共查询到18条相似文献,搜索用时 156 毫秒
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Gemini表面活性剂的吸附、自聚和性质 总被引:16,自引:1,他引:16
Gemini表面活性剂通常是由两 (或三 )条疏水链、两个亲水基和一个连接基组成的两性分(离 )子 ,与由单亲水基和单疏水基构成的单体表面活性剂分 (离 )子相比较 ,在临界胶团浓度、界面性质和溶解性等方面有着独特的性质。由于其电荷密度高 ,临界胶团浓度低 ,并且有很低的 Krafft点 ,能在低浓度下与高碳烷烃形成超低界面张力 ,在石油开发中有着很好的应用前景。详述了该类新型表活性剂的吸附、自聚、性质 ,比较了与单体表面活性剂的差别 相似文献
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利用座滴法研究了阳离子表面活性剂居贝特醇十六烷基醚羟丙基季铵盐(C16GPC)溶液在石英表面上的润湿性能,并考察了非离子表面活性剂辛基酚聚氧乙烯醚(Triton X-100)及不同类型电解质对其接触角的影响趋势。研究发现,C16GPC在石英表面通过静电作用形成定向排列的单分子层,而后在cmc附近形成双层结构,接触角随浓度变化的趋势存在一个极大值;Triton X-100与C16GPC在界面上混合吸附,进一步降低表面张力,且影响固/液界面膜排列的规整性,从而造成接触角明显降低;电解质促进表面活性剂在气/液界面的吸附,同时抑制其在固/液界面的吸附,共同导致接触角降低。 相似文献
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vGemini表面活性剂的聚集行为及应用的新进展 总被引:1,自引:0,他引:1
综述了已报道的几种新型Gemini表面活性剂的化学结构,并对它们在气/液、气/固界面及溶液中的聚集行为和应用做了讨论。 相似文献
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Gemini表面活性剂的性能及应用 总被引:2,自引:0,他引:2
Gemini表面活性剂是一类新型的表面活性剂,它是由联结基团通过化学键将两个或多个单体表面活性剂连接在一起而形成。综述了Gemini表面活性剂结构特征与性能(包括界面吸附、表面活性、临界胶束浓度和协同效应等),并就它在助染、新材料制备、药物、驱油、环境保护、生物技术和抗病毒等方面的应用作了介绍。 相似文献
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Noulkamol Arpornpong Ampira Charoensaeng David A. Sabatini Sutha Khaodhiar 《Journal of surfactants and detergents》2010,13(3):305-311
The micellar, adsorption, and adsolubilization properties of a novel ethoxy carboxylate extended surfactant are measured and
compared to an extended sulfate surfactant. The critical micelle concentration (CMC) of the ethoxy carboxylate extended surfactant
is measured to be 0.02 mM while it is 0.07 mM for the extended sulfate surfactant. Adsorption and adsolubilization studies
are carried out on alumina oxide surfaces. The extended sulfate surfactant has a higher maximum adsorption capacity onto the
aluminum than the ethoxy carboxylate extended surfactant (0.47 vs. 0.14 mmol/g, respectively). For adsolubilization, the extended
sulfate surfactant shows a slightly higher phenanthrene adsolubilization compared to the ethoxy carboxylate extended surfactant
(log Kadm of 6.15 vs. 5.71, respectively). In contrast, for solubilization, the ethoxy carboxylate extended surfactant exhibits higher
phenanthrene solubilization capacities than the extended sulfate surfactant (log Kmic of 5.61 vs. 5.42, respectively). Relative to surfactant loss from the solid surface, the ethoxy carboxylate extended surfactant
shows a higher desorption capacity as compared to the extended sulfate surfactant. From these measurements, the ethoxy carboxylate
extended surfactant has better properties for micellar applications (lower CMC, higher Kmic), while the extended sulfate surfactant has better properties for admicellar applications (higher qmax and Kadm values, and less desorption). 相似文献
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Ampira Charoensaeng David A. Sabatini Sutha Khaodhiar 《Journal of surfactants and detergents》2009,12(3):209-217
Adsolubilization reaches its maximum when a surfactant adsorbed onto the solid–liquid interface achieves complete bilayer
or maximum adsorption. The attempt to enhance the adsolubilization of organic solute is accomplished by increasing interaction
between the hydrophobic core of adsorbed admicelles and the organic solute. Solubilization and adsolubilization were studied
with linker-based and extended-surfactant-based systems. Extended surfactants have propylene oxide (PO) groups of intermediate
polarity inserted between hydrophobic and lipophilic moieties in the surfactant molecule. This study evaluated the adsolubilization
of polar (phenylethanol) and nonpolar (ethylcyclohexane) solutes into conventional linker-based and extended-surfactant-based
admicelles. The results demonstrated that the extended-surfactant-based systems showed higher solubilization capacity than
the conventional sodium dodecyl sulfate alone or with linker. For the polar solute, the presence of PO group has a greater
effect than the number of PO groups or the tail length, while for the nonpolar solute as the number of POs groups and the
tail length increased, the adsolubilization capacity also increased. Preliminary explanations for these observations are provided.
相似文献
Sutha Khaodhiar (Corresponding author)Email: |
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Emma Asnachinda Sutha Khaodhiar David A. Sabatini 《Journal of surfactants and detergents》2009,12(4):379-386
One of the problems of using surfactant-modified adsorbents in a surfactant-based adsorption process is loss of surfactant
because of desorption. Recently, polymerizable surfactants have been used to minimize surfactant losses by polymerization
of the surfactant admicellar structure to help secure it to the solid oxide surface. In this study, adsorption of polymerizable
cationic gemini surfactant was used to form polymerized bilayers on silica. UV light was used to irradiate and initiate the
polymerization process. Surfactant adsorption and desorption were evaluated to compare the efficiency of polymerized and non-polymerized
surfactants using gemini and conventional surfactants, respectively. Results demonstrate that the increased stability of the
polymerized surfactant-modified surface can reduce the desorption of surfactant from the surface, thereby improving operating
characteristics of the surfactant-modified media (e.g., maintaining adsolubilization potential, dispersion stability, etc.). 相似文献
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Haifeng Tang Jiamei Song Mengling Zha Jincheng He Zhihu Yan 《American Institute of Chemical Engineers》2022,68(5):e17625
The structure–activity relationship between the molecular structure of Gemini surfactants and foam properties has not yet been deeply revealed. In this study, we clarified for the first time the structure–activity relationship between foam properties and molecular structure of Gemini surfactant by discussing the variation characteristics of parameters such as free energy of interface formation, radial distribution function, and mean square displacement calculated by molecular simulation method. The research results show that (1) the Gemini surfactant with the sulfonic acid head group has the most excellent foam properties; (2) the foam properties increase monotonously with the increase of the hydrophobic tail chain length; (3) the foam properties decrease monotonously with the increase of the spacer group length. It is hoped that this article can further broaden the application range of surfactants as foaming agents in industrial fields such as oil and gas exploitation. 相似文献
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对流体在固体表面超铺展特性的研究进展进行了综述,总结了具有超铺展特性的动态湿润体系、超铺展特性的影响因素、内在机理以及实验关联式建立和数值模拟方法。部分丙硅氧烷类和烷基乙氧基化物类以及少数离子型表面活性剂溶液具有超铺展特性,浓度和固体表面能是超铺展的重要影响因素。气液界面的浓度Marangoni效应被认为是超铺展过程的控制因素,表面活性剂在气液、固液和三相接触线前缘固气界面的输运和吸附对浓度Marangoni效应有重要影响。分析认为,实验方面未来应拓展实验体系,建立超铺展产生的判据;深入研究宏观影响因素以及微观输运和吸附机理,同时考虑外加物理场影响,为超铺展的实际应用奠定基础。理论方面需综合考虑表面活性剂向界面的输运、吸附对界面性质的作用规律以及浓度Marangoni效应的影响,借鉴相对成熟的牛顿流体动态湿润理论,建立描述超铺展特性的全过程理论模型。数值模拟方面应以分子动力学模拟为基础建立表面活性剂输运和界面吸附的微观物理模型,将其引入流体动力学模型,实现对超铺展过程精确定量化的描述。本文还给出了可能的超铺展体系铺展全过程的物理图景。 相似文献
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Sakai K Nakajima E Takamatsu Y Sharma SC Torigoe K Yoshimura T Esumi K Sakai H Abe M 《Journal of oleo science》2008,57(8):423-429
Adsorption of a cationic gemini surfactant (1,2-bis(dodecyldimethylammonio) ethane dibromide, 12-2-12) and the corresponding monomeric surfactant (dodecyltrimethylammonium bromide, DTAB) on montmorillonite has been characterized with a combination of adsorption isotherm, interlayer spacing and FT-IR spectroscopic data. Adsolubilization of vitamin E into the adsorbed surfactant layers has also been studied. The adsorption isotherm data reveal that the adsorption of the two surfactants is driven by the two factors: one is the cation exchange that occurs on the interlayer basal planes and the other is the hydrophobic interaction between hydrocarbon chains of the surfactants. Although the adsorbed amount measured in the saturation region (in mol g(-1)) is almost identical for the two surfactants, the conformation of the intercalated surfactant molecules differs significantly from each other. The adsorption of DTAB results in a lateral bilayer arrangement in the limited interlayer space, whereas 12-2-12 gives a normal bilayer arrangement in the expanded interlayer space. Adsolubilization of vitamin E takes place into the adsorbed surfactant layers, and interestingly, all the vitamin E molecules added in the montmorillonite suspensions are hybridized at lower surfactant concentrations due to the great specific surface area of the clay material. Since the maximum adsolubilization amount is usually obtained just below the critical micelle concentration, the gemini surfactant is deemed to be more efficient than the corresponding monomeric one to achieve the great adsolubilization amount. 相似文献
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Interfacial Dynamic Properties and Dilational Rheology of Sulfonate Gemini Surfactant and its Mixtures with Quaternary Ammonium Bromides at the Air–Water Interface
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Lu Lai Ping Mei Xiao-Mei Wu Li Cheng Zhao-Hua Ren Yi Liu 《Journal of surfactants and detergents》2017,20(3):565-576
The dynamic interfacial properties and dilational rheology of gemini sulfonate surfactant (SGS) and its mixtures with quaternary ammonium bromides (DTAB, CTAB) at the air–water interface were investigated using drop shape analysis. Results suggest that the adsorption process of these surfactants is diffusion-controlled at dilute concentrations, whereas the adsorption mechanism gradually shifts to a mixed kinetic-diffusion control with increasing surfactant concentration. The mixed surfactant system possesses the best surface activity when the molar ratios of SGS/DTAB and SGS/CTAB mixtures are 9:10. The formation of catanionic complexes shields the electrostatic repulsion between surfactant molecules and lowers the electrostatic adsorption barrier. Therefore, SGS/DTAB and SGS/CTAB mixtures exhibit higher adsorption rates than either component alone. The effects of oscillating frequency and surfactant concentration on the surface dilational properties of SGS, DTAB, CTAB, SGS/DTAB, and SGS/CTAB mixtures were also determined. As the oscillating frequency increases, the dilational elasticity of these surfactants gradually increases. The dilational elasticity peaks at a certain concentration, which is less than the critical micelle concentration (CMC). Results show that the dilational elasticity of SGS/DTAB and SGS/CTAB mixtures is higher than that of either component, resulting from the formation of a denser monomolecular adsorption layer at the air–water interface. Our study provides a basis for understanding the interaction mechanism of catanionic surfactant mixtures containing Gemini surfactant at the air–water interface. 相似文献