阴离子与阳离子双结构表面活性剂的相互作用

1、概述 自最早的表面活性剂投入市场以来,在市场上只出现了很少几种新型表面活性剂.最近,双结构表面活性剂已逐渐引起了人们的关注,并取得了商业成功."双结构表面活性剂"原指有双疏水尾的表面活性剂,后来也用来表述一些多头表面活性剂.     

酯型双子阳离子表面活性剂与甲基橙的相互作用

通过紫外-可见光谱法研究了一系列具有不同疏水基的、含酯基双子季铵盐阳离子表面活性剂(EDC-1,2,3,4)与甲基橙(MO)之间的相互作用.结果表明,表面活性剂浓度在1.0×10-5 mol·L-1左右时(远低于其cmc),EDC和MO聚集.这种聚集导致MO的紫外吸收光谱中π→π*吸收带蓝移98 nm,即在365 nm处形成一个新的吸收带.进一步增加EDC浓度至cmc以上时,由于MO增溶于EDC胶束内部,使λmax移至430 nm处.并且分离出了EDC与MO聚集产生的聚合物,经1HNMR分析,其中EDC与MO的摩尔比为12.     

双子阳离子表面活性剂改性蒙脱土的制备与表征

合成了新型双子阳离子表面活性剂Gemini-16,并用其对钠基蒙脱土进行改性。红外光谱(FTIR)、热重(TGA)分析表明,Gemini-16已插层到蒙脱土片层间。X射线衍射(XRD)表明,改性后蒙脱土层间距从1.47 nm增加到3.48 nm。分散性实验表明,经Gemini-16改性的蒙脱土在液体石蜡中表现出很好的相容性和分散性,改性效果优于目前常用的CTAB处理效果,更有利于聚合物单体进入蒙脱土层间形成聚合物/蒙脱土纳米复合材料。     

双子型苯并咪唑阳离子表面活性剂的合成及性能

以苯并咪唑、溴代正十二灴烧、二溴代烷烃为原料合成了3种双子型苯并咪唑阳离子表面活性剂,通过1HNMR和元素分析对合成的中间体和表面活性剂进行了结构表征.测试出该类表面活性剂的水溶液在70℃下的临界胶束浓度分别为2.9×10-3mol·L-1、4.5×10-6mol·L-1和2.6×10-6 mol·L-1;最低表面张力分别为37·6 mN·m-1、39.4 mN·m-1和39.7 mN·m-1.计算出对应的饱和吸附量分别为3.9×10-1mol·cm-2、3.6×10-11mol·cm-2、3.4×10-11mol·cm-2;饱和吸附面积分别为4.26 nm2、4.6 nm2、4.88 nm2.此外,还对合成的表面活性剂的克拉夫特点、各种溶剂中的溶解度、泡沫、乳化等性能进行了测试.     

含酯基双子季铵盐阳离子表面活性剂的合成及性能

分别以氯乙酸辛酯 ,氯乙酸十二醇酯、氯乙酸十四醇酯和四甲基乙二胺反应合成了相应的含酯基双子季铵盐阳离子表面活性剂化合物 (Ⅰ～Ⅲ )。滴体积法测定化合物Ⅰ～Ⅲ的表面张力和cmc。γcmc分别为2 7 3 1、 3 3 73和 3 4 0 1(mN/m) ,cmc分别为 5 0 1× 10 -3 、 3 98× 10 -3 和 3 16× 10 -3 (mol/dm3 )。     

含特殊官能团阳离子型Gemini表面活性剂的合成进展

本文着重介绍含特殊官能团阳离子型Gemini表面活性剂的合成,包括多烷基多季铵盐、联接基特殊、疏水链特殊、非对称、含杂环、聚季铵盐等.并指出今后的工作重点和发展方向.     

含酰胺基双子阳离子表面活性剂的合成与性能研究

以N,N-二甲基丙二胺分别与十二酸、十四酸、十六酸和十八酸反应得到酰胺基叔胺,再制成其盐酸盐,盐酸盐与环氧氯丙烷在水溶剂中合成了相应的含酰胺基双子(gemini)阳离子表面活性剂,采用红外光谱、质谱、元素分析、核磁共振波谱进行了结构表征,并测定了阳离子表面活性剂表面化学性能.结果表明,真空干燥后含酰胺基gemini阳离子表面活性剂的质量分数大于98%,该含酰胺基gemini阳离子表面活性剂具有很强的表面吸附和胶束生成能力,随着脂肪碳链长度由12增加到18,cmc由9.12×10-5mol·L-1减少至3.31×10-5mol·L-1,ccmc/c20由3.02增加到3.98,Krafft点也有升高的趋势.     

Recent advances in gemini surfactants: oleic Acid-based gemini surfactants and polymerizable gemini surfactants

Gemini surfactants recently developed by our research group are introduced from the standpoints of their syntheses, aqueous solution properties, and potential applications. Two series of gemini surfactants are introduced in this short review, the first of which is the oleic acid-based gemini surfactants, and the second is the polymerizable gemini surfactants. These gemini surfactants have been developed not only as environmentally friendly materials (the use of gemini surfactants enables the reduction of the total consumption of surfactants in chemical products owing to their excellent adsorption and micellization capabilities at low concentrations) but also as functional organic materials.     

Aqueous solution properties of disulfide linked gemini and cleaved monomeric thiol surfactants

Monomeric thiol surfactants, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SH]Br, were produced by the cleavage of gemini surfactant containing a disulfide bond in the spacer chain, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SSCH(2)CH(2)N(CH(3))(2)C(n)H(2n+1)]2Br. The disulfide bond was completely reduced by the addition of four times moles of dithiothreitol in water at room temperature. The critical micelle concentrations of monomeric surfactants were significantly increased in comparison with original gemini surfactants. The monomeric thiol surfactants were stable in the presence of dithiothreitol, whereas they returned gradually to their original gemini surfactants within several days due to air oxidation in water without dithiothreitol. The micelle formation induced by the disulfide linkage formation was suggested by the fluorescence intensity ratio of pyrene. The time course of decrease in thiol concentration associated with the recovery of gemini surfactants was confirmed by the absorption spectra utilizing the reactions with 4,4'-dithiopyridine.     

表面活性剂在聚合物/蒙脱石纳米复合材料制备中的应用

简要叙述了蒙脱石的结构;综述了阳离子表面活性剂插层蒙脱石以形成有机蒙脱石的机理、插层方法以及阳离子表面活性剂的结构对被插层蒙脱石的层间距的影响;讨论了不同类型的聚合物/蒙脱石纳米复合材料制备方法;同时比较了所得到的纳米复合材料的力学性能、热性能与纯聚合物的力学性能和热性能。结果表明:前者的力学性能和热性能比后者均有较大程度的提高。最后提出了聚合物/蒙脱石纳米复合材料目前存在的问题、发展方向和应用前景等。     

双子表面活性剂的应用研究进展

结合双子表面活性剂的独特结构和优良性质,综述了双子表面活性剂在制备新材料、皮革加工、生物技术及石油工业中三次采油、油田杀菌、压裂液等方面的应用,并指出了双子表面活性剂今后发展的方向。     

Characterization of monomeric and gemini cationic amphiphilic molecules by fluorescence intensity and anisotropy. Part 2

Four fluorophores of different nature, structure and properties were employed as probes for the characterization of a series of alkanediyl-α,ω-bis(alkyldimethyl ammonium bromide) surfactants. Pyrene and 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (coumarin 6) fluorescence intensity as well as coumarin 6 and fluorescein sodium salt fluorescence anisotropy were used to determine cmc whilst coumarin 6, fluorescein sodium salt and perylene fluorescence anisotropy was exploited to provide information on micellar structure; cmc values were confirmed using conductivity measurements. Conductivity data were analysed by means of a method which reveals the formation of ion pairs or premicellar aggregates; this approach was useful to justify and confirm results obtained using fluorescence.     

Synthesis,surface active and thermal properties of novel imidazolium cationic monomeric surfactants

A series of long chain water soluble cationics have been synthesized by using renewable raw materials like fatty alcohols and epichlorohydrin. The surface activity of the molecules has been determined by measurement of their conductance and surface tension in aqueous solution. The dynamics of surface activity of these surfactants have also been investigated in the presence of sodium halides, NaCl and NaBr by surface tension measurement. A series of useful parameters like critical micelle concentration (cmc), surface tension at the cmc (γ_cmc), adsorption efficiency (pC20), effectiveness of surface tension reduction (Π_cmc), Gibbs free energy of the micellization (ΔG_0 mic) and Gibbs free energy of adsorption (ΔG_0 ads) have been determined from the measurements obtained by surface tension and conductivity method. Further with the application of the Gibbs adsorption isotherm, maximum surface excess concentration (θ_max) and minimum surface area/molecule (A_min) at the air–water interface were also estimated. Thermal stability of these long chain cationics has been measured by thermal gravimetric analysis under nitrogen atmosphere. Analysis of thermal stability measurement indicated that the thermal stability of these long chain imidazoliums increase with an increase in chain length.     

Mixtures of anionic and cationic surfactants with single and twin head groups: Solubilization and adsolubilization of styrene and ethylcyclohexane

Mixtures of anionic and cationic surfactants with single and twin head groups were used to solubilized styrene and ethylcyclohexane into mixed micelles and adsolubilize them into mixed admicelles on silica and alumina surfaces. Two combinations of anionic and cationic surfactants were studied: (i) a single-head anionic surfactant, sodium dodecyl sulfate (SDS), with a twin-head cationic surfactant, pentamethyl-octadecyl-1,3-propane diammonium dichloride (PODD), and (ii) a twin-head anionic surfactant, sodium hexadecyl-diphenyloxide disulfonate (SHDPDS), with a single-head cationic surfactant, dodecylpyridinium chloride (DPCl). Mixtures of SDS/PODD showed solubilization synergism (increased oil solubilization capacity) when mixed at a molar ratio of 1∶3; however, the SHD-PDS/DPCl mixture at a ratio of 3∶1 did not show solubilization enhancement over SHDPDS alone. Adsolubilization studies of SDS/PODD (enriched in PODD) adsorbed on negatively charged silica and SHDPDS/DPCl adsorbed on positively charged alumina showed that while mixtures of anionic and cationic surfactants had little effect on the adsolubilization of styrene, the adsolubilization of ethylcyclohexane was greater in mixed SHPDS/DPCl systems than for SHDPDS alone. Finally, it was concluded that whereas mixing anionic and cationic surfactants with single and double head groups can improve the solubilization capacity of micelles or admicelles, the magnitude of the solubilization enhancement depends on the molecular structure of the surfactant and the ratio of anionic surfactant to cationic surfactant in the micelle or admicelle.     

含杂环的阳离子双子表面活性剂合成研究进展

综述了合成含杂环的阳离子双子表面活性剂的研究工作,着重介绍了含咪唑、吡啶、三嗪、四氢吡咯、六氢哌啶和三唑等杂环的阳离子双子表面活性剂的制备方法。同时简单阐述了其临界胶束浓度、表面张力、胶束聚集数等性能,并展望了含杂环的阳离子双子表面活性剂的发展方向。     

Adsorptive and stripping behavior of methylene blue at gold electrodes in the presence of cationic gemini surfactants

The adsorptive and stripping behavior of methylene blue (i.e. methylene blue chloride, MB) at a gold electrode has been studied with voltammetry, alternating current impedance spectra (ACIS) and quartz crystal microbalance (QCM). MB exhibits a pair of cyclic voltammetry peaks at about −0.3 V (versus SCE) in 0.05 M pH 6.9 phosphate buffer solutions. In the presence of cationic gemini surfactants such as C₁₆H₃₃N(CH₃)₂-C₄H₈-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₄-C₁₆), C₁₆H₃₃N(CH₃)₂-C₄H₇OH-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₄OH-C₁₆), C₁₆H₃₃N(CH₃)₂-CH₂-C₆H₄-CH₂-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-ph-C₁₆) and C₁₆H₃₃N(CH₃)₂-C₁₂H₂₄-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₁₂-C₁₆), the anodic peak grows rapidly and moves in positive direction, but the cathodic peak gradually decreases, due to the association adsorption and electrostatic interaction of the geminis with MB and its reduced product (i.e. leuko methylene blue, LMB). With the aid of geminis the adsorption amount of MB increases under open-circuit, but the impedance of the mixed adsorption film to Fe(CN)₆^3−/4− almost keeps unchanged, compared with either bare gold electrodes or MB film, while the adsorption film of geminis exhibits greater impedance. This probably is due to the electron medium action of MB in the film. Gemini surfactants with same alkyl-chain (i.e. -(CH₂)₁₅CH₃) but different molecular structure, exhibit different influence. The enhancing action of geminis studied follows such order as: C₁₆-ph-C₁₆ > C₁₆-C₄-C₁₆ > C₁₆-C₄OH-C₁₆ > C₁₆-C₁₂-C₁₆. The change of peak potential was ascribed to the interaction between MB and surfactants, as well as the blocking action of surfactant film. For comparison, the influence of dihexadecyldimethylammonium bromide (DCAB) and cetyltrimethylammonium bromide (CTAB) was studied, and the influence of other factors is discussed as well.     

双酯基阳离子Gemini表面活性剂的合成

以环氧氯丙烷,月桂酸为原料合成月桂酸丙(2-羟基-3-氯)酯中间体(CHPL),再与四甲基乙二胺进一步反应合成标题化合物(CEGS).研究了反应时间、反应温度和反应物投料物质的量比对CEGS收率的影响,确定合成目标产物的最佳反应条件为异丙醇作反应介质,中间体CHPL,与四甲基乙二胺(TMED)的物质的量比为2.2:1,异丙醇的回流温度下反应30 h,回收率82.2%.终产物结构通过IR和1HNMR分析得到证实.     

季铵盐型双子表面活性剂的合成和性能

以烷基二甲基叔胺R(CH32N(R为C12H25、C14H29和C16H33)、盐酸、环氧氯丙烷为原料合成了系列季铵盐型双子表面活性剂GnCl2(n=12,14,16),样品经核磁共振及元素分析证实其结构.研究了其水溶液的表面活性、泡沫性能和杀菌性能.结果表明,所合成的双子阳离子表面活性剂具有较高的表面活性,烷基链越长,临界胶束浓度越小;不同链长的GnCl2体系中,G12Cl2溶液的起泡和稳泡效能最高,起泡和稳泡效率最低;通过纸片扩散法测定其杀菌性能表明,双季铵盐型表面活性剂具有优良的杀菌能力.     

Synthesis and characterization of glucosamide-based trisiloxane gemini surfactants

A new family of glucosamide-based trisiloxane gemini surfactants of the general formula (CH₂OCH₂)_n (Me₃SiOSiMeR¹OSiMe₃)₂ (where R¹=(CH₂)₃NR²(CH₂)₂NHCO (CHOH)₄CH₂OH; R²=CH₂CH(OH)CH₂OCH₂; and n=0, 1, or 2) was prepared and characterized, both structurally and as aqueous surfactants. The monomer was prepared by amidation of the precursor amine functional trisiloxane with d-gluconic acid δ-lactone. Gemini surfactants were then prepared by the alkylation of the precursor secondary amine with oligoethylene glycol diglycidyl ethers. They were structurally and elemental analysis. Members of this family reduced the surface tension of water to approximately 21 mN/m at concentration levels of 10⁻⁵ mol/L. These gemini compounds showed two critical aggregation concentration values. This behavior resulted from the formation of premicellar aggregates before true micelles were formed.