A Study of the Solubilization of Polar Oily Materials by Alkyl Polyglucoside and Sodium Dodecyl Sulfate in Mixed Surfactant System

The effects of different alkyl chains of nonionic surfactants and solubilized polar oily material on the solubilizing capacity of binary anionic‐nonionic mixed surfactant systems were studied. This system includes surface tension measurements to determine the critical micelle concentration. Results were analyzed using regular solution theory to obtain the mixed micelle and the interaction parameter β, in order to evaluate the type of interactions of surfactants in the mixed micelle. Solubilizing capacity has been investigated by measuring the optical density of solubilized polar oily materials like octanol, decanol, and dodecanol. The solubilizing phenomenon exhibited by mixed surfactants systems showed better results than that of the individual surfactant system. The amount of solubilization in mixed surfactant increases with increase in carbon chain length of alkyl polyglucoside.     

静电场诱导十二烷基硫酸钠结晶行为的研究

用透射电镜、X射线衍射及DSC等方法 十二烷基硫酸钠（SDS）极稀水溶液（溶液介于临界聚集浓度和临界胶束浓度之间）在静电场作用下的结晶行为,静电场作用诱导SDS形成规则的四方单晶与从甲醇中重结晶所得样品的晶体结构相同,DSC结果表明,从有序到无序结构变化的一级相转变热焓相同,但由于电场诱导结晶的晶体较小而表现为转变温度的降低,没有施加静电场处理的样品只具有较低的有序程度。     

十二烷基磺酸钠对大豆过氧化物酶活性和构象的影响

在不同的pH值体系中, 利用酶活测量、圆二色谱、荧光谱和电子吸收谱研究了十二烷基磺酸钠(SDS)对大豆过氧化物酶(SBP)活性与构象的影响情况. 在pH 2.6和4.2 的体系中, 少量的SDS分子可通过静电作用与SBP结合, 进而与SBP分子中的His169残基结合, 降低其与铁卟啉的配位能力, 使其Soret吸收带蓝移, 二级结构发生轻微的变动, 活性永久丧失. 在pH 5.2体系中, SDS和SBP分子都带负电, 由于静电排斥作用, SDS无法进入SBP的分子内部, 失去与SBP分子中His169残基结合的能力, 对SBP分子的二级结构没有影响, 仅对SBP分子的三级结构有所影响. 当SDS的浓度大于临界胶束浓度时, 由于胶束与SBP的静电排斥作用增强, 限制了铁卟啉中乙烯基的运动, 乙烯基与卟啉环的共轭程度增大, Soret 吸收带红移. 由于SBP活性可完全恢复, 此变化是可逆的.     

Precipitating Sodium Dodecyl Sulfate to Create Ultrastable and Stimulable Foams

Ultrastable foams are made very simply by adding salt (NaCl or KCl) to sodium dodecyl sulfate. The addition of high concentrations of salt leads to the precipitation of the surfactant on the bubble surfaces and as crystals in the interstices between the bubbles. As a consequence, the ageing of the foams is stopped to make them stable indefinitely, or until they are heated above the melting temperature of the crystals. The use of KCl is shown to be much more effective than that of NaCl because potassium dodecyl sulfate has a higher melting temperature and faster rates of crystallization. The crystalline structures have been investigated inside the foam using small angle neutron scattering. The larger lattice spacing of the crystals formed with NaCl in comparison with KCl has been evidenced. These simple temperature stimulable foams could have many potential applications.     

CnNCl和SDS在水溶液中的相互作用

CnNCl和SDS在水溶液中的相互作用;滴定式微量热法; 烷氧基羟丙基三甲基氯化铵; 十二烷基硫酸钠;胶束;疏水作用     

十二烷基硫酸钠对酶抑制光度法测定农药残留的增敏作用

采用植物酯酶抑制法测定了蔬菜中农药的残留,研究了阴离子表面活性剂十二烷基硫酸钠对显色体系的作用.结果表明,十二烷基硫酸钠具有显著的增敏效果,其增敏幅度达到70%,同时对显色剂有增稳作用.用所建立的方法测定蔬菜中残留的敌敌畏,线性范围为0.11 mg/L~1.6 mg/L,最低检出限0.04 mg/L.     

Atomic Absorption Spectrophotometry of Chromium Using an Enhancing Effect of Sodium Dodecyl Sulfate

Abstract

In the atomic absorption spectrophotometry of chromium with the air-acetylene flame, the absorption of chromium was increased by about 120% in the presence of sodium dodecyl sulfate (SDS) above the critical micelle concentration (CMC). This phenomenon was applied to overcoming interferences from many coexisting cations and some acids.     

The Electrooxidation of Tetracycline at Acetylene Black Electrode in the Presence of Sodium Dodecyl Sulfate

The electrooxidation of tetracycline (TC) at acetylene black electrode has been studied in the presence of sodium dodecyl sulfate (SDS). Tetracycline (TC) exhibited very sensitive oxidation peak in this system. The peak current was proportional to TC concentration, and the detection limit was 1.2×10-8 mol/L. The system was used to the determination of TC in Pharmaceuticals.     

L-半胱氨酸在SDS吸附胶束中的电化学催化氧化

The electrochemical oxidation of L-cysteine can be catalyzed by sodium dodecyl sulfate (SDS) admicelles. The catalytic efficiency increases hardly when SDS concentration is lower than the critical admicelle concentration (CAC) and increases rapidly when SDS concentration is between CAC and the critical micelle concentration (CMC), but decreases when SDS concentration is higher than CMC. Both results of rate constant k^0 and Gibbs free energy ΔG^ck accord with that of catalytic efficiency.     

Phase Behavior in Mixtures of Cationic Dimeric and Anionic Monomeric Surfactants

The formation of mixed aggregates has been investigated in the mixture of oppositely charged surfactants vastly differing in molecular geometry and size. The systems considered is mixture of the cationic gemini surfactant, ethanediyl-1,2-bis(dodecyldimethylammonium bromide), and anionic surfactant, sodium dodecyl sulfate. Various mixed nano- and microaggregates (micelles, vesicles, thin lamellar sheets, and tubules) were formed depending on bulk composition and total surfactant concentration. Two types of aggregates were found in precipitate, the tubules as prevailing aggregates on the gemini-rich side, and vesicles as prevailing aggregates on the SDS-rich side. The tubules formation was ascribed to mutual influence of specific structure of cationic dimeric surfactant and electrostatic interactions at the bilayer/solution interface. The proposed mechanism involved the formation of lamellar sheets, which rolled-up into tubules.     

Growth Mechanism of Large Monodispersed Silica Particles Prepared from Tetraethoxysilane in the Presence of Sodium Dodecyl Sulfate

Monodispersed silica particles up to ca. 1.2 μm in diameter were prepared by hydrolysis of tetraethoxysilane in the presence of sodium dodecyl sulfate (SDS). The particle size was increased with an increase of SDS added. The geometrical standard deviation of the particles was decreased with an increase of SDS. In the earlier reaction stage, double spherical particles by the coalescence of the particles were frequently observed when large amounts of SDS were added. Particle size was gradually increased after the coalescence occurred and spherical particles were finally obtained. The results of Nielsen’s chronomal analysis suggest that the polynuclear layer growth took place after the coalescence of the particles in the presence of larger amount of SDS.     

γ－环糊精－SDS胶束电动色谱法分离十八甲基炔诺酮光学异构体

研究了ＣＤ－ＳＤＳ胶束电动色谱（ＣＤ－ＭＥＫＣ）对电中性及疏水性的手性化合物的分离，并讨论了不同类型ＣＤ的手性识别作用。使用γ－ＣＤ可以有效地拆分十八甲基块诺酮（ＮＯＧ）旋光异构体。选择了最佳分离条件，通过调节ＣＤ和ＳＤＳ浓度以及其它操作条件可以把ＮＯＧ异构体很好的分离。     

Rheological Behavior of Aqueous Solutions of Cationic Guar in Presence of Oppositely Charged Surfactant

The cationic guar (CG) is synthesized and the rheological behavior of aqueous solutions of CG in the presence of sodium dodecyl sulfate (SDS) is studied in detail. The steady viscosity measurements show that the zero shear viscosity enhancement can be almost 3 orders of magnitude as the concentration of SDS increases from 0 to 0.043%. The gel-like formation is observed as the concentration of SDS is greater than 0.016%. The oscillatory rheological measurements of CG solutions in the presence of SDS show that the crossover modulus is almost independent of the concentration of SDS whereas the apparent relaxation time increases swiftly upon increasing the concentration of SDS. The experimental results indicate that the strength rather than the number of the cross-links is greatly affected bySDS molecules. The mechanism concerning the effect of SDS upon the rheology of CG solutions can be coined by the two-stage model. Before the formation of cross-links at the critical concentration, the electrostatic interaction between SDS and cationic site of CG chains plays a key role and the SDS molecules bind to CG chains through the electrostatic interaction. After the formation of cross-links at the concentration greater than the critical concentration, the cooperative hydrophobic interaction become dominant and SDS molecules bind to the cross-links through the hydrophobic interaction. The rheological behavior of aqueous solutions of CG in the presence of SDS is chiefly determined by the micelle-like cross-links between CG chains. In fact, the flow activation energy of CG solution, obtained from the temperature dependence of the apparent relaxation time, falls in the range of transferring a hydrophobic tail of SDS from the micelle to an aqueous environment.     

激光光散射和电子自旋共振技术研究十二烷基硫酸钠与聚乙烯吡咯烷酮的相互作用

应用动态激光光散射(DLS)和电子自旋共振(ESR)测定研究了单长链表面活性剂十二烷基硫酸钠(SDS)与聚乙烯吡咯烷酮(PVP)相互作用.DLS测定结果表明:SDS在水中形成动力学半径约为61 nm的胶束聚集体,PVP在水中卷曲成动力学半径约为12 nm的线圈,DLS确定的SDS临界胶束浓度(cmc)为6.4×10^-3 mol·L^-1, PVP-SDS具有强的相互作用,PVP分子缠绕在SDS胶束聚集体的周围,屏蔽了SDS胶束聚集体表面碳氢基团与连续水相的接触;ESR结果表明:自由基探针5-doxyl stearic acid在SDS形成胶束聚集体后,从一个较强极性的连续相转变到较小极性的胶束聚集体内核中,胶束聚集体内核的微粘度较纯水的大,SDS与PVP复合聚集体的微观粘度较SDS胶束溶液的大,ESR确定SDS的cmc为6.8×10^-3 mol·L^-1.     

Room Temperature Synthesis of Gold Nanokites in Polyvinyl Alcohol‐Sodium Dodecyl Sulfate Aggregations Aqueous Solution

Controlled synthesis of asymmetrical gold nanokites was realized by reducing HAuCl₄ with polyvinyl alcohol (PVA) in PVA‐sodium dodecyl sulfate (SDS) aggregations aqueous solution at room temperature without any additional reducing agents. The crystal structures, optical property and growth process of the gold nanokites were investigated by X‐ray diffraction (XRD), Vis‐NIR spectrum and transmission electron microscope (TEM). HAuCl₄ concentration dramatically influenced the morphologies of the products. When HAuCl₄ concentration was increased from 0.5 mmol·L⁻¹ to 2.2 mmol·L⁻¹, the products changed from network‐like nanostructures to nanokites, nanoleaves and microplates. SDS was indispensable for the formation of gold nanokites and without SDS super‐branched structures became the dominant products.     

Analysis of the Interactions of Polyvinylpyrrolidone with Conventional Anionic and Dimeric Anionic Surfactant

Classical physical method has been applied in the present study of interaction between water soluble polymer with anionic dimeric and conventional anionic surfactants. Micellization activity of carboxylate-based anionic dimeric (CAD) as well as sodium dodecyl sulfate (SDS) surfactants in the presence of nonionic polymer, that is, polyvinylpyrrolidone (PVP), has been studied through conductometric and surface tensiometric measurements. From these methods the critical aggregation concentrations (CACs), critical micelle concentrations (CMCs), and the effective degree of counterion binding (β) were determined. For the evaluation of behavior of CAD toward the PVP various thermodynamic properties viz. standard Gibbs energy of micellization, standard enthalpy, and entropy of micellization of CAD/PVP mixed system have also been estimated and discussed. The results exhibit that anionic dimeric surfactant interacts strongly with PVP as compared to conventional surfactant.     

SDS对PEO-PPO-PEO嵌段共聚物溶液行为的影响

对PEO-PPO-PEO（127）三嵌段共聚物的水溶液行为及添加十二烷基硫酸钠（SDS）后对共聚物溶液行为的影响进行了研究．利用荧光探针技术对不同SDS浓度下F127／SDS体系的胶来形成进行研究,并研究了SDS对F127浓溶液凝胶化行为的影响．结果表明：随着SDS浓度的增大,F127稀溶液胶束的形成受到抑制,SDS浓度愈大,形成的胶束结构就愈疏松．对F127浓溶液来说,SDS与F127摩尔比小于2时,体系易于凝胶化;但当SDS浓度增大,其与F127摩尔比大于2时,体系开始难于凝胶化,直至摩尔比大于5时,体系不再形成凝胶．     

Competitive Process of Binding Between the Anionic Surfactants Sodium Dodecyl Sulfate and Sodium Cholate in Bovine Serum Albumin

Summary: In this study sodium cholate (NaC) was used as a representative bile salt for the competitive binding between NaC and sodium dodecyl sulfate (SDS) in bovine serum albumin (BSA), in 0.02 M tris-HCl buffer solution at pH 7.50 and 25 °C. The NaC and SDS associations with BSA were monitored at low surfactant concentrations where only this specific binding process can develop. The applied method to monitor the binding was based on the analysis of the effect of SDS and NaC concentrations and their mixtures upon the fluorescence intensity of the BSA tryptophan residues. This consists of the measurement of the surfactant monomer partitioning between the dispersion medium and the microaggregates on the protein molecule where the binding is indicated by the quenching of the fluorescence chromophores. Experimentally, varying the protein concentration, the surfactant concentration needed to reach a given I_o/I ratio (I_o and I are the intensities with and without protein, respectively) was measured. The analyses, based on the average number of surfactant molecules bound on the protein, indicated that the SDS is a more efficient quencher than the bile salt. The need for 4–6 NaC bound molecules to give the same protein quenching efficiency by a single molecule of SDS was estimated. We concluded that the differences in the competitive binding on the protein are exclusively related to the quenching efficiency in the formation of the nonfluorescent fluorophore-quencher complex via a physical contact and static quenching process.     

Micellization of Sodium Dodecyl Sulfate in Glycerol Aqueous Mixtures

The effect of glycerol on both micellar formation and the structural evolution of the sodium dodecyl sulfate (SDS) aggregates in the context of the action mechanism of the cosolvent has been studied. The critical micelle concentration and the degree of counterion dissociation of the surfactant over a temperature range from 20°C to 40°C were obtained by the conductance method. The thermodynamic parameters of micellization were estimated by using the equilibrium model of micelle formation. The analysis of these parameters indicated that the lower aggregation of the surfactant is mainly due to a minor cohesive energy of the mixed solvent system in relation to the pure water. The effect of glycerol on the mean aggregation number of the micelles of SDS was analyzed by the static quenching method. It was found that the aggregation number decreased with the glycerol content. This reduction in the micellar size seems to be controlled by an increase in the surface area per headgroup, which was ascribed to a participation of glycerol in the micellar solvation layer. Studies on the micropolarity of the aggregates, as sensed by the probe pyrene, indicated that this microenvironmental parameter is almost unaffected by the presence of glycerol in the mixture. However, an increase in the micellar microviscosity at the surface region was observed from the photophysical behavior of two different probes, rhodamine B and auramine O. These results suggest a certain interaction of the cosolvent in the micellar solvation of SDS micelles.     

Interaction of Sodium Dodecyl Sulfate with Poly(ethyleneimine) in Bulk Solution and at the Air-Solution Interface

Interaction of sodium dodecyl sulfate (SDS) with the cationic polyelectrolyte poly(ethyleneimine) (PEI) was investigated in this study. Turbidity measurements were performed in order to analyze the interaction and complex formation in bulk solution as a function of polymer concentration and pH. Surface tension measurements were made to investigate the properties of SDS/PEI/water mixtures at air/solution interface. Results revealed that SDS/PEI complexes form in solution depending on the surfactant and polymer concentration. A decrease was observed in surface tension values in the presence of SDS/PEI mixtures compared to the values of pure SDS solutions. Both solution and interfacial properties exhibited pH dependent behavior. A shift was seen in the critical micelle concentration of SDS solutions as a function of PEI concentration and solution pH. Monovalent and divalent salt additions showed some influence on the interfacial properties of SDS solutions in the presence of PEI.