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51.
Quanwei?Yu Jens?Fr?mmel Thomas?WolffEmail author Karel?Procházka 《Colloid and polymer science》2004,282(9):1039-1043
Solid stoichiometric complexes of [3,12]-ionene and dodecyl sulfate form upon reaction of the bromide of the ionene and the silver salt of dodecyl sulfate in methanol. IR, DSC, and TG investigations indicated that the solid complexes are stable between 30 and 120 °C. TG and DSC also showed that the complexes easily take up water at ambient conditions. These samples are optically isotropic. When exposed to an increased humidity they exhibit optical anisotropy, i.e., birefringence, which is caused by the formation of a hexagonal mesogenic phase. Mesogenicity is necessarily accompanied by a further uptake of water (4–5 H2O molecules per ionic unit), which is dependent on the relative humidity. The phase behavior as a function of temperature and controlled relative humidity was studied using birefringence measurements and polarizing microscopy. 相似文献
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53.
表面活性剂混合物水溶液中的囊泡形成 总被引:1,自引:0,他引:1
1:1烷基羧酸钠-溴化烷基三甲铵混合水溶液的浓度在cmc以上时, 能自发或超声分散形成一类新型混合表面活性剂囊泡(单层膜), 正负离子表面活性剂的突出囊泡形成能力以及不同表面活性剂结构组合变化所显现的多样特性, 皆预示出混合功能有序组合体研究的广阔前景。 相似文献
54.
We studied the adsorption behaviour at the liquid/air and liquid/solid interface of a new anionic surfactant derived from sugar, the sodium decyl galacturonate. The surface tension of aqueous solutions, measured in equilibrium and as a function of time, is particularly affected by the presence of decanol, synthesis residue, which amount ranges between about 0 and 13%. The surface tension lowering is accelerated in presence of decanol, owing to its rapid diffusion to the interface or/and because it affects the mobility and adsorption process of the anionic surfactant molecules. The wetting power of surfactant solutions were also investigated in relation with textile treatment applications. We measured the kinetics of absorption of surfactant solutions in a piece of standard cotton and compared it to the absorption of pure decanol, a completely wetting liquid and to the absorption of an alkylpolyglucoside. The time at which the fabric piece is saturated appears to be related to the adsorption of surface-active molecules on the fibers at the advancing liquid front/fabric contact line. Decanol was found to promote absorption and micellar life-time seem to reflect the differences observed at high concentration. This study shows the importance of controlling the amount of surface-active residues which may alter the kinetics of surfactant adsorption, particularly in industrial processes where equilibrium conditions are not reached. 相似文献
55.
IntroductionTriazenereagentsareinterestingbecauseoftheirstrongcomplexationabilitieswithtransitionmetals .1 6However,littledecolorationofthemcatalyzedbysilverionhasbeenstudiedinanalyticalchemistry .Manyanal ysistshavereportedtheuseofcatalyticreactionsfort… 相似文献
56.
The interaction of fluorocarbon containing hydrophobically modified polyelectrolyte(FMPAANa) with two kinds of nonionic surfactants(hydrogenated and fluorinated)in a semidilute (0.5wt%) aqueous solution had been studied by rheological measurements,Association behavior was found in both systems.The hydrophobic interaction of FMPAANa with fluorinated surfactant(FC171) is much stronger than that with hydrogenated surfactant(NP7.5) at low surfactoant concentrations.The interaction is strengthened by surfactants being added for the density of active junctions increased.Whereas distinct phenomena for FC171 and NP7.5 start to be found as the surfactants added over their respective certain concentration.The interaction of polyelectrolyte with fluorinated surfactant increases dramatical ly while that with hydrogenated surfactant decreases. 相似文献
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The aggregation behavior of fluorinated surfactant in aqueous solution was investigated using dissipative particle dynamics (DPD) simulation method. Simulation results show that fluorinated surfactants behave mainly as their hydrocarbon analogues, having similar sequences of phases and aggregate structures, which are capable of building micelle, hexagonal phase and lamellar phase. But fluorinated surfactants also show interesting differences from hydrocarbon analogues, which can easily form hexagonal and lamellar structures with comparative little curvature. They can also form ellipsoid or rod-like micelles even in very low concentrations instead of spheroid ones. The dynamic aggregation behavior of fluorinated surfactants, as well as the comparison with hydrogenated ones, was also investigated. 相似文献
59.
L. Camacho A. Cruz R. Castro C. Casals J. Pérez-Gil 《Colloids and surfaces. B, Biointerfaces》1996,5(6):271-277
The effect of pH on the interfacial adsorption activity of pulmonary surfactant was examined. Measurements of the surface tension were made in a Wilhelmy-like surface microbalance specially designed to assay small volumes of hypophase in thermostatically controlled conditions. Alkaline pH caused a significant decrease of the surface activity of both pulmonary surfactant and a lipid extract from surfactant (LES) (containing all of the lipids and surfactant protein-B (SP-B) and surfactant protein-C (SP-C) hydrophobic surfactant proteins, but lacking surfactant protein-A). The pK calculated from the change of surface activity versus pH was 9.18±0.26 and 9.27±0.31 for pulmonary surfactant and LES, respectively. The results from this study support the idea that electrostatic interactions between basic residues of SP-B and SP-C and negatively charged surfactant phospholipids could be important for the interfacial adsorption activity of pulmonary surfactant. 相似文献
60.
A vesicle-forming chiral cationic surfactant (1R,2S)-(-)-N-dodecyl-N-methyl-ephedrinium bromide was evaluated as a pseudo-stationary phase in micellar electrokinetic chromatography (MEKC) for enantioseparation of eight non-steroidal anti-inflammatory drugs e.g., carprofen, flurbiprofen, fenoprofen, ibuprofen, indoprofen, ketoprofen, naproxen and suprofen by capillary electrophoresis. The effects of varying experimental conditions such as pH and concentration of surfactant in the running buffer on the enantiomer separation of the drugs are reported. A mixture of five of the above drugs was separated and each enantiomeric pair was also separated simultaneously in a single run by use of the surfactant. The strong electrostatic interactions between the analytes and the vesicles seemed to have a major role in the enantiomeric separation of the profens. 相似文献