Synthesis,Characterization, Surface and Biological Activity of Diquaternary Cationic Surfactants Containing Ester Linkage

Two series of diquaternary cationic surfactants designated as E9Nm and E11Nm having two different alkyl chains in their chemical structure were synthesized. The chemical structures of these surfactants were confirmed using elemental analysis, FTIR and ¹H‐NMR spectra. The surface activities of the different surfactants were determined using surface and interfacial tension at 25 °C. The surface parameters including: critical micelle concentration, effectiveness, efficiency, maximum surface excess and minimum surface area were determined. The surface activities of the cationic surfactants were correlated with their chemical structure. The surface activities of the surfactants increased with increasing the hydrophobic chain length. The adsorption and micellization tendencies of the surfactants in solution were determined using the free energies of adsorption and micellization. The synthesized surfactants were evaluated as biocides against bacteria and fungi. Biocidal activity data showed that a gradual increase in the hydrophobic chain length of the surfactant molecules gradually increases the efficiency of these surfactants as biocides.     

Synthesis and Evaluation of Bis-quaternary-Based Surfactants as Additives for Water-Based Mud

Two series of cationic gemini surfactants, alkanediyl-α,ω-bis[N,N-dimethyl alkyl (octyl or dodecyl)ammonium] dibromide (R-s-R; s = 6, 10, 12 and R = 8 and 12) were prepared and evaluated as additives for water-based mud. The chemical structures of the prepared surfactants were confirmed using FTIR and mass spectroscopy. Surface activity of these compounds has been studied and their surface properties including surface tension, emulsification power, critical micelle concentration, effectiveness, maximum surface excess and minimum surface area were determined. The results showed that the prepared compounds have significant surface activity, especially those of longer hydrophobic chain length. The prepared cationic gemini surfactants were evaluated as viscosifiers and filter loss additives for water-based mud formulated from local Na-montmorillonite clay. XRD analysis was carried out to the Na-montmorillonite clay to determine the interaction of the surfactants with inter layers of the clay structure. Rheological properties, gel strength, thixotropy, filtration properties and the effect of temperature on rheological properties of the water-based mud were studied. The results indicated that the gemini surfactants have a positive effect on the rheological and filtration properties of the Na-montmorillonite clay according to American Petroleum Institute specifications.     

蓝晶石和石英浮选行为的研究（待续）

通过表面张力测试、浮选试验和红外光谱的测定，研究了蓝晶石和石英在阴／阳离子混合表面活性剂系统中的浮选行为。研究结果说明了表面活性剂混合物引起的表面张力下降中的协同作用。在浮选系统中，由于这一协同作用的存在，油酸钠／十二胺的添加导致在很宽的ｐＨ范围内，浮选回收率提高。文中还分析了在阴／阳离子混合表面活性剂系统中捕收剂的吸附机理。     

微通道反应器中工业混合直链烷基苯磺酸盐的连续合成工艺研究

直链烷基苯磺酸是一种重要的阴离子表面活性剂,由其合成的直链烷基苯磺酸盐是价格低廉的表面活性剂之一,广泛应用于洗涤和三次采油等领域。以某煤制油企业的工业混合烯烃生产的直链烷基苯为原料,在微通道反应器中连续合成直链烷基苯磺酸,考察磺化温度、原料摩尔比以及磺化剂浓度等工艺条件对磺酸产物的影响规律,并与纯十六烷基苯磺化规律进行对比。研究发现混合直链烷基苯磺化过程中各个工艺条件对产品收率的影响较大。在反应温度为50℃,SO₃与LAB摩尔比为1.0∶1,停留时间为5.09 s条件下,最终产品中活性物含量可达到94.5%(质量)。同时,设计并搭建了微反应器小试平台,实现连续合成混合烷基苯磺酸盐,磺酸盐产品收率在90%以上,可为该工艺的工业应用提供技术支持。     

阴阳离子表面活性剂复配微乳液增溶性定量分析

利用Winsor相图及最佳增溶参数曲线对比了4种常见阴离子表面活性剂——十二烷基硫酸钠(SDS)、十二烷基磺酸钠(SLS)、十二烷基苯磺酸钠(SDBS)、乙氧基化烷基硫酸钠(AES)微乳液的增溶性能,增溶能力为SDBS>AES>SDS>SLS。选取增溶能力较小的SDS、SLS分别和阳离子表面活性剂十八烷基三甲基氯化铵(OTAC)复配微乳液,当达到最优复配比时,SDS/OTAC、SLS/OTAC体系的最佳增溶参数(SP*)较SDS、SLS体系分别增加了150%、170%,最佳盐度(S*)分别减少了91%和95%。研究还发现,当温度在20~50℃时,SDS/OTAC复配微乳体系的最佳增溶参数略微减小,最佳盐度稍微增加;温度超过50℃后,最佳增溶参数急剧减小,最佳盐度迅速增大。     

阴阳离子表面活性剂复配微乳液增溶性定量分析

摘要：利用Winsor相图及最佳增溶参数曲线对比了四种常见阴离子表面活性剂（十二烷基硫酸钠（SDS）、十二烷基磺酸钠（SLS）、十二烷基苯磺酸钠（SDBS）、乙氧基化烷基硫酸钠（AES））微乳液的增溶性能,增溶能力为SDBS＞AES＞SDS＞SLS。选取增溶能力较小的SDS、SLS分别和阳离子表面活性剂十八烷基三甲基氯化铵(OTAC)复配微乳液,当达到最优复配比时,SDS/OTAC、SLS/OTAC体系的最佳增溶参数（SP*）较SDS、SLS体系分别增加了150%、170%,最佳盐度（S*）分别减少了91%和95%。研究还发现,当温度在20～50℃间变化时,SDS-OTAC复配微乳体系的最佳增溶参数略微减小,最佳盐度稍微增加;温度超过50℃后,最佳增溶参数急剧减小,最佳盐度迅速增大。     

二氢月桂烯醇型三硅氧烷表面活性剂的合成及性能

在自制的Pt-聚甲基乙烯基硅氧烷(PMVS)催化剂作用下,1,1,1,3,5,5,5-七甲基三硅氧烷与二氢月桂烯醇型聚醚在甲苯中经硅氢加成合成系列三硅氧烷表面活性剂(Sxy)。通过FTIR和1HNMR验证了Sxy系列产物的结构,并测试了产物的表面与界面性能,与市售三硅氧烷表面活性剂BD-3077进行比较。结果表明,Sxy可将水的表面张力降低至23 mN/m以下,略高于BD-3077(21 mN/m);质量分数为0.5%的S36、S39和S312溶液在室温下澄清,浊点高于85℃;Sxy均具有优良的水解稳定性,远优于BD-3077。     

A review of fracturing fluid systems used for hydraulic fracturing of oil and gas wells

Hydraulic fracturing has been used by the oil and gas industry as a way to boost hydrocarbon production since 1947. Recent advances in fracturing technologies, such as multistage fracturing in horizontal wells, are responsible for the latest hydrocarbon production boom in the US. Linear or crosslinked guars are the most commonly used fluids in traditional fracturing operations. The main functions of these fluids are to open/propagate the fractures and transport proppants into the fractures. Proppants are usually applied to form a thin layer between fracture faces to prop the fractures open at the end of the fracturing process. Chemical breakers are used to break the polymers at the end of the fracturing process so as to provide highly conductive fractures. Concerns over fracture conductivity damage by viscous fluids in ultra‐tight formations found in unconventional reservoirs prompted the industry to develop an alternative fracturing fluid called “slickwater”. It consists mainly of water with a very low concentration of linear polymer. The low concentration polymer serves primarily to reduce the friction loss along the flow lines. Proppant‐carrying capability of this type of fluids is still a subject of debate among industry experts. Constraints on local water availability and the potential for damage to formations have led the industry to develop other types of fracturing fluids such as viscoelastic surfactants and energized fluids. This article reviews both the traditional viscous fluids used in conventional hydraulic fracturing operations as well as the new family of fluids being developed for both traditional and unconventional reservoirs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40735.     

On the Effect of pH,Temperature, and Surfactant Structure on Bovine Serum Albumin–Cationic/Anionic/Nonionic Surfactants Interactions in Cacodylate Buffer–Fluorescence Quenching Studies Supported by UV Spectrophotometry and CD Spectroscopy

Due to the fact that surfactant molecules are known to alter the structure (and consequently the function) of a protein, protein–surfactant interactions are very important in the biological, pharmaceutical, and cosmetic industries. Although there are numerous studies on the interactions of albumins with surfactants, the investigations are often performed at fixed environmental conditions and limited to separate surface-active agents and consequently do not present an appropriate comparison between their different types and structures. In the present paper, the interactions between selected cationic, anionic, and nonionic surfactants, namely hexadecylpyridinium chloride (CPC), hexadecyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), polyethylene glycol sorbitan monolaurate, monopalmitate, and monooleate (TWEEN 20, TWEEN 40, and TWEEN 80, respectively) with bovine serum albumin (BSA) were studied qualitatively and quantitatively in an aqueous solution (10 mM cacodylate buffer; pH 5.0 and 7.0) by steady-state fluorescence spectroscopy supported by UV spectrophotometry and CD spectroscopy. Since in the case of all studied systems, the fluorescence intensity of BSA decreased regularly and significantly under the action of the surfactants added, the fluorescence quenching mechanism was analyzed thoroughly with the use of the Stern–Volmer equation (and its modification) and attributed to the formation of BSA–surfactant complexes. The binding efficiency and mode of interactions were evaluated among others by the determination, comparison, and discussion of the values of binding (association) constants of the newly formed complexes and the corresponding thermodynamic parameters (ΔG, ΔH, ΔS). Furthermore, the influence of the structure of the chosen surfactants (charge of hydrophilic head and length of hydrophobic chain) as well as different environmental conditions (pH, temperature) on the binding mode and the strength of the interaction has been investigated and elucidated.     

AIP型非离子表面活性剂的制备及在废纸脱墨中的应用

以月桂醇聚氧乙烯醚(AEO-3)、异佛尔酮二异氰酸酯(IPDI)和不同相对分子质量的聚乙二醇(PEG)为原料制备了一系列AIP型非离子表面活性剂.考察了最佳合成工艺,并研究了合成产物及复配产品在浮选法废纸脱墨中的应用.结果表明,使用相对分子质量400的PEG,在反应温度50℃,反应时间1.5h,催化剂用量1.0％,n(AEO-3)∶n(IPDI)∶n(PEG-400)=1∶1∶1时制备的AIP(即AIP-400)具有较好的浮选脱墨效果;AIP-400、AEO-3和脂肪醇聚氧乙烯醚硫酸钠(AES)复配使用时的脱墨效果有进一步的提高,m(AIP-400)∶m(AES):m(AEO-3)=1:2:1,用量为0.2％时,废杂志纸脱墨后的白度为67.8％,残余油墨量为43.2 mm2/m2.