Dimeric and monomeric surfactants derived from sulfur-containing amino acids
Dimeric and monomeric surfactants derived from sulfur-containing amino acids
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DOI：
10.1016/j.jcis.2010.08.007
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发表时间：
2010-11-15
影响因子：
9.9
通讯作者：
Garcia-Rio, Luis
中科院分区：
文献类型：
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作者：
Faustino, Celia M. C.;Calado, Antonio R. T.;Garcia-Rio, Luis
合成了氨基酸L-胱氨酸、D-胱氨酸和DL-胱氨酸衍生的阴离子脲基二聚体（gemini）表面活性剂以及L-半胱氨酸、L-蛋氨酸和L-磺基丙氨酸衍生的单体表面活性剂，并通过电导率、平衡表面张力和稳态荧光光谱技术表征了它们的溶液性质。研究的双子显示出最低的临界胶束浓度（cmc）值，然而单体半胱氨酸对应物在降低表面张力方面表现出优越的上级效率，这是一个不寻常的发现，可以归因于游离巯基。手性似乎在双子表面活性剂的表面活性性质中起作用，但不是胶束形成。所有的表面活性剂研究显示出更高的偏好吸附在空气/水界面，而不是形成胶束，这可能是有关的尿素部分的事实。用溶剂化显色探针E-T（30）（Reichardt甜菜碱染料）测量的界面区域的极性与十二烷基硫酸钠（SDS）胶束相似。(C)2010年爱思唯尔公司All rights reserved.
Anionic urea-based dimeric (gemini) surfactants derived from the amino acids L-cystine, D-cystine and DL-cystine, as well as monomeric surfactants derived from L-cysteine, L-methionine and L-cysteic acid were synthesized and their solution properties characterized by electrical conductivity, equilibrium surface tension, and steady-state fluorescence spectroscopy techniques. The geminis studied showed the lowest critical micelle concentration (cmc) values, however the monomeric cysteine counterpart exhibited superior efficiency in lowering surface tension, an unusual finding that can be attributed to the free sulfhydryl group. Chirality seems to play a role in the surface active properties of the gemini surfactants, but not on micelle formation. All the surfactants studied showed a higher preference for adsorption at the air/water interface rather than to form micelles, a fact that may be related to the urea moiety. The polarity of the interfacial region, measured with the solvatochromic probe E-T(30) (Reichardt's betaine dye), was similar to sodium dodecyl sulphate (SDS) micelles. (C) 2010 Elsevier Inc. All rights reserved.