阴／非离子复合表面活性剂驱油剂的制备研究

研究了阴离子表面活性剂AES与非离子表面活性剂OP-10和阴离子表面活性剂AES与非离子表面活性剂TX分别以不同比例混合后对表面／界面张力的影响,并从机理上进行了相关探讨。实验结果表明：当AES与OP-10和AES与TX的质量比分别为8：2和6：4时,表面／界面张力均降低至最低值。二者比较来看,AES与TX的复配体系较AES与OP-10的复配体系降低表面／界面张力的效果明显。     

阴离子/非离子表面活性剂体系洗涤含油污泥

针对新疆某油田重度石油污染土壤,进行了洗涤剂的复配及洗脱条件的优化研究。考察了阴离子表面活性剂浓度、非离子表面活性剂浓度以及硅酸钠助剂浓度对残油量的影响。正交实验结果表明,十二烷基苯磺酸钠（LAS）与烷基酚聚氧乙烯醚（平平加,APEO）间存在着较强的交互协同作用;两者复配可以增强洗涤效果,并减少药剂用量。优化的复配洗涤剂配方为： LAS 2g/L,平平加3g/L,Na2SiO3 3g/L。复配洗涤剂洗涤含油污泥的最佳操作条件为：液固质量比10∶1、洗涤温度70℃、洗涤时间1h,在此条件下污泥含油量从26.07%降低至1.21%。对污泥洗涤前后的红外光谱检测表明该复配洗涤剂对于污泥中原油的饱和分、芳香分、胶质和沥青质都有洗涤效果,特别是对饱和分的去除效果尤为显著。     

Tuning the polydispersity of alcohol ethoxylates for enhanced oily soil removal

Commercially available alkyl alcohol ethoxylates have a broad distribution of ethylene oxide (EO) units and also a somewhat narrower distribution of alkyl chain length. Generally, the purer the surfactant sample (narrower distribution), the better is its detergency performance, and detergency peaks at the phase inversion temperature (PIT) for a given oil. However, in real detergency processes this may not hold true since soils are typically mixtures of several oily components, and temperature variations are significant. Therefore, if a polydispersity index (PDI) of ethoxylates is defined as the ratio of weight average EO moles to number average EO moles in the sample, then it is conceivable that an optimal PDI might be obtained. We compared the detergency of hexadecane for pentaethylene glycol monododecyl alcohol (C₁₂EO₅) samples in a broad PDI range, using an oil-soluble dye. While detergency at 55°C (PIT of hexadecane with C₁₂EO₅) decreases monotonically with increasing creasing PDI, average detergency over a 20°C temperature range around the PIT tends to show a maximum at PDI of ca. 1.1 (narrow-range ethoxylate). Similarly, for a mixture of undecane/hexadecane/tetracosane (30∶50∶20 w/w/w) for which the average PIT is approximately the same as that of hexadecane detergency at 55°C shows a maximum as a function of PDI at a value of ∼1.37 (broad-range ethoxylate). All detergency results are in general agreement with the reverse trends in oil/water interfacial tension and suggest that, having decided the optimal EO moles for a given application based on PIT, one can further improve the performance of alcohol ethoxylates in real detergency processes by tuning their polydispersity.     

Composition of mixed anionic/nonionic surfactant micelles

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium dodecyl sulfate-polyoxyethylene 23 lauryl ether (Brij 35) in water and in 0.1 M sodium chloride solution at 25°C. This technique applies the Gibbs-Duhem equation to the mixed micelle, which is treated as a pseudophase. This proposed methodology which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.     

Selecting the optimal linear alcohol ethoxylate for enhanced oily soil removal

Use of nonionic surfactants in detergent products has become increasingly popular because of their tolerance to hardness ions and their effect on lowering the critical micelle concentration of anionics. Their performance as detergents, however, is very sensitive to changes in temperature and electrolyte concentration, which need to be carefully controlled in order to ensure that phase inversion conditions prevail. For a fixed temperature in an application, the only variables available for optimizing the performance of a system containing nonionics are: the type of nonionic, and the concentrations of electrolytes and anionics. Based on the mutual interactions of these ingredients in mixed systems, we have devised some guidelines for selection of the optimal ethylene oxide (FO) chain length in lauryl alcohol ethoxylate type of nonionics for a range of electrolytes and anionic surfactant concentrations. For any given concentration of electrolytes (sodium carbonate and sodium tripolyphosphate), anionic (sodium linear alkyl benzene sulfonate) and nonionic, the detergency of synthetic sebum from blended polyester/cotton fabrics shows a maximum as a function of average FO moles in the nonionic. Oil/water interfacial tension shows an expected reverse trend. The optimal EO moles (for maximal detergency) show a monotonically increasing trend when plotted as a function of the ratio of nonionic to anionic concentration for a fixed level of electrolyte. The optimal EO moles also increase with increasing level of electrolytes in the system. However, the effect of nonionic/anionic ratio is much stronger than the effect of electrolytes on the optimal EO moles.     

Vapor-liquid equilibria of carbon dioxide and nonionic surfactant system at elevated pressures

Aqueous solutions of the polyoxyethylene nonionic amphiphiles have been extensively investigated at atmospheric pressure, but only a few data of nonionic amphiphile — carbon dioxide system are available at elevated pressures. Isothermal vapor-liquid equilibrium data for the binary ethylene glycol propyl ether (C3E1) — carbon dioxide system at 313.15 K, 323.15 K were measured at elevated pressures. We used two-phase circulating type equipment with a view cell. Modeling of the experimental data has been performed using the Peng-Robinson equation of state, statistical associating fluid theory (SAFT) and Sanchez-Lacombe equation of state.     

Remediation of phenanthrene contaminated soils by nonionic surfactants enhanced soil washing coupled with ozone oxidation

In the present work, soil washing followed by ozone oxidation for remediation of phenanthrene (PHE) contaminated soils was investigated. The PHE removal efficiencies of TX-100 and Brij-35 at 3000 mg/L were 80.2% and 73.8%, respectively. In the ozone oxidation process, the oxygen supply rate was more rapid and the ozone concentration in the water rose quickly after 2 h. The degradation efficiencies for PHE, Brij-35, and TX-100 at 20 mg/L ozone concentration were 99%, 99%, and 45%, respectively. Our investigation suggests that coupling ozone oxidation with surfactant-enhanced soil washing is an effective method for removing hydrophobic compounds from soils.     

Loading characteristics of filter pretreated with anionic surfactant for monodisperse solid particles

Anionic surfactant (sodium oleate, SO) was used to pretreat polypropylene fibrous filters to make them negatively charged. This work examines the effects on particle loading of an anionic surfactant-pretreated filter. Also, the effects of various factors, such as the particle size, the face velocity, concentration of the surfactant, and particle distribution (mono and poly) on the particle loading characteristics were evaluated.Experimental data reveal that the electric field of a filter treated with anionic surfactant (SO) could be directly measured using an electrofieldmeter, suggesting that the pretreatment with surfactant charged the filters. The results demonstrate that pretreating the filter with SO surfactant increases its particle-loading capacity. The clogging points of the untreated filter, and of the 0.01, 0.05 and 0.08 M SO-pretreated filter are 18, 23, 28 and 33 g/m². The loading behavior of the SO-pretreated filter depended on the size of the particles and the operating face velocity. Additionally, the loading behavior of the SO-pretreated filter with polydisperse particles is much the same as that with monodisperse particles. However, the clogging point of the SO-pretreated filter with polydisperse particles is higher than that with monodisperse equal size.     

Switching effects of electrode polarity and introduction direction of reagents in electrokinetic-Fenton process with anionic surfactant for remediating iron-rich soil contaminated with phenanthrene

This study investigated effective operating method of enhanced electrokinetic-Fenton (EK-Fenton) process with anionic surfactant to remediate contaminated iron-rich clayey soil with phenanthrene, which had soil properties being frequently in contaminated sites. Introduction of 30 mM SDS as H₂O₂ stabilizer improved not only H₂O₂ stability but also degradation of phenanthrene compared to experiment without SDS. However, electrical potential drop in regions near cathode terminated electro-osmotic flow, and then phenanthrene in region near cathode kept initial concentration before switching of the electrodes polarities and introduction direction of reagents. After the polarity of the electrodes and introduction direction of reagents were switched, electro-osmotic flow was re-generated with re-distribution of electrical potential and electrical current. Furthermore, after switching electrode, decrease of iron concentration and pH in the soil specimen near cathode before switching electrode generated decrease of H₂O₂ decomposition rate. Therefore, H₂O₂ could be introduced in the cathode regions before switching the polarity of the electrodes and introduction direction of reagents. Furthermore, residual phenanthrene was degraded homogeneously after switching of the electrodes polarity and introduction direction of reagents, and then about 70% phenanthrene could be degraded.     

Well-dispersed surfactant-stabilized Pt/C nanocatalysts for fuel cell application: Dispersion control and surfactant removal

A simple surfactant-stabilized method was investigated for the preparation of well-dispersed platinum nanoparticles supported on carbon black (Pt/C), using 3-(N, N-dimethyldodecylammonio) propanesulfonate (SB12) as the stabilizer. First, TEM analysis demonstrated that Pt dispersion can be improved by the increase of molar ratio of SB12 to Pt precursor. Moreover, pH environment plays a crucial role in Pt dispersion, and the optimal dispersion with an average Pt particle size of 2.2 nm was obtained under neutral or slightly alkaline environment. Pt dispersion mechanism was shown to involve the electrosteric stabilization of Pt nanoparticles by the zwitterionic surfactant SB12, which is highly pH-dependent. At pH ≥ 7, a stable electrosteric repulsion exists between the Pt particles covered by SB12, where the positively charged part is adsorbed on the particle surface and the negatively charged part (SO₃⁻) and the bulky alkyl chain (C₁₂H₂₅) are pointed away from particles. At pH < 7, protons H⁺ directly interact with Pt particles or SO₃⁻ groups of SB12, resulting in the destruction of the electrosteric stabilization and the following agglomeration of Pt nanoparticles. Furthermore, XPS and cyclic voltammetry showed that the surfactant on Pt particles can be efficiently removed by ethanol wash without any destruction on the dispersion and particle size of Pt, when compared to heat treatment and centrifugation. Electrochemical measurements showed that the ethanol-washed pH-controlled Pt/C catalyst has higher electrochemical surface area and catalytic performance than the commercial one.     

Correlation between adhesion of aqueous solutions of nonionic and anionic surfactant mixture with short-chain alcohols to polymer surface and their adsorption at interfaces. I. Adhesion tension and adsorption

Contact angle measurements of aqueous solutions of a p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycol) (Triton X-100)/sodium dodecylsulfate (SDDS) mixture with a short-chain alcohol (methanol, ethanol or propanol) on polytetrafluoroethylene (PTFE) and nylon-6 surfaces were made. Complete spreading of the studied solutions was observed only in the case of nylon-6. Contact angle isotherms were considered with regard to alcohol activity as well as the adsorption of the surfactant mixture and alcohol at the polymer-solution interface. For this analysis solid-liquid interfacial tension and changes of adhesion tension as a function of the surface tension of the solution were taken into account. It appeared that in the range of alcohol concentration in which it is present in the monomeric form in the bulk phase, the Gibbs surface excess concentration of the surfactant mixture and alcohol at the PTFE-solution interface is close to that at the solution-air interface. However, alcohol activity at these interfaces differ from each other. The adsorption of the surface active agents at the nylon-6-solution interface is much lower than at the solution-air interface.     

The HLD Study of Surfactant Partitioning for Oilfield Corrosion Inhibitors

The partitioning of corrosion inhibitor (CI) products is a measure of their potential to protect oilfield pipelines. In this paper the hydrophilic–lipophilic deviation (HLD) model is first used to quantify their partitioning in terms of the characteristic curvature (C _c,act) of a series of anionic (alkoxylated phosphate esters) and cationic (alkoxylated amines, aromatic amines, imidazoline acetates and quaternary amines) actives. This parameter is expressed over a range of pHs within which pipeline corrosion occurs. The HLD model is next used to predict the partitioning of each active from water into toluene at increased salinities. Linear mixing rules are lastly used to predict the characteristic curvature of Product A (C _c,mix) as a function of the C _c,act of a subset of actives.     

Decomposition of nonionic surfactant in a labyrinth flow photoreactor with immobilized TiO2 bed

The photocatalytic oxidation of nonionic surfactant polyoxyethylene nonyl phenyl ether (Rokafenol N9) in water in the labyrinth flow reactor with immobilized catalyst bed was investigated. Tytanpol A11 titanium dioxide supplied by Chemical Factory “Police” S.A. (Poland) was used as a photocatalyst. The influence of various factors, including reaction mixture flow rate, initial surfactant concentration and time of the process performance on the photodegradation of model compound were examined. It was found that the effect of the initial surfactant concentration on the effectiveness of Rokafenol N9 removal was practically negligible in the range of the investigation, whereas the reaction mixture flow rate has a significant effect on the effectiveness of Rokafenol N9 decomposition. The highest surfactant photodegradation (92%) was obtained at the solution flow rate equal to 11.98 dm³/h and the lowest (86%) at 1.64 dm³/h. The apparent rate constant k was linearly dependent on the reaction mixture flow rate. Extension of the reaction time from 5 to 60 h did not result in a complete mineralization of Rokafenol N9 to CO₂ and water.     

Synergism and Performance for Systems Containing Binary Mixtures of Anionic/Cationic Surfactants for Enhanced Oil Recovery

The surfactant structure–performance relationship and application properties in enhanced oil recovery (EOR) for binary mixtures of anionic and cationic surfactants are presented and discussed. A polyoxyethylene ether carboxylate anionic surfactant was blended with a quaternary ammonium chloride cationic surfactant and tested for a high-temperature, low-salinity, and high-hardness condition as found in an oil reservoir. These mixtures were tailored by phase behavior tests to form optimal microemulsions with normal octane (n-C8) and crude oil having an API gravity of 48.05°. The ethoxy number of the polyoxyethylene carboxylate anionic surfactant and the chain length of the cationic surfactant were tuned to find an optimal surfactant blend. Interfacial tensions with n-C8 and with crude oil were measured. Synergism between anionic and cationic surfactants was indicated by surface tension measurement, CMC determination, calculation of surface excess concentrations and area per molecule of individual surfactants and their mixtures. Molecular interactions of anionic and cationic surfactants in mixed monolayers and aggregates were calculated by using regular solution theory to find molecular interaction parameters β ^σ and β ^M . Morphologies of surfactant solutions were studied by cryogenic TEM. The use of binary mixtures of anionic/cationic surfactants significantly broadens the scope of application for conventional chemical EOR methods.     

An observation of the coexistence of multimers and micelles in a nonionic surfactant C10E4 solution by dynamic light scattering

The bulk phase of nonionic surfactant C₁₀E₄ solution was monitored by a dynamic light scattering (DLS) system at 20 °C in a narrow range of concentration near the cmc. Two particle aggregations were observed. The DLS data show (i) there exist premicellar multimers (or called sub-micelles) and (ii) micelles coexist with multimers. The C₁₀E₄ sub-micelles have a narrow size distribution with an averaged hydrodynamic diameter (D_h) of 1.35 nm. The D_h of the micelles is around 10.5 nm at 1.0 × 10⁻⁶ mol/mL and increases slightly with C₁₀E₄ concentration. It is illustrated from the DLS data that (i) at C = 0.78-0.82 μmol/mL, monomers and premicellar multimers coexist and (ii) at C = 0.84-0.92 μmol/mL, monomers + submicellar multimers + micelles coexist. At more elevated concentrations, only the signals from the micelles are detected by DLS.     

Optimization of experimental parameters for separation of nonionic surfactants by supercritical fluid chromatography

A synthetic polymer generally consists of a mixture of many compounds that share the same repeating unit but have different degrees of polymerization. Because of its ability to cope with a wide range of molecular weights, supercritical fluid chromatography (SFC) is a powerful technique for separating the individual components of polymers. However, the separation conditions for SFC are more sensitive than those of other types of chromatography, and many experimental parameters need to be carefully selected to achieve high resolutions. Methods for optimizing the experimental parameters for SFC of a polymeric surfactant were investigated by chemometric techniques. Increases or decreases in peak resolution and elution times were measured for the separation by SFC of the nonionic surfactant poly(ethylene glycol) nonylphenyl ether for various column temperatures, flow-rate gradients of modifier, and modifier compositions. To maximize the separation efficiency, the experimental results were analyzed by using the chromatographic response function (CRF). This is a function of the desired peak resolution, the maximum acceptable elution time, and an arbitrary weighting factor that is adjusted to achieve an optimal balance between the peak separation and the elution time. Because the numerical value of the CRF changes in response to the chromatographic performance, it provides a means of identifying the conditions for achieving optimal separation for a particular SFC system.     

Surfactant-assisted removal of 2,4-dichlorophenol from soil by zero-valent Fe/Cu activated persulfate

The organic compounds contaminated soil substantially threatens the growth of plants and food safety. In this study, we synthesis zero-valent bimetallic Fe/Cu catalysts for the degradation of 2,4-dichlorophenol (DCP) in soils with persulfate (PS) in combination of organic surfactants and exploring the main environmental impact factors. The kinetic experiments show that the 5% (mass) dosage of Fe/Cu exhibits a higher degradation efficiency (86%) of DCP in soils, and the degradation efficiency of DCP increases with the increase of the initial PS concentration. Acidic conditions are favorable for the DCP degradation in soils. More importantly, the addition of Tween-80, and Triton-100 can obviously desorb DCP from the soil surface, which enhances the degradation efficiency of DCP in soils by Fe/Cu and PS reaction system. Furthermore, the Quenching experiments demonstrate that SO₄^-· and ·OH are the predominant radicals for the degradation of DCP during the Fe/Cu and PS reaction system as well as non-radical also exist. The findings of this work provide an effective method for remediating DCP from soils.     

Photooxidation of anionic surfactant (sodium lauryl sulfate) in a three-phase fluidized bed reactor using TiO2/SiO2 photocatalyst

The photooxidation of sodium lauryl sulfate (=sodium dodecyl sulfate) in two different types of three-phase fluidized bed reactors was investigated. A low concentration of sodium lauryl sulfate (0.1–0.6 mM) in aqueous solution was photocatalytically decomposed by a TiO₂ photocatalyst immobilized on a porous SiO₂ support. In order to determine the optimum operating conditions in the fluidized beds, the effects of the air flow rate, amount of catalyst, initial concentration of surfactant, light source power, and pH on the photooxidation rate were investigated. From the experimental results, it was observed that the superficial air velocity was an important parameter in determining the reaction rate for both reactors. The photooxidation reaction rate increased with increasing UV lamp power and the experimentally obtained reaction rates showed good agreement with the Langmuir adsorption model. Also, a higher reaction rate was observed when the aqueous solution was acidic.     

A novel and facile method for direct synthesis of cross-linked polysiloxanes by anionic ring-opening copolymerization with Ph12-POSS/D4/Ph8D4

The cross-linked polysiloxanes were directly synthesized by anionic ring-opening copolymerization of Ph₁₂-POSS as multifunctional monomer with D₄ and Ph₈D₄ under KOH or Me₄NOH siloxanolate. And the influences of the polar additive DMAc on gelation time were investigated. The results of gel content and swelling ratio, GPC, solid-state ²⁹Si and ¹³C NMR, FT-IR, WAXD showed that Ph₁₂-POSS was reacted and most of the product was cross-linked. The DSC and TG results indicated that the cross-linked polysiloxanes exhibited distinct glass transition temperatures (T_g) and excellent thermal stability. Compared to that with KOH siloxanolate, the cross-linked polysiloxane synthesized with Me₄NOH siloxanolate has more preferable thermal stability.     

Application of chitosan/nonionic surfactant mixture in reactive dyes for dyeing wool fabrics

The feasibility of wool fabrics pretreated with a chitosan/nonionic surfactant mixture and dyed with reactive dyes was studied. The results showed that the presence of the chitosan/surfactant improved the application to wool, which greatly enhanced the color strength when dyed at 50°C but little change was observed when dyed at 80°C. The higher the concentration of chitosan/surfactant added, the greater was the color strength of the dyed wool fabrics. The amounts found to be optimum for dyeing were 0.5% chitosan and 1.0% surfactant. The washing fastness of the dyed wool fabrics was in the range of grades 4–5, the dry rubbing fastness was in the range of grades 4–5, and the wet rubbing fastness was in the range of grades 3–4. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2859–2864, 2001