Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

Study on nanomaterials has attracted great interests in recent years. In this article, zirconia nanocrystallites of different structures have been successfully synthesized via hydrothermal methods with cationic surfactant （CTAB） and anionic surfactant （SDS）, respectively. Differential Scanning Calorimeter （DSC-TG）, X-ray Diffractometer （XRD）, Transmission Electron Microscope （TEM）, Ultraviolet-Visible （UV-vis） and N2 adsorption-desorption analyses are used for their structure characteristics. The results show that the cationic surfactant has a distinctive direction effect on the formation of zirconia nanocrystallites, while the anionic surfactant has a self-assembly synergistic effect on them. The sample synthesized with the cationic surfactant presents good dispersion with the main phase of tetragonal zirconia, and the average nanocrystal size is around 15 nm after calcination at 500 ℃. While the sample synthesized with the anionic surfactant exhibits a worm-like mesoporous structure with pure tetragonal phase after calcination at 500 ℃ and with good thermal stability.

Phase Separation and Microstructure of Mixed Surfactants Solution Containing Cationic Geminis and Traditional Anionic Surfactant

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.

Theoretical and Experimental Studies on Interactions of Cationic-Anionic Surfactants

Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol-1, -3.3394kJ·mol-1 and 0.1204kJ·mol-1 for the molecular pairs with fluocarbon and hydrocarbon chain: C4H10/C5H12, C4F10/C5H12, and C4F10 /C5F12, respectively. When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol-1, -311.18kJ·mol-1 and -345.83kJ·mol-1. The results show that there is strong static interaction between cationic and anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is enhanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbon chains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-I) was synthesized, mixture effects of ANF-I with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium bromide were studied. The results indicate that the efficiency of mixing increased and the theoretical prediction was testified. These results can provide useful information for the design of new surfactants.

Pilot test of polymer microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants under harsh conditions in a sandstone reservoir

The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone reservoir to demonstrate the potential of this novel technique to improve oil recovery.A critical micelle concentration(CMC)of 4.82 mg/L,an ultralow interfacial tension(IFT)of 8104 mN/m,and a high oil solubilization of 22 were obtained.Static and dynamic adsorptions of Sa/c on natural core containing 15 wt%clay were reduced to about 2.20 and 0.30 mg/g-core,respectively,with the addition of adsorption inhibitor(AI).Since June 2014,the pilot test of PMAS was carried out in a Sinopec reservoir with a temperature of 87C,a salinity of 260,393 mg/L,and a hardness of 6,401 mg/L.Twelve cycles of alternative injection of 0.0125 PV Sa/c with a concentration of 0.1%and 0.0125 PV polyacrylamide microsphere with a concentration of 0.2%were conducted at an injection rate of 0.1 PV/yr,for a total of 0.3 PV chemical injection.As a result,the net daily oil production increased from 0 t to 6.5 t,and the water cut decreased from 96.3%to 93.8%,leading to an ultimate improved oil recovery of 6.3%original oil-in-place.

Partitioning of biomaterials in aqueous two-phase systems of mixed cationic-anionic surfactants

In a previous paper, we have showed that, when aqueous solutions of cationicand anionic surfactants at certain concentrations were mixed, the solution separatedspontaneously into two immiscible phases (aqueous two-phases), one phase was rich,and the other was poor in the mixed surfactants. A clear interfacial boundary existsbetween two phases.

Overview of Simple Test for Determination of Surfactants by Adhesion Method

A simple, sensitive, and rapid analytical method is reported for the determination of surfactants. This is based on the use of an oppositely charged dye as the ion pair to form an ionic associate with the surfactant in a vessel, thus affording ion-associated adhesion on the inner wall of the vessel. After the adhesion, the remaining solution in the vessel is removed, and the ionic associate is dissolved in a suitable solvent. The absorbance of the resulting solution is measured spectrophotometrically to determine the concentration of the surfactant. Further, the mechanism of adhesion is elucidated.

Study on aqueous two-phase systems of the mixture SDS/CTAB surfactants

The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate(SDS) and cetyl trimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molar ratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in the both phases by TEM image.

Phase behavior and properties of salt-free cationic/anionic surfactant mixtures of oleic acid and stearic acid

Cationic base surfactant, tetradecyltrimethylammonium hydroxide (TTAOH), can be obtained through anion exchange from tetradecyltrimethylammonium bromide (TTABr). Salt-free cationic and anionic (catanionic) surfactant mixtures were studied by mixing TTAOH with oleic acid (OA) or stearic acid (SA) in water. The phase behavior of TTAOH/OA/H2O is compared with that of TTAOH/SA/H2O. It was found that the phase behavior of TTAOH/OA/H2O and TTAOH/SA/H2O system differs from each other due to the existence of the unsaturated double carbon bond (C=C) in OA. At fixed total surfactant concentration (25 mg/mL) of TTAOH/OA/H2O system at 25℃, one can observe an isotropic L1 phase, and a L1/Lα two-phase region with increasing OA content. The volume of top turbid Lα phase increases while the bottom phase changes gradually from transparently clear to a bit turbid until a single Lα-phase is reached. Finally at high OA concentration, excess OA is separated from the bulk aqueous solutions. TTAOH/SA/H2O system usually forms white precipitating at 25℃ due to the high chain melting temperature of SA. When heated to 60℃, however, the state of samples changes. At fixed total surfactant concentration of 25 mg/mL, an isotropic L1 phase and a milk-white or bluish Lα-phase are observed with increasing SA concentration. Transparent thin layers which are strongly birefringent form at the tops of some samples within the Lα-phase region. Finally, at high SA concentration, excess SA is separated from the bulk aqueous solutions. In addition to phase behavior study, we also measured the conductivity of TTAOH/OA/H2O system at 25℃ and TTAOH/SA/H2O system at 60℃, respectively. Surface tension and rheological measurements were also performed on typical samples.

Cloud point phenomenon in aqueous mixtures of cationic-anionic surfactants

It used to be held that the cloud point phenomenon was only a characteris-tic of nonionic surfactants alone. Such phenomenon is rarely observed in ionicsurfactants. The present study shows that the mixture of cationic-anionic surfac-tants not only has a krafft point which is the characteristic of an ionic surfactant,but also exhibits the cloud point phenomenon obviously at certain concentrations.

油田采出水过滤器滤料高效清洗剂的研制与应用

以脂肪醇聚氧乙烯醚羧酸钠和十六烷基三甲基氯化铵为原料制备了一种滤料清洗剂,利用接触角测试、界面张力测试等方法评价了该滤料清洗剂的性能,并在东部某油田注水站进行了现场试验。实验结果表明,该滤料清洗剂具有良好的润湿性调控性能,可将被原油污染的基材表面恢复至亲水;有效含量为1~5 g/L时可将油水界面张力降至10^(-3)m N/m数量级,具有高界面性能;对原油具有良好的乳化增溶能力;对被污染的滤料进行动态清洗,洗油效率约99%。现场试验结果显示,经该滤料清洗剂处理后过滤罐的前后压差明显降低,后端滤出水含油量不大于5 mg/L,达到良好的恢复滤料性能的效果。

Gemini阳离子/含氟阴离子表面活性剂混合体系的界面润湿调控及解水锁机制研究

为有效解决低渗透致密砂岩气藏开采普遍存在的水锁伤害问题,研究了Gemini阳离子表面活性剂双季铵盐BQ-16和含氟阴离子表面活性剂全氟辛基磺酸钾(PPS)在降低表面张力和润湿调控方面的协同作用,并探究了BQ-16/PPS表面活性剂混合体系的润湿调控及解水锁机制。结果表明,当PPS的摩尔分数(α_(PPS))为0.7时,BQ-16/PPS表面活性剂混合体系的表面张力达到最低,低于任一纯组分,此时BQ-16/PPS表面活性剂混合体系接近电中性;BQ-16和PPS在岩心表面润湿调控方面表现出协同效应,当BQ-16/PPS表面活性剂混合体系总浓度为1×10^(-4)mol·L^(-1)、α_(PPS)为0.7时,盐水滴接触角最大,达到84.23°;BQ-16/PPS表面活性剂混合体系(α_(PPS)=0.7)在石英砂表面的吸附过程符合准二级动力学方程和Freundlich等温吸附模型,低浓度时为单分子层吸附,高浓度时为多分子层吸附;BQ-16/PPS表面活性剂混合体系(α_(PPS)=0.7)可将岩心的液体饱和度降至0.410,并将渗透率恢复值提高至0.78,说明BQ-16/PPS表面活性剂混合体系可有效解决水锁伤害,这主要与混合体系能够显著降低表面张力并通过在岩心表面的吸附改变岩心表面润湿性有关。

阴阳离子表面活性剂对煤层自转向酸液的性能影响及优选

针对煤矿粉尘污染严重问题,研究了煤层OAPB自转向酸液均匀布酸,从而提高煤体含水率,借助黏度、荷电性、官能团等方法研究了不同阴阳离子表面活性剂对自转向酸液增黏、润湿性能的影响规律,探究了性能变化的内部原因,并根据测试结果进行了优选。结果表明:阳离子表面活性剂会直接导致自转向酸液破胶,阴离子表面活性剂的添加使自转向酸液黏度增加;SSA/SDBS润湿性能较好,表面张力最低为24.12 mN/m;SSA/SDBS-16表面张力值总体较高,自身润湿性能差,对煤体的吸附性能也较弱;通过红外实验发现在SSA/SDBS作用下OAPB分子更倾向于形成氢键,并通过三轴渗流实验验证了自转向酸液的渗流效果。

高浓度无机盐对正负离子等摩尔混合表面活性剂表面活性的影响

一般认为无机盐对等链长正负离子表面活性剂等摩尔混合体系的表面活性没有明显影响 .通过测定等摩尔癸基三乙基溴化铵和癸烷磺酸钠混合体系在卤化钠 (NaX ,X =F-,Cl-,Br-,I-)溶液中的表面活性 ,发现高浓度的无机盐具有明显影响 ,使混合表面活性剂的临界胶束浓度 (cmc)降低 ,水溶液的最低表面张力 (γcmc)升高 .无机盐的影响程度随NaX中X的离子半径增加而增大 .可通过无机反离子对正负离子表面活性剂头基之间吸引作用的“屏蔽”及“盐析”

SDS及其与十二烷基三乙基溴化铵混合体系在矿化水中的表面活性

测定了十二烷基硫酸钠 (SDS)、十二烷基三乙基溴化铵 (DTEAB)单一体系及不同摩尔比的混合体系在矿化水溶液中的表面活性 ,并与在纯水和NaCl水溶液中的表面活性作了比较 .所得结果表明 :( 1)阴离子表面活性剂SDS在含Ca2 + ,Mg2 + 等的矿化水中有比在纯水和NaCl水溶液中更好的表面活性 .这一方面是由于矿化水中的Ca2 + ,Mg2 + 对负电胶团和表面吸附层的强烈电性作用 ,另一方面在大量Na+ 存在时 ,钠钙盐混合表面活性剂Krafft点提高不多 ;( 2 )SDS和DTEAB混合物在矿化水中具有很强的增效作用 ,其表面活性的变化规律与在纯水和NaCl水溶液中基本相同 ,表明阴阳离子表面活性剂混合体系具有优异的抗矿化水性能 .这些结果可用阴。

碳氟-碳氢表面活性剂混合水溶液在油面上铺展

本文研究RfCONH(CH2 ) 3N(C2 H5) 2 CH3I CnH2n + 1 COONa及RfCOONa CmH2m + 1 N(CH3) 3Br(Rf=F[CF(CF3)CF2 O]2 CF(CF3) ;n =7,9,11,13;m =8,10 ,12 )两类正、负离子碳氟 碳氢表面活性剂混合水溶液在油面上的铺展及对油面的密封性能。研究表明在碳氟表面活性剂中加入异电性碳氢表面活性剂可大大降低碳氟表面活性剂水溶液的铺展浓度 ,也可使一些因表面张力较高而不能铺展的碳氟表面活性剂水溶液在油面上铺展。在碳氟表面活性剂中加入异电性碳氢表面活性剂可提高水膜对油面的密封性。若在混合表面活性剂中加入黄原胶 。

阳、阴、非离子表面活性剂胶束对酯碱性水解的影响

应用紫外分光光度法和热动力学方法研究了芳香酸酯和正脂肪酸酯在表面活性剂ＤＴＡＢ、ＴＴＡＢ、ＣＴＡＢ、ＳＤＳ、Ｂｒｉｊ３５、ＴｒｉｔｏｎＸ－１００胶束中的碱性水解反应。阳、阴、非离子表面活性剂胶束对酯的碱性水解均有禁阻作用。讨论了胶束对酯碱性水解禁阻作用的原因。

阴、阳离子混合表面活性剂的表面活性──表面张力、润滑能力和乳化能力

辛基本基聚氯乙烯醚硫酸钠C．H17C6H4（OC2H4）10SO4Na（CaE10S）和十二烷基三甲基溴化铵C12H25N（CH3）3Br（Cl2NM3）不仅能在水溶液中形成透明的均匀溶液，而且混合体系的临界波团浓度（cmc）和γcmc比单一组份的低得多．在C8E10S而中引入的C12NM3量小于10％时，C8E10S－C12NM3的润湿能力不变，大于10％时，润湿能力增加；超过20％时，润湿能力下降．混合比改变时，C8E10S-C12NM3对煤油的乳化能力出现两个极大值和一个极小值。

阴-阳离子表面活性剂复配研究与应用

综合介绍了阴 -阳离子表面活性剂复配体系在各种物化性能的增效效应 ,例如降低表面张力的效能、表面张力的效率、降低临界胶束浓度的能力、改善表面吸附的能力 ,以及这些增效效应在去污、增溶、泡沫、润湿、乳化等方面的应用。讨论了提高阴 -阳离子表面活性剂之间的可配伍性之对策 ,诸如采用非等摩尔比复配、在离子型表面活性剂中引入聚氧乙烯链及加入非离子或两性表面活性剂进行调节等手段以优化配方性能和提高综合经济效益。总结了阴—阳离子表面活性剂复配体系用于洗涤用品的可行性配方技术 ,即采取无机助剂。

阴/阳离子表面活性剂复配体系的物化性能——不同乙氧基化数对溶解性及表面张力的影响

研究了十二烷基甲基聚氧乙烯氯化铵与脂肪醇聚氧乙烯醚硫酸盐复配体系在不同乙氧基化数的溶解性、表面张力及临界胶束浓度。复配体系的溶解性随乙氧基化数的增加而增加,乙氧基化数为2的阳离子与乙氧基化数为2、3的阴离子复配,在较大的浓度范围内可以在水中形成透明的均匀溶液;乙氧基化数为5的阳离子与乙氧基化数为2、3的阴离子复配,在活性物质量分数为25%以下时完全透明。复配体系的临界胶束浓度(cmc)及其表面张力(γcmc)较单一组分低得多,且表面活性随乙氧基化数增加而下降。未经提纯的阴、阳离子表面活性剂,复配后其γ-c曲线中最低值现象明显减弱至消失。

正负离子表面活性剂与高聚物混合双水相体系的相行为及蛋白质的分配

报道了由正负离子表面活性剂与高聚物混合溶液形成的一种可用于蛋白质的分离及分析的新型双水相萃取体系 .研究了正负离子表面活性剂 (溴化十二烷基三乙铵 /十二烷基硫酸钠 )分别与葡聚糖和聚乙二醇混合双水相体系的形成规律、相行为及牛血清蛋白和溶菌酶在双水相体系中的分配 .通过在高聚物分子中接上亲和配基 ,研究蛋白质在双水相体系中的亲和分配 .结果表明 ,在该体系中 ,表面活性剂与高聚物分别富集于不同相中 .升高温度及加入无机盐均可促进双水相体系的形成 ,不同蛋白质可分配于不同的相中 .亲和配基的引入极大地增强了蛋白质分配的选择性 .