Addition Of Sodium Dodecyl Benzene Sulfonate Research Articles

Synthesis of Bi2WO6 photocatalyst modified by SDBS and photocatalytic performance under visible light

Bismuth tungstate (Bi2WO6) photocatalysts, which modified with different ratios of sodium dodecyl benzene sulfonate (SDBS) and with enhanced visible light-driven activity, were synthesized by a facile solvothermal process. The photocatalysts were characterized by X-ray diffraction, scanning electron and transmission electron microscopies, and X-ray photoelectron and ultraviolet–visible diffuse reflectance spectroscopies. SDBS addition was found to control particle morphology and improve photocatalytic activity of Bi2WO6 catalysts. The solvent-thermal reaction time was critical in determining the catalysts’ structures and shapes and optimal at 16 h. Photocatalytic activities of SDBS–Bi2WO6 were determined by photocatalytic degradation of tetracycline (TC) in aqueous solution under visible light irradiation. Optical properties and TC degradation tests showed these SDBS–Bi2WO6 catalysts to exhibit enhanced visible light-driven photodegradation for TC. The photocatalytic activity for TC degradation was maximized at 90.39% after 90 min at 1.0 wt% SDBS dosage. In addition, the possible mechanisms for catalyst formation and photocatalytic degradation were discussed.

Change of Thermal Conductivity and Cooling Performance for Water Based Al2O3-Surfactant Nanofluid with Time Lapse

An experimental research was performed to study the effect of time lapse on the change of water-Al2O3 nanofluid thermal conductivity and its convection heat transfer. The size of Al2O3 nanoparticle size was 20[Formula: see text]nm and 70[Formula: see text]nm, and initial volumetric concentration range was from 0.5% to 3%. A surfactant was added to the nanofluid and the change of thermal conductivity and convection heat transfer was also measured. The surfactant was Sodium Dodecyl Benzene Sulfonate (SDBS) and its mass fractions in the nanofluid were from 0.5% to 3.0%. Thermal conductivity of water and nanofluid was measured by the transient hot wire method. The accuracy of the measurement method was confirmed by the measurement error with 0.92% for distilled water at 20[Formula: see text]C. The thermal conductivity of the nanofluid without SDBS increased up to 11.3% and the enhancement decreased with time lapse. The reduction of thermal conductivity enhancement with the time lapse could be retarded by the addition of SDBS and its effect became higher with the increase of its mass fraction. The convection heat transfer characteristics of the nanofluid was measured in a small cooling system. Compared with pure water, nanofluid convection heat transfer could be enhanced but higher pressure drop also occurred. Compared with the convection heat transfer enhancement for the nanofluid without SDBS, the addition of SDBS decreased the enhancement at the initial stage of the experiment, but it could retard the reduction of convection heat transfer with time lapse.

Investigating the synergic effects of chemical surfactant (SDBS) and biosurfactant produced by bacterium (Enterobacter cloacae) on IFT reduction and wettability alteration during MEOR process

In the current study, a novel approach which takes into account the effectiveness of both convectional surfactants and biosurfactants was investigated. The biosurfactant produced by Enterobacter cloacae strain was utilized concomitant with conventional surfactant (sodium dodecyl benzene sulfonate (SDBS)) to evaluate its capability to reduce the SDBS adsorption on rock surface (biosurfactant acts as sacrificial agent) or synergistically enhance the effectiveness of the SDBS. In this regard, the wettability alteration and interfacial tension (IFT) measurements and calculation of spreading coefficient were performed considering two different scenarios. In the first scenario, SDBS was added to the incubated bacterial solution medium while in the second case, SDBS was added to the bacterial solution before the incubation stage. Based on the obtained results, it was revealed that the wettability altered from original oil wet towards water wet state using bacterial solution, while the addition of SDBS deteriorated this trend for both scenarios. According to IFT measurements, the first scenario was more effective than the individual solution of bacteria and SDBS as well as the second scenario. In conclusion, the measured spreading coefficient demonstrated that the bacterial solution was a more effective EOR agent in comparison to other studied cases.

Crystallization of Ammonium Persulfate in the Presence of an Additive: Experimental and Molecular Dynamics Simulation Studies

AbstractBinding energy effects have been considered the main cause behind additives hindering crystal growth. In this study, the effects of the diffusion coefficient between the additive and the crystal surface is further investigated. The influence of the additive sodium dodecyl benzene sulfonate (SDBS) on the morphology of ammonium persulfate (APS) crystals is investigated in both experimental procedures and molecular dynamics simulation studies. It is observed that the growth of (10‐2) surface is more significantly inhibited by the addition of SDBS than is the formation of (11‐1) surface, which contributes to an elongated morphology of the APS crystal. The mechanisms of this effect are examined by performing a molecular dynamics (MD) simulation. The interaction energy and the diffusion coefficient during crystal growth are calculated.

Spectrophotometric determination of anionic surfactants: optimization by response surface methodology and application to Algiers bay wastewater.

A simple analytical method for quantitative determination of an anionic surfactant in aqueous solutions without liquid-liquid extraction is described. The method is based on the formation of a green-colored ion associate between sodium dodecylbenzenesulfonate (SDBS) and cationic dye, Brilliant Green (BG) in acidic medium. Spectral changes of the dye by addition of SDBS are studied by visible spectrophotometry at maximum wave length of 627nm. The interactions and micellar properties of SDBS and cationic dye are also investigated using surface tension method. The pH, the molar ratio ([BG]/[SDBS]), and the shaking time of the solutions are considered as the main parameters which affect the formation of the ion pair. Determination of AS in distilled water gives a significant detection limit up to 3 × 10-6 M. The response surface methodology (RSM) is applied to study the absorbance. A Box-Behnken is a model designed to the establishment of responses given by parameters with great probability. This model is set up by using the three main parameters at three levels. Analysis of variance shows that only two parameters affect the absorbance of the ion pair. The statistical results obtained are interesting and give us real possibility to reach optimum conditions for the formation of the ion pair. As the proposed method is free from interferences from major constituents of water, it has been successfully applied to the determination of anionic surfactant contents in wastewaters samples collected from Algiers bay.

Kinetic study of hydrate formation for argon + TBAB + SDS aqueous solution system

In this communication, the effects of initial temperature and pressure, aqueous TBAB (tetra-n-butylammonium bromide) solution concentration, and sodium dodecyl benzene sulfonate (SDS) concentration on the kinetic behaviour of semi-clathrate hydrates of Ar+aqueous TBAB solutions were investigated. Kinetic experiments were performed in a high pressure equilibrium cell with an inner volume of approximately 40cm3 at initial temperatures of (281, 285 and 287.5)K and initial pressures of (6.1, 8.1 and 10.1)MPa. The results indicate that induction time decreases significantly with an increase in the initial pressure. However, the kinetic constant, and consumption of Ar during the semi-clathrate hydrate formation, increases. The same trends were detected with a decrease in the initial temperature, at a constant pressure. In addition, with an increase in the TBAB concentration, from 0.1 to 0.3mass fraction TBAB, the rate of semi-clathrate hydrate nucleation and consumption of Ar, increases during the hydrate formation, while the induction time decreases, significantly. The results therefore show a positive kinetic effect of TBAB on Ar hydrates which indicates that TBAB is a reliable promoter to increase the rate of argon hydrate formation. The results for the addition of SDS (at concentrations of 100, 200ppm) at initial temperatures of 285K and initial pressures of (6.1 and 8.1)MPa indicate that SDS increases the induction time of the semi-clathrate hydrate formation for the system of Ar+0.1mass fraction TBAB+0.9mass fraction water, but there is no systematic trend between induction times and the SDS concentrations for this system.

Elimination of bleaching in a material based on aqueous fluid with carbon nanoparticles for optical limiters

The possibilities of correcting the functional properties of nonlinear optical limiters based on carbon nanoparticles using polymer dopants have been considered. The results of analyzing the characteristics of nonlinear optical limiting of a suspension of carbon black with addition of sodium dodecylbenzene sulfonate and polyvinyl alcohol are given. The forms in which particles exist in the suspension have been investigated by different physicochemical methods. Optical measurements have confirmed the efficiency of these additives.

Dynamic characteristics of an environment-friendly refrigerant: Ammonia-water based TiO2 nanofluids

A device combining operation and dispersion was constructed to investigate the dynamic characteristics of ammonia-water based TiO2 nanofluids, including suspending ability, viscosity and surface tension for the first time. The results show that the dynamic circulating process can greatly improve the suspending ability of ammonia water based TiO2 nanofluids. Effect of sodium dodecyl benzene sulfonate (SDBS) on the suspending ability is investigated experimentally and theoretically. The absorbency ratio of TiO2 nanofluids with SDBS declines faster than that without surfactant at first, and then trends to gentle or even increase slightly in the later stages, which exhibits a better suspending ability for a long-term operation. Ultrasonic vibration brings a sudden but unsustainable rise in suspending ability. The results also showed that the dynamic circulating process has little effect on the viscosity of TiO2 nanofluids and the surface tension is primarily determined by the addition of SDBS.

Influence of Low-Level Anionic Surfactant on PES Ultrafiltration Performance: Membrane Fouling and Rejection of Nuclides

Surfactants always play a special role in wastewater processes due to their amphiphilic properties. The performance of ultrafiltration was investigated for the treatment of wastewater containing low-level anionic surfactant and trace-level nuclides. Results showed that sodium dodecyl benzene sulfonate (SDBS) below the critical micelle concentration (CMC) caused significant effects on membrane fouling and rejection of nuclides. The membrane flux decreased at SDBS concentrations below the CMC but increased at the concentrations near the CMC. The phenomenon was caused by two distinct effects of SDBS, pore blocking by the monomers and enhancement of nuclide scaling caused a decrease in flux, while hydrophilic modification of the membrane surface by micelles caused an increase in flux. The nuclides alone had no significant effect on membrane fouling, but the flux decreased upon an increase in nuclide concentration when coexisting with SDBS. After the addition of low-level SDBS, the rejections of nuclides increased sharply from 20–30 to 60–98 %. The rejections of Sr(II) and Co(II) were higher than those of Ag(I) and Cs(I) due to stronger complexation of SDBS with divalent cations compared with monovalent cations. Deposition of nuclides increased with the addition of SDBS and with increasing of nuclide concentration, resulting in more radioactive solid waste production and more frequent replacement of membrane module.

Sulfur/Multiwalled Carbon Nanotube Composite Cathode for High Performance Lithium/Sulfur Batteries

Lithium/sulfur batteries have gained intense attention as one of the most promising candidates for high energy density rechargeable batteries due to their high theoretical specific capacity of 1672 mAh g-1 and theoretical energy density of 2600 Wh kg-1 based on cathode materials. In addition, sulfur has the advantages such as low cost, natural abundance, and environmental friendliness. Herein, we report on the preparation of the long-time stabilized MWNT aqueous suspension with the addition of sodium dodecylbenzene sulfonate (SDBS) surfactant, and a well-dispersed sulfur/multiwalled carbon nanotube (S/MWNT) composite synthesis via a simple stirring mixing of the resultant MWNT suspension with commercial nanosized sulfur aqueous suspension. This preparation method based on the suspension mixing possesses the advantages of simplicity and low cost. Homogeneous dispersion and integration of MWNT in the composite results in a porous, highly conductive and mechanically flexible framework with enhanced electronic conductivity and ability to absorb the polysulfides into its porous structure. The cell with this S/MWNT composite cathode demonstrates a high reversibility, resulting in a stable reversible specific discharge capacity of 708 mAh g-1 after 100 cycles at 0.1 C. Furthermore, the S/MWNT composite cathode with sulfur content of 62.5 wt% exhibits a good rate capability with discharge capacities of 946, 780 and 516 mAh g-1 at 0.5, 1 and 1.5 C, respectively.

Effect of surface-active agent on morphology and properties of electrospun PVA nanofibres

After the addition of a surface-active agent, sodium dodecyl benzene sulfonate (SDBS), electrospun polyvinyl alcohol (PVA) nanofibres showed a significant enhancement in the mechanical properties, such as improved tensile strength and elongation at break. The improved crystallinity and strong intermolecular hydrogen bonds between the molecules of SDBS and PVA were the two main factors that improved the mechanical properties. In addition, a sharp decrease in surface tension of PVA solution with the addition of SDBS was observed, and the protruding droplet at the tip of needle diminished in the electrospinning process.

Solvothermal synthesis of hollow Fe3O4 sub-micron spheres and their enhanced electrochemical properties for supercapacitors

Uniform hollow Fe3O4 sub-micron spheres (HFOS) with particle size ranging from 350 to 450nm have been fabricated by a controlled solvothermal synthesis with ferric chloride hexahydrate as sole iron source and sodium dodecylbenzenesulfonate (SDBS) as a surfactant. The suitable addition of SDBS has been proved to promote the formation of monodisperse Fe3O4 hollow particles with narrow size distribution. Good intrinsic magnetic properties including high saturation magnetization of 80.1A·m2kg−1 and very low coercivity of 7.3Oe are observed in these HFOS due to their high purity and spherical morphologies. The electrochemical studies have revealed that these high-purity monodisperse HFOS exhibit high specific capacitance of 294Fg−1 at 0.5Ag−1 and good cycle stability with a maintenance of about 90.8% original capacitance after 500charge/discharge cycles. The excellent electrochemical properties for these HFOS can be attributed to their high purity and large specific surface area resulting from their hollow structure, which promises their big potential application for high-performance supercapacitors.

Dispersion stability of multi-walled carbon nanotubes in refrigerant with addition of surfactant

In order to apply surfactant for improving the stability of multi-walled carbon nanotubes (MWCNTs) nanorefrigerant in refrigeration system, the effects of surfactant type, ultrasonication time, surfactant concentration, initial MWCNT concentration and MWCNT structure on the dispersion stability of MWCNTs in refrigerant with surfactant are investigated in the present study. In the experiments, R141b was selected as host refrigerant for the preparation of nanorefrigerant, UV–vis spectrophotometer method was used to quantitatively evaluate the dispersion stability of MWCNTs, and Fourier transform infrared spectroscopy (FTIR) as well as dynamic light scattering (DLS) analysis were performed to understand the dispersion stability mechanism. The experimental results show that the good dispersion stability of MWCNTs is obtained with addition of sodium dodecylbenzene sulfonate (SDBS) as a surfactant, and the increase of ultrasonication time improves the dispersion stability. The relative concentration increases with the increase of SDBS concentration and then decreases, while increases with the decrease of initial MWCNT concentration at the optimal SDBS concentration. It is also found that the decrease of MWCNT length or outer diameter leads to the increase of relative concentration.

Effect of Preparation Technology of Nano-ZnO on Its Morphology and Photocatalytic Activity

Using Zn(NO3)2•6H2O and NaOH as raw materials, hydrothermal method was employed to prepare nano-ZnO by changing the proportion of materials and adding surfactant. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that at n(OH−):n(Zn2+) = 4:1, the nano-ZnO had a sheet-like structure with average thickness of 80 nm; at (OH−):n(Zn2+) = 10:1, nano-ZnO had a pencil-like structure with the diameter of 220 nm. Rhodamine was used as pollutant to carry out photocatalytic experiments. The results indicated that the photocatalytic performance of sheet-like ZnO was superior to that of pencil-like ZnO. As to the influence of different surfactants, the ZnO had a rod-like structure with the addition of dodecyltrimethylammonium bromide (DTAB), and its photocatalytic performance was enhanced. The photocatalytic performance of ZnO prepared with the addition of Sodium dodecylbenzenesulfonate (DBS) was also improved, though by a smaller extent compared with the addition of DTAB.

Effects of sodium dodecyl benzene sulfonate on the crystal structures and photocatalytic performance of ZnO powders prepared by hydrothermal method

A facile and efficient route for the controllable synthesis of ZnO nanostructures by hydrothermal method using sodium dodecyl benzene sulfonate (SDBS) as surfactant was reported. The obtained products were well characterized with the aid of various techniques to probe their crystallographic, morphological, chemical, electrochemical and optical properties. The prepared products were used as photocatalysts in the application of the degradation of metronidazole (MNZ)-contained wastewater under visible light irradiation. A 4.5-fold augmentation of degradation efficiency was in turn observed for optimal ZnO (ZO-0.75) photocatalyst compared with that of sample without SDBS addition (ZO) under the visible light irradiation. The effects of SDBS dosage on the crystal structures of prepared samples as well as the crystal growth mechanism were also probed.

Synthesis and characterization of organic intercalated layered double hydroxides and their application in bitumen modification

Organic layered double hydroxides (LDHs) intercalated by sodium dodecylbenzenesulfonate (SDBS) were prepared by anion-exchange method and applied to modify bitumen aiming at improving ageing resistance of bitumen. The organic LDHs (SDBS–LDHs) were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Ultraviolet and visible (UV–vis) spectrophotometry. The effect of SDBS–LDHs and LDHs on physical and anti-ageing properties of bitumen was evaluated by means of conventional and rheological test. The results of XRD, FTIR and SEM show that SDBS is successfully intercalated into interlayer of LDHs, and the UV–vis reflectance and absorbance curves illustrate that intercalation of SDBS enhances the UV shielding effect of LDHs. The addition of SDBS–LDHs or LDHs has little influence on physical properties of bitumen because SDBS–LDHs and LDHs are physically mixed in bitumen. Compared with pristine bitumen after TFOT and UV irradiation ageing, the introduction of SDBS–LDHs and LDHs significantly improves thermal- and photo-oxidative ageing resistance of bitumen. Notably, bitumen with SDBS–LDHs exhibits better anti-ageing performance than that with LDHs, implying more effective modification of SDBS-LDHs which is due to the enhanced UV protective ability and compatibility with bitumen of SDBS–LDHs.

Synergistic effects of inorganic salt and surfactant on phenanthrene removal from aqueous solution by sediment.

The economic and effective application of surfactant enhanced remediation (SER) technology in a sediment-freshwater/saline water system was investigated by batch method using the combined effects of inorganic salt (sodium chloride, NaCl) and anionic surfactant (sodium dodecylbenzene sulfonate (SDBS)) on phenanthrene (PHE) removal via sorption by sediment. In all cases, PHE sorption followed a linear equation and partition as the main mechanism for PHE removal from aqueous solution. Separate addition of SDBS (2 mmol L(-1)) and NaCl (2-100 mmol L(-1)) moderately enhanced PHE removal, while with their combined addition the enhancement was substantial, and the removal efficiency achieved a peak of 92.8%. The combined effect expressed a synergy, and the sorption enhancement increased by factors of 2.7, 3.2 and 3.4 when compared with the sum of the separate entities at elevated salinity. This was because the sorbed SDBS, with increasing amount and a high packing conformation at elevated salinity, outcompeted aqueous SDBS for PHE partition. Moreover, a combination of 2 mmol L(-1) SDBS and 2 mmol L(-1) NaCl was optimal for PHE removal. Therefore, SER technology appears more effective for PHE removal in saline water than in freshwater, and preliminary water quality monitoring is essential for economic and efficient SER application.

Study on preparation and associative properties of fluorinated hydrophobically associating polyacrylamide

This paper describes the preparation of a novel fluorinated surface-active monomer (FSM) based on isophorone diisocyanate (IPDI), dodecafluoroheptanol (FOH) and allyl polyethylene glycol (APEG1000) and its copolymer (FAPAM) with 2-acrylamido -2- methyl propane sulfonic acid (AMPS) and acrylamide (AM) through a new micellar system. The chemical structures of FSM-1 and FSM were characterized by FT-IR and 1H-NMR. The hydrophobically associative behaviors of FAPAM as well as the relationship between the content of monomers and hydrophobically associative properties were studied by a combination of viscosimetry, rheological measurements, fluorescence spectroscopy and dynamic light scattering (DLS). The influences of sodium dodecyl benzene sulfonate (SDBS) on associative properties of FAPAM were also studied. The results showed that the micellar copolymerization of AM, AMPS and polymerizable fluorinated surfactant FSM can be favorably realized. The hydrophobically associative properties of FAPAM were affected by the content of FSM and AMPS. The incorporation of FSM endowed the copolymer with both stronger salt and heat resistance. SDBS with low concentration (below the CMC of SDBS) was good for associative properties of FAPAM under CAC (critical association concentration). When the FAPAM was above its CAC, the addition of SDBS into the solution was adverse to their associative properties of FAPAM.

Enzymatic polymerization of phenol catalyzed by horseradish peroxidase in aqueous micelle system

Enzymatic polymerization of phenol catalyzed by horseradish peroxidase (HRP) has been carried out in aqueous micelle system using sodium dodecyl benzene sulfonate (SDBS) as a surfactant. The addition of SDBS to buffer greatly enhances the polymer yield. With a usage of SDBS over 0.4g for 5mmol of phenol monomer, the polymer could be obtained almost quantitatively. The number-molecular weight of the THF-soluble part determined by GPC is increased from 1100 to 2000 with increasing the dosage of SDBS. The phenol polymerization maintains high yields in aqueous micelle system over a wide pH range from 4 to 10. The activity of enzyme in buffer is so high that the phenol polymerization in aqueous micelle system could be completed only in 2h with high yield. The resulting polymer is a kind of powdery material, which is partly soluble in DMF, DMSO and THF. IR analysis showed that the polymer structure contained a mixture of phenylene and oxyphenylene units. From TG analysis, the polymer was found to possess high thermal stability.

Wettability of Fly Ashes from Four Coal-Fired Power Plants in China

Wet flue gas desulfurization, heterogeneous condensation, and chemical agglomeration have been reported to be promising methods for controlling fine particulate matter (PM) from coal combustion flue gas. The effectiveness of these processes is affected by the wettability of the fly ash particles. A novel method based on the flotation mechanism using a laser particle size analyzer was used to measure the wettability of fly ash particles in water, sodium dodecylbenzene sulfonate (SDBS), and Triton X-100 (TX100) solutions. Fly ash samples were collected from four coal-fired power plants in China [Xuanwei (XW), Jungar (JG), Xiaolongtan (XLT), and Yangzonghai (YZH)], representing high-silicon, high-aluminum, high-calcium, and high-iron fly ashes, respectively. The particle size distributions, surface areas, zeta (ζ) potentials, densities, chemical compositions, mineral compositions, and morphologies of the fly ash samples were investigated as well. PM0.1 and PM10+ were readily wetted in water, but most particles within the 1–10-μm range exhibited lower wettabilities. The wettability of fly ashes in water is related to other physical or chemical characteristics and follows the trend YZH > XLT > XW > JG. For YZH fly ash, PM0.1 and PM1+ can be completely wetted in water. For XW, JG, and XLT fly ashes, only PM0.1 and PM10+ can be wetted completely in water. Addition of SDBS or TX100 promoted most wetting processes, and the promotional effect is also related to other characteristics of fly ash particles such as surface roughness, surface area, and ζ potential.