磺酸盐型Gemini表面活性剂合成研究进展

磺酸盐型Gimini表面活性剂是一类新型的阴离子表面活性剂,它由联结基团通过化学键将2个或多个单体磺酸盐型表面活性剂连接在一起,由此产生高表界面活性,低临界胶束浓度值,增强了洗涤能力,与传统的阴离子表面活性剂有较好的复配性,奇异的流变特性和良好的抗盐性等一系列的性质,从而具有广泛的应用前景。 本文以原料来源不同分类,综述了一系列磺酸盐型Gemini表面活性剂的合成方法,展望了合成磺酸盐型Gemini表面活性剂的研究方向。     

表面活性剂的增效作用在光度分析中应用

表面活性剂是能够显著降低水的表面张力的物质.它是由极性的亲水基和非极性的憎水基两部分组成.这样的结构从本质上决定了表面活性剂的性质,表面活性剂是优良的增效分析试剂,对分析、分离方法有增溶、增敏、增稳等增效作用.表面活性剂应用于分析化学虽然只有三十年的时间,但发展迅速,特别在光度分析中的应用成了热点之一.下面就将表面活性剂的结构、性质及在光度分析中的应用作一简要概述.1 表面活性剂的分类、结构及性质1.1 分类和结构目前常用的表面活性剂按离子类型分类,溶于水能离解成离子的叫离子型表面活性剂;在水中不能离解成离子的叫非离子型表面活性剂;还有一类它的亲油基很小,或分散于亲水基之间,但仍有一定的表面活性,归属于特殊表面活性剂.离子型表面活性剂又可分为阳离子型、阴离子型和两性表面活性     

农药用有机硅表面活性剂的研究进展

有机硅表面活性剂是一种新型的农药用表面活性剂，本文对它在农药中的一些应用及其研究进展以及卓越的湿润性、极佳的延展性、气孔渗透率、良好的抗雨冲刷性能等进行了综述。     

生物表面活性剂应用研究进展

生物表面活性剂是由微生物产生的天然产物,具有表面活性高、对环境无污染、生物可降解性及良好的抑菌作用等优于化学合成的表面活性剂的独特性质。本文对生物表面活性剂的特性、分类及其制备方法进行了介绍,对生物表面活性剂在石油工业、环境工业、医药、食品、农业和化妆品工业等领域的应用进行了总结,展望了生物表面活性剂的良好应用前景。     

吸附胶团和吸附胶团催化

介绍了吸附胶团的结构特点、影响吸附胶团催化的一些因素和在固体表面上的固定化表面活性剂体系的催化作用。吸附胶团是表面活性剂在固-液界面形成的缔合结构,它可以是吸附单层、双层、半球形、球形等。吸附胶团和利用接枝等技术在固体表面形成的不溶性表面活性剂体系,在一定条件下,可对某些反应起催化作用,有利于提高反应产率并使反应产物分离变得容易,这将使胶团催化的实际应用成为可能。     

Dendrimer与表面活性剂相互作用的研究进展

聚酰胺-胺(PAMAM)是目前最具应用前景的树枝状大分子(Dendrimer),它与表面活性剂相互作用后能够形成聚集体,这种聚集体能有效地改变体系的微观环境和物理化学性质。本文综述了小分子表面活性剂与Dendrimer相互作用研究方面所取得的进展,重点讨论了阴离子表面活性剂和阳离子表面活性剂与Dendrimer混合体系中溶液的疏水环境、浊度以及形成聚集体中值粒径等物理化学性质的变化,在此基础上,讨论了Dendrimer与小分子表面活性剂相互作用在机理方面所取得的研究进展,为进一步扩大Dendrimer的应用领域提供参考。     

树枝状大分子与表面活性剂相互作用的研究进展

聚酰胺-胺(PAMAM)是目前最具应用前景的树枝状大分子(Dendrimer),它与表面活性剂相互作用后能够形成聚集体,这种聚集体能有效地改变体系的微观环境和物理化学性质。本文综述了小分子表面活性剂与Dendrimer相互作用研究方面所取得的进展,重点讨论了阴离子表面活性剂和阳离子表面活性剂与Dendrimer混合体系中溶液的疏水环境、浊度以及形成的聚集体的中值粒径等物理化学性质的变化,在此基础上,讨论了Dendrimer与小分子表面活性剂相互作用机理研究所取得的进展,为进一步扩大Dendrimer的应用领域提供参考。     

寡聚表面活性剂的合成及其聚集行为的研究

寡聚表面活性剂是由2个或2个以上单头单链的表面活性剂在头基处或靠近头基处由连接基团通过化学键连接而成的二聚、三聚、四聚乃至更高寡聚度的分子.Gemini表面活性剂(二聚表面活性剂)是最简单,也是最早被发现的寡聚表面活性剂,已经被大量报道.已有综述很好地总结了Gemini表面活性剂的物理化学性质.本文主要综述三聚及三聚以上寡聚表面活性剂的研究进展,包括寡聚表面活性剂的合成和结构、表/界面性质以及溶液中的聚集行为等,以期使研究者比较全面地认识寡聚表面活性剂领域的研究进展.     

低聚表面活性剂的合成及性能研究

低聚表面活性剂是指通过连接基将两个以上的传统表面活性剂连接在一起而形成的一类新型表面活性剂。相对于对应的传统表面活性剂,这类表面活性剂具有临界胶束浓度(cmc)低、表面活性高等优点。本文介绍了本研究团队近年针对低聚表面活性剂所开展的研究,包括分子结构不对称的双子表面活性剂、同时具有阳离子和阴离子头基的甜菜碱型双子表面活性剂、三聚和四聚阳离子表面活性剂以及通过原子转移自由基聚合制备的低聚表面活性剂等。     

新书消息

《表面活性剂物理化学》本书系统地介绍了表面活性剂的化学结构、分类、特性及其应用,包括界面现象、表面张力、毛细现象等基础知识。着重叙述了表面活性剂溶液的基本性质,是认识表面活性剂本质及其作用     

Gemini表面活性剂合成进展

系统总结了近百种Gemini表面活性剂的合成路线和方法,并且按照其结构特点分门别类地进行比较和归纳,对今后Gemini表面活性剂的合成发展方向提出了一些看法,这对促进此类新颖表面活性剂的工业化进程将具有指导意义。     

新一代表面活性剂: Geminis

表面活性剂Gemini (或称dimeric) 是由两个单链单头基普通表面活性剂在离子头基处通过化学键联接而成, 因而阻抑了表面活性剂有序聚集过程中的头基分离力, 极大提高了表面活性。与当前为提高表面活性而进行的大量尝试, 如添加盐类、提高温度或将阴离子表面活性剂与阳离子表面活性剂混合相比较, Gemini 表面活性剂是概念上的突破, 因而被誉为新一代的表面活性剂。     

New ethoxylated inositol surfactant

Carbohydrates are an attractive class of starting materials for organic syntheses because they are of natural origin, environmentally friendly, and highly functionalized, in this way promoting a sustainable chemistry. A somewhat exotic but nevertheless readily available family of carbohydrates allowing a fascinating chemistry are inositols (cyclohexane-1,2,3,4,5,6-hexols), which we currently use for the synthesis of new surfactants. In our previous work, we reported on the synthesis of a number of new regiochemically defined myo-inositol ethers and esters and studied their surface activity in aqueous solution as well as their ability to form thermotropic liquid crystals. It turned out that the hydrophilicity of the myo-inositol head group alone does not ensure sufficient water solubility of these surfactants. To improve the water solubility, we increased the inositol head group by the introduction of a tri(ethylene oxide) unit. The resulting surfactant is the first representative of a new class of inositol-based surfactants (CiEjIk) that combine the properties of classical sugar surfactants (CnGm) and oligo(ethylene oxide) alkyl ether surfactants (CiEj).     

Derivation and synthesis of renewable surfactants

This critical review focuses on the origins and preparation of bio-based surfactants, defined here as non-soap, amphiphilic molecules in which the carbon atoms are derived from annually renewable feedstocks. Environmental concerns and market pressures have led to greater relevance of these chemicals in commercial applications in recent years and extensive research has gone into exploring new classes of surfactants. Highlighted here are examples of bio-based surfactants that are produced on an industrial scale and/or are based on abundant starting materials. The trend of increasing use of renewable resources as starting materials for surfactants is introduced, followed by extensive discussion of the major classes of bio-derived hydrophobes and hydrophiles. Also discussed is the status of research and development with regard to biosynthetically produced surfactants. Finally, concluding remarks address the potential for new surfactant molecular structures as a result of ongoing development in the chemistry of biorefineries, i.e., that the transformation of lignocellulose into fuels is likely to support the manufacturing of new bio-based coproducts (238 references).     

Aggregation‐Induced Emission Active Probe for Light‐Up Detection of Anionic Surfactants and Wash‐Free Bacterial Imaging

Anionic surfactants are widely used in daily life and industries, but their residues can cause serious damage to the environment. The current detection methods for anionic surfactants suffer from various limitations and a new detection strategy is highly desirable. Based on 2‐(2‐hydroxyphenyl)benzothiazole fluorogen with aggregation‐induced emission characteristics, we have developed a fluorescent probe HBT‐C₁₈ for selective and sensitive detection of anionic surfactants. By in situ formation of catanionic aggregates or micelles with anionic surfactants, the emission intensity of the HBT‐C₁₈ probe can increase with increasing keto/enol emission ratio through restriction of intramolecular motion and excited‐state intramolecular proton‐transfer mechanisms. The probe can also be used for wash‐free imaging of bacteria enveloped by a negatively charged outer membrane. The results of this study provide a new strategy for sensitive detection of anionic surfactants and wash‐free bacterial imaging.     

New Oleic Acid-Capped Mesoporous Silica Particles as Surfactant-Responsive Delivery Systems

A new delivery microdevice, based on hydrophobic oleic acid-capped mesoporous silica particles and able to payload release in the presence of surfactants, has been developed. The oleic acid functionalization confers to the system a high hydrophobic character, which avoids cargo release unless surfactant molecules are present. The performance of this oleic-acid capped microdevice in the presence of different surfactants is presented and its zero-release operation in the absence of surfactants is demonstrated.     

Synthesis and self aggregation properties of ester-functionalized heterocyclic pyrrolidinium surfactants

Linear fatty alcohols on reaction with chloro/bromo acetic acid in the presence of catalytic amount of p-toluene sulphonic acid monohydrate under solvent-free conditions are converted into alkyl-2-haloacetate which on reaction with N-methyl pyrrolidine gives ester-functionalized pyrrolidinium surfactants. Thus, new series of ester-functionalized heterocyclic pyrrolidinium head group containing cationic surfactants have been synthesized by green approach via energy saving and cost effective methodology. These new surfactants have been investigated for their surface properties by surface tension, conductivity, and fluorescence method. Surface properties of these surfactants have been found to be far better compared to conventional heterocyclic cationic surfactants having similar hydrophobic alkyl chain length.     

Synthesis and Physicochemical Study of New Surfactants Derived from Carboxylic Acid Sugars

Surfactants based on sugars are important for a variety of applications, and for this reason we present the synthesis of new sugar carboxylate/amine salts. These surfactants were obtained via a simple synthesis in high yields. Their interfacial properties were measured and the results of these tests are presented and analyzed to provide suggestions for how these surfactants might be used. Some of these surfactants demonstrated water solubility over a wide temperature range, ability to form stable foams or emulsions, and stability in the presence of calcium salts.     

Phospholipid Bilayer-Perturbing Properties Underlying Lysis Induced by pH-Sensitive Cationic Lysine-Based Surfactants in Biomembranes

Amino acid-based surfactants constitute an important class of natural surface-active biomolecules with an unpredictable number of industrial applications. To gain a better mechanistic understanding of surfactant-induced membrane destabilization, we assessed the phospholipid bilayer-perturbing properties of new cationic lysine-based surfactants. We used erythrocytes as biomembrane models to study the hemolytic activity of surfactants and their effects on cells' osmotic resistance and morphology, as well as on membrane fluidity and membrane protein profile with varying pH. The antihemolytic capacity of amphiphiles correlated negatively with the length of the alkyl chain. Anisotropy measurements showed that the pH-sensitive surfactants, with the positive charge on the α-amino group of lysine, significantly increased membrane fluidity at acidic conditions. SDS-PAGE analysis revealed that surfactants induced significant degradation of membrane proteins in hypo-osmotic medium and at pH 5.4. By scanning electron microscopy examinations, we corroborated the interaction of surfactants with lipid bilayer. We found that varying the surfactant chemical structure is a way to modulate the positioning of the molecule inside bilayer and, thus, the overall effect on the membrane. Our work showed that pH-sensitive lysine-based surfactants significantly disturb the lipid bilayer of biomembranes especially at acidic conditions, which suggests that these compounds are promising as a new class of multifunctional bioactive excipients for active intracellular drug delivery.