系列N-脂肪酰基天冬氨酸钠的胶束化热力学性能研究

采用表面张力仪对系列N-脂肪酰基天冬氨酸钠表面活性剂的表面张力进行了测定,研究了系列N-脂肪酰基天冬氨酸钠表面活性剂在水溶液中胶束化的热力学性质,并考察了温度与碳链长度对分子胶束化过程的影响。实验结果表明,N-脂肪酰基天冬氨酸钠系列表面活性剂具有优异的表面活性,尤其是N-十四酰基天冬氨酸钠和N-十六酰基天冬氨酸钠。热力学性质表明,系列N-脂肪酰基天冬氨酸钠表面活性剂在水溶液中的胶束化是一个自发过程,主要来自熵驱动,温度升高不利于胶束化。随着碳链长度的增加,所形成胶团的稳定性也在增加,主要是熵增加引起的变化,所以胶束的形成主要是由碳链增加所引起的熵增加引起的。     

α-癸基甜菜碱的表面活性和胶体性质

研究了两性表面活性剂α-癸基甜菜碱的表面活性与溶液性质.α-癸基甜菜碱亲水基团的立体结构有利于正、负电荷的相互作用,使得表面吸附层和胶束中表面活性剂分子排列更加紧密.实验测得溶液的最低表面张力为38.2 mN/m,临界胶束浓度为6.9×10-3mol/L,胶束形成标准自由能为-22.3 kJ·mol-1,胶束聚集数为74;表面活性剂溶液在等电点pH区域具有最低表面张力和临界胶束浓度.     

通过表面活性剂分子结构预测胶束特性的定量计算方法

表面活性剂性能的表现要通过表面活性剂分子形成胶束才可以体现。因此揭示表面活性剂胶束的性质是非常重要的，本文对影响表面活性剂胶束性质的因素进行了研究，提出了切实的计算公式。     

弱相互作用调控表面活性剂自组装(Ⅲ)——响应性表面活性剂

天然的或合成的两亲分子(表面活性剂)可以自组装形成多尺度的聚集体结构,比如胶束、囊泡、液晶和纤维等。在表面活性剂中引入功能性基团,借助外界环境(比如光、温度、pH、CO2、磁等)的改变可以实现对表面活性剂的聚集方式的调控。本文主要介绍响应性表面活性剂的种类、结构以及环境刺激与响应性能之间的关系。     

烷基甜菜碱类两性离子型表面活性剂胶束化行为的分子模拟研究

以两性离子型表面活性剂甜菜碱为研究对象,采用粗粒度分子动力学方法,构建不同结构的烷基甜菜碱模型,考察其联结基团和疏水尾链对溶液体系中自聚体的溶液行为的影响,分析了自聚体胶束的弯曲角分布、相对形状各异性以及径向分布函数等参数,探究了球形、棒状、分支状胶束的形状转变机制。研究结果表明,随着浓度的增加,在联结基团的作用下,两性离子型表面活性剂分子发生弯曲,小胶束交联融合形成棒状—分支状胶束转变;疏水尾链长度增加会导致胶束体积变化从而降低分子间相互作用,小胶束易融合形成球形—棒状胶束的形状转变。文章为相似体系下的理论探索提供了一种创新的思维角度,对两性离子型表面活性剂的研究和应用有一定的指导意义。     

稳态荧光法测定Gemini水溶液聚集性质

用稳态荧光法测定合成的Gemini阴离子表面活性剂水溶液的聚集性质,并与其它方法如电导法、表面张力法测定的结果进行对比,结果吻合,表明荧光法作为一种测定Gemini阴离子表面活性剂水溶液聚集性质的方法是可行的,并对Gemini和单基表面活性剂在临界胶束浓度Ccmc前后荧光相对强度变化规律做了简要分析。     

双羟基Gemini表面活性剂的溶液性能及其聚集形态

以1-溴十二烷、2-甲氨基乙醇、1,3-二溴丙烷、1,4-二溴丁烷、1,6-二溴己烷、1,8-二溴辛烷、1,10-二溴癸烷和1,12-二溴十二烷为原料,制得含有双羟基的Gemini表面活性剂〔缩写为12(OH)-s-12(OH),其中s=3、4、6、8、10和12〕。并测定了双羟基Gemini表面活性剂的热稳定性及其在水溶液中的表面张力及泡沫性能;采用耗散粒子动力学(DPD)方法预测了Gemini表面活性剂在水溶液中的聚集形态。结果表明,该类型Gemini表面活性剂具有较好的热稳定性和泡沫性能,随着连接基团长度的增加(s≤6),其在水溶液中的临界胶束浓度(CMC)从0.62mmol/L(s=3)降至0.21mmol/L(s=6)左右,且当连接基团长度s6后CMC基本不变。随着Gemini表面活性剂摩尔分数的增加,胶束形态从球状胶束→棒状胶束→层状胶束→反胶束网络结构逐渐转变,且连接基团长度的改变几乎不影响其在水溶液中的胶束形态转变。     

期刊文献

聚氧乙烯醚型表面活性剂的合成及表面性质黄海龙,李红玉,张雷,任天瑞摘要:合成了一系列不同聚合度的聚壬基酚聚氧乙烯醚型非离子表面活性剂,通过红外光谱和核磁共振等手段对其结构进行表征,用表面张力法对合成产物的表面性能进行研究。结果表明,随着表面活性剂分子中亲水基团环氧乙烷(EO)片段的增加,单体、二聚体和三聚体的临界胶束浓度(cmc)值都逐渐增大,当EO数目相同时,单体、二聚体和三聚体的cmc值依次明显降低。二聚体与三聚体都显示出很好的表面性质,其中三聚体的     

GSS362/TX-100复配体系在水中的溶液行为研究

研究了1,3-丙二醇双子琥珀酸二异辛酯磺酸钠(GSS362)和辛基酚聚氧乙烯醚(TX-100)复配物在水中的表面性质和胶束化行为,并对理想混合临界胶束浓度以及混合体系中各组分在表面吸附层和胶束中的组成、相互作用参数和热力学参数进行分析计算。结果表明,复配物在水溶液中不存在协同效应,但是TX-100的加入明显降低了GSS362的临界胶束浓度,混合胶束的形成为自发过程,胶束中GSS362与TX-100分子具有较弱的相互作用,胶束中富含非离子表面活性剂TX-100。     

阴离子表面活性剂与阳离子表面活性剂的相互作用(Ⅱ)——稀溶液性质

介绍了阴离子表面活性剂与阳离子表面活性剂相互作用的稀溶液性质。在水溶液中,阴/阳离子表面活性剂混合体系因分子间极性基正/负离子的强静电吸引作用,易形成棒状胶束,浓度超过cmc后,可能发生聚集,出现浑浊、分相等情况,使用短链表面活性剂、引入聚氧乙烯链及非等摩尔复配在一定程度上可避免这种现象。均相阴/阳离子表面活性剂混合溶液,对非极性有机物的增溶存在增效作用,但对极性有机物的增溶能力则有可能下降;在一定浓度及混合比范围内还可能出现类似非离子表面活性剂的浊点效应。     

Acyl Poly(Glycerol-Succinic Acid) Oligoesters: Synthesis,Physicochemical and Functional Properties,and Biodegradability

Biobased surfactants were synthesized using poly(glycerol-succinate) as the polar head group and variable acyl groups as hydrophobic tails. Acyl chain lengths ranged from 8 to 14 carbon atoms. The resulting oligomeric surfactants were characterized by quantitative ¹³C nuclear magnetic resonance (NMR), acid values and size exclusion chromatography. Investigation of the physicochemical properties of the acyl poly(glycerol-succinate) surfactants revealed their potential for use in a wide array of applications. The acyl poly(glycerol-succinate) functional properties appeared to be particularly concentration-dependent. This study highlights the relative impact of acyl chain length on the polymeric structure, physicochemical and functional behaviors, and biodegradability of the acyl poly(glycerol-succinate) surfactants.     

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.     

Polymer thin film photodegradation and photochemical crosslinking: FT-IR imaging, evanescent waveguide spectroscopy, and QCM investigations

Photodegradation and photocrosslinking of benzophenone blended polystyrene (PS) thin films were investigated primarily using Fourier transform infrared (FT-IR) imaging, evanescent waveguide spectroscopy (WS), and quartz crystal microbalance (QCM) methods. The main objective is to observe the changes (spectral and chemical) indicative of these competitive processes in an ultrathin polymer film. This also serves as a model study in the application of combined spectroscopic, optical, and acoustic methods towards understanding crosslinking and degradation phenomena within the same time frame of observation. To induce photocrosslinking, 1,12-dodecanediylbis(oxy-4,1-phenylene)] [bis[phenylmethanone] (2BP12), a small molecule with two benzophenone groups, was blended with PS in solution, spincast onto glass and silicon substrates, and irradiated with ultraviolet light. Photodegradation and benzophenone-mediated crosslinking were observed both directly via functional group spectroscopies and indirectly via their effects on thin film surface properties and morphologies. Atomic force microscopy (AFM) and QCM were used to elucidate local morphology change and mass-uptake kinetics in the presence of O₂ in air, respectively. All results correlated well with the two photoprocesses occurring simultaneously and competitively on these films with the refractive index, thickness, and mass change differing with the presence of 2BP12. Crosslinking was observed to cause an increase in thickness while photodegradation gave a decrease. Both processes resulted in an increase in the refractive index and mass. While various methods have separately identified these observations, this is the first instance that the in situ chemical, optical, and structural dimensionality of the photodegradation and photocrosslinking phenomena in a thin polymer film is correlated within the same time frame of observation.     

Flexible Semicrown Ether-Linked Symmetric Cationic Gemini Surfactants: Synthesis and Evaluation as Catalysts for Acceleration of Diastereoselective [3 + 2] Cycloaddition Reaction in Reversed Phase Micellar Media

Novel cationic gemini surfactants with a hydrophilic oligo-oxyethylene spacer group were synthesized and their physicochemical properties were identified. Computational studies for these compounds were also performed; molecular geometry, frontier molecular orbitals, and quantum chemical parameters were calculated using density functional theory (DFT). After exploration for catalytic activity, it was found that these surfactants can efficaciously accelerate the [3 + 2] cycloaddition reactions in reversed phase micellar media.     

Preparation and properties of novel water‐soluble surfactants. I. Synthesis and surface activity of polycarboxylated multihydrophilic surfactants

A series of novel surfactants containing multianionic and nonionic hydrophilic moieties were prepared by reacting fumaric acid with polyoxyethylenated stearyl ether in the presence of a peroxy‐type free radical initiator to form a carboxylic‐acid‐group‐containing addition product. The structure of these surfactants was confirmed by infrared, nuclear magnetic resonance, and elemental analysis. These surfactants exhibit excellent functional properties of self‐sequestering. This means that besides good surfactant properties, including surface tension, foaming, and wetting, they possess autonomous sequestering ability without any help of additional sequestering agent. When used in cotton bleaching procedures, these surfactants increase the penetration of the fibers of gray fabrics and increase the whiteness of bleached cotton. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3559–3564, 2006     

Novel hydrolyzable and biodegradable cationic gemini surfactants: Bis(ester-ammonium) dichloride having a butenylene or a butynylene spacer

Novel cationic gemini surfactants, bis(ester-ammonium) dichlorides having a butenylene or a butynylene spacer and an oxycarbonyl group in the lipophilic part, were prepared conveniently and almost quantitatively by the reaction of the corresponding mono(ester-amine) with a highly reactive allylic- or propargylic dichloride. Most of these surfactants showed excellent surface-active properties and good biodegradability. The effects of the structure of spacer, the position of the oxycarbonyl group in the lipophilic part, the alkylene length between the oxycarbonyl and the ammonio groups, and the acyl chain length of the surfactants on their surface-active properties were examined.     

Succinylation of Non-ionic Surfactants: Physicochemical Characterization,Functional Properties,Biodegradability and Mathematical Modeling of the Polarity Tuning

Anionic surfactants comprising succinic acid end groups were synthesized by succinylation of non-ionic surfactants using succinic anhydride as a potentially bio-sourced building block. A solvent- and catalyst-free synthesis was designed for succinic anhydride mono esterification with octyl-, decyl and dodecylpolyxylosides, di- and tetraethylene glycol dodecylethers and glycerol monolaurate. The physicochemical and functional properties of anionic surfactants thus obtained were studied and compared with their non-succinylated counterparts. A correlation between these properties and the polarity changes induced by the addition of the hydrophilic succinic acid moiety was established. The biodegradability of the succinylated surfactants has also been investigated. Finally, through a desirability function approach, mathematic predictions were correlated to the properties in order to find an optimum and to discriminate surfactants with respect to targeted physicochemical properties and resulting applications.     

Clay Swelling Inhibition Using Novel Cationic Gemini Surfactants with Different Spacers

Hydration of shale formation by water-based drilling fluids leads to several problems, such as the collapse of boreholes, tight holes, and stuck pipe, which may impede further drilling and time loss in rectifying the problems, leading to heavy economic losses. This study reports the development of new gemini cationic surfactants as shale-swelling inhibitors. These gemini surfactants are structurally similar but differ in terms of the spacer group. Saturated butyl group ( GS1 ) and unsaturated 2-butenyl ( GS2 ) and 2-butynyl ( GS3 ) were introduced as spacer groups of gemini surfactants. To assess the performance of new gemini cationic surfactants, two reliable clay sources were considered. The first clay is from an unconventional formation and the second clay is sodium bentonite. The inhibition characteristics of gemini surfactants were evaluated using dynamic swelling, hot rolling, rheology, and filtration experiments. Different formulations based on commercially available solutions for shale-swelling inhibitors were applied and compared with cationic shale inhibitors. It was observed that the new gemini cationic surfactants with different spacers (saturated and unsaturated) reduced the shale swelling by different percentages. The GS2 surfactant, containing an unsaturated double bond proved to be a good swelling inhibitor as compared to GS1 and GS3 . It also showed acceptable performance compared with the common shale inhibitor (KCl) used in the industry. The addition of surfactant has less impact on the rheological properties as compared to KCl. The filtration properties of the base mud were unchanged when surfactants were used. However, the commercial inhibitor, KCl, significantly increased the filtration volume that is associated with the disintegration of the clay. In summary, unlike commercial inhibitors, the synthesized surfactants reduced the clay swelling without affecting the other properties of the drilling fluids.     

Surface active hydroxamic acids. II. Comparison of surface properties of hydroxamic acids with ketones and methyl esters with similar hydrophilic and lipophilic structure

Some surface properties of hydroxamic acids, ketones and methyl esters, which all contained long-chain alkyl[tetra-(oxyethylene)] group, were measured and compared to clarify the influence of the terminal functional group on surface properties. From the results of cloud point (T _cp ), CMC, γ _CMC , adsorption area per molecule at the surface (A) and foaming properties, it was proved that hydroxamic acids had better hydrophilicity and showed better surface properties than the corresponding ketones, methyl esters or typical monodisperse nonionic surfactants.     

Thermal stability of surfactants with amino and imido groups in poly(ethylene terephthalate)/clay composites

Effects of thermal stability of surfactants with amino and imido groups on thermal properties of poly(ethylene terephthalate) (PET)/clay composites were studied. The imidosilane surfactant was synthesized successfully from the imide reaction between amino silane and phthalic anhydride. TGA shows that imidosilane decomposition behaviors have two major stages according to the degradations of different functional groups. After melt extrusion, the decomposition of amino functional groups in amino surfactants decreases the thermal stability of organoclay and accelerates the degradation behaviors of PET composites. Because of the enhanced thermal stability of imidosilane surfactants, PET/imido‐palygorskite (PT) composites represent enhanced thermal stability, good dispersion and low thermal expansion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008