尾链长度高度不对称的阴/阳离子表面活性剂自组织

通过引进新的溶液制备方法,以光散射、流变、电镜等方法研究了烷烃链长度不对称的阴/阳离子表面活性剂等摩尔混合体系,其中阳离子为二十二烷基三甲基溴化铵(C₂₂TABr),阴离子是烷基羧酸钠(C_n-1COONa, n = 4, 6, 8, 10, 12, 14, 16).结果表明,烷烃链长度高度不对称时(C22/n4)生成了球状胶束,随着降低不对称度,聚集体向棒状、蠕虫状直至囊泡转变.在构成囊泡的体系中,随着降低链长不对称度,聚集体尺寸明显增大.机理分析表明,阴/阳离子对的几何形状决定了聚集体的形貌以及它们的转变.     

阴阳离子表面活性剂混合体系在克拉玛依油田中获得超低界面张力

利用阴阳离子表面活性剂复配技术,在克拉玛依油田实际油水体系中获得了超低界面张力.通过添加非离子保护剂的第三组分,阴阳离子表面活性剂混合体系在克拉玛依油田回注水体系中的溶解度大大提高.确定了相关体系能够获得超低界面张力的表面活性剂的浓度和混合的比例范围,在克拉玛依油田的多个实际油水体系中获得了具有较大复配比例和较低表面活性剂浓度的实际配方,其中部分体系油水界面张力可接近10-4mN·m-1.同时,这类阴阳离子表面活性剂混合体系具有很好的抗吸附能力,在石英砂吸附72 h后体系依然呈现优良的超低界面张力.     

Silicon-Modified Carbohydrate Surfactants III: Cationic and Anionic Compounds

Ionic siloxanyl-modified carbohydrate surfactants have been synthesized by alkylation/esterification of precursors containing tertiary amino functions. Depending on the reaction strategy, the siloxanyl moiety is part of the alkylating agent or the substrate. Polyhydroxylated tertiary amines can be quaternized by siloxanyl-modified chloroacetic acid esters or epoxysiloxanes in the presence of glacial acetic acid. The esterification of tertiary amines bearing carbohydrate and siloxanyl subunits by cyclic acid anhydrides yields, after neutralization, carboxylate salts. The reaction of hydroxyl groups and sulfamic acid leads to sulfates. The new substances were characterized by means of ¹³C NMR spectroscopy, gas chromatography, elemental analysis and their solubility profile. © 1997 John Wiley & Sons, Ltd.     

短链烷基对多取代烷基苯磺酸盐界面性质的影响

利用悬挂滴方法研究了2,5-二乙基-4-壬基苯磺酸钠(292)、2,5-二丙基-4-壬基苯磺酸钠(393)和2,5-二丁基-4-壬基苯磺酸钠(494)在空气-水表面和正癸烷-水界面的扩张流变性质,考察了时间、界面压、工作频率及体相浓度对扩张弹性和粘性的影响。研究发现,在低表面活性剂浓度条件下,表面吸附膜类似弹性膜,其强度由膜内分子的相互作用决定;高浓度下体相与表面间的扩散交换过程控制表面膜的性质。油分子的插入导致界面吸附分子之间相互作用的削弱,扩散交换过程主导界面膜性质;但随着短链烷基长度增加,油分子的影响变小。表面膜的强度在吸附达到平衡前已经决定,而界面膜在吸附饱和后仍然随界面分子重排而变化。     

高盐油藏下两性/阴离子表面活性剂协同获得油水超低界面张力

研究了在高盐油藏中, 利用两性/阴离子表面活性剂的协同效应获得油水超低界面张力的方法. 两性表面活性剂十六烷基磺基甜菜碱与高盐矿化水具有很好的相容性, 但在表面活性剂浓度为0.07%-0.39%(质量分数)范围内仅能使油水界面张力达到10^-2 mN·m^-1量级, 加入阴离子表面活性剂十二烷基硫酸钠后则可与原油达到超低界面张力. 通过探讨表面活性剂总浓度、金属离子浓度、复配比例对油水动态界面张力的影响, 发现两性/阴离子表面活性剂混合体系可以在高矿化度、低浓度和0.04%-0.37%的宽浓度范围下获得10^-5 mN·m^-1量级的超低界面张力, 并分析了两性/阴离子表面活性剂间协同获得超低界面张力的机制.     

可断键芳磺酸盐表面活性剂的合成与表面活性

三聚氯氰;可断键表面活性剂;表面张力;稳态荧光法     

Molecular Exchanging Energy of Anionic／Cationic Surfactants System on the Surface of Solution

In order to study synergism of the mixed surfactants system with molecular exchanging energy ( ε ), the Lennard-Jones formula has been firstly introduced to evaluate the ε of the mixed system, CH3(CH2)nOSO 3^- /CH3(CH2)nN^ (CH3)3, directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical.     

助表面活性剂对阴/阳离子表面活性剂复配形成微乳液的影响

中相微乳液;盐度扫描;助表面活性剂对阴/阳离子表面活性剂复配形成微乳液的影响     

Synthesis and Surface Activity of Anionic Gemini Surfactants with Alkyl Spacers

A series of anionic Gemini surfactants called alkanediyl-α,ω-bis(m-octylphenoxy sulfonate) with different length of (CH₂)_x spacer, C₈C_xC₈ (x = 2, 4, 6, 8), have been synthesized from 4-n-octylphenol and their basic physicochemical properties are investigated. The results indicate that they are different from cationic Gemini surfactants called alkanediyl-α,ω-bis(dimethyldodecylammonium bromide), 12-(CH₂)_s-12, in the literature. It is found that as the carbon atom number of the spacer increases, the cmc (critical micelle concentration) decreases gradually, and the surface area per molecule (A_min) decreases initially and then increases. The breakpoints appear at number 4 of carbon atom in the spacer. Though the length of the spacer is different for the Gemini surfactants from C₈C₂C₈ to C₈C₆C₈, there is no obvious change on the micropolarity.     

Selective Separation of Dodecyltrimethylammonium Bromide from Other Cationic and Nonionic Surfactants

JPC – Journal of Planar Chromatography – Modern TLC - Thin-layer chromatography (TLC) of cationic and nonionic surfactants has been performed on soil, silica gel, alumina, and...     

聚丙烯酰胺对烷基苯磺酸盐界面吸附膜扩张流变性质的影响

采用小幅低频振荡和界面张力弛豫技术, 研究了部分水解聚丙烯酰胺(Mo-4000)和阴离子表面活性剂2-丙基-4,5-二庚基苯磺酸钠(377)体系在癸烷/水界面上的扩张黏弹性质, 并考察了电解质对体系界面流变性质的影响. 研究结果发现, 低表面活性剂浓度时, 聚合物的加入大大降低了扩张模量; 而高表面活性剂浓度时, 聚合物的存在导致了界面膜更接近弹性膜. 一方面电解质压缩双电层, 增加界面膜的紧密程度, 造成高频条件下扩张模量增大; 另一方面, 电解质增强表面活性剂分子在界面与体相间的扩散交换作用, 增大了扩张模量的频率依赖性, 造成低频条件下扩张模量降低.     

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.     

Interaction of Quercus Infectoria Natural Dye with Cationic and Anionic Surfactants: Adsorption/Micellization of Dye

The interaction of Indian natural dye, that is, Himalaya (Quercus infectoria) with cationic surfactant (cetyl trimethyl ammonium bromide) and anionic surfactant (sodium lauryl sulphate) has been studied. The spectrophotometric data showed an interaction between the natural dye and surfactants. Critical micelle concentration (CMC) of the surfactants, determined by measurement of specific conductance and surface tension methods, was found to be increase in case of anionic surfactant while that was found to decrease in case of cationic surfactant. Thermodynamic and surface parameters showed domination of micellization of dye in case of cetyl trimethyl ammonium bromide and domination of adsorption of dye in case of sodium lauryl sulphate.     

pH-Responsive Rheological Properties and Microstructure Transition in Mixture of Anionic Gemini/Cationic Monomeric Surfactants

Surfactant aggregates have long been considered as a tool to improve drug delivery and have been widely used in medical products. The pH-responsive aggregation behavior in anionic gemini surfactant 1,3-bis(N-dodecyl-N-propanesulfonate sodium)-propane (C₁₂C₃C₁₂(SO₃)₂) and its mixture with a cationic monomeric surfactant cetyltrimethylammonium bromide (CTAB) have been investigated. The spherical-to-wormlike micelle transition was successfully realized in C₁₂C₃C₁₂(SO₃)₂ through decreasing the pH, while the rheological properties were perfectly enhanced for the formation of wormlike micelles. Especially at 140 mM and pH 6.7, the mixture showed high viscoelasticity, and the maximum of the zero-shear viscosity reached 1530 Pa·s. Acting as a sulfobetaine zwitterionic gemini surfactant, the electrostatic attraction, the hydrogen bond and the short spacer of C₁₂C₃C₁₂(SO₃)₂ molecules were all responsible for the significant micellar growth. Upon adding CTAB, the similar transition could also be realized at a low pH, and the further transformation to branched micelles occurred by adjusting the total concentration. Although the mixtures did not approach the viscosity maximum appearing in the C₁₂C₃C₁₂(SO₃)₂ solution, CTAB addition is more favorable for viscosity enhancement in the wormlike-micelle region. The weakened charges of the headgroups in a catanionic mixed system minimizes the micellar spontaneous curvature and enhances the intermolecular hydrogen-bonding interaction between C₁₂C₃C₁₂(SO₃)₂, facilitating the formation of a viscous solution, which would greatly induce entanglement and even the fusion of wormlike micelles, thus resulting in branched microstructures and a decline of viscosity.     

阴离子表面活性剂－溴化十二烷基二甲基苄基铵－溴百里酚蓝显色反应的分光光度法研究

本文研究了溴化十二烷基二甲基苄基铵－溴百里酚蓝与阴离子表面活性剂显色反应的适宜条件。结果表明，在ｐＨ７．４～８．２范围内阴离子表面活性剂与题示试剂形成１：２：１的绿色离子缔合物，其最大吸收峰位于６１４ｎｍ处。表现摩尔吸光系数分别为：＝３．９９×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）；＝３．７０×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）；＝１．７１×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。ＳＤＢＳ在０～１９５μｇ／１０ｍＬ，ＳＤＳ在０～１５８μｇ／１０ｍＬ，ＳＬＳ在０～６０μｇ／１０ｍＬ范围内遵守比耳定律。该法用于河水和生活废水中阴离子表面活性剂测定，结果满意。     

Equilibrium and Dynamic Surface Tension of Carboxymethylchitosan and Alkyl Trimethylammonium Bromide Mixtures

A water-soluble derivative of chitosan, carboxymethylchitosan (CMCH), was mixed with alkyltrimethylammoniumbromides (C_mTAB) and was studied on the adsorption at air/water interface using equilibrium and dynamic surface tension method. The effects of surfactant and polymer concentrations, surfactant chain length, as well as pH of solution were investigated. Addition of the surfactants remarkably promotes the polymer adsorption. Increasing any one of surfactant concentration, surfactant chain length, and pH will facilitate the adsorption of the mixture whereas little effects of polymer concentration were observed. The results are explained in terms of the interaction between CMCH and C_mTAB under different conditions.     

Dynamic Interfacial Tension Behavior of Water/Oil Systems Containing In situ-Formed Surfactants

Time-dependent interfacial tension (IFT) has been investigated for an interfacially reactive immiscible system composed of model-acidified oil and alkaline water. The acidified oil was composed of either lauric acid or linoleic acid dissolved in n-dodecane. Drop volume tensiometry was employed to measure the interfacial tension between the two phases. In the case of lauric acid, the IFT value was found to decrease sharply with increasing alkali concentration, even at low drop formation times. In the case of linoleic acid, the IFT decrease with the drop formation time was more gradual, especially at low alkali concentration. The rate of formation of the interfacial area was also found to be dependent on alkali concentration.     

Modeling of Equilibrium Adsorption and Surface Tension of Cationic Gemini Surfactants

A series of equilibrium tension models are used to evaluate the adsorption behavior of a novel class of lipoaminoacid gemini cationic surfactants, N^α,N^ω-bis(long-chain N^α-acylarginine)α,ω-dialkylamides or bis(Args). For purposes of comparison, the monomer LAM (the methyl ester of N^α-lauroyl arginine) was also examined. These surfactants are of particular interest for both their low toxicity and biocompatibility. The tension models are based on the Gibbs adsorption isotherm and classified as “ionic” when the surface charge and the electric double layer are accounted for or as “pseudo-nonionic” when the surface charge is ignored. Both model predictions and fitted parameter values are evaluated with respect to physical plausibility and overall goodness of fit to the available tension and density data. In particular, the inferred values for the standard Gibbs free energy of adsorption ΔG°, determined from an equilibrium constant defined on a nondimensional basis, without including artifacts due to an electrostatic contribution, are analyzed. The most reliable values of ΔG° are found with the combined model to range from −110 to −120 kJ mol⁻¹ for the three dimers examined and −80 kJ mol⁻¹ for the monomer. For spacer chain lengths n=3, 6, or 9, the maximum surface area of surfactant adsorption and the maximum free energy of adsorption are observed for the surfactant with the spacer chain length of 6.     

Influence of the Alkyl Tail Length on the Anionic Surfactant-PVP Interaction

The effect of the surfactant tail length on the interaction between sodium alkylsulfates (C _n OS, n = 6, 8, 10, 12) and poly(vinylpyrrolidone) (PVP) in aqueous solution has been investigated by electron paramagnetic resonance (EPR) spectroscopy employing TEMPO-choline (TC) as a spin probe. Experimental evidence show that all of the considered surfactants molecularly interact with PVP. However, the cooperative behavior of the surfactant molecules when self-aggregating onto the polymer strongly increases with the surfactant tail length. In fact, in the case of C₆OS, the TC EPR parameters indicate that surfactant monomers randomly associate with the polymer chain. In the case of C₈OS, formation of surfactant-polymer clusters occurs simultaneously to free micellization. In the case of C₁₂OS and C₁₀OS, the nitrogen isotropic hyperfine coupling constant of TC (< A _N >) shows that formation of surfactant-polymer clusters occurs. The correlation time (τ _C ) of the nitroxide in the same systems shows that electrostatic repulsion among the clusters, formed on the PVP macromolecules, favors a broadening of the polymer coil and a stiffening of its chain. The average number of surfactant molecules participating in each cluster adsorbed onto the polymer, as determined by fluorescence quenching measurements, is much higher for C₁₂OS than for C₁₀OS.