基于液液非均相的离散相润湿性能影响分析

多层斜板重力沉降分离器分离液液非均相物系过程中，离散相与接触壁面的润湿特性对分离效率有明显的影响。利用可视化与图像后处理技术，实验研究了水下环境中配比不同碘质量分数的CCl₄油滴与3种常用板材的润湿性能。结果表明：聚甲基丙烯酸甲酯(PMMA)和不锈钢为水下亲油表面，玻璃为水下疏油表面。水下油滴含杂质质量分数相同的条件下，与玻璃表面的接触角较大，PMMA和不锈钢表面接触角接近。随着油滴含杂质质量分数的增加，水下油滴在PMMA表面的接触角增大，润湿时间增加；在玻璃表面接触角减小，润湿时间基本不变；3种材质表面滑动角均呈现减小趋势。该研究对液相环境下离散相油滴在壁面上润湿性能提供基础数据，为相关设备的选材和角度设计提供优化设计方案。     

生物柴油浸没喷吹的雾化特性

以生物柴油替代柴油进行浸没喷吹熔池熔炼是发展低碳铜冶炼的重要途径。针对该过程建立生物柴油浸没喷吹雾化流动过程计算模型,本文模拟计算了喷枪在水模型中浸没深度为20mm时不同油气比条件下生物柴油雾化颗粒的雾化特性,并实验验证了计算模型。研究结果表明：油滴颗粒的贯穿距随着空气流速的增加而增大;在气泡内油滴颗粒以一定的雾化半角向前扩散;当油滴颗粒到达气泡底部时,油滴颗粒以气泡底部平面为中心向整个空间扩散;气泡内距离喷枪轴向越远的观察面内大颗粒数目越多;油滴颗粒的索特平均直径（SMD）沿喷枪轴向先增大后减小;气泡内距喷枪口越远油滴颗粒SMD越大,进入水区域的油滴颗粒SMD逐渐减小;雾化空气流速越大,油滴颗粒SMD最大值的位置距喷口越远。     

表面疏水改性促进煤系黏土矿物沉降的机理及试验研究

针对选煤厂高泥化煤泥水难沉降的现状，以煤系黏土矿物为研究对象，探索了絮凝剂聚丙烯酰胺(PAM)分别与十二烷基三甲基溴化铵(DTAB)、十六烷基三甲基溴化铵(CTAB)配合使用后黏土矿物沉降规律，并通过聚团影像观测、XPS分析、润湿热和接触角测定及Zeta电位试验，半定量分析了PAM分别与DTAB、CTAB配合使用，促进黏土矿物沉降的作用机理。结果表明：DTAB和CTAB的添加能够促进黏土矿物颗粒生成大聚团，进而提高黏土矿物颗粒初始沉降速度，并大幅度降低上清液浊度，且CTAB作用效果优于DTAB作用效果；当CTAB用量为1 800 g/t、PAM用量为80 g/t时，矿物质悬浮液沉降效果较好，对应矿物颗粒初始沉降速度为43.32 m/h,浊度值为76 NTU,沉淀物高度为19 mm,聚团直径最大约为2.6 mm;通过XPS及矿物表面润湿性测试，发现阳离子表面活性剂与矿物表面作用，活性剂带正电荷的亲水基朝向带负电荷的矿物颗粒表面，通过“电中和”作用降低矿物颗粒表面负电位，使矿物颗粒间静电斥力减小，同时，活性剂疏水基脱离矿物颗粒表面定向排列，罩盖矿物颗粒表面含氧基团而增加矿物颗粒表面含碳基团...     

Wood液态合金在NaOH溶液中的电化学反应及表面张力变化行为

通过改变液体金属在NaOH溶液中所处的环境介质,利用石墨电极对其施加电场,研究了液态金属的表面张力、界面电化学反应、氧化膜的产生、溶液中电润湿等动态过程。实验发现Wood合金液滴在阳极发生电化学反应产生的氧化膜会迅速减小表面张力并发生铺展,在阴极发生还原反应会使带氧化膜的金属在3 s内恢复到原状,电毛细作用力使氧化膜破裂,各氧化物与NaOH反应产生Sn（OH）₆^2-、SnO₃^2-、SnO₂^2-、PbO₃^2-、Cd（OH）₄^2-使溶液的颜色发生改变,溶液中生成Bi₂O₃-Bi（OH）₃白色共聚物。薄膜电介质层润湿和溶液中电润湿机理在本质上相同,表面张力随着电压的增大而减小并发生明显的电润湿铺展过程,但由于金属液滴通过电化学反应所能吸附的OH^-数量有限,润湿角存在饱和性。     

纳米管表面和自润湿溶液相耦合的传热性能

采用阳极氧化法在光滑钛板表面制备了高度有序的纳米管表面，利用扫描电镜、原子力显微镜和全自动接触角测量仪表征了纳米管表面和光滑表面的形貌及表面特性，配制自润湿溶液并进行热物性测定，将不同的加热面(光滑表面和纳米管表面)与不同工质(蒸馏水和自润湿溶液)组合进行池沸腾实验，从不同角度对比了不同组合工况的传热效果，从微观和宏观两方面对纳米管表面和自润湿溶液耦合强化传热的机理进行了分析。结果表明，具有超亲水性和较大粗糙度的纳米管表面与自润湿性溶液耦合时，最大传热系数和临界热流密度较高，分别为11.963 kW/(m2?℃)和623.706 kW/m2，比光滑表面与蒸馏水的常规组合传热分别提高了84.1%和143.8%。纳米管表面和自润湿溶液对系统的最大传热系数和临界热流密度强化作用稍有不同，二者协调强化沸腾传热性能。纳米管表面具有更多的有效汽化核心、更大的粗糙度和更好的润湿性，结合自润湿溶液特殊的表面张力特性形成冷热液体微循环，促进冷热液体运动，及时进行二次润湿，大幅减小气泡脱离直径，提高其脱离频率，出现微气泡，增加了对系统的扰动，有效增强了传热性能，是提高系统最大传热系数和临界热流密度的主要原因。     

葡萄糖酰胺季铵盐表面活性剂的合成与性能

以葡萄糖酸内酯、N, N-二丁基-1, 3-丙二胺和溴代烷为原料，采用先胺酯反应、后季铵化两步法合成了系列葡萄糖酰胺季铵盐表面活性剂（CnDGMAPB，n=8、10、12、14、16)。采用FTIR、1HNMR和13CNMR对中间体和产物结构进行了鉴定，并对其表面活性、润湿性能、乳化性能、泡沫性能和产品毒性等性能进行研究。结果显示，CnDGMAPB具有较好的表面活性，随着碳链的增长，临界胶束浓度（cmc）和分子截面积（Amin）逐渐减小，表面活性效率（pC20）和饱和吸附量（Гmax）逐渐增大，表面张力（γcmc）在28~32 mN/m之间。在考察浓度（0.01-5 mmol/L）范围内，C12DGMAPB和C16DGMAPB溶液与聚四氟乙烯膜（PTFE）的接触角降低到47o，此类糖基酰胺季铵盐具有较好的润湿和乳化性能。5 min时泡沫体积都很小，属于典型的低泡型产品。细胞毒性和急性经口毒性实验均显示，此类葡萄糖酰胺季铵盐表面活性剂为低毒产品。当C12DGMAPB质量浓度在0.2 g/L时，对大肠杆菌和金黄色葡萄球菌的抑菌率都能达到100%，对皮肤无刺激，具有较好的抗静电性能。     

含气泡油滴撞击矩形沟槽壁面的数值分析

采用耦合水平集-体积分数（CLSVOF）方法对含气泡油滴撞击矩形沟槽壁面现象进行数值模拟研究,考察了油滴撞击壁面后的形态演化过程,分析了中心射流形成机理和气体夹带的分布规律,并探究了沟槽宽度、沟槽深度和撞击位置对油滴铺展特性的影响。研究表明：含气泡油滴在矩形沟槽壁面铺展时会形成中心射流,沟槽内部存在气体夹带现象。气泡底部的速度旋涡是形成中心射流的主要原因,沟槽内的气体夹带受油滴铺展速度影响呈现规律性分布。沟槽宽度对含气泡油滴在垂直沟槽方向和平行沟槽方向的铺展长度影响较大,但对铺展高度影响较小。当无量纲沟槽宽度为0.3时,油滴形成颈部射流并在运动后期使垂直沟槽方向的铺展长度迅速增加。此外,沟槽深度也对含气泡油滴在各方向的铺展有重要影响,沟槽深度越大,中心射流现象越难形成。撞击位置变化不改变油滴在沟槽壁面上的运动演化过程,但对沟槽内部的气体夹带规律有一定影响。     

驱油剂对三元复合驱含油污水中油滴稳定性的影响

三元复合驱技术已在大庆油田成功进行工业化应用。三元复合驱含油污水中由于含有残余的化学药剂，导致其很难处理，从而限制了三元复合驱技术的推广。本文首先采用室内实验制备模拟三元复合驱含油污水，然后通过沉降实验研究驱油剂对油滴稳定性的影响，最后结合驱油剂对油水界面张力、油滴Zeta电位、油滴粒径大小的影响来阐释驱油剂对油滴稳定性的作用机制。结果表明：油滴的稳定性随着NaOH浓度的增大先增大后减小，当NaOH浓度由0增大到400mg/L时，NaOH与原油中的酸性物质反应生成表面活性剂增强油滴的稳定性；当NaOH浓度大于400mg/L时，NaOH本身作为电解质压缩双电层，使油滴的稳定性减小。油滴的稳定性随着表面活性剂浓度的增大而增大，这是因为表面活性剂可以吸附在油滴表面，使油水界面张力减小，同时增大油滴表面的Zeta电位，从而使油滴的稳定性增强。油滴的稳定性随着聚合物浓度的增大先减小后增大，当聚合物的浓度小于300mg/L时，聚合物的桥接、絮凝作用起主导作用，聚合物分子可以吸附到油滴表面，将油滴连接到一起，同时聚合物分子可以压缩液滴表面的双电层，从而有利于油滴的聚结；当聚合物的浓度大于300mg/L时，体系的黏度增大，油滴的运动速度减小，此时聚合物分子占满油滴表面，表现出空间位阻作用，从而使油滴的稳定性增强，不利于油滴的聚结。     

对《表面活性剂 湿润力的测定 浸没法》化工行业标准的说明

HG／T2575一94（表面活性剂润湿力的测定浸没法》自1994年10月实施以来，各方面反映良好。但从获悉的贯彻标准的情况看，有些单位对“润湿时间一浓度曲线”的绘制等有不甚明了之处。由于“润湿力”（原称为渗透力）是表面活性剂类产品的比较重要的理化指标之一，为更好地推进标准的实施，本文针对上述问题将标准的一些重点内容和技术细节介绍如下。1修订标准的目的我所曾于1985年参照DIN53901—76·1《表面活性剂溶液润湿能力的测定》的原理制定了GB5557一85（表面活性剂纺织助剂渗透力测定润湿法。。该标准为从事表面活性剂产品生产的…     

低电导率工质中气泡的极化运动实验研究

为探讨电场作用下气泡在低电导率工质中的极化运动特性,采用高速数码摄像技术对气泡在正庚烷溶液中的生长和分散过程进行了可视化研究,并结合无量纲数分析了不同气体流量和施加电压下的气泡演变特征以及极化力主导的气泡运动规律。结果表明,增大电场强度可导致气泡生长周期缩短,气泡尺寸显著减小,产生频率加快。在低电场强度下,气泡运动主要表现为流体动力学特性;而在强电场作用下,气泡首先受极化力主导而表现为电流体动力学特性,其直线轨迹高度随Bo_E增大而增大。但随着电场强度在竖直方向上的衰减以及液相阻力影响,气泡运动速度不断减小;当气泡脱离极化力主导区域后,其运动再次表现为流体动力学特性,受尾迹诱导和气泡间相互作用影响,气泡在竖直方向上沿毛细管轴向四周扩散。     

Surface activity of mixtures of dodecyl trimethyl ammonium bromide with sodium perfluorooctanoate and sodium octanoate

In this study, the surface tension of mixtures of cationic surfactant dodecyl trimethylammonium bromide (DTAB) and anionic surfactant sodium perfluorooctanoate (SPFO) was evaluated as a function of DTAB-SPFO composition and total surfactant concentration, with and without added electrolyte. It was found that the critical micelle concentration (CMC) of these mixtures was reduced by more than two orders of magnitude when compared to the CMC of SPFO and DTAB alone. The surface tension, after CMC, of the mixtures was close to that of SPFO with added electrolyte and even lower than that of SPFO without added electrolyte. Using the appropriate, combination of SPFO and DTAB, surface tensions near 18 mJ/m² were obtained using a concentration 1/500 of that required for SPFO alone. When these results were compared to those obtained for DTAB-sodium octanoate (SOCT) mixtures, it was evident that the DTAB-SPFO system shows a larger degree of synergism than the DTAB-SOCT system. Contact angle measurements on Teflon^® surfaces corroborates that the lower surface tension of DTAB-SPFO mixtures improves wetting on these hydrophobic surfaces. Using the regular solution theory to interpret the data of CMC and C45mJ/m² (monolayer formation) versus DTAB-SPFO composition, it was concluded that even when small concentrations of SPFO are introduced in the mixture, the composition of the micelles (at the CMC) and monolayer adsorbed at the air-water interface tends to be equimolar in SPFO and DTAB.     

阳离子型双子表面活性剂的合成及表面活性

合成了一种季铵盐型双子表面活性剂Gem in i 12-3-12,采用红外光谱、元素分析和两相滴定法对其结构和纯度进行了分析,测定了不同浓度表面活性剂水溶液的表面张力,并得到临界胶束浓度(CMC)、饱和吸附量(Γm ax)、单分子饱和吸附面积(Am in)。结果表明,Gem in i 12-3-12的收率为77.2%,纯度为98.4%,它与相应的单尾基十二烷基三甲基溴化铵(DTAB)的表面活性相当,但CMC比DTAB低14倍左右。     

The study of Sunset Yellow anionic dye interaction with gemini and conventional cationic surfactants in aqueous solution

In the present study, the interaction of an anionic azo dye, Sunset Yellow, with two cationic gemini surfactants with different spacer lengths (s = 3, 6 methylene groups) and their monomeric counterpart, dodecyl trimethyl ammonium bromide (DTAB), was investigated by surface tension, UV–Vis spectroscopy, and zeta potential measurements. The critical micelle concentration (CMC) was determined from plots of the surface tension (γ) as a function of the logarithm of total surfactant concentration. Moreover, the values of binding constants (K_b) of dye-surfactant complexes were calculated by UV–Vis spectroscopy. The UV–Vis spectra showed that the dye–surfactant interaction occurred in the solution at concentrations far below the CMC of each surfactant. The gemini surfactant with a shorter spacer showed stronger interaction with dye in comparison to DTAB and the gemini with longer spacer. The effect of surfactant chemical structure on solubilization of dye-surfactant aggregates at surfactant concentration above CMC was investigated by zeta potential.     

静止非牛顿流体中气泡生成过程的传质

气泡生成过程中气液传质是气液接触设备的设计、优化的重要参考指标。以二氧化碳气泡在羧甲基纤维素钠(carboxymethyl cellulose,CMC)溶液中生成过程中的传质为研究对象,分别考察了气速、CMC溶液浓度、针头直径对气泡生成过程气液传质的影响,采用具有CCD显微相机的动态接触角分析仪测量了气泡形状、表面积和体积的变化,进而获得气泡生成过程气液传质系数k_l。实验结果表明,CMC浓度从0.2%增加到0.8%,黏度逐渐增大,传质系数随CMC浓度的增大而增大;针头直径从2.5 mm增加到4 mm,传质系数也随之增大;气速从1 ml·min^-1增加到9 ml·min^-1,传质系数也逐渐增大。     

Interfacial Dynamic Properties and Dilational Rheology of Sulfonate Gemini Surfactant and its Mixtures with Quaternary Ammonium Bromides at the Air–Water Interface

The dynamic interfacial properties and dilational rheology of gemini sulfonate surfactant (SGS) and its mixtures with quaternary ammonium bromides (DTAB, CTAB) at the air–water interface were investigated using drop shape analysis. Results suggest that the adsorption process of these surfactants is diffusion-controlled at dilute concentrations, whereas the adsorption mechanism gradually shifts to a mixed kinetic-diffusion control with increasing surfactant concentration. The mixed surfactant system possesses the best surface activity when the molar ratios of SGS/DTAB and SGS/CTAB mixtures are 9:10. The formation of catanionic complexes shields the electrostatic repulsion between surfactant molecules and lowers the electrostatic adsorption barrier. Therefore, SGS/DTAB and SGS/CTAB mixtures exhibit higher adsorption rates than either component alone. The effects of oscillating frequency and surfactant concentration on the surface dilational properties of SGS, DTAB, CTAB, SGS/DTAB, and SGS/CTAB mixtures were also determined. As the oscillating frequency increases, the dilational elasticity of these surfactants gradually increases. The dilational elasticity peaks at a certain concentration, which is less than the critical micelle concentration (CMC). Results show that the dilational elasticity of SGS/DTAB and SGS/CTAB mixtures is higher than that of either component, resulting from the formation of a denser monomolecular adsorption layer at the air–water interface. Our study provides a basis for understanding the interaction mechanism of catanionic surfactant mixtures containing Gemini surfactant at the air–water interface.     

Aggregation and Adsorption Behavior of Cationic Surfactants (Cetyltrimethylammonium Bromide and Dodecyltrimethylammonium Bromide) in Aqueous Solutions of Antibiotic Drug (Amikacin Sulphate) at Different Temperatures

Conductivity and spectroscopy techniques have been accomplished to comprehend the mechanism of supramolecular assembly of cetyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium bromide (DTAB) in aqueous solution of amikacin sulphate (0.001, 0.005, and 0.010 mol kg⁻¹). For CTAB, the normal boost of the CMC value with rise in temperature manifests the significant role of aquaphilic dehydration. However, the aquaphobic dehydrations become prominent with temperature and depict typical U-shaped behavior of CMC for DTAB. The thermodynamic parameters of micellization have been derived from CMC values. The outcomes have been conferred in terms of solvation of hydrophobic part of surfactants by hydrophobic part of amikacin sulphate and micellization becomes more favorable for surfactant with more hydrophobic character in the presence of drug. The alteration in micro-environment of the ternary (drug/surfactant/water) system has been explained in terms of fluorescence emission intensity of surfactant solutions which has been found to decrease by the addition of drug. The obtained absorbance spectrum by varying concentrations of surfactant/drug affords noteworthy information regarding the diverse interactions in studied systems. Moreover, the exhaustive understanding of surfactant micellar behavior have been discussed in consideration of use of surfactants as drug delivery agents and hence to amplify drug bioavailability consequently remodeling its treatment efficacy.     

Numerical study on hydrodynamic characteristics of spherical bubble contaminated by surfactants under higher Reynolds numbers

It is of significance to investigate deeply the hydrodynamic features of the bubble contaminated by impurities in view of the fact that the industrial liquid is difficult to keep absolutely pure. On the basis of the finite volume method, the bubble interface contaminated by the surfactant (1-pentanol) is achieved through solving the concentration transport equations in liquid and along the bubble interface, and solving the absorption and desorption equation at the bubble interface. And the three-dimensional momentum equation is solved at the same time. It is investigated in detail on the influence of interfacial contamination degrees (described with the cap angle θ) on hydrodynamic characteristics of the spherical bubble when the bubble Reynolds number (Re) is larger than 200. The θ is realized by changing the surfactant concentration (C₀) in liquid. The present results show that the hydrodynamic characteristics, such as interfacial concentration, interfacial shear stress, interfacial velocity and wake flow, are related to both Re and C₀ for the contaminated bubble. When C₀ is relatively low in liquid (i.e., the contamination degree of the bubble interface is relatively slight), the hydrodynamic characteristics of the bubble can still keep the 2D features even if Re > 200. The decrease of θ or the increase of Re can promote the appearance of the unsteady wake flow. For the present investigation, when Re > 200 and θ ≤ 60°, the hydrodynamic characteristics of the bubble show the 3D phenomena, which indicates that axisymmetric model is no longer valid.     

Effect of Electrolyte and Temperature on Volatile Organic Compounds Removal from Wastewater Using Aqueous Surfactant Two-Phase System of Cationic and Anionic Surfactant Mixtures

Abstract

Benzene, toluene, ethylbenzene, and xylene are frequently observed contaminants in industrial wastewaters causing concerns about environmental and health effects. An aqueous surfactant two-phase (ASTP) extraction system using mixtures of cationic and anionic surfactants have been shown to be a promising surfactant-based separation technique to concentrate solutes such as proteins and dyes from aqueous solution. A phase separation of a surfactant solution occurs at certain surfactant compositions and concentrations, forming two isotropic phases. One is rich in surfactant aggregates (surfactant-rich phase) and the other is lean in surfactant aggregates (surfactant-dilute phase). Most of the organic contaminants tend to solubilize and concentrate in the surfactant-rich phase, leaving the surfactant-dilute phase containing only small amounts of contaminants as remediated water. The effect of NaCl addition on the critical micelle concentration (CMC) and the extraction ability of ASTP formed by mixtures of cationic surfactant (dodecyltrimethylammonium bromide; DTAB) and anionic surfactant (alkyl diphenyloxide disulfonate; DPDS) at 50 mM total surfactant concentration with a 2:1 molar ratio of DTAB:DPDS was investigated; the CMC of the mixture slightly decreases with increasing NaCl concentration. The extraction and preconcentration of benzene are greatly enhanced by added NaCl. The higher the degree of hydrophobicity of contaminants, the greater the extraction into the surfactant-rich phases. At 1.0 M NaCl addition, about 95% of xylene, 92% of ethylbenzene, 90% of toluene, and 79% of benzene are extracted into the surfactant-rich phase within a single stage extraction and the contaminant partition ratios can be as high as 395 for xylene, 273 for ethylbenzene, 206 for toluene, and 84 for benzene, which are greater than those obtained from the conventional ASTP extraction system using nonionic surfactants.     

MD膜驱剂与阳离子表面活性剂混合体系的胶束性质

通过电导率法测定临界胶束浓度(CMC),研究了MD膜驱剂的浓度、温度及不同无机盐对MD膜驱剂与十二烷基三甲基溴化铵(DTAB)混合体系CMC的影响。研究表明:MD膜驱剂与DTAB混合后,可降低DTAB的CMC,并且CMC随着MD膜驱剂浓度的增加而减小。温度从25℃升高到50℃时,4 mmol/L MD膜驱剂/DTAB混合体系的CMC增大。无机盐的加入有利于混合体系CMC的降低,相同价态的阴离子对CMC的影响相近,高价阴离子降低CMC的效果好于低价阴离子。     

COMPREHENSIVE STUDY OF THE GAS HOLD UP AND BUBBLE SIZE DISTRIBUTION IN HIGHLY VISCOUS LIQUIDS II. CMC SOLUTIONS

Following properties of short bubble columns employing CMC solutions (1.0, 1.4 and 2.0%) and perforated plates (0.5, 1.0 and 3.0 mm hole diameters) were determined: relative mean gas hold up, E_G, bubble size distribution, Sauter bubble diameter, d_s, and the specific geometrical bubble surface areas, a' and a' due to the “intermediate to large bubbles.” The a' values were compared with the corresponding volumetric mass transfer coefficients, k_La's and the mass transfer coefficients, k_L, were estimated. The properties of these systems were investigated as function of the superficial gas velocity, W_SG, CMC concentration and aerator type.