Different Kinds Of Surfactants Research Articles

Recovery of Low Permeability Reservoirs Considering Well Shut-Ins and Surfactant Additivities

To investigate the mechanism whereby well shut-ins and surfactant additivities can increase hydrocarbon output after hydraulic fracturing, in this paper, we simulated well shut-ins with one end open (OEO) rock samples and performed a serious of imbibition experiments with different surfactant additivities based on contact angle (CA) and interfacial tension (IFT) measurements. Scanning electron microscope (SEM) and nuclear magnetic resonance (NMR) methods were also been adopted in the detection before and after shut-ins. The results demonstrated that cationic surfactants result in better improving oil recovery (IOR) performance due to their high wettability alteration ability on vertical fracture faces, while different kinds of surfactants have a similar ability in lowering IFT. As for shut-ins duration, the NMR transverse relaxation time (T2) spectrum move towards the left side, indicating that aqueous phases migrate to smaller pores spaces and deeper distances. Aqueous migration during the shut-ins period can remove near-fracture trapped water, while surfactant additivities can accelerate and enhance this process, and these two points are the most direct reasons for the observed hydrocarbon output increases.

Effect of surfactant for magnetic properties of iron oxide nanoparticles

For different medical applications nanoparticles (NPs) with well-defined magnetic properties have to be used. Coating ligand can change the magnetic moment on the surface of nanostructures and therefore the magnetic behavior of the system. Here we investigated magnetic NPs in a size of 13nm conjugated with four different kinds of surfactants. The surface anisotropy and the magnetic moment of the system were changed due to the presence of the surfactant on the surface of iron oxide NPs.

Preparation of Nano Melamine Phosphate and Its Application in Phenolic Foam

Nano melamine phosphate(NMP) flame retardant was synthesized using melamine and phosphoric acid as reagents by means of a solvothermal method. The prepared NMP was then characterized by means of Fourier transform infra-red spectroscopy, X-ray diffraction, and transmission electron microscopy. Effect of solvents, different kinds of surfactants(i.e. SDS, CTAB and NP), reaction temperature and time on the morphology of reaction product was investigated. It is found that the NMP can only be obtained by using benzene as a solvent. If distilled water and anhydrous ethanol were used as solvent, the particle size of the product is in micro scale. As reaction temperature or reaction time increases, the morphology of the products changes greatly. Moreover, types of surfactants have a great influence on the morphology of the products. Moreover, The polyethylene glycol toughened phenolic foam with addition of NMP exhibits a flexural strength 39% higher than that with addition of micro MP.

Simultaneous determination of naphthol isomers at poly(3-methylthiophene)-nano-Au modified electrode with the enhancement of surfactant.

A polymer film incorporated gold nanoparticle modified electrode was fabricated. The fabricated process involved eletrodeposition of gold nanoparticles and electropolymerization of the 3-methylthiophene (abbreviated 3MT) onto the glassy carbon electrode (GCE). The resulting electrode (P3MT-nano-Au/GCE) was characterized by scanning electron microscopy (SEM), and a simultaneous determination of naphthol isomers at P3MT-nano-Au/GCE was studied using semi-derivative voltammetry. Because of the synergistic effect of gold nanoparticles and poly(3MT), the sensitivity and distinguishability in the simultaneous determination of naphthol isomers were greatly increased. Besides, a further increase in the detecting sensitivity of naphthol isomers could be obtained in the presence of surfactant, cetyl trimethyl ammonium bromide (CTAB). Also, the role of different kinds of surfactants was texted and the action mechanism was discussed in detail. Under the optimal conditions, the linear calibration ranges of the determination of naphthols were 7.0×10(-7) to 1.5×10(-4) mol/L for 1-naphthol and 1.0×10(-6) to 1.5×10(-4) mol/L for 2-naphthol with detection limits of 1.0×10(-7) and 3.0×10(-7) mol/L (S/N=3), respectively.

Effects of different kinds of surfactants on Nafion membranes for all vanadium redox flow battery

To investigate the effects of different surfactants on the properties of Nafion membrane, recast Nafion membranes were prepared with cationic (tetramethylammonium bromide (TMAB)), anionic (sodium dodecyl sulfate (SDS)), and nonionic surfactants (Triton X-100 (TX-100)). The prepared composite membranes were analyzed by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), AFM, WXRD, and small-angle X-ray scattering (SAXS) to investigate the microstructure of the membrane. The properties of the composite membrane, including the water uptake, ion exchange capacity, proton conductivity, VO2+ permeability, water transport, as well as the single cell performance are evaluated in detail. Results show that both the physical and electrochemical properties of the surfactant-modified Nafion membranes were quite different from the unmodified recast Nafion (r-Nafion) membrane. Vanadium redox flow battery (VRB) single cell tests indicate that the nonionic modified Nafion membrane possesses the best comprehensive performances among the three surfactants modified and r-Nafion membranes. At current density of 40–80 mA cm−2, the average energy efficiency (EE) of the VRB with TX-100 Nafion membrane is 2.6 % higher than that of unmodified r-Nafion membrane, while the average EE of the VRB with TMAB/Nafion is 3.2 % lower than that of r-Nafion membrane. Another important effect of surfactants on the Nafion is the water transport behavior across the different membranes. TMAB can decrease the water transport across Nafion membrane, while the SDS and TX-100 can slightly increase the water transport across Nafion membrane.

Influence of surfactants on bioleaching of arsenic-containing gold concentrate

To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.

Preparation of Ag/TiO2/SiO2 films via photo-assisted deposition and adsorptive self-assembly for catalytic bactericidal application

The deterioration of water supply quality due to the waterborne bacteria is an environmental problem requiring the urgent attention. Due to the excellent and synergic antimicrobial capability, Ag-loaded TiO2 photocatalyst emerges as a feasible measure to guard the water. In our work, Ag nanoparticles have been prepared by the photoassisted reduction of AgNO3 on the TiO2 film fabricated by solution-based adsorptive self-assembly approach. The role of surfactant on the growth rate and size controlling of particles is also studied. In this connection, different kinds of surfactants, such as PVP, Tween-20, Tween-40 and so on, are applied in the system to investigate the formation of Ag nanoparticles. The surface profile and elemental analysis of Ag/TiO2/SiO2 films are examined by scanning electron microscopy and attached energy-dispersive X-ray spectroscopy, respectively. In the anti-bacteria detection, Ag nanoparticles are found to enhance the bactericidal efficiency strongly comparing with the pure TiO2 film under the same condition. In addition, by comparison with Ag/TiO2/SiO2 film in the dark environment as the reference experiment, UV–visible light plays a vital role in the improved bactericidal behavior, demonstrating the more efficient charge separation induced by metal silver. Because of the versatility of the method, the present photoreductive route is also exploited for the synthesis of Au nanoparticles on TiO2/SiO2 films. The corresponding photocatalytical detection results demonstrate the loading of Au nanoparticles can improve the photodegradation efficiency of methyl orange assigned to the similar electron-trapping effect to silver.

Research on the Sol-Gel Method of Preparing Ternary Nano SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub> Materials

Tetraethyl orthosilicate (TEOS), butyl titanate [Ti (OBu)4] and aluminium isopropoxide were used as molecular precursor of ternary nanoSiO2-Al2O3-TiO2 materials. The influences of temperature and the dosage of compounds on the characteristic of ternary nanomaterials were investigated. Transmission electron microscopy (TEM), x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were employed to investigate the characteristics of the nanomaterials synthesized by the sol-gel method. In addition, the adsorption of nanomaterials for different kinds of surfactants was also studied. Results revealed that the influences of temperature, compounds dosages and water on the size of ternary nanomaterials had a significant impact. With the increase of ammonia dosage, the concentration of the OH- ion became higer, and system showed a faster reaction rate. The higer temperature of the system was, the larger size of the ternary nanomaterials was. Moreover, the higer tempreature woule also lead to divide into layer and precipitate. Optimal parameters can be chosen to prepare monodispersed ternary nanoSiO2-Al2O3-TiO2 materials. Results also showed that the surface characteristic of ternary nanoSiO2-Al2O3-TiO2 particles differed from nanosilica, which manifested in forms of the adsorption dosage of surfactants.

Simple and fast voltammetric procedure of U(VI) determination in the presence of high concentrations of surface active substances

In this work, a simple and fast procedure for elimination of interfering surface active substances and for U(VI) adsorptive stripping voltammetric determination was developed. The adsorption in the form of U(VI)-cupferron complexes was performed, because as it was proved before, U(VI) forms with cupferron stable complexes, which were employed in voltammetric procedures. The procedure is based on two steps: the first is an adsorption of surface active substances onto an Amberlite XAD-16 or XAD-7 resin and the second is a voltammetric determination of U(VI) with a pulsed potential of accumulation alternate –0.65–0.3 V with the frequency of 0.5 Hz and then the differential pulse voltammogram was recorded, whereas the potential was scanned from –0.65 to –1.2 V. The detection limit estimated from three times the standard deviation for a low U(VI) concentrations was equal to 1.7 × 10−10 mol L−1 (7.2 × 10−8 g L−1). The linear range of U(VI) was observed over the concentration range from 5.0 × 10−10 mol L−1 (2.1 × 10−7 g L−1) to 2.0 × 10−8 mol L−1 (8.5 × 10−6 g L−1) for an accumulation time of 60 s. The influence of different kinds of surfactants, such as non-ionic, cationic and anionic on the uranium voltammetric signal was studied. The results confirm the possibility of U(VI) determination in water samples containing high concentrations of surface active substances even up to 50 mg L−1.

Influence of surfactants on shear-thickening behavior in concentrated polymer dispersions

Concentrated dispersions consisting of 310 nm poly(styrene–ethylacrylate) nanospheres and ethylene glycol, which exhibited pronounced shear-thickening behavior, were prepared in this work. The influence of surfactants on their shear-thickening behavior was investigated, which indicated that the surfactants affected the shear-thickening behavior by changing the surface force and interparticle force. Various surfactants, such as cationic, anionic, nonionic, and zwitterionic surfactants were added to the shear-thickening fluid (STF) and their rheological properties were measured. The results indicated that all kinds of surfactants could enhance shear-thickening behavior by changing their electrostatic, steric, or lubrication interaction, especially for nonionic surfactant Triton X-100 (TX100) and cationic surfactant cetyltrimethyl ammonium bromide (CTAB). TX100 led to the maximum viscosity up to 1,650 Pa s and CTAB enhanced the maximum viscosity up to 1,000 Pa s when the introduced surfactants were only 2 and 0.3 %, both values were nearly five times larger than the neat STFs. A plausible explanation for the enhancing mechanism by different kinds of surfactants was discussed.

Development of tacrolimus-loaded transfersomes for deeper skin penetration enhancement and therapeutic effect improvement in vivo

The aims of this study were to prepare novel transfersomes (TFs) for tacrolimus to treat atopic dermatitis, and to observe the therapeutic effects on mice atopic dermatitis, as compared to commercial tacrolimus ointment (Protopic®) and liposomes-gel. Different kinds of surfactants—sodium cholate, Tween 80 and Span 80 were investigated to prepare TFs respectively. TFs-Tween 80 was selected as the optimal carrier owing to the best deformability and the highest drug retentions. Entrapment efficiency and diameter were also evaluated. The optimized TFs were further made into gel and in vitro drug release of TFs-gel after 24 h was higher than the commercial ointment. Cumulative drug release from TFs-gel after 12 h in vitro was 37.6%. The optimized TFs-gel illustrated remarkably highest drug skin retentions when compared with liposomes-gel and commercial ointment in vivo skin retention experiments. The amounts of tacrolimus in epidermis and dermis from TFs-gel were 3.8 times and 4.2 times respectively as much as ointment, while liposomes-gel was only 1.7 times and 1.4 times respectively as compared to ointment. Topical application of TFs-gel displayed the best therapeutic effect on mice atopic dermatitis induced by repeated topical application of 2,4-dinitrofluorobenzene. Thus TFs displayed superior performance and effective skin target for topical delivery of tacrolimus.

The Influence of Different Kinds of Surfactants on Rheology in Polymer/Surfactant Complex Flooding

Because of alkaline declining the sweep efficiency, causing scale formation problem in the reservoir and the well bottom and the tubular pipes, so polymer/surfactant compound flooding technology is the emphasis in the research of enhanced recovery. So the articles study the regulation of different kinds of surface active agents at different temperature by MARS Rheometer. The testing result showed that the variation of viscocity under the interaction between the surface active agent and association polymer according to “three stage” model .The linear viscoelastic region of stress decrease when different surface active agents are put into polymer liquor, and the higher frequency, the better elasticity of polymer liquor. The hydrophobic association between the surface active agents and polymer decrease with a higher temperature, but the ionic surfactant is aggravate. The systematic study of binary system rheology can contribute to correctly understand and apply binary system.

Surfactant effects on the microstructures of Fe3O4 nanoparticles synthesized by microemulsion method

A water-in-oil microemulsion route has been devised to synthesize nanosized magnetite (Fe3O4) particles using different kinds of surfactant as the surfactant phase, n-heptane as the oil phase, and n-hexanol as the co-surfactant phase, respectively. The X-ray diffraction (XRD), transmission electron microscopy (TEM) and 57Fe Mössbauer technique were employed to investigate the characteristic of the nanoparticles. The Fe3O4 powder derived from various microemulsions possessed an average spherical particle size of 13–15nm based on TEM observation. The 57Fe Mössbauer spectroscopy results reveal that surfactant structure plays an important role in regulating the microstructure of Fe3O4 nanoparticles. The relationships among the crystal lattice defect (vacancy parameter), magnetite stoichiometry and the surfactant structure have been discussed in terms of headgroup charge, hydrophobic chain length, headgroup size. The temperature effects on the particle size and defect are performed and the most remarkable factor of surfactant structures on the lattice defect and magnetite stoichiometry against the temperature variation is also discussed. Moreover, the influence of lattice defect and magnetite stoichiometry on the magnetic property has also been explored.

Surfactant modified/mediated thin-layer chromatographic systems for the analysis of amino acids.

This review incorporates a large number of chromatographic systems modified by the surfactants. A large number of solvent systems and stationary phases are summarized in this paper. Three different kinds of surfactants (anionic, cationic, and nonionic) are used as modifiers for stationary phases as well as solvent systems. Surfactants are used at all the three different concentration levels (below, above, and at critical micelle concentration) where surfactants behave differently. Modifications of both stationary phases and solvent systems by surfactants produced a new generation of chromatographic systems. Microemulsion solvent systems are also incorporated in this paper. Microemulsion thin-layer chromatography is a new approach in the field of chromatography.

The Design of Surfactant Multiplex System for Lowering Threshold Pressure

In order to increase surfactant compound system injection in low permeability reservoir of Chaoyanggou oilfield, we do research into formula of surfactant compound system according to reservoir condition. By contrasting to interfacial tension of different kinds of surfactants, we choose petroleum sulfonate surfactant T720-40# as main agent. As equilibrium interfacial tension of this surfactant cannot meet the requirements, so we add Na2CO3 as auxiliary agent to decrease interfacial tension. The results of laboratory experiment research show that equilibrium interfacial tension of this multiplex surfactant system can reach 2×10-2mN/m. It has good thermal endurance, salt resistance, and also has good compatibility with Chaoyanggou injection water and formation water. It can make rock wettability reverse, reduce threshold pressure and displacement pressure and it can improve recovery by 5% contrasting to water flooding.

The effect of different surfactants on the electrospinning poly(vinyl alcohol) (PVA) nanofibers

The surface tension of the spinning solution is an important parameter in the electrospinning process. Surfactants can change the surface tension of the solution. In this paper, four different kinds of surfactants were added into 10 wt% polyvinyl alcohol/water solution. The effect of different surfactants on the solution properties, the morphology of the resulting mats, the thermal performance, and the inner structure of nanofibers were investigated. The results showed that the surface tension of the spinning solution decreased significantly when the surfactant content was less than 1 %. The viscosity and electric conductivity of the solution increased with the increasing of cationic and anionic surfactant content. The fiber diameter of poly(vinyl alcohol) mats remarkably decreased from 405 to 100 nm as the non-ionic surfactant content within the range of 1 % (v/v) increased. Besides that, the surfactant content also had some influence on the thermal performance and inner structure of nanofibers. With the surfactant content increasing, both the heat of fusions and crystallinity increased significantly.

Capsule‐like α‐Fe2O3 nanoparticles: Synthesis, characterization, and growth mechanism

AbstractUniform capsule‐like α‐Fe2O3 particles were synthesized via a simple hydrothermal method, employing FeCl3 and CH3COONa as the precursors and sodium dodecyl sulfate (SDS) as soft template. X‐ray powder diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), and high‐resolution transmission electron microscopy were used to characterize the structure of synthesized products. Some factors influencing the formation of capsule‐like α‐Fe2O3 particles were systematically investigated, including different kinds of surfactants, the concentration of SDS, and reaction times. The investigation on the evolution formation reveals that SDS was critical to control the morphology of final products, and a possible five‐step growth mechanism was presented by tracking the structures of the products at different reaction stages.

New Method of Synthesis of Stable Zero Valent Iron Nanoparticles (Nzvi) by Chelating Agent Diethylene Triamine Penta Acetic Acid (DTPA) and Removal of Radioactive Uranium From Ground Water by using Iron Nanoparticle

Nowdays, iron nanoparticles due to their unique characteristics are used in all of sciences and technology. These nano particles due to their electrical, magnetic, optical and catalytic properties and having high area and activity that is promped by their small size and most importantly many scientists from the entire world are interested in their low cost production. In this project we used method of reduction in the liquid phase for synthesis of iron nano particles. Unlike synthesis so far has been done and they used different kinds of surfactants and capping or they used starch for stabilization, we used chelating agent diethylene triamine penta acetic acid (DTPA) for increasing the stability of iron nano particles for the first time in the world. Ammonium iron(II) sulfate were used for make iron nano particle and Sodium borohydride was used for reduction. This method not only was simple and cheap but also didn’t need special instruments. Also determining of structure, size, particles distribution and surface morphology of this nano particles we used the analysis of FT-IR, XRD and SEM that all of them showed the synthesis of zero valent iron nanoparticles, metallic iron, has been done correctly. The average of synthesis of zero valent iron nano particles is 18 nm and crystal structure of nano particles was designed by using vertical nano lab software. Finally, we studied opration Removal of Radioactive Uranium From groundwater by using iron nanoparticle.

Studies of Interfacial Activities of Four Kinds of Surfactants at Oil/Water Interface

This article aims to compare the interfacial activities of different kinds of surfactants in the same oil/water system. The anionic surfactants of alkylbenzene sulfonates, the polyoxyethylenated nonionic surfactants, the cationic surfactants of alkyl trimethyl ammonium chlorides, and the zwitterionic surfactants of alkyl hydroxyl sulfobetaines were used, and the interfacial tensions of the surfactant solutions against kerosene at different NaCl concentrations were measured. It is found that the interfacial activities of the alkylbenzene sulfonates are high and ultralow interfacial tensions (<0.01 mN/m) can be obtained at proper salinities. While, the nonionic surfactants have relatively low interfacial activities and the minimum tensions are around 0.01 mN/ms. The salinity scanning curves of the alkylbenzene sulfonates and nonionic surfactants decrease first, then increase, showing their interfacial activities can be changed by the salinity effectively. The cationic and zwitterionic surfactants have very low interfacial activities, of which all the tensions are higher than 0.1 mN/ms and are hard to be changed by the salinity. The experimental results may have important reference values for enhanced oil recovery.

Plate Coating: Influence of Concentrated Surfactants on the Film Thickness

We present a large range of experimental data concerning the influence of surfactants on the well-known Landau-Levich-Derjaguin experiment where a liquid film is generated by pulling a plate out of a bath. The thickness h of the film was measured as a function of the pulling velocity V for different kinds of surfactants (C(12)E(6), which is a nonionic surfactant, and DeTAB and DTAB, which are ionic) and at various concentrations near and above the critical micellar concentration (cmc). We report the thickening factor α = h/h(LLD), where h(LLD) is the film thickness obtained without a surfactant effect, i.e., as for a pure fluid but with the same viscosity and surface tension as the surfactant solution, over a wide range of capillary numbers (Ca = ηV/γ, with η being the surfactant solution viscosity and γ its surface tension) and identify three regimes: (i) at small Ca α is large due to confinement and surface elasticity (or Marangoni) effects, (ii) for increasing Ca there is an intermediate regime where α decreases as Ca increases, and (iii) at larger (but still small) Ca α is slightly higher than unity due to surface viscosity effects. In the case of nonionic surfactants, the second regime begins at a fixed Ca, independent of the surfactant concentration, while for ionic surfactants the transition depends on the concentration, which we suggest is probably due to the existence of an electrostatic barrier to surface adsorption. Control of the physical chemistry at the interface allowed us to elucidate the nature of the three regimes in terms of surface rheological properties.