新型树枝状非离子表面活性剂的温度与盐效应研究

以3.0代聚酰胺-胺(PAMAM G-3.0)为起始剂,合成了一种新型树枝状非离子表面活性剂。通过表面张力与稳态荧光法研究了其在水溶液和无机盐溶液中的表面性质与聚集行为,并考察了温度对其性质的影响。结果表明,随着温度的升高,表面活性剂的表面张力逐渐降低,但在研究的温度范围内,临界胶束浓度(CMC)的变化不大。当加入质量浓度为1.0%的NaCl、NaBr及Na2SO4时,均使其表面张力增大;而3种无机盐的加入,对表面活性剂CMC的影响不大。     

不同类型的离子表面活性剂对甲苯的增溶作用

通过电导法测定SDBS、CTAB、FMES 3种离子表面活性剂水溶液在25,30,35℃时的临界胶束浓度(CMC),并依据CMC和范特霍夫方程计算了3种体系下的ΔH■、ΔS■和ΔG■,测定无机盐(NaCl、Na_2SO_4)和有机物(乙醇、十二醇)对表面活性剂增溶甲苯的影响。结果表明,3种体系下ΔG■均为负,这说明3种表面活性剂在水溶液中均易于形成胶团;3种离子表面活性剂的CMC大小顺序与对甲苯溶解量的大小顺序不同,说明CMC大小并不是影响甲苯增溶的唯一因素;添加一定量有机物[n(乙醇)∶n(FMES)=1∶4]或者无机盐(0.2 mol/L浓度的NaCl)对甲苯增溶效果更好。     

不同类型的离子表面活性剂对甲苯的增溶作用

通过电导法测定SDBS、CTAB、FMES 3种离子表面活性剂水溶液在25,30,35℃时的临界胶束浓度(CMC),并依据CMC和范特霍夫方程计算了3种体系下的ΔH■、ΔS■和ΔG■,测定无机盐(NaCl、Na_2SO_4)和有机物(乙醇、十二醇)对表面活性剂增溶甲苯的影响。结果表明,3种体系下ΔG■均为负,这说明3种表面活性剂在水溶液中均易于形成胶团;3种离子表面活性剂的CMC大小顺序与对甲苯溶解量的大小顺序不同,说明CMC大小并不是影响甲苯增溶的唯一因素;添加一定量有机物[n(乙醇)∶n(FMES)=1∶4]或者无机盐(0.2 mol/L浓度的NaCl)对甲苯增溶效果更好。     

Tween20/40的CMC测定及NaCl的影响

以高浓度碘的水溶液作为显色剂,用紫外吸收分光光谱法测定非离子表面活性剂Tween20和Tween40的临界胶束浓度（CMC）分别为519×10-5 mol/L和190×10-5 mol/L,再采用黏度法测定这2种表面活性的CMC分别为500×10-5 mol/L和193×10-5 mol/L,并研究了不同浓度的NaCl溶液对临界胶束浓度和黏度的影响。结果表明黏度法的测定结果与文献基本接近。当体系中存在NaCl溶液时,CMC值基本无变化,而溶液的相对黏度随着盐的浓度增大呈下降趋势。当NaCl为定值时,体系的相对黏度呈现先增加,在CMC之后,体系黏度基本保持不变。 关键词：分光光度法;黏度;临界胶束浓度     

基于酪氨酸的Bola型表面活性剂的合成及胶束化行为研究

用L-酪氨酸和1,12-二氨基十二烷合成了Bola型表面活性剂1,12-二酪氨酸基十二烷基二胺盐(DADT),用1HNMR对其结构进行了表征。通过电导率法和等温滴定量热法结合三维荧光光谱法考察了DADT在水溶液的自聚集行为。结果表明,其临界胶束浓度(CMC)为0.16 mmol/L左右,随温度升高,CMC值逐渐增大;随离子强度增强,CMC值明显降低。同时,DADT具有荧光信号,在浓度低于0.18 mmol/L时,荧光强度随浓度的增大而增大,当浓度增大到0.18 mmol/L时,由于发生自聚集导致荧光猝灭,从而荧光强度随浓度的增大而减小。研究还发现,DADT分子自身荧光猝灭浓度与其临界胶束浓度一致,为研究其胶束化行为提供了一种简便方法。     

Gemini表面活性剂溶液的胶束聚集数研究

以芘为荧光探针、二苯甲酮为猝灭剂,用稳态荧光探针法测定了系列阴离子型Gemini表面活性剂的胶束聚集数（Nm）。以芘的饱和水溶液为溶剂配制表面活性剂溶液,二苯甲酮的适宜浓度取小于1.00 mmol/L时,可以获得满意的实验结果。当表面活性剂溶液浓度为5～10倍cmc时,Nm随表面活性剂浓度增大而线性增大,而随温度的变化略有波动。Cs=CMC时,Nm值为一本征值,定义为临界胶束聚集数[Nm]。[Nm]值可从Nm～Cs实验曲线外延得到。     

烷基酚聚氧乙烯醚羧甲基钠盐的合成及其表面活性

以烷基酚聚氧乙烯醚为原料 ,采用氯乙酸法合成一种非离子—阴离子型表面活性剂烷基酚聚氧乙烯醚羧甲基钠盐NPC(Na)—n(n =2 ,7,10 ,15 ) ,并通过正交实验得到了该合成方法的最佳工艺条件。利用表面张力法研究了烷基酚聚氧乙烯醚羧甲基钠盐的有关表面化学特性 ,EO数增大时 ,临界胶团浓度CMC、表面饱和吸附量Гmax及反离子结合度K0 均减小 ,而γCMC增大 ;加入NaCl可使NPC(Na) -n的CMC、γCMC显著减小 ,该表面活性剂具有较好的抗盐性能     

季铵盐型Gemini表面活性剂G12对纳米P(St-BA)乳液性能的影响

自制新型Gemini阳离子表面活性剂G12,通过电导法确定其临界胶束浓度(CMC)比对应的传统表面活性剂如十二烷基三甲基溴化铵的CMC低接近一个数量级,且随温度的升高而增大;以G12为乳化剂,在偶氮二异丁基脒盐酸盐(AIBA)的作用下,制备了纳米阳离子型苯乙烯—丙烯酸丁酯聚合物乳液,分别考察了G12用量、聚合温度、引发剂用量对乳液性能的影响。结果表明,乳胶粒子的粒径随聚合温度的升高逐渐减小、随G12用量和AIBA用量的增加而减小。当G12用量为2%、温度为75℃、AIBA用量为0.8%时制得的乳液性能最佳。     

无机盐对磺酸盐型双子表面活性剂溶液表面性能的影响

在(30±0.2)℃下,用直接观察法、表面张力法和旋转液滴法考察了不同无机盐(NaCl、CaCl2和MgCl2)对磺酸盐型双子表面活性剂DJ溶液溶解性、临界胶束浓度(CMC)值和界面张力的影响。结果表明,磺酸盐型双子表面活性剂DJ具有良好的抗盐性,溶解度可以达到20 000 mg/L以上;在低盐度范围时(小于500 mg/L),随着无机盐质量浓度的增加,表面活性升高,CMC降低;随着阳离子(Na+、Ca2+和Mg2+)价数的增加,CMC降幅增大,且Ca2+的影响程度大于Mg2+;在无机盐质量浓度达到10 000 mg/L时,CMC呈上升趋势;无机盐的加入使溶液界面张力先降后升,然后趋于平稳。无机盐质量浓度在100～1 000 mg/L内,磺酸盐型双子表面活性剂DJ溶液的界面张力可以达到最低。     

表面张力法探究温度对表面活性剂临界胶束浓度的影响

临界胶束浓度是表面活性剂的一个重要性质。本文用表面张力法测定了非离子型表面活性剂的临界胶束浓度。结果表明,随着温度升高,非离子型表面活性剂的临界胶束浓度反而会降低。对温度影响表面活性剂临界胶束浓度的机理进行了初步分析。     

Surfactant precipitation in aqueous solutions containing mixtures of anionic and nonionic surfactants

The salinity tolerance (precipitation phase boundary) is measured for a mixed anionic/nonionic surfactant system above the CMC. For any total surfactant concentration, the salinity tolerance is shown to increase as the percentage of nonionic surfactant in the system is increased. A model is developed which can predict the phase boundaries for the mixed surfactant system from the pure anionic surfactant phase boundary and information about mixed micelle formation. In the model, precipitation is viewed as a solubility product relationship between the anionic surfactant monomer and the total unassociated counterion. The reason that salinity tolerance (or counterion concentration necessary to cause precipitation) increases with addition of nonionic surfactant is that mixed micelle formation reduces the anionic surfactant monomer concentration. For the experimental studies, sodium dodecyl sulfate is the anionic surfactant, a polyethoxylated nonylphenol is the nonionic surfactant, and sodium chloride is the added salt.     

Properties of aqueous solution of sodium cyclododecyl sulfate

Sodium cyclododecyl sulfate was prepared from cyclododecyl alcohol and chlorosulfonic acid to investigate the physical and surface active properties of the surfactant. Its Krafft point, critical micelle concentration (CMC), surface tension, emulsifying power, wetting time and dispersing power were examined and compared with those of sodium dodecyl sulfate which has a linear structure and contains the same number of carbon atoms in the hydrophobic portion. The sodium cyclododecyl sulfate, in contrast to the sodium dodecyl sulfate, had a higher (about two times) Krafft point, much larger (about 10 times) CMC, showed the same excellent wetting property, but exhibited lower emulsifying power. Also the sodium cyclododecyl sulfate is more insoluble (as shown by the Krafft point) than the sodium dodecyl sulfate, while calcium ion stability of the cyclododecyl sulfate surfactant is greater than that of the linear anionic surfactant.     

温度及无机盐对LMEE和SDS混合溶液表面张力的影响

通过表面张力的测定,研究了温度和不同无机盐对月桂酸甲酯乙氧基化物(laurylmethylesterethoxylate,简称LMEE)与十二烷基硫酸钠(SDS)复配物表面张力及临界胶束浓度(CMC)的影响。研究表明:混合体系的CMC在很宽的复配比例内出现最低值,25℃、未加无机盐时可使CMC最低降至3 8×10-5mol/L;温度对复配体系表面张力的影响较小,温度上升复配物的CMC略有降低。3种价态无机盐的加入均可使复配物的CMC有所降低,但与单一表面活性剂相比,温度和无机盐对复配物的CMC影响均不大,说明复配体系的抗温变及抗盐能力均有增强。     

Determination of critical micelle concentration of surfactant by ultraviolet absorption spectra

A method was investigated for determining the critical micelle concentration (CMC) by the shift of absorption maxima when an organic compound (I) with ultraviolet absorption was added to an aqueous solution of a surfactant. When I was added to the surfactant solution at higher concentrations (above the CMC), λ_max of I approached the value inn-octane, since I was solubilized in the hydrocarbon atmosphere of the inner part of the surfactant micelle. At lower concentrations (below the CMC), however, I was present in the water phase and λ_max approached the value in water. The curve of λ_max vs. surfactant concentration declined from the high concentration values as the CMC was approached and at the CMC, the curve broke upward sharply. Then, it rose for some time and approached the value in water. N,N′-diethylaniline was used because it exhibited larger shifts of λ_max. The standard amount used was 0.002 ml/3–10 ml of aqueous solution of the surfactant. The CMC values obtained agreed with those obtained by the electric conductivity method, dye adsorption method and light scattering method, for surfactants such as tetradecyldimethylbenzylammonium chloride, sodium dodecyl sulfate and polyoxyethylene cetyl ether.     

表面活性剂对气体水合物生成过程的定量影响

为确定HCFC?141b水合物生成条件下阴离子表面活性剂十二烷基硫酸钠(SDS)和十二烷基苯磺酸钠(SDBS)的临界胶束浓度(CMC),在0~20℃温度下,通过圆环法实验研究了不同浓度表面活性剂溶液体系的表面张力,考察了表面活性剂对溶液体系表面张力的影响机理并通过C3H8水合物的生成过程实验进行了验证,确定了SDS和SDBS的临界胶束浓度. 结果表明,当SDS和SDBS的质量浓度分别低于500?10?6和100?10?6时,表面活性剂降低水表面张力的效果最明显,二者的CMC分别为1950?10?6和400?10?6,表面活性剂能明显缩短水合反应的诱导时间,提高了其平均生成速率.     

分光光度法研究十二烷基硫酸钠的临界胶束浓度

在碘的水溶液和I<'-><,3>溶液2种体系中测定了十二烷基硫酸钠(SDS)的临界胶束浓度(CMC),并讨论了在I<'-><,3>体系中,不同硫酸钠和氯化钾2种盐对测定结果的影响,在碘的水溶液中研究了不同碘浓度对SDS的CMC的影响.采用分光光度法求得SDS在两种体系中的CMC值,硫酸钠与氯化钾对CMC的值有影响,且无...     

A Systematic Study of Mixed Surfactant Solutions of a Cationic Ester-Bonded Dimeric Surfactant with Cationic, Anionic and Nonionic Monomeric Surfactants in Aqueous Media

A novel cationic biodegradable dimeric (gemini) surfactant, ethane-1,2-diyl bis(N,N-dimethyl-N-hexadecylammoniumacetoxy) dichloride (16-E2-16), containing an ester-linked spacer was synthesized. Its pure and mixed micellization properties with monomeric surfactants cetyl trimethyl ammonium chloride, cetyl pyridinium chloride, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, cetyl alcohol ethoxylate (20EO) and tert-octylphenol ethoxylate (9.5EO) were investigated by surface tension measurements at 30 °C. The critical micelle concentration (CMC) of 16-E2-16 is well below that of cetyl trimethyl ammonium chloride containing the same number of carbon atoms in the hydrophobic tail per polar head. At different mole fractions of the gemini surfactant, the CMCs of the gemini-conventional binary mixtures were determined and were found to be less than the ideal CMC values in all the cases indicating synergistic interactions. Aggregation number and Stern–Volmer constant, obtained by the fluorescence quenching technique, also support the synergistic behavior of the surfactant systems.     

无机电解质对十二烷基硫酸钠性质影响的研究

选择不同类型的无机电解质(NaCl、Na2SO4、Na3PO4、MgCl2、AlCl3),考察了电解质对十二烷基硫酸钠(SDS)表面张力、临界胶束浓度、润湿力、发泡力、乳化力的影响规律。实验表明,无机电解质对SDS的CMC影响显著,随着无机盐的加入,CMC降低,表面活性增强。当加入的氯化钠浓度达到0.3mol/L时,SDS的CMC降到了原来的十分之一,高价位离子对CMC影响大于低价位离子,同价位不同离子影响差别不大;SDS润湿性、乳化性、泡沫性能较好,加入电解质后,其润湿性增强,乳化性、泡沫高度和稳泡性降低。     

Use of Foam Flotation to Remove tert-Butylphenol from Water

Abstract

The surfactants cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) were used in a study of an adsorptive bubble flotation process in batch mode to remove tert-butylphenol (TBP) from water. The TBP removal is maximized when the surfactant concentration is around the critical micelle concentration (CMC). Since micelles form above the CMC, this indicate that the higher the surfactant monomer concentration, the better the removal, but the micelles compete with the air/water interface for the TBP, resulting in micelles reducing removal efficiency. The addition of NaCl to the feed solution results in a significant reduction of the ability of CPC to remove TBP, while it improves the ability of SDS to remove TBP.     

A Generalized Theoretical Model for the Relationship Between Critical Micelle Concentrations,Pressure, and Temperature for Surfactants

Directional solvent extraction (DSE) has been gaining interest as a water treatment technology in recent years. DSE utilizes the process of micellization for the purposes of species separation between water and complex chemical systems. In this article, we develop a conformal geometric algebra-based formulation that models surfactants, their solubilities, and critical micelle concentration (CMC), with relation to temperature and pressure. Molecules are represented as spatially distributed networks embedded in R ^4,1 space, and the mathematical characterizations of these molecules are shown to be effective in modelling CMC as a function of temperature and pressure. One of the contributions of this work is the utilization of this formulation to develop a governing expression, in the form of a three-dimensional relationship, between CMC, pressure, and temperature for a general surfactant. In prior works, the CMC–temperature plane and CMC–pressure plane expressions have been extensively documented for sodium alkyl sulfates. In this work, we extend the formulation to model the CMC of decanoic acid, sodium octyl sulfate, sodium decyl sulfate, sodium dodecyl sulfate, and sodium tetradecyl sulfate. Using this theoretical model, a relationship between CMC and the directional solubility of water in a surfactant is determined. Directional solubility is related to temperature and pressure, and on this basis, we devise a directional solubility–pressure–temperature expression for an arbitrary surfactant to improve the state of the art for DSE. From this expression, we propose a novel isothermal DSE process for water treatment.