The influence of solution pH, initial TCP concentration and temperature has been tested in kinetic runs. The results showed that the kinetic adsorption could be described by a pseudo-second order model very well. The equilibrium isotherm for TCP uptake was fitted to the Langmuir model with correlation coefficient R 2 of 0.998 at low concentrations and 0.992 for all concentrations. Its maximum adsorption amount is 240.5 mg/g from this model, while the real amount is 160 mg/g at 298 K and pH 4. The negative value of Δ G° and the positive value of Δ H° indicate the spontaneous and endothermic nature of the process.

Physicochemistry of Interaction between the Cationic Polymer Poly(diallyldimethylammonium chloride) and the Anionic Surfactants Sodium Dodecyl Sulfate, Sodium Dodecylbenzenesulfonate, and Sodium N-Dodecanoylsarcosinate in Water and Isopropyl Alcohol−Water Media

The physicochemistry of interaction of the cationic polymer poly(diallyldimethylammonium chloride) (PDADMAC) with the anionic surfactants sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium N-dodecanoylsarcosinate was studied in detail using tensiometry, turbidimetry, calorimetry, viscometry, dynamic light scattering (DLS), and scanning electron microscopy (SEM). Fair interaction initially formed induced small micelles of the surfactants and later on produced free normal micelles in solution. The interaction process yielded coacervates that initially grew by aggregation in the aqueous medium and disintegrated into smaller species at higher surfactant concentration. The phenomena observed were affected by the presence of isopropyl alcohol (IP) in the medium. The hydrodynamic sizes of the dispersed polymer and its surfactant-interacted species were determined by DLS measurements. The surface morphologies of the solvent-removed PDADMAC and its surfactant-interacted complexes from water and IP-water media were examined by the SEM technique. The morphologies witnessed different patterns depending on the composition and the solvent environment. The head groups of the dodecyl chain containing surfactants made differences in the interaction process.

Self-Aggregation of Mixtures of Oppositely Charged Polyelectrolytes and Surfactants Studied by Rheology, Dynamic Light Scattering and Small-Angle Neutron Scattering

In this study, the phase behavior, structure and properties of systems composed of the cationic, cellulose-based polycation JR 400 and the anionic surfactants sodium dodecylbenzenesulfonate (SDBS) or sodium dodecylethoxysulfate (SDES), mainly in the semidilute regime, were examined. This system shows the interesting feature of a very large viscosity increase by nearly 4 orders of magnitude as compared to the pure polymer solution already at very low concentrations of 1 wt%. By using rheology, dynamic light scattering (DLS), and small-angle neutron scattering (SANS), we are able to deduce systematic correlations between the molecular composition of the systems (characterized by the charge ratio Z=[+(polymer)]/[−(surfactant)]), their structural organization and the resulting macroscopic flow behavior. Mixtures in the semidilute regime with an excess of polycation charge form highly viscous network structures containing rodlike aggregates composed of surfactant and polyelectrolyte that are interconnected by the long JR 400 chains. Viscosity and storage modulus follow scaling laws as a function of surfactant concentration (η~c(s)(4); G(0)~c(s)(1.5)) and the very pronounced viscosity increase mainly arises from the strongly enhanced structural relaxation time of the systems. In contrast, mixtures with excess surfactant charges form solutions with viscosities even below those of the pure polymer solution. The combination of SANS, DLS, and rheology shows that the structural, dynamical, and rheological properties of these oppositely charged polyelectrolyte/surfactant systems can be controlled in a systematic fashion by appropriately choosing the systems composition.

Enhanced remediation of simulated wastewaters contaminated with 2-chlorophenol and other aquatic pollutants by TiO 2-photoassisted ozonation in a sunlight-driven pilot-plant scale photoreactor

Solar photoassisted remediation of a simulated wastewater contaminated with 2-chlorophenol (2-CP) was carried out by various advanced oxidation processes in a pilot-plant-scale Pyrex glass tubular-type photoreactor using solar cell derived electricity to drive the whole setup. The UV-assisted degradation and mineralization (loss of total organic carbon, TOC) of 2-CP in the co-presence of TiO 2 and ozone (UV/TiO 2/O 3) was enhanced significantly compared with ozonation alone (UV/O 3) and conventional TiO 2 photocatalysis in oxygenated dispersions (UV/TiO 2/O 2). The mineralization process was monitored by TOC assays and chloride ion analyzes. The utilization of immobilized TiO 2 was also examined with a TiO 2-coated glass photoreactor and compared with dispersed TiO 2 in aqueous media. In addition, simulated wastewaters contaminated with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), the endocrine disruptor bisphenol-A (BPA), the anionic surfactants sodium dodecylbenzenesulfonate (DBS) and sodium butylnaphthalenesulfonate (BNS), together with the cationic benzyldodecyldimethyl- ammonium bromide (BDDAB) surfactant were also efficiently remediated under otherwise identical conditions. The TiO 2-photoassisted ozonation of organic wastewater contaminants is a promising synergistic methodology to accelerate the remediation of such wastewaters, even when the TiO 2 is immobilized which can lead to reduced costs of operation.

Equilibrium Studies on the System Water + Hydrogen Peroxide + Urea + Carbon Dioxide

To develop a new method for separating the residual liquid of peroxide urea production by the formation of gas hydrate, the equilibrium of the system water + hydrogen peroxide + urea + carbon dioxide was studied under the conditions of P = (1.2 to 1.9) MPa and T = (273.15 to 303.15) K. The equilibrium pressure and temperature of gas hydrate formation were investigated at the different concentrations of hydrogen peroxide and urea with the anionic surfactant sodium dodecyl sulfate (SDS) and the sodium dodecyl benzene sulfonate (SDBS) in the system and without either. It was found that the equilibrium pressure of gas hydrate formation increased with the increase of temperature and the mass fraction of hydrogen peroxide and urea. The addition of anionic surfactant SDBS and SDS lowered the equilibrium pressure of the gas hydrate formed. The equilibrium pressure of the gas hydrate formed was calculated by Chen−Guo thermodynamic model, and the calculated values were in accord with the experimental results.

Influence of coexisting contaminants on the sorption of 17β-estradiol by marine sediments

The adsorption behavior of 17β-estradiol (E2) on marine sediments treated by different methods was investigated in the presence of bisphenol A (BPA), dibutyl phthalate (DBP), cationic surfactant cetyltrimethylammonium bromide (CTAB), nonionic surfactant polyoxyethylene (80) sorbitan esters (Tween 80) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS). Four sets of experiments were conducted to determine the adsorption isotherms of E2 with coexisting contaminants, to explore the effects of concentrations and types of coexisting contaminants on the E2 adsorption capacity, and to examine the influence of pH on E2 adsorption on the sediments. The adsorption behavior of E2 to marine sediments without the addition of surfactant mainly related to organic carbon content of sediments and fitted well with the Freundlich model. The presence of CTAB or Tween 80 enhanced the adsorption capacity of E2 of marine sediments. In contrast, the presence of BPA, DBP and SDBS inhibited the adsorption capacity of E2. The pH value of the solution could influence the adsorption behavior of E2 of the marine sediments. A decline in pH values was beneficial to the adsorption of E2 with the addition of surfactants.

Chemical Vapor Deposition Synthesis of Carbon Nanotubes Using Iron Catalysts

Single-walled carbon nanotubes (SWNTs) were synthesized via a novel chemical vapor deposition (CVD) technique incorporating iron catalysts. Stable aqueous solutions of the nanotubes using the anionic surfactant sodium dodecylbenzene sulfonate were also obtained, and the properties of as-produced SWNTs were documented through atomic force microscopy and Raman spectroscopy and compared with purified HiPCO SWNTs as a reference.

Dispersing Individual Single-Wall Carbon Nanotubes in Aqueous Surfactant Solutions below the cmc

Dispersions of single-wall carbon nanotubes (SWCNTs) in surfactant solutions below the critical micelle concentration (cmc) have been studied theoretically and experimentally. Dissipative particle dynamics (DPD) simulations of a coarse-grained model predict that surfactant adsorption on small diameter tubes is dominated by aggregation of the surfactant molecules into adsorbed micelles at C ≈ 0.3Ccmc. We also find that the surfactant adsorption is nearly complete at a concentration of around C ≈ 0.5Ccmc. Further increase of the surfactant concentration has only minor effects on the radial density of surfactant headgroups, indicating that SWCNT may be fully stabilized in solutions below the cmc. SWCNT dispersions in solutions of anionic surfactants sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS) below the cmc show a significant fraction of dispersed individual tubes and small bundles, in agreement with the model calculations.

Photoluminescence and optical characterization of CdS nanoparticles prepared by solid-state method at low temperature

The photoluminescence (PL) and optical properties of CdS nanoparticles prepared by the solid-state method at low temperature have been discussed. The effects of NaCl and anionic surfactant SDBS (sodium dodecylbenzene sulfonate) on the luminescent properties of CdS nanophosphors prepared using this method, without the inert gas or the H2S environment, were studied separately. The synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscope (FESEM), and energy dispersive X-ray spectroscopy (EDAX). UV–VIS absorption and PL spectra were also studied. XRD studies confirmed the single-phase formation of CdS nanoparticles. TEM micrograph revealed the formation of nearly spherical nanoparticles with a diameter of 2.5 nm. The PL emission for the CdS shows the main peak at 560 nm with a shoulder at 624 nm, with an increase in the PL intensity after the addition of SDBS. The effect of Mn doping on PL intensity has also been investigated. The PL spectra show that the emission intensity decreases as the dopant concentration increases.