Amount Of Sodium Dodecyl Benzene Sulfonate Research Articles

Investigating thermo-physical properties and thermal performance of Al2O3 and CuO nanoparticles in Water and Ethylene Glycol based fluids

The thermophysical properties and thermal performance of water- and ethylene-glycol-based nanofluids containing and CuO nanoparticles were examined. Nanofluids were prepared at four concentrations (1- 4 vol%) using an electric mixer and magnetic stirrer, and the thermophysical properties were measured. Surfactants were used to improve stability. The transient hot-wire method (KD2-Pro device), Dynamic Light Scattering (DLS), and Ostwald viscometer (ASTM D445-06) were used to measure the resulting thermal conductivity coefficient, nanoparticle diameter, and nanofluid viscosity, respectively. The experiments were carried out in the 20 to 50 °C temperature range. Adding 1 wt% sodium dodecyl sulfate (SDS) to the CuO–water and the same amount of sodium dodecylbenzene sulfonate (SDBS) to the –water nanofluid were found to stabilize them for 20 and 22 days, respectively. Increasing the nanoparticle volume fraction, raising the temperature, and reducing nanoparticle diameter were found to increase the thermal conductivity coefficient. The density also increases with the nanoparticle volume fraction in the base fluid increasing. Moreover, at the same volume fraction, the CuO–water nanofluid had a higher density than –water. Better base fluid thermal properties amplify the effect on the nanofluid's thermal conductivity coefficient. The actual thermal conductivity coefficient was determined by comparing model predictions of the coefficient.

1-dodecanthiol-assisted aqueous synthesis and characterization of Bi[formula omitted]Te[formula omitted] nanotubes

This article reports a novel synthetic methodology for preparing Bi2Te3 nanotubes as well as tailoring their size and aspect ratio, which provides a strong potential interest in the field of thermoelectrics. Bi2Te3 nanotubes were synthesized via a 1-dodecanethiol (DDT) assisted aqueous two-steps synthesis. One of its main advantages is to be easily scalable because it is carried under mild experimental conditions. The complexation of the capping ligand DDT to the bismuth yields to layered structural complexes Bi(DDT)3, which may act as a soft templates promoting the growth of Bi2Te3 nanotubes. The products were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Transmission Electron Microscopy (TEM) and High-Resolution Transmission Electron Microscopy (HRTEM). Microstructure investigations of powders show that the Bi2Te3 nanotubes are 200–500 nm long with an average diameter of 50–100 nm. The HR-TEM and selected area electron diffraction (SAED) results reveal the presence of 20–30 nanometers crystallized nanodomains and support the growth of the nanotubes via a rolling up mechanism of (a, b) planes. Using sodium dodecylbenzene-sulfonate (SDBS), as an additional structuring agent, lowers the yield of Bi2Te3 tubes synthesis and increases the heterogeneity of their size distribution. However, with an increased amount of SDBS very long Bi2Te3 (up to 20μm) tubes have been obtained. As a conclusion, using the capping ligand DDT allows obtaining Bi2Te3 nanotubes in mild conditions according to an easily scalable procedure. Moreover, for the first time the addition of another shape directing agent such as the surfactant SDBS in presence of DDT is shown to be a promising way to tune the dimensions and aspect ratio of these Bi2Te3 nanotubes, and as a consequence tailor their electronic properties, since the longest hollow Bi2Te3 tubes ever synthesized have been obtained.

Role of sodium dodecyl benzene sulfonate in enhancing coal dewatering: Experiments and theoretical calculations

The surface of low-rank coal has many oxygen functionalities, which leads to poor coal slime dehydration. To improve the effect of coal slime dewatering, sodium dodecyl benzene sulfonate (SDBS) was used as accelerator in the coal slime dehydration process. In addition, the mechanism of acceleration was studied using X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulations. The results of dehydration experiments showed that adding a certain amount of SDBS into the slurry water was conducive to promoting the removal of water. When the concentration of the SDBS solution was 0.06 g/L, the water content of the filter cake decreased from an initial value of 59.98% to 54.55%. XPS measurements and MD simulations show that the polar groups (sulfonic acid) of SDBS are adsorbed on the oxygen-containing functional groups on the coal surface, thus, exposing the nonpolar groups (alkyl chains) of the molecule to the solution. The calculation of the self-diffusion coefficient (D) of water molecules in the simulated system indicate that the presence of SDBS improves the mobility of water at the coal surface, which is helpful in improving the loss of water from the coal surface, thus, improving its hydrophobicity. Crucially, the results of the MD simulations are consistent with those from experiment. Highlights Addition of a certain amount of SDBS helps to remove moisture from the coal slime. Oxygen-containing functional groups on the coal surface are effectively covered by SDBS. The interaction mechanism of SDBS at coal/water interface was studied by combining experiments and theoretical calculations.

Selective adsorption of sodium dodecylbenzenesulfonate from a Cs ion mixture by electrospun mesoporous silica nanofibers

Sodium dodecylbenzenesulfonate (SDBS) is commonly used to remove radioactive nuclides such as Cs ions during decontamination of shut-down nuclear power plants. Potential environmental problems still remain because of the incomplete removal of large amounts of SDBS from radioactive liquid waste. For the first time, mesoporous silica nanofibers (MSFs) were fabricated for an efficient SDBS separation. MSFs were prepared by electrospinning using tetraethyl orthosilicate, a surfactant, and a template polymer; the product had a large surface area, a high pore volume, and a uniform pore size distribution. The internal pores or external surface were modified with quaternary ammonium salt, providing affinity to water and an electrostatic interaction with SDBS. The MSF-based adsorbent had excellent adsorption ability for SDBS (158.98 mg/g) over conventional adsorbents. In addition, the MSF-based adsorbent could selectively adsorb SDBS from a mixed solution of SDBS and Cs ions. Judging from the Freundlich pseuso second-order kinetic adsorption, the adsorption isotherm indicated that the SDBS adsorption was a kind of multilayer physisorption.

Degradation of SDBS in water solutions using plasma in gas-liquid interface discharge: Performance, byproduct formation and toxicity evaluation

Sodium Dodecyl Benzene Sulfonate (SDBS) is a major anionic surfactant and is widely used in the detergent industry. The large amount of SDBS discharged into water bodies can cause eutrophication of water bodies and produce toxic effects in aquatic organisms. In this study, the degradation of SDBS and variation in toxicity during the plasma treatment process were evaluated using gas-liquid interface discharge. The experimental results showed that SDBS could be removed effectively after discharge for 8 min at an initial concentration of 30 mg/L. The SDBS removal could be fitted by the first-order kinetic model. The plasma voltage and initial pH had great effects on the removal of SDBS. At the same voltage, SDBS could be removed faster under alkaline conditions. Compared to ozonation, much higher SDBS and TOC removal performance was achieved by plasma treatment. HO, which was mainly derived from the reaction of H2O2 and ozone in the solutions, played a major role in the oxidation process. The toxicity evaluation showed that plasma treatment could reduce the acute toxicity effectively initially, and also indicated that the formed intermediates of formate, oxalate, malonate and sulfate had no negative effects. However, further treatment caused an increase in toxicity, which was mainly correlated with the excessive residual H2O2 formed during the plasma process. This study indicated that while applying plasma treatment, the conditions should be optimized comprehensively to maintain a low H2O2 residual in the effluent.

Preparation Process of Epoxy Resin Microcapsules for Self - healing Coatings

The self-healing microcapsules were prepared by in-situ polymerization with urea formaldehyde resin and epoxy resin E-5l as the wall material and core material separately in this paper. The effects of the amount of epoxy resin, sodium dodecyl benzene sulfonate (SDBS), ammonium chloride, resorcinol and the stirring rate on the particle size of microcapsules were discussed. The microcapsules were added into the epoxy resin composite coating for corrosion resistance evaluation. The results showed that when the ratio of epoxy resin to urea was 24%, the amount of SDBS was 8%, the amount of ammonium chloride was 5.6%, the content of resorcinol was 10.4% and the stirring speed was 450 rpm, the average particle size of the capsules was 55.7 μm. When the addition number of microcapsules was 2% in the coating, the corrosion resistance was best with its service life prolonged by about 4 times.

Effects of TiO₂ Nanofluid on the Surface State of Brass.

The surface states of brass in simulated cooling water (SCW) containing or free of sodium dodecyl benzene sulfonate (SDBS) and TiO2 nanofluid were analyzed by means of scanning electron microscope (SEM), energy spectrum analysis (EDS) and X-ray diffraction (XRD). The concentrations of Cu and Zn ions in the solution after brass immersion were analyzed using a plasma emission spectrometer. The relationship between the surface states and corrosion resistance of brass was investigated by electrochemical impedance spectroscopy (EIS). The results showed that the brass surface was mainly covered with zinc compound Zn5(OH)6(CO3)2 as corrosion product in SCW. In SCW containing SDBS, a large amount of SDBS was adsorbed on the brass surface. In TiO2 nanofluid, the brass surface was relatively bare and mainly contained cuprous oxide. There was no obvious adhesion of SDBS aggregates and no accumulation of zinc compound on brass surface in TiO2 nanofluid. TiO2 nanoparticles inhibit the adsorption of SDBS on brass surface. Solution analysis results showed that the concentrations of Cu and Zn ions in TiO2 nanofluid was obviously higher than that in SCW and SCW containing SDBS, indicating that most of corrosion products of brass dissolved into the nanofluid. The EIS results illustrated the brass electrode had a larger reaction resistance in SCW containing SDBS, indicating the good protective performance of the adsorbed SDBS film on brass surface. The reaction resistance of the brass electrode was the smallest in TiO2 nanofluid, which illustrated that TiO2 nanoparticles in solution promoted the corrosion of brass.

Adsorption Characteristics of Anionic Surfactant Sodium Dodecylbenzene Sulfonate on the Surface of Montmorillonite Minerals.

The adsorption characteristics of sodium dodecylbenzene sulfonate (SDBS) on the surface of montmorillonite can lay a foundation for obtaining the optimum concentration of the anionic surfactant. The best absorption wavelength of SDBS was determined using an ultraviolet spectrophotometer. The standard curves of concentration and absorbance of SDBS were established. The amount of SDBS adsorbed on the surface of montmorillonite at various concentrations was calculated by stirring adsorption method. Scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS), X-ray diffraction (XRD), zeta potentiometer, and Fourier transform infrared (FTIR) spectroscopy were used to observe the changes of the structure, main ions, interlayer spacing, potential, and main functional groups on the montmorillonite surface before, and after, adsorption. The test results of SEM with EDS (SEM–EDS) showed that the surface of the montmorillonite after SDBS adsorption was rougher, and the adsorption capacity of the surface was enhanced as the SDBS concentration increased. The XRD results indicated that SDBS adsorbed on the interlayer of montmorillonite repulsed interlayer water and reduced the interlayer water content. With the increase of SDBS concentration, the interlayer spacing of the montmorillonite available for adsorbing SDBS decreased further. Additionally, interlayer adsorption and surface adsorption exist simultaneously in montmorillonite in SDBS solution. The distribution of total adsorption capacity of SDBS in the layers and on the surface of montmorillonite accords with the adsorption result simulated by a pseudo-second-order kinetic model. The increase in concentration of SDBS adsorbed by montmorillonite is the main reason for the decreased initial adsorption rate. The zeta potential test showed that the addition of H+ to the SDBS solution could reduce electrostatic repulsion and promote the adsorption of SDBS on montmorillonite. The results of this study provide an experimental basis for the study of the mechanism of SDBS adsorption on montmorillonite.

A facile and clean process for exfoliating MoS2 nanosheets assisted by a surface active agent in aqueous solution

A facile, efficient and environmentally friendly process to exfoliate MoS2 is essentially critical to apply the obtained mono- and few-layer nanosheets in various electronic devices and sensors. Here we report a liquid phase exfoliation method for exfoliation of MoS2, which employs a surfactant of sodium dodecyl benzene sulfonate (SDBS) in water. The nonpolar benzene rings in SDBS can firmly bind to the MoS2 layer, facilitating the effective exfoliation of nanosheets in aqueous solution. It is found that the exfoliation efficiency and thickness of MoS2 nanosheets are related to the concentration of SDBS, and the mechanism was investigated. Defect free mono- and few-layer MoS2 nanosheets are obtained by controlling the amount of SDBS in solution, which exhibit stable dispersion in water over months, and it renders them as having great potential for solution-based device fabrication.

Stability and electrical conductivity of water-base Al2O3 nanofluids for different applications

In this study, Al2O3–H2O nanofluids were synthesized using sodium dodecylbenzenesulfonate (SDBS) dispersant agent by ultra-sonication method. Different amounts of SDBS i.e. 0.1, 0.2, 0.3, 0.6, 1 and 1.5wt.% were tested to stabilize the prepared nanofluids. The stability of nanofluids was verified using optical microscope, transmission electron microscope and Zeta potential. After selecting the suitable amount of dispersant, nanofluids with different volume fractions of Al2O3 were prepared. Zeta potential measurement of nanofluids with low alumina and intermediate fractions showed good dispersion of Al2O3 nanoparticles in water, but nanofluids with high mass fraction were easier to aggregate. The stabilized nanofluids were subjected for measuring of rheological behavior and electrical conductivity. The electrical conductivity was correlated to the thermal conductivity according to Wiedemann–Franz law. The results revealed that the nanofluid containing 1% SDBS was the most stable one and settling was observed for the fluid contained 0.75vol.% of Al2O3 nanoparticles which gave higher viscosity. The rheological measurements indicated that the viscosity of nanofluids decreased firstly with increasing shear rate (shear thinning behavior). Addition of nanoparticles into the base liquid enhanced the electrical conductivity up to 0.2vol.% of Al2O3 nano-particles after which it decreased.

Effects of Different Acids and pH on the Degradation of Sodium Dodecyl Benzene Sulfonate by TiO<sub>2</sub>-Bentonite

Five types of TiO2-bentonite catalyst, #1, #2, #3, #4, and #5, were prepared separately using hydrochloric acid, nitric acid and perchloric acid by the sol-gel method. The original concentration of sodium dodecyl benzene sulfonate (SDBS) in the aqueous solutions was 20 mg/L. The amounts of SDBS degraded by #1, #2, #3, #4 and #5 under a 6 W ultraviolet lamp were compared, the influences of #1 and #2 on the chemical oxygen demand (COD) of the aqueous solutions studied. And the influences of the initial pH on the degradation of SDBS and on the COD of aqueous solutions were investigated. The results showed as the following. (1) When the catalyst input was 0.5‰ and the solutions were irradiated with a 6 W ultraviolet lamp, 81.0%, 90.5% 47.5%, 39.5% and 26.5% of the SDBS in the aqueous solutions was degraded within 2 hours by catalysts #1, #2, #3, #4 and #5, respectively. The COD was reduced by 8.81% and 50.84%by catalysts #1 and #2, respectively. (2) Under an ultraviolet lamp, 94.5% and 99.3% of the SDBS in the aqueous solutions was degraded and 33.59% and 96.93% of the COD was reduced within 6 hours by catalysts #1 and #2, respectively. TiO2-bentonite catalyst #2 was the best based on the effects on the degradation of SDBS and on the reduction of the COD of aqueous solutions. Using nitric acid was better than using hydrochloric acid or perchloric acid for the preparation of TiO2-bentonite. (3) Under the same conditions (20 mg/L SDBS, 20°C, ultraviolet light irradiation time of 2 h, electromagnetic mixing, 0.5‰ input of TiO2-bentonite #2 ), 90.3% and 90.5% of SDBS was degraded by TiO2-bentonite #2 at pHs 6 and 8, respectively. The optimal pH range for SDBS degradation was 6~8. The COD was reduced by 59.5% and 63.5% pHs 4 and 6, respectively. The optimal pH range for the COD reduction was 4 ~ 6. The pH had a clear effect on SDBS degradation and the COD of the aqueous solutions.

In‐situ spectroscopic study of surfactant adsorption onto hematite from binary mixtures and the effect of inorganic ions

Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy has proven to be a powerful tool for surfactant adsorption studies. In many practical applications, surfactant mixtures and waters with different chemistry are employed, which significantly complicates adsorption studies. In this work, we investigate the effect of calcium and carbonate ions, frequently found in natural waters, on the co‐adsorption of sodium dodecylbenzenesulfonate (SDBS) and a non‐ionic primary alcohol ethoxylate (NEODOL 25–7) onto hematite at pH 8 and 10.5 using ATR‐FTIR spectroscopy. Adsorption of SDBS was affected by pH and the presence of inorganic ions to a greater extent than the adsorption of NEODOL 25–7. A larger amount of SDBS was adsorbed at pH 8 than at pH 10.5 in all the experiments. The effect of co‐adsorbing ions on the amount of SDBS adsorbed was significant only at pH 10.5 and not at pH 8. Calcium ions promoted adsorption of SBDS onto hematite, whereas addition of carbonate decreased the amount of SDBS adsorbed. In the presence of both calcium and carbonate ions, calcium carbonate precipitate was formed on the hematite surface, promoting accumulation of NEODOL 25–7 at the surface. NEODOL 25–7 was found to have a strong effect on the hydrophilicity of the hematite film when adsorbed in combination with SDBS. A more hydrophilic surface was obtained upon adsorption of the surfactants in the presence of sodium chloride, film dispersion occurred in the presence of calcium chloride, and a less hydrophilic surface was obtained in the presence of both calcium chloride and sodium carbonate. Copyright © 2014 John Wiley & Sons, Ltd.

Role of Surfactant Adsorption in Controlling Morphology of Single-Walled Carbon Nanotubes/Polythiophene Nanohybrid

We have prepared nanohybrids of short single-walled carbon nanotubes (SWNTs) covered by a polythiophene (PT) layer. The SWNTs have an average length of 1 μm and are well dispersed in water in the presence of sodium dodecyl benzene sulfonate (SDBS). The PT layer on the short SWNTs has been produced by catalytic oxidative polymerization in aqueous solution. It is found that the morphology of the PT layer is oriented by the morphology of the adsorbed SBDS on the SWNTs. It follows that, depending on the amount of SDBS added in the system, the PT on the SWNTs can be not only in the form of layer but also in the form of several spherical-like particles strung along each SWNT (i.e., in the beaded form). This result confirms the proposal (Vaisman et al. Adv. Colloid Interface Sci. 2006, 128–130, 37) that the SDBS adsorption on the SWNT sidewall is in the form of condensed assemblies. It is this condensed assembly that templates the beaded form of PT on the SWNTs.

N-Type Thermoelectric Performance of Functionalized Carbon Nanotube-Filled Polymer Composites

Carbon nanotubes (CNTs) were functionalized with polyethyleneimine (PEI) and made into composites with polyvinyl acetate (PVAc). CNTs were dispersed with different amounts of sodium dodecylbenzenesulfonate (SDBS) prior to the PEI functionalization. The resulting samples exhibit air-stable n-type characteristics with electrical conductivities as great as 1500 S/m and thermopowers as large as −100 µV/K. Electrical conductivity and thermopower were strongly affected by CNT dispersion, improving the properties with better dispersion with high concentrations of SDBS. This improvement is believed to be due to the increase in the number of tubes that are evenly coated with PEI in a better-dispersed sample. Increasing the amount of PEI relative to the other constituents positively affects thermopower but not conductivity. Air exposure reduces both thermopower and conductivity presumably due to oxygen doping (which makes CNTs p-type), but stable values were reached within seven days following sample fabrication.

Synthesis of mesoporous silica by a surface charge reversal route

Pore size adjustable mesoporous silica was synthesized by adsorption of varying amounts of sodium dodecyl benzenesulfonate at the surface of silica activated by zinc ion via a novel surface charge reversal route. The pore size and volume can be adjusted from 5.9 to 13.76 nm and 0.88 to 1.08 cm(3) g(-1), respectively, with increasing the SDBS concentration from 0.77 to 3.08 mmol L(-1). Adsorption of Zn(2+) as a function of pH and N(2) adsorption/desorption isotherms demonstrated that the metal ions such as Zn(2+) could be readily removed with dilute nitric acid without apparent collapse of the pore structure at the proper range of SDBS concentration.

One-dimensional hexagonal-phase NaYF4: Controlled synthesis, self-assembly, and morphology-dependent up-conversion luminescence properties

One-dimensional (1D) hexagonal-phase NaYF4 with various morphologies including nanowires, nanowire bundles, submicrorods, and hexagonal microprisms have been selectively synthesized via a facile complexing reagent-surfactant-assisted hydrothermal route. The effects of reaction temperature, the amount of SDBS (sodium dodecylbenzenesulfonate) and citric acid, and the sorts of surfactants and complexing reagents on the morphology, size, and crystal phase purity of the as-synthesized products have been investigated in detail. By choosing NaYF4 nanowire as a candidate, its formation mechanism was proposed on the basis of XRD analysis and SEM observation of the products at the different reaction time periods. The studies on the up-conversion emission of hexagonal-phase Yb3+, Er3+ ions-codoped NaYF4 including nanowires, submicrorods, and hexagonal microprisms showed that the optical properties of the as-synthesized materials are morphology-dependent. It was found that NaYF4 : Yb, Er nanowires had the highest ratios between the intensities of green and red band emission whereas hexagonal NaYF4 : Yb, Er microprisms had the lowest ones. The synthesis of hexagonal-phase NaYF4 with controllable size and morphology, optical properties, together with the realization of self-assembly of NaYF4 nanowires reported in this work will be useful for further applications in the fabrication of optoelectronic nanodevices.

Influence of sodium dodecyl benzene sulfonate (SDBS) on the morphology and negative thermal expansion property of ZrW 2O 8 powders synthesized by hydrothermal method

ZrW 2O 8 powders were prepared by hydrothermal thermal method using sodium dodecyl benzene sulfonate (SDBS) as surfactant. The products were investigated by X-ray diffraction (XRD) method, scanning electron microscopy (SEM), thermogravimetric and differential scanning calorimetry (TG–DSC) and Fourier transform infrared (FTIR) absorption spectra. Results indicate that the resulting powders are single cubic phase with high crystallinity. With increasing the amount of SDBS, morphology and particle size change from rod-like with an average dimension of 1.2 μm × 1.2 μm × 10 μm to layered column with an average diameter of 0.4 μm. ZrW 2O 8 powders exhibit negative thermal expansion property. And the amount of SDBS is not influence on the average thermal expansion coefficients. The thermal expansion coefficients are about similar with an average value of −5.8 × 10 −6 °C −1 from room temperature to 500 °C. However, the morphology has some effect on the thermal expansion coefficient of α-ZrW 2O 8.

Rheologic Properties of a Water-Soluble Terpolymer with Vinyl Biphenyl

A water-soluble acrylamide-modified terpolymer (PAAP) with sodium 2-acrylamido-2-methylpropane sulfonate and vinyl biphenyl as the hydrophobic monomer was synthesized to obtain a polymeric thickening agent applied in middle- and low-permeability oil reservoirs. The polymer is expected to possess a low molecular weight and high solution viscosity. The steady-state consecutive shear cycles of PAAP in aqueous and brine solutions were measured, and the viscoelastic properties of PAAP solutions were investigated as a function of polymer, NaCl and sodium dodecylbenzene sulfonate (SDBS) concentrations. The aqueous PAAP solutions exhibits pseudoplastic and thixotropic behavior over the range of shear rate and shear thickening behavior at very low shear rate. The steady-state shear results show that some disrupted associating aggregates at high shear rate can be reformed during the shear reversion process and the suitable shear rate is favorable to the formation of hydrophobically associative structures in the brine solutions. Above 0.05 g⋅dL−1 PAAP, aqueous PAAP solutions have predominantly elastic character over the range of angular frequency that is strengthened with increasing polymer concentration. The PAAP brine solutions exhibit predominantly elastic behavior only above 3 rad⋅s−1 and a salt-thickening effect. By addition of an optimum amount of SDBS (0.5–0.8 mmol⋅L−1), the complex viscosities become much higher than the dynamic viscosities, although the loss tangent values increase owing to the formation of loose associative structures.

Hydrothermal Synthesis of Mesoporous InVO4 Hierarchical Microspheres and Their Photoluminescence Properties

In this work, uniform InVO4 hierarchical microspheres with the assistance of sodium dodecyl benzene sulfonate (SDBS) have been successfully synthesized by a facile hydrothermal method. X-ray diffraction, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction were used to characterize the as-synthesized samples. The results indicate that such 3D hierarchical architecture InVO4 microspheres are polycrystalline and assembled by numerous nanocrystals. Nitrogen adsorption-desorption measurement and the pore size distribution curve suggest that mesopores exist in these hierarchical microarchitectures. The formation mechanism has been proposed based on Oswald ripening and nonoriented attachment. It is further found that SDBS plays a key role in the formation process, and when the amount of SDBS is adjusted, the average diameter of such InVO4 microspheres could be controlled from 5 to 1 microm. UV-vis diffuse reflectance and PL spectra are employed to estimate the photoluminescence property of as-prepared InVO4 samples.

RETRACTED: Micellar solubilization of TCE and PCE by mixed surfactant: Effects of surfactant partitioning and DNAPL mixing

Efforts to remove the dense nonaqueous phase liquids (DNAPLs) in subsurface by mobilizing them face with risks of driving the contaminants deeper into aquifer zones. This spurs research for modifying the approach for in situ remediation. In this paper, micellar solubilization of trichloroethene (TCE), tetrachloroethene (PCE) and their mixture (TCE-PCE) by mixed nonionic and anionic surfactant, Triton X-100 (TX100) and sodium dodecylbenzene sulfonate (SDBS) in DNAPL/water systems was presented. Given 1:40 phase ratio of DNAPL/water (v/v) and the total surfactant concentration from 200 to 10,000mg/L, mixed TX100-SDBS at the total mass ratios of 3:1, 1:1 and 1:3 exhibited significant solubilization for TCE, PCE and TCE-PCE mixture (1:1, v/v). The solubilization extent of sole TCE by TX100-SDBS was much larger than by single TX100 and even larger than by single SDBS at the ratios of 1:1 and 1:3. The solubilization extent of sole PCE by TX100-SDBS was between those by single TX100 and single SDBS. In mixed TCE-PCE system, the solubilization extent of TCE or PCE by TX100-SDBS was larger than by single SDBS at the ratios of 1:1 and 1:3 while less than by single TX100 at large surfactant concentration. TX100 partitioning into the organic phase dictated the solubilization extent. The TX100 losses into TCE and TCE-PCE phases were great when single TX100 was used, while those into PCE phase were much less. No partitioning of SDBS into DNAPLs was observed. In mixed surfactant systems, SDBS decreased greatly the partition loss of TX100 into DNAPLs. The extent of TX100 partition decreased with the amount of SDBS increasing and the polarity of DNAPL decreasing. The mechanism for reduction of TX100 partition was discussed. TX100 and SDBS formed mixed micelles in the solution phase. The inability of SDBS to partition into DNAPLs and the mutual affinity of SDBS and TX100 in the mixed micelle controlled the partitioning of TX100 into DNAPL phase. The work presented here demonstrates that mixed nonionic-anionic surfactants may be probably potentially better systems than the corresponding single ones for remediation of polar DNAPLs, which could decrease risks of driving the contaminants deeper into aquifers.