乙二亚甲基-双（十六烷基二甲基溴化铵）稀水溶液的特性

合成并表征了阳离子Gemini表面活性剂乙二亚甲基-α,β-双（十六烷基二甲基溴化铵）（16-2-16）.用表面张力和粘度法确定了其cmc，通过表面张力曲线计算了16-2-16的表面吸附量、吸附分子面积和胶束形成自由能；并用悬滴法测定了16-2-16在空气表面和十二烷界面的动态表（界）面张力.用改进的Washburn方法测定16-2-16水溶液在硅胶粉末表面的接触角，并进一步讨论了16-2-16在硅胶表面的吸附引起的润湿性变化. 探讨润湿性变化与动态张力的关系. 将16-2-16 与溴代十六烷基三甲胺(CTAB)做比较:两种物质在含油硅胶粉末上引起的最高脱油率（实验室模拟驱油）均发生在cmc附近,但16-2-16的最高脱油率是68％， CTAB的是63％.而所用CTAB的cmc比16-2-16的约大50倍,也就是说用16-2-16可以获得更高的脱油率.     

硅胶与高岭土的润湿性及荧光和驱油研究

利用Washburn方程测量固体粉末的润湿性,研究了十二烷基苯磺酸钠(SDBS)水溶液在硅胶及高岭土两种固体粉末表面上的接触角,用荧光猝灭法测定了SDBS在水溶液里的胶束平均聚集数。并由此探讨了十二烷基苯磺酸钠水溶液在固体粉末表面的润湿性,表面活性剂的临界胶束浓度(CMC)与表面含油粉末脱油率的关系。     

单分子链胶束的胶束化行为与相关新概念的提出

采用水溶液均聚合方法,制备了阳离子型表面活性单体（2-丙烯酰胺基）乙基十四烷基二甲基溴化铵（AMC14AB）的均聚物,使用荧光探针法、表面张力测定及电导测定法,重点考察了均聚物P（AMC14AB）在水溶液中的胶束化行为与表面吸附现象．在水溶液中,均聚物P（AMC14AB）呈现单分子链胶束的聚集形态,具有零临界胶束浓度（CMC=0）,从开始加入P（AMC14AB）起,水溶液中随即产生单分子链胶束,不存在Krafft温度．P（AMC14AB）在溶液表面也发生表面吸附,使水的表面张力下降,即P（AMC14AB）也具有表面活性;随着浓度增大,表面吸附量增大,水的表面张力持续下降;当表面吸附达到饱和时,表面张力一浓度曲线上出现突变点,该点应该定义为饱和的表面吸附浓度（SSAC）,而不应该再称为临界胶束浓度．P（AMC14AB）单分子链胶束溶液对疏水有机物（甲苯）的增溶情况,明显不同于普通小分子表面活性剂十六烷基二甲基溴化铵（CTAB）的多分子胶束溶液,甲苯增溶量-P（AMC14AB）浓度的关系曲线上无突变点,而且对甲苯的增溶能力高于CTAB的多分子胶束溶液．     

表面活性剂对驱油聚合物界面剪切流变性质的影响

利用双锥法研究了表面活性剂十二烷基苯磺酸钠(SDBS)和十六烷基三甲基溴化铵(CTAB)对油田现场用部分水解聚丙烯酰胺(PHPAM)和疏水改性聚丙烯酰胺(HMPAM)溶液的界面剪切流变性质的影响,实验结果表明:HMPAM分子通过疏水作用形成界面网络结构,界面剪切复合模量明显高于PHPAM.SDBS和CTAB通过疏水相互作用与HMPAM分子中的疏水嵌段形成聚集体,破坏界面网络结构,剪切模量随表面活性剂浓度增大明显降低.同时,界面膜从粘性膜向弹性膜转变.低SDBS浓度时,少量SDBS分子与PHPAM形成混合吸附膜,界面膜强度略有升高;SDBS浓度较高时,界面层中PHPAM分子被顶替,吸附膜强度开始减弱.阳离子表面活性剂CTAB通过静电相互作用中和PHPAM分子的负电性,造成聚合物链的部分卷曲,从而降低界面膜强度.弛豫实验结果证实了表面活性剂破坏HMPAM网络结构的机理.     

苄基取代甜菜碱对聚四氟乙烯表面润湿性的影响

利用座滴法研究了两性离子表面活性剂苄基取代烷基羧基甜菜碱(BCB)和苄基取代烷基磺基甜菜碱(BSB)在聚四氟乙烯(PTFE)表面上的润湿性质,考察了表面活性剂浓度对接触角的影响趋势,并讨论了粘附张力、固-液界面张力和粘附功的变化规律.研究发现,在低浓度时,表面活性剂通过疏水作用吸附到PTFE表面,疏水链苄基取代支链化使其在固-液界面上的吸附明显低于气-液界面,接触角在很大的范围内保持不变.当体相浓度增加到大于临界胶束浓度(cmc)时, BCB和BSB分子在固-液界面上继续吸附,分子逐渐直立,造成PTFE-液体之间的界面张力(γ_SL)进一步降低,表面亲水性增加,接触角随浓度增加明显降低;另一方面, BSB由于具有较大的极性头,在高浓度时空间阻碍作用明显,导致其对PTFE表面润湿性改变程度小于BCB.     

全内反射荧光光谱法研究水溶性卟啉在正己烷/水界面的吸附行为

在自行组装的全内反射荧光测定装置上实现了液／液界面全内反射荧光光谱的测绘,比较了水溶性的meso-四（对磺酸基苯基）卟啉（TPPS）在正己彬水界面上与在水相中荧光性质的差异,研究了全内反射荧光强度随表面活性剂种类、浓度及溶液pH值的变化情况,探索了TPPS的界面吸附行为,着重考察了阳离子表面活性剂CTMAB对TPPS界面荧光性质的影响。结果表明,在阳离子表面活性剂存在的条件下,未质子化的TPPS能够选择性地吸附在正己烷／水界面上,静电力在TPPS界面吸附过程中应起重要作用。     

吸附与润湿I非离子表面活性剂在SiO2/水和SiO2/环己烷界面的吸附层结构

根据Triton X-100在硅胶/水和硅胶/环己烷界面以及Triton x-305在硅胶/水界面的吸附结果,提出了两种简单的吸附模型,在硅胶/环己烷界面上形成的是单分子吸附层,吸附质分子以乙氧基链躺在硅胶表面上而以碳氢链伸入环己烷的方式取向.在硅胶/水界面上形成的是双分子吸附层,第一层中的分子以乙氧基链躺在硅胶表面上而以碳氢链朝外;第二层中的分子取向相反,即以碳氢链朝向第一层分子形成的碳氢链层,而以乙氧基链伸进水中,对石英玻璃-水-环己烷的接触角(θ水)的测定结果表明,θ水随水相中表面活性剂浓度的增加先升后降,进一步支持了上述吸附模型。     

亚砜类非离子型表面活性剂在固/液界面上的吸附(III)碳黑/水溶液界面上的吸附

研究了癸基甲基亚砜在水溶液/炭黑界面上的吸附及温度、加盐(Nacl)、加酸(HCl)对吸附的影响.吸附等温线呈完整的双平台形式. 第一平台吸附量～6 μmol·m~(-2); 第二平台吸附量,即极限吸附量, 为42—48 μmol·m~(-2). 随着吸附增加, 炭黑/水溶液接触角下降, 润湿性, 悬浮性改善.应用两阶段吸附模型和吸附等温线通用公式可以对实验结果作定性和定量的解释. 提供了吸附热力学数据. 指示吸附第二阶段是与体相中表面活性剂胶团化作用相似的熵驱动过程。     

亚砜类非离子型表面活性剂在固/液界面上的吸附 (Ⅲ)碳黑/水溶液界面上的吸附

研究了癸基甲基亚砜在水溶液/炭黑界面上的吸附及温度、加盐(Nacl)、加酸(HCl)对吸附的影响.吸附等温线呈完整的双平台形式.第一平台吸附量～6μmol·m~(-2);第二平台吸附量,即极限吸附量,为42—48μmol·m~(-2).随着吸附增加,炭黑/水溶液接触角下降,润湿性,悬浮性改善.应用两阶段吸附模型和吸附等温线通用公式可以对实验结果作定性和定量的解释.提供了吸附热力学数据.指示吸附第二阶段是与体相中表面活性剂胶团化作用相似的熵驱动过程。     

两相催化体系中长链烯烃氢甲酰化反应研究：—阳离子胶束的动力学作用机理

研究了以水溶性铑－膦配合物RhCl(CO)(TPPTS)2为催化剂,三苯基膦三磺酸钠（TPPTS）为配体,在阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）存在下,水／有机物两相催化体系中,1－十二烯甲酰化反应与CTAB浓度的关系,为了进一步揭示阳离子表面活性剂在该反应体系中的动力学作用机理,分别应用分光光度法和光散射法,测定了1－十二烯在CTAB胶束中的增溶曲线和铑民位催化剂、配体TPPTS和1－十二烯对CTAB胶束摩尔质量的影响,结果表明,阳离子表面活性剂对长烯烃烯氢甲酰化两相催化反应具有加速作用,可能是由于;（1）催化剂及配体吸附于胶束界面并富集;（2）烯烃增溶于胶束内核,容易与催化活性物种发生配位反应。     

Mimic oil recovery with a SDBS–dodecane–silica gel system

The wettability of the solid powder of silica gel was determined via a modified Washburn equation expressed as contact angles. The interfacial tension (γ) between the dodecane and the dilute sodium dodecyl benzene sulfonate (SDBS) aqueous solution was obtained using the spinning drop (γ<10 mN m⁻¹) or drop volume methods (γ>10 mN m⁻¹). Contact angle changes for SDBS aqueous solutions on the surface of a silica gel powder were studied. The average aggregation number of SDBS micelles in aqueous solution was determined using the fluorescence quenching method. The relationship between the wettability of the powder surface, the critical micelle concentration (CMC) of SDBS and the mimic oil recovery of the resident oil on the powder surface has been explored. It has been found that good residual oil recovery was achieved by surface wettability changes at the interfacial tensions around 4–5 mN m⁻¹, which is far from the ‘ultra low’ condition (≤10⁻³ mN m⁻¹).     

短链烷基对多取代烷基苯磺酸盐界面性质的影响

利用悬挂滴方法研究了2,5-二乙基-4-壬基苯磺酸钠(292)、2,5-二丙基-4-壬基苯磺酸钠(393)和2,5-二丁基-4-壬基苯磺酸钠(494)在空气-水表面和正癸烷-水界面的扩张流变性质,考察了时间、界面压、工作频率及体相浓度对扩张弹性和粘性的影响。研究发现,在低表面活性剂浓度条件下,表面吸附膜类似弹性膜,其强度由膜内分子的相互作用决定;高浓度下体相与表面间的扩散交换过程控制表面膜的性质。油分子的插入导致界面吸附分子之间相互作用的削弱,扩散交换过程主导界面膜性质;但随着短链烷基长度增加,油分子的影响变小。表面膜的强度在吸附达到平衡前已经决定,而界面膜在吸附饱和后仍然随界面分子重排而变化。     

Evaluation of adsorption of nonionic surfactants blend at water/oil interfaces

The inherent biocompatibility of Span and Tween surfactants makes them an important class of nonionic emulsifiers that are employed extensively in emulsion and foam stabilization. The adsorption of Span-Tween blend at water/oil surface of emulsion has been investigated using a population balance model for the first time. Destability of emulsion was modeled by considering sedimentation, coalescence and interfacial coalescence terms in population balance equation (PBE). The terms of coalescence efficiency and interfacial coalescence time were considered as a function of surface coverage of droplets by surfactant molecules. The surface coverage at different surfactant concentrations was determined by minimization of difference between the model predictions and experimental average droplet sizes. After optimization, the surface coverage outputs were fitted with different adsorption isotherms to evaluate the adsorption behavior of Span-Tween surfactants blend at water/oil surface. The results show that Freundlich isotherm can predict the adsorption behavior of closer to the experimental observation. Moreover, fitted parameters imply the favorable adsorption of Span-Tween blend at water/oil interface.     

The adsorption of cetyltrimethylammonium bromide and propanol mixtures with regard to wettability of polytetrafluoroethylene II. Adsorption at polytetrafluoroethylene-aqueous solution interface and wettability

Measurements of contact angles (theta) of aqueous solutions of cetyltrimethylammonium bromide (CTAB) and propanol mixtures at constant CTAB concentration equal to 1x10(-5), 1x10(-4), 6x10(-4) and 1x10(-3) M on polytetrafluoroethylene (PTFE) were carried out. The obtained results indicate that the wettability of PTFE by aqueous solutions of these mixtures depends on their composition and concentration. They also indicate that, contrary to Zisman, there is no linear relationship between cos theta and the surface tension (gamma(LV)), but a linear relationship exists between the adhesional (gamma(LV)cos theta) and surface tension of aqueous solutions of CTAB and propanol mixtures. Curve gamma(LV)cos theta vs gamma(LV) has a slope equal -1 suggesting that adsorption of CTAB and propanol mixtures and the orientation of their molecules at aqueous solution-air and PTFE-aqueous solution interfaces is the same. Extrapolating this curve to the value of gamma(LV)cos theta corresponding to theta=0, the value of the critical tension of PTFE wetting equal 23.4 mN/m was determined. This value was higher than that obtained from contact angles of n-alkanes on PTFE surface (20.24 mN/m). The difference between the critical surface tension values of wetting probably resulted from the fact that at cos theta=1 the PTFE-aqueous solution of CTAB and propanol mixture interface tension was not equal to zero. This tension was determined on the basis of the measured contact angles and Young equation. It appeared that the values of PTFE-aqueous solution of the CTAB and propanol mixtures interface tension can be satisfactorily determined by modified Szyszkowski equation only for solutions in which probably CTAB and propanol molecules are present in monomeric form. However, it appeared that using the equation of Miller et al., in which the possibility of aggregation of propanol molecules in the interface layer is taken into account, it is possible to describe the PTFE-solution interfacial tension for all systems studied in the same way as by the Young equation. On the basis of linear dependence between the adhesional and surface tension it was established that the work of adhesion of aqueous solution of CTAB and propanol mixtures does not depend on its composition and concentration, and the average value of this work was equal to 46.85 mJ/m(2), which was similar to that obtained for adhesion of aqueous solutions of two cationic surfactants mixtures to PTFE surface.     

Effect of cetyltrimethylammonium bromide addition on the emulsions stabilized by montmorillonite

The wettability of montmorillonite could be in situ modified by cationic surfactant cetyltrimethylammonium bromide (CTAB). The type and stability of emulsions prepared from montmorillonite with different concentrations of cationic surfactant were investigated, and a double phase inversion of emulsions was observed. The adsorption of CTAB on montmorillonite particles was studied by surface tension and zeta potential measurements, and the variation of the wettability of particles with the concentration of CTAB was characterized by the contact angle measurements. The adsorption of particles at the surface of emulsion droplets was observed by laser-induced confocal scanning microscopy. At low surfactant concentrations, the adsorption of CTAB on montmorillonite increased the hydrophobicity of the particles, and the stability of oil-in-water emulsions was enhanced. With the increase of the CTAB concentration, montmorillonite particles changed from hydrophilic to hydrophobic, and water-in-oil emulsions were obtained. However, at higher surfactant concentrations, the emulsions inverts to O/W again because montmorillonite particles were reconverted into hydrophilic due to the formation of CTAB bilayer on the surface of montmorillonite.     

受限空间内油水界面动态特性及粘附行为的荧光原位观测

水污染作为润滑油污染的常见形式,对润滑油本身以及机械系统都有巨大的危害。为了模拟实际非均匀多相系统中的界面行为,本文搭建了高精度点接触实验台来研究传统的不溶相替换问题。将目前静态平行受限空间内油水界面行为的研究推广到动态点接触楔形受限空间内,探究了游离水滴穿过点接触狭缝间毛细油池过程中的界面特性。重点关注固壁润湿性以及固壁的分离运动对整个侵入过程中液滴动态行为的影响。实验发现了铺展系数是决定油水界面融合和分离特性的关键因素,揭示了固壁润湿性和球盘间的相对分离运动会影响游离水滴穿过毛细油池之后的粘附行为。表面张力和液体与壁面之间的粘附功能够解释观测的实验现象。     

Interaction between polymer and anionic/nonionic surfactants and its mechanism of enhanced oil recovery

Various experimental methods were used to investigate interaction between polymer and anionic/nonionic surfactants and mechanisms of enhanced oil recovery by anionic/nonionic surfactants in the present paper. The complex surfactant molecules are adsorbed in the mixed micelles or aggregates formed by the hydrophobic association of hydrophobic groups of polymers, making the surfactant molecules at oil-water interface reduce and the value of interfacial tension between oil and water increase. A dense spatial network structure is formed by the interaction between the mixed aggregates and hydrophobic groups of the polymer molecular chains, making the hydrodynamic volume of the aggregates and the viscosity of the polymer solution increase. Because of the formation of the mixed adsorption layer at oil and water interface by synergistic effect, ultra-low interfacial tension (～2.0?×?10^?3 mN/m) can be achieved between the novel surfactant system and the oil samples in this paper. Because of hydrophobic interaction, wettability alteration of oil-wet surface was induced by the adsorption of the surfactant system on the solid surface. Moreover, the studied surfactant system had a certain degree of spontaneous emulsification ability (D50?=?25.04?µm) and was well emulsified with crude oil after the mechanical oscillation (D50?=?4.27?µm).     

Wettability of tri-block copolymer coated hydrophobic surfaces Predictions and measurements

Hydrophobic surfaces with adsorbed tri-block copolymers are wetted by oil in spite of the hydrophilic buoy groups of the block copolymer that are present near the surface. The effect of the buoy group length of the adsorbed molecules on the wettability of hydrophobic surfaces is studied by contact angle measurements and by computer modelling.

The computer model predicts an increase in interfacial free energy with increasing buoy group length for equilibrium adsorption of block copolymer from water. Molecules with large buoy groups occupy more lateral space; therefore the “bare” surface gets more exposed and the anchor groups contribute less to the interfacial free energy which thus increases with the buoy group length.

The calculations showed that the variation of the interaction parameter between solvent and buoy group hardly influences the interfacial free energy. In contrast the interaction parameter between solvent and surface influences the interfacial free energy to a large extent because the oil/surface interactions have a lower energetic value as compared to water/surface interactions and therefore the interfacial free energy is lower than in water. The interfacial free energy varies slightly with increasing buoy group length, depending on the value chosen for the solvent/surface interaction parameter.

Advancing and receding contact angles of hexadecane, sunflower oil and hydrolysate (partly hydrolysed sunflower oil) were measured on hydrophobic surfaces. All oil/water contact angles were small, indicating a hydrophobic apolar surface character. It was found that, for oils with a “good” interaction with the surface (hexadecane and sunflower oil), the contact angle has a minimum value at a certain buoy group length. For hydrolysate (less-strong interaction with the surface) the contact angle decreases monotonically with increasing buoy group length. The results for hexadecane, sunflower oil and hydrolysate are in reasonable agreement with the model predictions. The effect of increasing buoy group length is weak; both decreasing and increasing angles are found, depending on the type of oil used.     

Interfacial rheology of protein–surfactant mixtures

The distribution of proteins and surfactants at fluid interfaces (air–water and oil–water) is determined by the competitive adsorption between the two types of emulsifiers and by the nature of the protein–surfactant interactions, both at the interface and in the bulk phase, with a pronounced impact on the interfacial rheological properties of these systems. Therefore, the interfacial rheology is of practical importance for food dispersion (emulsion or foam) formulation, texture, and stability. In this review, the existence of protein–surfactant interactions, the mechanical behaviour and/or the composition of emulsifiers at the interface are indirectly determined by interfacial rheology of the mixed films. The effect on the interfacial rheology of protein–surfactant mixed films of the protein, the surfactant, the interface and bulk compositions, the method of formation of the interfacial film, the interactions between film forming components, and the displacement of protein by surfactant have been analysed. The last section tries to understand the role of interfacial rheology of protein–surfactant mixed films on food dispersion formation and stability. The emphasis of the present review is on the interfacial dilatational rheology.