- Synthesis and surface properties of a pH-regulated and pH-reversible anionic Gemini surfactant
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A new series of N,N′-dialkyl-N,N′-diacetate ethylenediamine, differing by the length of the carbon tails (8, 10, and 12), was synthesized in two steps. Their surface properties and aggregation behavior were studied in aqueous solution using pH titration,
- Lv, Jing,Qiao, Weihong,Xiong, Chongqiao
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- Synthesis and Performance Evaluation of CO2/N2 Switchable Tertiary Amine Gemini Surfactant
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A type of switchable tertiary amine Gemini surfactant, N,N′-di(N,N-dimethyl propylamine)-N,N′-didodecyl ethylenediamine, was synthesized by two substitution reactions with 3-chloro-1-(N,N-dimethyl) propylamine, bromododecane and ethylene diamine as main raw materials. The structure of the product was characterized by FTIR and 1H-NMR. We also investigated the surface tension when CO2 was bubbled in different concentrations of surfactant solution and the influence of different CO2 volumes on surface tension under a constant surfactant concentration. Finally the surface tension curve and the related parameters were acquired by surface tension measurements. The experimental results showed that the structure of the synthesized compounds were in conformity with the expected structure of the surfactant, and displayed a better surface activity after bubbling CO2. The critical micelle concentration (CMC) surface tension at CMC (γcmc) pC20 (negative logarithm of the surfactant’s molar concentration C20, required to reduce the surface tension by 20?mN/m) surface excess (Γmax) at air/solution interface and the minimum area per surfactant molecule at the air/solution interface (Amin) were determined. Results indicate that the target product had good surface activity after bubbling CO2.
- Zhou, Ming,Wang, Gang,Xu, Yaoyang,Zhang, Ze,Li, Sisi,Hu, Buhua,Zhao, Yunlong
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- Thermochemical and Structural Studies of New Chiral and Achiral Long Alkyl Chain Functionalized Imidazolinium Ionic Liquids
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Adding to the versatile class of ionic liquids (ILs), an entirely new series of imidazolinium-based ionic liquids is reported herein, offering chirality and important thermal characteristics, such as polymorphism, glass transition, and plastic crystalline behavior. An efficient and general procedure for the preparation of long N,N′-alkyl chain-substituted compounds with either saturated (s) or chiral (c) cyclohexyl (cyC6)-substituted imidazolium (Im) backbones, namely, [C12C12RsIm][A] (A = Br-, [BF4]-, [ClO4]-, [PF6]- R = H, Me, iPr) and [C12C12cIm-cyC6][A] (A = Br-, I-, [I3]-, [BF4]-, [ClO4]-, [PF6]-, [SbF6]-, [BPh4]-), was developed, and the novel compounds were studied by thermochemical methods (DSC, TGA), X-ray diffraction in the small angle regime (SAXS), single-crystal X-ray diffraction (SC-XRD), and specific rotation analysis.
- Seidl, Vera,Sternberg, Michelle,Heinemann, Frank W.,Schmiele, Martin,Unruh, Tobias,Wasserscheid, Peter,Meyer, Karsten
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p. 6276 - 6288
(2021/10/20)
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- PH-responsive surface activity and solubilization with novel pyrrolidone-based gemini surfactants
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A new series of pH-responsive Gemini surfactants with 2-pyrrolidone head groups, N,N′-dialkyl-N,N′-di(ethyl-2-pyrrolidone)ethylenediamine (Di-CnP, where n = 6, 8 10, 12), were synthesized and characterized by 1H NMR, 13C NMR, ESI-MS, and elemental analysis. The surface activity and micellization behavior at acidic, neutral, and basic conditions were characterized by equilibrium surface tension and fluorescence techniques. It was found that the surface activity of Di-CnP depends on the pH of aqueous solutions due to the protonation state of surfactant molecules when pH was varied. The new compounds have lower cmc and γcmc in comparison with that of m-2-m type conventional cationic Gemini surfactants and gluconamide-type nonionic Gemini surfactants. Fluorescence data confirm that micelles are formed when the concentration is above the cmc. Since micellization is of fundamental importance in surfactant applications such as solubilization, microemulsion, and related technologies, the significant difference in cmc at different pH of this new Gemini surfactant is employed to solubilize cyclohexane. The preliminary result indeed shows that the solubilization capacity of Di-CnP can be tuned by pH.
- Jiang, Zan,Li, Xuefeng,Yang, Guangfu,Cheng, Li,Cai, Bo,Yang, Yi,Dong, Jinfeng
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scheme or table
p. 7174 - 7181
(2012/07/31)
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- SUGAR COMPOUND AND SURFACTANT COMPOSED THEREOF
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PROBLEM TO BE SOLVED: To easily provide a compound giving little stimulation and preferable feeling to the skin, etc., and useful as a base for hair and skin cosmetics, a cleaning agent, an emulsifying agent, a conditioning agent, etc., and producible with decreased number of reaction steps. SOLUTION: A 2-hydrophobic 2-hydrophilic nonionic surfactant especially having a sugar amide chain as the hydrophilic group is extremely effective among 2-hydrophobic 2-hydrophilic nonionic surfactants.
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Page/Page column 4
(2008/06/13)
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- Macrocyclic polyether tetralactams I: Synthesis and cyclization studies
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A three-step method for the synthesis of new 18,21 or 24-membered macrocyclic tetralactams with two dimethyleneoxy moieties is described. The method consists in the ring closure of a bis-secondary amine with a diamide diacid derivative activated by the th
- Duriez,Pigot,Picard,Cazaux,Tisnes
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p. 4347 - 4358
(2007/10/02)
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