十二烷基苯磺酸钠扩散系数的电化学测定

表面活性剂水溶液体系胶束扩散系数的测定是研究表面活性剂水溶液体系性质的重要方法之一。胶束扩散系数的测定已有准弹性光散射[1]、小角X-射线散射[2]、扩散-粘度[3]、极谱法[4]、循环伏安[5]等方法报导。但有关十二烷基苯磺酸钠(sod ium dodecy benzene sulfonate,SDBS)水溶     

CTAB在硅胶表面吸附引起的润湿性变化和模拟驱油

用椭圆偏振法测定溴代十六烷基三甲胺（CTAB）水溶液在光滑的二氧化硅膜片上的吸附，其结果符合两阶段模型，即在不同浓度下发生单分子层和近似双分子层的吸附，并与其表面润湿性变化的数据吻合.用改进的Washburn方程测量改性硅胶粉末的润湿性, 研究了CTAB水溶液在硅胶粉末表面上吸附引起的润湿性变化.并由此探讨了CTAB水溶液在硅胶粉末表面的润湿性,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，对在非超低界面张力条件下通过改变固/液界面润湿性提高原油采收率作了实验探讨.     

共振光散射方法研究钙存在下十二烷基苯磺酸钠的聚集行为

利用共振光散射技术在不引入探针的条件下,建立了室温下直接测定十二烷基苯磺酸钠(SDBS)的临界胶束浓度(CMC)的方法.研究发现:在室温下,SDBS水溶液的共振光散射强度(RLS)随SDBS浓度的增加而增强;且当SDBS接近其临界胶束浓度时,RLS强度增强显著,共振光散射峰分别位于330和396 nm.396 nm处的RLS强度与SDBS浓度关系曲线呈S型曲线,本文将曲线突升起点处两条切线的交点对应的SDBS浓度,确定为SDBS的临界胶束浓度(CMC),这与荧光芘探针和电导率等方法测定结果基本一致.并利用此方法分别研究了Ca2+浓度对SDBS及其SDBS-聚乙二醇辛基苯基醚(OP)复配体系聚集行为的影响.结果表明,SDBS与OP以1∶ 3复配时,增强了体系的抗钙能力.     

阴离子表面活性剂SDBS胶束溶液的介电弛豫行为

用射频介电谱方法研究了0.1-80 mmol·L-1浓度的十二烷基苯磺酸钠(SDBS)水溶液体系的介质弛豫行为. 测量发现频率接近107 Hz时, 在临界胶束浓度(CMC)附近出现显著的介电弛豫现象. 采用Cole-Cole函数拟合SDBS体系介电数据, 其拟合参数具有明显变化规律: 介电增量(△ε)随SDBS摩尔浓度(cs)的增加而增大, 表现为两种线性关系, 并在cs=36 mmol·L-1附近出现拐点; 特征弛豫时间(τ0)却在cs=45 mmol·L-1出现极小值. 利用胶束电模型分析了介电弛豫机制, 认为束缚Na+对离子数量和胶束体积变化是引起介电增量和特征弛豫时间变化的两个重要原因.     

十四烷基三甲基氯化铵/十二烷基苯磺酸钠混合表面活性剂双水相体系的萃取性能

研究了十四烷基三甲基氯化铵(TTAC)与十二烷基苯磺酸钠(SDBS)混合表面活性剂水溶液双水相体系的分相情况、萃取性能及两相的微观结构.结果表明,TTAC/SDBS混合表面活性剂水溶液在30℃下能够形成稳定的双水相体系;该双水相体系对亚甲基蓝、靛红都具有一定的萃取分离作用.其上、下两相的微观结构明显不同,这是其能够形成稳定双水相体系且具有萃取作用的重要原因.     

在阴离子表面活性剂中对甲苯胺对尼罗红的荧光开关效应

研究了不同浓度的对甲苯胺对十二烷基苯磺酸钠(SDBS)形成自组装体系的影响。以尼罗红作为荧光探针,对甲苯胺为荧光开关,根据紫外和荧光光谱的变化,对自组装体系进行分析:在SDBS的胶束状态下,加入对甲苯胺促进了表面活性剂紧密堆积,使SDBS体系从胶束转变为囊泡,导致体系的荧光强度增强。继续增加对甲苯胺的浓度至3 mmol/L以上时,体系的荧光强度反而开始减小,此时对甲苯胺转变为尼罗红的荧光猝灭剂。而在十二烷基磺酸钠(SDSN)和十二烷基硫酸钠(SDS)胶束溶液中,对甲苯胺对尼罗红只有荧光猝灭的作用。因此在不同阴离子表面活性剂中,对甲苯胺引起的尼罗红荧光开关效应是不一样的。在SDBS与对甲苯胺相互作用聚集形成的囊泡中尼罗红的荧光寿命大幅增加,这些为研究荧光探针在生物环境下的作用机理提供新思路。     

聚(2-丙烯酰胺甲基-6-十二烷基硼酸二乙醇胺酯)与十二烷基苯磺酸钠混合溶液的表面活性

聚(2-丙烯酰胺甲基-6-十二烷基硼酸二乙醇胺酯)(PADB)是一类两亲性聚硼酸酯.本文通过表面张力法考察了不同相对分子质量的PADB水溶液的表面活性;重点研究了PADB与十二烷基苯磺酸钠(SDBS)在0.5 mol.L-1 NaCl溶液中的相互作用,通过正规溶液理论,计算PADB/SDBS混合体系的胶束化参数,并与单体ADB/SDBS混合溶液体系进行了比较.结果表明,PADB相对分子质量可达1.5×104-3.5×104,随分子量增加,PADB水溶液中临界胶束浓度(cmc)增大,但cmc时的表面张力(γcmc)维持在31 mN.m-1左右(298 K);加入PADB后,SDBS溶液表面张力-浓度对数(γ-lgc)曲线出现两处转变点,即c1和c2点,但c1和c2皆小于纯SDBS溶液的临界胶束浓度(cmcSDBS),即c1c2cmcSDBS.PADB加入量越大,相对分子质量越低,SDBS溶液的表面活性越强.将聚硼酸酯PADB溶液视为特殊状态的单体ADB溶液,通过近似处理,计算得到PADB/SDBS混合胶束中相互作用参数βm在-2.4到-4.7之间,活度系数f1m1,表明聚硼酸酯PADB与SDBS有较强的相互作用;当混合体系中PADB的ADB结构单元摩尔分数x1为0.47时,|βm|达到最大.相比于单体ADB/SDBS混合体系,当x10.8时,PADB/SDBS混合体系|βm|值较大,相互作用更强;随x1增大,混合胶束中聚合物PADB的ADB结构单元摩尔分数x1m不断增加,但其值低于ADB/SDBS混合体系.     

Ru(phen)_2dppx~(2+)-SDBS-DNA体系共振瑞利散射光谱及其分析应用研究

在水溶液中,带正电荷的Ru(phen)2dppx2+在阴离子表面活性剂十二烷基苯磺酸钠(SDBS)的表面聚集后,产生很强的共振瑞利散射.由于Ru(phen)2dppx2+与DNA之间有较大的结合常数(KB≥106 L·5mol-1),DNA的加入会使体系中"光开关"与SDBS分离,散射光强度大大降低,且体系散射光的降低程度与DNA的浓度呈线性关系.据此建立了DNA的定量测定新方法.     

直接紫外法测定混合表面活性剂的临界胶束浓度

临界胶束浓度(C.M.C.)是表征表面活性剂性质的重要指标之一,是决定表面活性剂用量的依据。近年来,由于混合表面活性剂的协同增效作用,混合表面活性剂已被广泛用于生产和分析中,而其C.M.C.值报道较少。本文对工业生产和分析测试中常用的十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)、十六烷基三甲基溴化铵(CTMAB)、十二烷基二甲基苄基氯化铵(DDMBAC)与辛基酚     

表面活性剂胶束形状随浓度转变的核磁共振研究

运用核磁共振一维氢谱和自扩散实验方法研究了聚乙烯乙二醇异辛酚醚(TX-100)、十二烷基苯磺酸钠(SDBS)和十四烷基三甲基溴化铵(TTAB)三种不同类型的表面活性剂在重水溶液中的胶束形状转变, 发现它们在临界胶束浓度以上的各自相应浓度都有胶束形状的变化(由球状转变为椭球状或棒状). 在常温常压和没有其他添加剂的情况下, 表面活性剂溶液浓度高于其临界胶束浓度时, 球状胶束开始形成. 核磁共振一维氢谱和自扩散实验的结果显示, 当溶液浓度继续增加到一定程度时, 溶液中表面活性剂分子的化学位移和自扩散系数的变化速率都有明显的转折, 这说明溶液中球状胶束开始发生转变. 进一步通过仔细分析对比核磁共振一维氢谱中各基团谱峰, 发现表面活性剂胶束亲水表面上的质子的化学位移变化速率要远高于其疏水内核中的质子, 据此推测胶束形状很可能由球状转变为椭球状或棒状.     

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).     

Enhanced desorption of hexachlorobenzene from kaolin by single and mixed surfactants

This study investigated the enhanced desorption of hexachlorobenzene (HCB) from spiked kaolin by single and mixed surfactants. The sorption of surfactants on kaolin followed myristyl pyridinium bromide (MPB) > Tween 80 > sodium dodecyl benzene sulfonic (SDBS). The desorption of HCB by single surfactant increased linearly with the increase of the aqueous micelle concentrations. The potential to enhance HCB desorption was Tween 80 > SDBS > MPB. When the dual mixed surfactants of SDBS-Tween 80 (MPB-Tween 80) were present, the desorption of HCB was larger than that by single SDBS (MPB) and less than that by single Tween 80. The total adsorbed surfactants were kept almost constant in SDBS-Tween 80 but decreased with the increased fraction of Tween 80 above 0.5 in MPB-Tween 80. The presence of little MPB in Tween 80 highly reduced the sorption loss of Tween 80 but slightly decreased the desorption of HCB. Whereas in SDBS-MPB, the presence of little MPB in SDBS remarkably decreased the desorption of HCB and enhanced the loss of SDBS, while the addition of little SDBS in MPB significantly enhanced the desorption and reduced the loss of MPB.     

The Synergistic Effect of a Mixed Surfactant (Tween 80 and SDBS) on Wettability Alteration of the Oil Wet Quartz Surface

The synergistic effect of a new combination of Tween 80 and sodium dodecylbenzenesulfonate (SDBS) surfactants has been studied for wettability alteration of a reservoir rock. The contact angle decreased substantially for the aqueous solution of the mixed surfactant on a crude oil aged quartz substrate when compared to water and individual surfactants viz. SDBS and Tween 80. This established synergism between anionic and non-ionic surfactants. The optimal salinity for reduction of the contact angle has been figured out. The rheological effect of the mixed surfactant solution on the wettability alteration has been investigated. Adsorption of crude components at the solid–fluid interfaces has been observed to visualize the activity at the micro scale. Quantification of adsorption for the mixed surfactant on sand has been studied to meet the economical aspect. Reaction aspects of the mixed surfactant–quartz–crude oil system have been interpreted from FTIR. Functional groups present in the system have also been enquired.     

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.     

Contact angles of colloid silica and gold particles at air-water and oil-water interfaces determined with the gel trapping technique

We have used the recently developed gel trapping technique (GTT) to determine the three-phase contact angles of submicrometer silica particles partially coated with octadecyl groups. The particles were spread at air-water and decane-water surfaces, and the aqueous phase was subsequently gelled with a nonadsorbing polysaccharide. The particles trapped at the surface of the aqueous gel were lifted by molding with curable poly(dimethylsiloxane) and imaged with scanning electron microscopy (SEM) to determine the particle contact line diameter which allows their contact angle at the original air-water or oil-water interface to be estimated. We report for the first time the use of the GTT for characterizing the contact angle of individual submicrometer particles adsorbed at liquid interfaces. The SEM images also reveal the structure of the particle monolayer at the interface and the structure of adsorbed particle aggregates. We have also determined the contact angles of agglomerated gold powder microparticles at the air-water and the decane-water interfaces. It was found that agglomerated gold particles demonstrate considerably higher contact angles than those on flat gold-coated surfaces.     

Assemblies of amphiphilic compounds over rigid polymers: 2. Interaction of sodium dodecylbenzenesulfonate with chitosan-scleraldehyde gels

Gels based on chitosan cross-linked with scleraldehyde were prepared. The swelling behavior due to pH variation and to equilibration with solutions of sodium dodecylbenzene-sulfonate (SDBS) or sodium p-toluenesulfonate (p-STS) was investigated. Binding isotherms and the solubilization of Sudan III by gels equilibrated with SDBS were also determined. Gel collapse was at a SDBS concentration one order of magnitude smaller than the critical micelle concentration and was accompanied by moderately cooperative binding with K equal to 4120 M⁻¹. Binding of p-STS, which is characterized by a similar value of K but much smaller cooperativity parameter, was not accompanied by gel collapse. The formation of micelle-like aggregates of SDBS within the gel is discussed in terms of recent theoretical and experimental results.     

自探针荧光法研究十二烷基苯磺酸钠与TritonX-100相互作用

采用荧光光谱法研究了十二烷基苯磺酸钠（SDBS）与非离子表面活性剂TritonX-100混合体系在水溶液中聚集体的性质。 发现在浓度与荧光强度的关系曲线上存在2个转折点,分别对应于混合体系的临界胶团浓度和胶团形状发生转变的浓度。 通过混合胶团相互作用关系,计算了SDBS与TritonX-100的相互作用参数βM,说明SDBS以其自身所带生色基团苯磺酸与TritonX-100发生了协调效应且存在着较强的相互作用。     

Enzymatic polymerization of phenol catalyzed by horseradish peroxidase in aqueous micelle system

Enzymatic polymerization of phenol catalyzed by horseradish peroxidase (HRP) has been carried out in aqueous micelle system using sodium dodecyl benzene sulfonate (SDBS) as a surfactant. The addition of SDBS to buffer greatly enhances the polymer yield. With a usage of SDBS over 0.4 g for 5 mmol of phenol monomer, the polymer could be obtained almost quantitatively. The number-molecular weight of the THF-soluble part determined by GPC is increased from 1100 to 2000 with increasing the dosage of SDBS. The phenol polymerization maintains high yields in aqueous micelle system over a wide pH range from 4 to 10. The activity of enzyme in buffer is so high that the phenol polymerization in aqueous micelle system could be completed only in 2 h with high yield. The resulting polymer is a kind of powdery material, which is partly soluble in DMF, DMSO and THF. IR analysis showed that the polymer structure contained a mixture of phenylene and oxyphenylene units. From TG analysis, the polymer was found to possess high thermal stability.     

Thermodynamics of micelle formation of the counterion coupled gemini surfactant Bis(4-(2-dodecyl)benzenesulfonate)-Jeffamine salt and its dynamic adsorption on sandstone

A novel counterion-coupled gemini (cocogem) surfactant, DBSJ, was synthetized via the 2:1 coupling reaction between 4-(2-dodecyl)benzenesulfonic acid (Lutensit A-LBS) and polypropyleneglycol-bis(2-aminopropyl) ether (Jeffamine D230). The surfactant had a polydispersity index of Mw/Mn = 1.04, as determined by electrospray-ionization mass spectrometry. The micellar properties of DBSJ in water were investigated in the temperature range 283-348 K by conductometry and titration microcalorimetry. The critical micelle concentration (cmc) of the cocogem was found to be more than 1 order of magnitude less than that of monomeric sodium 4-(2-dodecyl)benzenesulfonate (SDBS). The mean degree of dissociation in the temperature range studied proved to be alpha = 0.39. The calorimetric enthalpies of micelle formation agreed well with the enthalpies calculated via the van't Hoff relation. The cmc versus T curve passes through a minimum just below room temperature, after which the micelle formation changes from endothermic to exothermic. The Gibbs free energy of micelle formation was nearly constant as the temperature was increased, due to enthalpy/entropy compensation. The isotherm for DBSJ adsorption from aqueous solution onto sandstone was determined by continuous flow frontal analysis solid/liquid chromatography at 298 K and 60 bar. The adsorption of DBSJ on sandstone followed an S-type isotherm. Surface aggregation occurred over an extended range of concentration. Surface saturation was reached at a solution concentration more than 1 order of magnitude less than for monomeric SDBS. This finding is a point of concern in the chemical flooding of oil reservoir rocks to enhance oil recovery.