阴离子与非离子表面活性剂复配体系反胶团的电导研究

在SDS/Tween60/正己醇/环己烷/水形成的反胶团复配体系中,电导率(κ)与水和表面活性剂的摩尔比(W0)关系曲线上存在最大值,随着复配体系中SDS的摩尔分数(xSDS)增大,最大增溶水量(W0,max)向W0值更大的方向移动.xSDS≤0.5时,随着xSDS的增大,W0,max所对应的电导率值增大;xSDS≥0.5时,其电导率值减小.在AOT/Tween60/环己烷/水体系中,出现了与SDS/Tween60/正己醇/正己烷/水体系类似的现象,但W0,max所对应的电导率值,随着xAOT的增大而增大,不会出现极大值,两者的差异主要是由于助表面活性剂醇的影响.在SDS/TritionX-100/正己醇/环己烷/水体系中也印证了该结论.     

Molecular-Thermodynamic Model of Solubilization in Direct Spherical Micelles of Nonionic Surfactants

Colloid Journal - A thermodynamic model has been formulated for the formation work of a molecular aggregate consisting of molecules of a nonionic surfactant and a solubilisate in a...     

Nanometer‐Scaled Hollow Spherical Micelles with Hydrophilic Channels and the Controlled Release of Ibuprofen

PS‐b‐PAA spherical micelles with a liquid core and a PAA shell are prepared with the assistance of 1,2‐dichloroethane. During the process of adding a mixture of PNIPAM‐b‐P4VP and PEG‐b‐P4VP, multi‐layered micelles with a mixed corona that consists of both PNIPAM and PEG chains are constructed through the electrostatic interaction and hydrogen bonding between the PAA block and the P4VP block. When heating above the LCST, the PNIPAM chains collapse onto the PAA/P4VP complex layer while the PEG chains still stretch into the solution through the collapsed PNIPAM layer, which leads to the formation of hydrophilic channels around the PEG chains. The ibuprofen encapsulated in the hollow space can diffuse through the channels and its release rate can be controlled by changing the ratio of PEG chains to PNIPAM chains in the corona.

     

Interaction of Anionic Gemini Surfactants with Other Surfactants

The interaction of anionic gemini surfactants with other surfactants (such as anionic, cationic, nonionic) was systematically overviewed, paying attention to synergism observed in various properties. These mixed systems were found to show remarkable synergism in micelle formation. The critical micelle formation values being lower than the individual gemini surfactants indicate that the mixed micellization is due to attractive interaction between the two components. Almost all combinations were discussed in terms of respective surface tension reduction effectiveness and surface tension reduction efficiency and aggregation number for evaluation of synergism.     

Interaction of Polyacrylamide with Conventional Anionic and Gemini Anionic Surfactants

The interaction of polyacrylamide (PAM) with conventional anionic (sodium lauryl sulphate, NaLS) and gemini anionic (sodium salt of bis(1-dodecenyl succinimic acid), represented as NaBDS) surfactants has been studied in alkaline medium by electrical conductance and surface-tension measurements at 35⁰C in order to compare the behavior of two surfactants toward the polymer. The surface parameters and thermodynamic parameters have been evaluated and compared. The results indicate more readily interaction of anionic gemini surfactant with the polymer (PAM).     

Interaction Mechanisms Between Anionic Surfactant Micelles and Different Metal Ions in Aqueous Solutions

In its using or eliminating processes, surfactant solutions usually exhibit different behaviors because of the different species or concentrations of the encountered metal ions. Interactions between anionic surfactant (SDS) micellar solutions and several familiar metal salt solutions (Al₂(SO₄)₃, FeCl₃, CaCl₂ and MgCl₂) were investigated. Precipitates were formed in all systems except SDS‐MgCl₂ visually. Stoichiometric analysis reveals that, in SDS‐Al₂(SO₄)₃ system, the precipitation phenomenon is mainly owing to the effect of adsorption‐charge neutralization between Al³⁺ ions and SDS micelles; in SDS‐FeCl₃ system, bridge connection effect of Fe(OH)²⁺ ions among SDS micelles becomes the dominant mechanism; while in SDS‐CaCl₂ system, all SDS micelles are decomposed and solubility product of Ca(DS)₂ crystal results in the precipitation. SEM photographs of the precipitates can serve as additional vivid proofs of the above conclusion.     

有机金属络合物用于高分子富氧膜的研究进展

本文介绍了能够可逆吸附分子氧的有机金属络合物用于高分子富氧膜的研究进展，以及以双重吸附理论进行的膜的促进输送机理。     

Photometric Determination of Novocaine with Preconcentration in Surfactant Micelles

Journal of Analytical Chemistry - The work deals with the extraction and preconcentration of novocaine using mixed surfactants of nonionic (Triton X-114) and anionic (sodium dodecyl sulfate) types...     

阴离子型聚丙烯酰胺与阳离子表面活性剂的相互作用

采用自由基水溶液共聚法制备了带有负电荷的水溶性聚丙烯酰胺,研究了水溶液中聚合物与阳离子表面活性剂的相互作用及所导致的水溶性、黏度和流变学性质的变化,为进一步研究驱油提供了理论基础.     

Precision Dilatometry of Microemulsions with Anionic Surfactants

Density ρ, isothermal compressibility β_Т, and thermal expansion coefficient α are measured with high accuracy at 15 and 25°C for water-n-octane-sodium dodecyl sulfate-n-pentanol microemulsions with a water/oil weight ratio varying from 0.05 to 4. The internal pressure of the microemulsions is shown to be calculable from the results of dilatometric measurements. The phenomenon of temperature inversion is revealed for the temperature coefficient of internal pressure ΔP _i/ΔT of the microemulsions. The analysis of this coefficient makes it possible to distinguish between three regions of the structural state in the microemulsions and a continuous structural transition in the associated microemulsions.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 4, 2005, pp. 479–484.Original Russian Text Copyright © 2005 by Kartsev, Shtykov, Shtykova.     

正、负离子表面活性剂混合体系溶致液晶生成的相行为

研究了烷基(C8,C12,C14)三甲基溴化铵、烷基(C12,C14)溴化吡啶与烷基(C8,C12)硫酸钠混合体系溶致液晶形成的条件与结构的变化.在高浓度的水溶液中,随着正、负离子表面活性剂摩尔比接近于1,液晶结构由六角相过渡为层状相.表面活性剂非极性链长改变,对相行为影响显著,短碳链的正、负离子表面活性剂混合体系,在等摩尔比时,体系为层状液晶或立方液晶为主,夹杂少许沉淀.随碳链增长,两类表面活性剂间的静电吸引效果表现为生成沉淀的摩尔比例范围变宽,沉淀量增多,共存的液晶相减少,甚至消失.若只改变正离子的极性头基,季胺盐比吡啶盐与烷基硫酸盐的作用要强,形成不溶物的混合摩尔比例范围更宽.     

In-Capillary Derivatization and Preconcentration for CE of Metal Ions as Their Phenanthroline Complexes

A simple and automated method involving in-capillary derivatization and in-capillary preconcentration was developed for the simultaneous determination of metal ions by capillary zone electrophoresis. Fe(II), Zn(II), Cu(II) and Cd(II) were derivatized using 1,10-phenanthroline as the derivatizing agent. The in-capillary derivatization and in-capillary preconcentration via large volume injection were performed sequentially as follows: 60 mmol L^?1 1,10-phenanthroline was first hydrodynamically injected (0.2 psi) for 2 s; metal ions were introduced by hydrodynamic injection (0.5 psi) for 60 s; 0.2 mol L^?1 acetate pH 5.5 containing 20 % methanol was used as the running buffer. Four metal ions can be determined within 8 min using 16 kV. The resulting preconcentration factors were in the range 12–21. Good linearity was obtained for concentrations of 0.1–8.0 mg L^?1 (r ² > 0.990). The mean recoveries of the metal ions evaluated by fortification of wine samples were in the range 90–102 %. The limits of detection ranged from 0.05 to 0.2 mg L^?1. The proposed method can be applied for directly determining metal ions in wine samples.     

Polymerization of Transition Metal Complexes in Solid Polymer Electrolyte Membranes

Prussian blue (PB), which is a mixed-valent polynuclear metal complex, was formed in the presence of the solid polymer electrolyte membrane Nafion (Nf). According to the stepwise dipping method, in which either Fe²⁺ or Fe(CN)₆ ^3? of the component ions of PB was first incorporated into the matrix membrane and then the membrane was immersed into a solution containing the other component ion, a thin layer of PB was deposited on the surface of Nf or inside Nf depending upon the sequence of incorporation of the component ions. A dissipative structure of periodic PB layer deposit inside Nf was found to be formed under a specific condition of the stepwise method. PB was also formed inside Nf as a broader line by the countercurrent diffusion method in which both component ions were incorporated into Nf from opposite surfaces. The position of PB in Nf varied with the concentration ratio of Fe²⁺ to Fe(CN)₆ ^3? in this case.     

Observations on the Anionic Polymerization of Ethylene Oxide by Alkali Metal Naphthalene and Anthracene Complexes

The anionic polymerization of ethylene oxide by alkali metal naphthalenes and anthracenes was studied in DMSO and THF to determine the effects of solvent and of polycyclic hydrocarbon, and to obtain information on the mode of initiation. No propagation occurred with lithium naphthalene, and this made it possible to isolate mono- and dihydroxyethyl naphthalene, the species formed on initiation.

The molecular weights obtained in the presence of DMSO were about half those obtained in THF, and were proportional to [monomer]/[initiator]. This was explained as being due to differences in initiation; i.e., formation of dimsyl anion as the true initiator in DMSO. The rate of polymerization was first order to monomer, and the molecular weights were found to increase linearly with percent inversion.     

Structure and Percolation of Inverted Cylindrical Branched Micelles

There have been strong indications that lecithin with trace amounts of water in isooctane forms branched cylindrical micelles at relatively high water content. At a certain volume fraction these micelles percolate to form a connected network. Here this phenomenon is studied by viscometry and dielectric spectroscopy as a function of volume fraction and temperature. The observed percolation threshold is used to estimate the mean length between, and the size of, branch points. There is however a discrepancy with the theoretical model which can be explained by a water content dependent ratio of branch points and end-caps. It is argued that this is related to the water induced change from dynamic to static percolation, indicated by the observed scaling exponents. From the temperature dependence of the phase boundary the free energy of a branch point is estimated. As a function of the water content branch point formation changes from driven entirely by enthalpy towards more entropically driven.     

Sorption of Anionic Surfactants on Layered Double Hydroxides

In the present study we investigated the adsorption of sodium dodecyl- and octylsulfate, and sodium dodecyl- and octylbenzenesulfonate, on a layered double hydroxide (LDH) under controlled conditions. The results were compared to those obtained for the adsorption of surfactants on mineral oxides and on LDHs, showing that the behavior of surfactant adsorption on LDHs can be approximately explained by the models proposed for surfactant adsorption on mineral oxides. The electrokinetic potential of the surfactant-adsorbed LDH particles in suspension was measured in order to monitor the variation of this potential as a function of the adsorption. The results showed a characteristic behavior of the surfactant-adsorbed LDH that can be correlated to a rearrangement of the adsorbed layer at concentrations above the CMC. Surfactant sorption was also studied, using SDS and the calcined LDH, showing the regeneration of the calcined material by intercalating the DS anions. Two processes can occur during the removal of surfactants from aqueous solutions by LDHs, depending on the starting material: (i) adsorption itself, when a noncalcined LDH intercalated with a nonexchangeable anion, such as carbonate, is used; and (ii) adsorption and intercalation, which occurs when a calcined LDH, like Mg-Al-CO(3), is used. The potential application of this material for surfactant removal is one of the reasons for the need for a better understanding of the mechanisms involved. As we demonstrate here, LDHs are very efficient in removing surfactants from aqueous solutions. Copyright 2000 Academic Press.     

Interactions of Polyglycol Ethers with Anionic Surfactants in Water

In order to determine the thermodynamic properties of the aggregation process between sodiun dodecyl sulfate (SDS) and polyglycol ethers (PEG) with average molar mass 35000, 20000, and 10000, the temperature dependence of polymer-surfactant ?nteraction is used. Surface tension, ionic conductivity, and solubilization methods have been used to quantify the interactions.It was found that the transfer of SDS micelles from aqueous media to aqueous polymer media is more feasible than the reverse. In addition, the hydropholic interaction seems to be important, as opposed to the charge-nonpolar type interaction.