新型Gemini表面活性剂的合成与结构表征

采用乙二胺、乙烯磺酸钠和癸酸等为主要原料,在低温常压下,经过加成、酰化等反应,合成了一种新的Gem in i(双子)表面活性剂——N,N’-双癸酰基乙二胺二乙磺酸钠,以1H NMR和IR进行结构表征,考察了原料的物料比、反应温度、反应时间等工艺条件对产物收率的影响。结果表明,最佳合成条件:以水和丙酮混合溶液作溶剂,中间体与癸酰氯的摩尔比为1∶2.1,反应温度10℃,反应时间5 h。     

表面活性剂在电化学分析中的应用

简介了近年来表面活性剂在电化学分析(包括离子选择性电极和极谱伏安分析)中的应用,并展望了表面活性剂在电化学分析中的应用前景。     

可聚合琥珀酸双酯磺酸钠乳化合成聚丙烯酸酯纳米乳液

采用半连续种子乳液聚合工艺,在可聚合乳化剂十六烷基烯丙基琥珀酸双酯磺酸钠(Ⅰ)和辛基酚聚氧乙烯醚烯丙基琥珀酸双酯磺酸钠(Ⅱ)存在下,合成了聚丙烯酸酯纳米乳液,探讨了可聚合乳化剂种类及用量、聚合温度、引发剂用量、聚合时间对丙烯酸酯乳液聚合及性能的影响,通过FTIR、TEM和DSC对聚合产物进行了表征分析。结果表明,可聚合乳化剂参与了与丙烯酸酯的共聚反应,所得聚合物乳胶膜的玻璃化温度为23.5℃;与传统乳化剂十二烷基硫酸钠(SDS)相比,可聚合乳化剂可提高乳胶膜的耐水性;当m(Ⅰ)∶m(Ⅱ)=1∶2,乳化剂质量分数2%,聚合温度85℃,引发剂质量分数0.5%,聚合时间2 h时,所得乳液的固体分质量分数为32.70%,平均粒径72.3 nm,分布指数0.143,吸水率4.57%。     

Synthesis and properties of new cationic surfactants: 1-Alkylthiomethyl-3-carbamoylpyridinium chlorides

1-Alkylthiomethyl-3-carbamoylpyridinium and 1-alkylthiomethyl-4-carbamoylpyridinium chlorides were prepared by the reaction of nicotinamide or isonicotinamide with chloromethyl alkyl sulfides. The obtained chlorides were examined for their antimicrobial activities. 4-Carbamoyl-1-dodecylthiomethylpyridinium chloride exhibited strong antimicrobial activity, similar to the activity of benzalkonium chloride. All synthesized chlorides underwent hydrolysis in aqueous solutions at temperatures higher than 70–75°C. In aqueous solution 1-alkylthiomethyl-3-carbamoylpyridinium chlorides reacted with ozone. A new generation of cationic surfactants that were hydrolyzed and ozone-reactive in an aqueous solution was synthesized during this study.     

SDS对甲烷水合物生成动力学和微观结构的影响

表面活性剂是促进水合物生成的有效手段之一。在高压反应釜中研究了十二烷基硫酸钠（SDS）对水合物生成过程的动力学影响,利用XRD和拉曼光谱探究了SDS存在条件下水合物的微观结构。宏观结果表明SDS缩短了诱导时间,加快了水合物生长速率。微观结果表明SDS没有影响sI型水合物的晶型结构,晶面间距与理想sI型水合物及纯水甲烷对比误差在千分之几。水合物中甲烷在大笼小笼中的拉曼位移分别为2904和2915 cm^-1,SDS没有改变大笼小笼结构。大笼绝对占有率（q_L）接近饱和时,SDS可以进一步提高小笼绝对占有率（q_S）,从微观角度证明了SDS可以减少水合数,提高储气率。     

基于响应曲面法的三相泡沫灭火剂基础配方优化设计

为得到发泡及稳定性能优异的三相泡沫,响应曲面法优化设计三相泡沫灭火剂基础配方。通过单因素实验确定表面活性剂及固相粉体为SDS、Fc-134、6501、2000目（6.91 μm）合成云母粉,以发泡高度及稳定时间为响应值,研究其交互作用。利用Box-Behnken方法,建立的二次回归模型显著可靠,该模型预测SDS、Fc-134、6501浓度分别为2.64%,0.096%,3%,合成云母添加量为10 g时,为最优组合,预测发泡高度1533.86 ml,稳定时间12.8792 min,实验得到发泡高度为1550 ml,稳定时间为12 min,误差分别为1.05%,6.82%。与未优化三相泡沫比较在发泡高度及稳定时间分别提高14.8%、26.3%。结果表明,经优化设计三相泡沫发泡及稳定性能较未优化三相泡沫有明显提高且响应曲面法建立的预测模型误差较小,因此,该模型可用于提升三相泡沫灭火剂的发泡及稳定性能,为三相泡沫灭火剂配方设计提供参考。     

Synthesis of stable high hydroxyl content self‐emulsifying waterborne polyacrylate emulsion

The stability of hydroxyl polyacrylate emulsion was studied from two aspects of the structure of latex particles and polymerization conditions. Waterborne polyacrylate was prepared through seeded semicontinuous emulsion polymerization method with pre‐emulsification process. HEMA was used to provide a high content of hydroxyl group, and the reactive emulsifier SE‐10 was introduced to substitute for the traditional emulsifier. The best conditions including polymerization process and temperature, monomer types and dropping time were determined, and the effects of emulsifier content and addition method, HEMA content, chain transfer agent content, and soft/hard monomer ratio on the properties of emulsion were investigated. Through the optimization of polymerization conditions and the control of the structure of particles, we have successfully synthesized the core‐shell structure of polyacrylate emulsion with a good appearance, low viscosity and a solid content of 46.5%. The hydroxyl polyacrylate exhibits good performance, which has great potential in development and application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44844.     

Preparation and Physicochemical Properties of Lauroyl-Glutamyl-Lysil-Lauroyl-Glutamate Vesicles

We investigate the compositions of vesicle formulation by assembling phase diagrams of the ternary components of lauroyl‐glutamyl‐lysil‐lauroyl‐glutamate (C₁₂‐GLG‐C₁₂) peptide‐based gemini‐type amphiphile/citric acid/water using visual and microscopic observations. To clarify interactions between C₁₂‐GLG‐C₁₂ and citric acid, turbidity and zeta potential of the mixtures were investigated. To improve the stability of metastable vesicles, appropriate additives were examined by measuring particle size and zeta potential, visual observation and transmission electron microscopy. The turbidity increased and the absolute value of zeta potential decreased with increasing citric acid concentration in C₁₂‐GLG‐C₁₂/citric acid solutions. Then, a metastable γ region having vesicles was formed. The stability of vesicles increased with increasing cholesterol concentrations. This result suggests that a coacervation has occurred due to the effective cross‐sectional area decreasing with increasing C₁₂‐GLG‐C₁₂ hydrophobicity, which was derived from inhibition of the carboxyl group dissociation. Furthermore, we hypothesized that the orientation of cholesterol between vesicle membranes is a contributing factor to improve the vesicle stability. From transmission electron microscopic observations, it was made clear that the vesicles consisting of cholesterol and C₁₂‐GLG‐C₁₂ at a molar ratio of 2:1 showed multilayered structures. The vesicles consisting of C₁₂‐GLG‐C₁₂, cholesterol and citric acid are expected to be used as transdermal drug delivery system carriers, as they can be easily prepared using biocompatible compounds without the use of organic solvents such as chloroform.     

Effect of Self-Assemblies on the Dynamics of the Briggs–Rauscher Reaction

The study involves the dynamic evolution of the Briggs–Rauscher (BR) reaction in the presence of various surfactants—SDS (sodium dodecyl sulphate) as anionic, CTAB (cetyl trimethylammonium bromide) as cationic and TritonX‐100 [4‐(1,1,3,3‐(tetramethylbutyl) phenyl polyethylene glycol] as a neutral one in single as well as mixed mode conditions (SDS + TX‐100 and CTAB + TX‐100). The reaction has been monitored potentiometrically at 30 °C under CSTR conditions. These surfactants affect the reaction dynamics to an extent which depends on the nature and concentration of the surfactant and the formation of their self‐assemblies. The experimental findings indicate that the oscillatory behavior of the BR reaction in the presence of surfactants is due to the efficacy of organized surfactant assemblies to selectively distribute the key species involved in the reaction, and their interaction with the counter ions in cases of ionic micelles. The study reveals that the evolution of oscillatory behavior is a characteristic feature of the surfactant.