十二烷基甜菜碱/十二烷基硫酸钠复配体系的表面活性

研究了两性表面活性剂十二烷基甜菜碱（C12BE）和阴离子型表面活性剂十二烷基硫酸钠（SDS）复配体系的形成胶束能力,降低表面张力效率,降低表面张力能力三种增效作用.发现C12BE和SDS摩尔比为6 :4时增效作用最显著.并考察了盐、醇对复配体系表面活性的影响,结果表明,加盐能导致表面活性的提高,加醇的机理比较复杂,乙醇对复配体系表面活性影响不大,而正丁醇影响则比较显著.     

Micellization of Sodium Dodecyl Sulfate in Glycerol Aqueous Mixtures

The effect of glycerol on both micellar formation and the structural evolution of the sodium dodecyl sulfate (SDS) aggregates in the context of the action mechanism of the cosolvent has been studied. The critical micelle concentration and the degree of counterion dissociation of the surfactant over a temperature range from 20°C to 40°C were obtained by the conductance method. The thermodynamic parameters of micellization were estimated by using the equilibrium model of micelle formation. The analysis of these parameters indicated that the lower aggregation of the surfactant is mainly due to a minor cohesive energy of the mixed solvent system in relation to the pure water. The effect of glycerol on the mean aggregation number of the micelles of SDS was analyzed by the static quenching method. It was found that the aggregation number decreased with the glycerol content. This reduction in the micellar size seems to be controlled by an increase in the surface area per headgroup, which was ascribed to a participation of glycerol in the micellar solvation layer. Studies on the micropolarity of the aggregates, as sensed by the probe pyrene, indicated that this microenvironmental parameter is almost unaffected by the presence of glycerol in the mixture. However, an increase in the micellar microviscosity at the surface region was observed from the photophysical behavior of two different probes, rhodamine B and auramine O. These results suggest a certain interaction of the cosolvent in the micellar solvation of SDS micelles.     

Extraction by Mixed Solvent and Spectrophotometric Determination of Sodium Dodecyl Sulfate in Sea Water

Mixed solvent was used to extract ion pairs formed from suitable cationic dye and sodium dodecyl sulfate in sea water. The extracts were used for spectrophotometric determinations. The extraction of ion pairs of various combinations is discussed. Ethyl violet and a mixture (1:1) of p-xylene and toluene are the most useful combination as the cationic dye and the extraction solvent. The extracts were determined spectrophotometrically at 611.2 nm; the molar absorptivity is 1.27 × 10⁵ M^?1 cm^?1. The detection limit is 2.0 ppb in water based on three times the standard deviation of the blank. Extraction with this mixed solvent is as rapid and sensitive as with the best single solvent.     

L-半胱氨酸在SDS吸附胶束中的电化学催化氧化

The electrochemical oxidation of L-cysteine can be catalyzed by sodium dodecyl sulfate (SDS) admicelles. The catalytic efficiency increases hardly when SDS concentration is lower than the critical admicelle concentration (CAC) and increases rapidly when SDS concentration is between CAC and the critical micelle concentration (CMC), but decreases when SDS concentration is higher than CMC. Both results of rate constant k^0 and Gibbs free energy ΔG^ck accord with that of catalytic efficiency.     

pH Induced Partitioning and Interactions of Ciprofloxacin Hydrochloride with Anionic Surfactant Sodium Dodecyl Sulfate Using Ultraviolet and Fourier Transformed Infrared Spectroscopy Study

Ultraviolet (UV) and Fourier transformed infrared (FTIR) spectra of ciprofloxacin hydrochloride (Cpf) were studied under different pH conditions. The effect of aqueous, strong acidic, (pH 0.5–1.0) and a basic (pH 9.2) conditions on spectral behavior of Cpf was investigated in aqueous as well as in micellar environment of sodium dodecyl sulfate (SDS). Cpf shows partitioning from aqueous to micellar phase in a strong acidic as well as in a basic environment. Cpf shows no partitioning or binding to micelle in aqueous phase. Conductivity studies show that critical micelle concentration of SDS is increased with increasing concentration of Cpf. Different sites are responsible for binding under different pH conditions.     

SDS对PEO-PPO-PEO嵌段共聚物溶液行为的影响

对PEO-PPO-PEO（127）三嵌段共聚物的水溶液行为及添加十二烷基硫酸钠（SDS）后对共聚物溶液行为的影响进行了研究．利用荧光探针技术对不同SDS浓度下F127／SDS体系的胶来形成进行研究,并研究了SDS对F127浓溶液凝胶化行为的影响．结果表明：随着SDS浓度的增大,F127稀溶液胶束的形成受到抑制,SDS浓度愈大,形成的胶束结构就愈疏松．对F127浓溶液来说,SDS与F127摩尔比小于2时,体系易于凝胶化;但当SDS浓度增大,其与F127摩尔比大于2时,体系开始难于凝胶化,直至摩尔比大于5时,体系不再形成凝胶．     

Structure and Activity of RNase A in Sodium Dodecyl Sulphate Solutions

The structure and activity of RNase A in sodium dodecyl sulphate solutions were investigated at 25.0±0.1 and pH 7.00. The results show that with increasing sodium dodecyl sulphate concentration, the structure of RNase A is collapsed gradually, however, the activity of RNase A is first increased and then decreased. This is mainly due to the different effect of SDS at different SDS concentration.     

Effect of a Weak Electrolyte on the Critical Micellar Concentration of Sodium Dodecyl Sulfate

The critical micellar concentration of sodium dodecyl sulfate is strongly altered bytris(hydroxy-methyl)methylammonium ions. The effect of buffer solutions containing this weak electrolyte as the counterion source has been studied using various concentrations of the acid–base system as well as modifying the pH. Results show that counterion concentrations ranging from 0 to 340 × 10⁻³M induce an appreciable diminution of the critical micellar concentration from 8 to 0.7 × 10⁻³M. The analysis of data suggests that the critical micellar concentration of sodium dodecyl sulfate depends on the concentration of weak electrolytes in a way very similar to that of strong electrolytes.     

聚酰胺-胺基两亲树枝状大分子与十二烷基硫酸钠混合体系的分子聚集行为

以浊度分析、动态激光光散射(DLS)、透射电子显微镜(TEM)以及原子力显微镜(AFM)等方法研究了以1.0代(G1)聚酰胺-胺(PAMAM)为核心、以聚环氧丙烷-聚环氧乙烷(PPO-PEO)为辐射臂的树枝状大分子与十二烷基硫酸钠(SDS)之间的相互作用.值得注意的是,当树枝状大分子溶液的浓度为1%(质量分数),SDS的浓度远低于临界胶束浓度(cmc)时,体系的浊度值开始明显升高,DLS、TEM以及AFM的研究结果显示出此时聚集体的尺寸逐渐增加,意味着SDS与树枝状大分子有着很强的分子间相互作用,形成了树枝状大分子与SDS构成的复合物.当SDS浓度增高至0.1mmol·L-1(约为cmc的1%)左右时,体系的浊度值随着SDS浓度的增加变化不大,DLS、TEM、AFM的实验结果显示,聚集体尺寸趋于稳定状态.当SDS的浓度继续升高至0.25和0.5mol·L-1时,体系中形成了SDS分子间的自聚集或者存在多个SDS分子与单个树枝状大分子的分子间聚集.     

十二烷基硫酸钠辅助下低温合成碱式碳酸镁微球

在SDS辅助下,利用氯化镁和碳酸钠溶液在较低温度下(<55℃)反应结晶直接合成碱式碳酸镁微球。利用XRD、FTIR,SEM等技术研究了SDS加入量,反应温度,反应物浓度以及NaCl浓度等合成条件对产物的影响。结果表明:在反应温度低于55℃时,控制反应物浓度小于0.20 mol.L-1,加入一定量的SDS,可以有效抑制无定形颗粒向MgCO3.3H2O生长,促使无定形纳米颗粒通过相转移与自组装直接向碱式碳酸镁4MgCO3.Mg(OH)2.4H2O转变。SDS加入量,反应温度,反应物浓度以及NaCl浓度对碱式碳酸镁微球尺寸和微观形貌均起到调节作用。     

A UV-Visible Study of Partitioning of Pyrene in an Anionic Surfactant Sodium Dodecyl Sulfate

The interaction of hydrophobic dye pyrene with sodium dodecyl sulphate (SDS), an anionic surfactant, was studied in the process of solubilization. Difference UV-Visible spectroscopy was used to carry out the study. The partition coefficient (K_x), and number of dye molecules incorporated per micelle (n) was calculated. High K_x value shows that pyrene is partitioned strongly from polar to nonpolar environment. Steady-state fluorescence spectroscopy is used to check the environment of the pyrene as it is a well-known fluorescent probe. Onset of slope in curves is used to determine the critical micelle concentration (CMC).     

醇对水中DDAHPS分子聚集行为的影响

分别用稳态荧光猝灭技术和时间分辨荧光方法研究醇对两性表面活性剂 (十二烷基羟基磺化甜菜碱 ,DDAHPS)在水中聚集行为的影响 .结果表明 :在 4.0 0× 1 0 - 2 mol·L- 1DDAHPS水溶液中 ,随着正丁醇浓度的逐渐增大 ,表面活性剂的聚集数 (N)逐渐降低 .恒定醇的浓度为 2 .1 4× 1 0 - 2mol·L- 1时 ,醇碳链越长 ,N值越大 .与无醇体系相比 ,正丙醇和正丁醇使N值变小 ,正戊醇、正己醇和正庚醇使N值变大 .本文同时还测定了醇对微环境的极性 ,芘的荧光寿命及胶束内芘的激基缔合物形成效率的影响 .     

Aggregation of Sodium 2,4,5-(tri-n-Alkyl)-benzene Sulfonates in Aqueous Solution: Micellization and Microenvironment Characteristics Studied by Electron Paramagnetic Resonance and Steady-State Fluorescence Quenching

The aggregation behaviors and microenvironmental characteristics of five sodium tri-n-alkylbenzene sulfonates (STABS) micelles have been investigated by electron paramagnetic resonance (EPR) and steady-state fluorescence quenching (SSFQ) techniques. The results indicated that the micropolarity of STABS micelles was less sensitive to the increase of the alkyl chain length, and showed slight decrease with the increasing solution concentration. The microviscosity of STABS micelles increased with the increase of the long alkyl chain length, decreased with the increase of the short alkyl chain length, and exhibited little increase when increase the solution concentration. The salinity of added inorganic salt exhibited obvious effect on the decrease of micropolarity and increase of microviscosity of STABS. These results suggested that these different alkyl chains showed different effects on the micellization of STABS and the salinity's effect was even bigger.     

壳聚糖在稀溶液中的聚集行为

壳聚糖在稀溶液中的聚集行为;荧光探针;荧光偏振;聚集行为     

The Properties of Mixtures of Sodium Dodecylsulfate and Diethylsulfoxide in Water

The aqueous mixtures of sodium dodecylsulfate (SDS) and diethylsulfoxide (DESO) have been studied using conductivity, viscosity and surface tension techniques. The critical micellar concentration (cmc) was determined in the presence of DESO at 30, 40, and 50 C from conductance and surface tension measurements. The enthalpy ( G_m), entropy ( S_m) and Gibbs energy ( G_m) of micellization were determined from the temperature dependence of the cmc. The results obtained were compared with published results for aqueous solutions of SDS and dimethylsulfoxide (DMSO). The data demonstrate a more pronounced inhibitory effect of DESO on the micellization of SDS, in comparison with the effect of DMSO. On the basis of the dependences of the relative viscosities on concentration, as given by the Jones–Dole semi-empirical equation, the B-coefficients have been calculated for the post-micelle composition region.     

Study of Interactions and Association Thermodynamics Between Sudan Red and Sodium Dodecyl Sulfate in Microemulsions

The absorption spectrum of Sudan red III (SR) in oil solutions and a series of O/W microemulsion with surfactant sodium dodecyl sulfate (SDS) has been determined by the UV-Vis spectrophotometer. We found that an association interaction existed between the stain SR and anionic surfactant SDS in water/mixed oil/SDS microemulsions. By measuring the absorbance of Sudan red in a series of microemulsions which has different R values and using the appropriate association models to analyze the experimental data, we obtain the association constants of SR and SDS, and the values of thermodynamics functions of associationΔ_r G _m has also been calculated from the association constants.     

CnNCl和SDS在水溶液中的相互作用

CnNCl和SDS在水溶液中的相互作用;滴定式微量热法; 烷氧基羟丙基三甲基氯化铵; 十二烷基硫酸钠;胶束;疏水作用     

Influence of Glycerol and Temperature on the Phase Behavior and Micellization of CTAB and SDS in Aqueous Solutions

In this work the micellization of sodium dodecylsulfate (SDS) and cetyltrimethyammonium bromide (CTAB) in water-glycerol mixed solvent have been investigated at 25, 35, and 45°C, respectively. The micellization of both surfactants in pure water at different temperatures has also been studied. The phase diagrams of the surfactants in water-glycerol mixed solvent were also established. From the conductivity measurements, the critical micelle concentration (CMC) and the degree of counterion dissociation (β) were obtained as a function of glycerol-water ratio and temperature. Standard free energy of micellization (ΔG°_mic) as a function of glycerol contents and temperature was calculated and discussed. It has been found that the micellization of the two surfactant in solutions with glycerol at 25°C and in pure water at higher temperatures are not the same although they have equal dielectric constants values.     

Phase Behavior and Dielectric Spectroscopy of the Sodium Dodecyl Trioxyethylene Sulfate／n－Butanol／Water System

Introduction　　Itiswellknownthatsurfactantsinanaqueoussolu tioncouldformmicellesataconcentrationhigherthanthecriticalmicelleconcentration (cmc) .Knowledgeofalcoholsolubilizationinaqueousmicellesolutionsisimportantinunderstandingtheaggregationbehaviorofsuchsystemsandisrelevanttoseveralindustrialprocesses .1Manystudieshavebeenreportedonphasebehaviorofternarysystemsofionicsurfactant,alcohol,andwater.2 7Generally ,inthecaseofshortchainalcohol,atransparent,isotropic ,andlow viscosityphaseappearse…     

十二烷基硫酸钠诱导Rhodobacter azotoformans外周捕光复合体LH2 B800细菌叶绿素特异性解离

采用吸收光谱法研究了十二烷基硫酸钠(SDS)诱导Rhodobacter azotoformans外周捕光复合体LH2 细菌叶绿素(bacteriochlorophylls, BChls)的解离行为和规律. 结果表明: 室温下, 在10 mmol•L^－1 Tris-HCl (pH 8.0)缓冲液中, 低浓度SDS只诱导LH2中B800 细菌叶绿素解离生成游离BChls, 而B850不受影响; 当浓度达到0.08% (w/V) 时, 能特异性地诱导B800缺失, 其缺失过程和游离BChls的生成过程均符合单指数模型, 且二者的速率常数近似相等. 高浓度SDS能同时诱导B800和B850解离生成游离BChls, 其中B800可发生缺失, 而B850则不完全解离, 解离过程均符合单指数模型; B800对SDS更敏感, 其解离速率常数约是B850的4倍, 游离BChls生成速率常数明显低于B800解离速率常数, 而与B850解离速率常数相接近.