壳聚糖保鲜膜界面润湿特性的研究

通过几种表面活性剂的性能比较发现 :在壳聚糖溶液中加入表面活性剂 Tween2 0 ,可有效改善壳聚糖涂膜保鲜水果时润湿性差的现状 ,界面接触角从原来的 10 5°降低到 5 2°。同时 ,研究了 Tween2 0的浓度和润湿时间与界面润湿性能的关系     

阴离子表面活性剂与多煤阶煤尘润湿过程实验研究

为了研究表面活性剂与煤尘润湿过程的机理,增加不同煤尘的润湿性,本文选取了八种煤化程度不同的煤,和十种表面活性剂的五种浓度(0.2%、0.4%、0.6%、0.8%、1.0%)进行煤尘沉降实验。实验结果表明:表面活性剂的润湿性能会随着溶液浓度的增加而增加,在达到最佳溶液临界胶束浓度后,润湿性能不变或降低。其中润湿性能较好的试剂有:月桂酰胺丙基氧化胺、改性烷基糖苷、咪唑啉、α-烯基磺酸钠。改性烷基糖苷对八种煤样的润湿性都最佳。而其他几种试剂只对部分煤样的润湿性较好。     

表面活性剂驱油效率的影响因素研究

在83℃下测定了3种表面活性剂DL-S、HL-Y/NNR、GZ-16的油水界面张力、乳化能力以及改变油藏岩石润湿性的能力。利用低渗透岩心驱油实验研究表面活性剂的这3种特性对驱油效率的影响。结果表明,表面活性剂的浓度在1 000 mg/L时,DL-S的油水界面张力达到10-3mN/m超低数量级,HL-Y/NNR表现出较为优越的乳化性能,GZ-16具有较好的润湿性能。在驱油实验中,具有最好乳化性能的HL-Y/NNR提高采收率的幅度最大为12.91%,其次为具有超低界面张力的DL-S,相较而言,改变润湿性的能力对驱油效率的影响最小。     

油田用润湿反转剂的应用与展望

本文主要论述油田用润湿反转剂的种类、作用机理及在油田现场中的应用效果和展望。对比了阳离子、阴离子及非离子表面活性剂等在界面的作用机理。化学剂在矿物表面的吸附、沉积或化学反应是岩石表面润湿性反转的基础。润湿性改变的方向和程度主要取决于所使用润湿反转剂的类型与浓度。岩石矿物成分、原油组分、地层水的化学组成及pH值等是润湿性改变方向和程度的影响因素。研究表明,表面活性剂在油层中的润湿性反转作用,使亲油表面变为亲水表面,润湿性的改变可大大影响油藏的最终采收率。     

基于可再生原料的表面活性剂复配体系的优异润湿性:吸附和胶束化过程中的协同效应

本文研究了由可再生原料制备的三种表面活性剂(APG、AE、脂肪酸钠)复配后的表面性能,主要目的是优化一元、二元、三元复配溶液和不同p H条件下产生最佳润湿性的复配表面活性剂比例。结果表明:几种复配表面活性剂溶液在界面张力、临界胶束浓度和混合胶束化过程中存在协同效应。AE-APG复配后展现了最佳润湿性能。AE-APG-脂肪酸钠三元复配体系在聚四氟乙烯表面和玻璃表面的接触角随着浓度增大而略微减小。此外,所有复配溶液在酸性、碱性及中性介质中都展现了良好的表面性能。与其他p H条件下相比,当p H=7时,AE∶脂肪酸钠(1∶2)、AE:APG(2∶1)和AE∶APG∶脂肪酸钠(1∶1∶1)提高了铝表面和玻璃表面的润湿力。以上研究表明:使用很少的表面活性剂可以达到清洗、润湿和增溶的效果,同时还可降低成本、保护环境。     

碱复合蒸汽驱提高高酸值稠油采收率机理研究

针对新疆油田J油藏稠油酸值高的特点，基于酸碱反应原位生成表面活性剂的机理，提出碱复合蒸汽驱提高采收率的方法，通过实验探究强碱和弱碱与高酸值原油反应对界面张力、润湿性及乳化性能的影响，进一步明确了碱与高酸值原油反应的机理和效果及碱蒸汽在多孔介质中的驱油效率。结果表明：质量分数0.1%的NaOH溶液与原油具有最小界面张力；同时质量分数0.1%的NaOH溶液改善润湿性效果较好，这是因为碱与原油中的酸反应生成表面活性剂，将岩石由油湿转化为水湿；乳液油水比为3∶7时，NaOH溶液具有最佳的乳化降黏效果。在蒸汽驱过程中，由于原油和蒸汽密度的差异，累积驱油效率仅为38.94%。在碱蒸汽复合驱过程中，注入碱溶液后，乳化降黏效果明显，稠油的流动能力增强，驱油效率提高，含水率降低。达到经济极限时，累积驱油效率达到54.02%，累积驱油效率提高了15.08%，具有更好的驱油效果。     

表面活性剂溶液润湿行为研究进展

润湿是指溶液在固体表面的铺展过程。本文主要从溶液铺展能力、表面活性剂吸附和固体表面性质等三个方面综述了表面活性剂溶液在固体表面的润湿行为及其研究和进展。     

岩石表面可润湿性反转对二元复合驱提高采收率的影响

考察了克拉玛依石油磺酸盐(KPS)、磺基甜菜碱(BS)、脂肪胺聚氧乙烯醚(FAPE)和十二烷基二甲基苄基氯化铵(1227)等4种表面活性剂的溶液改变含油天然岩芯砂模型表面可润湿性的能力和对新疆油田七东1区原油的静态洗油效率。分别将KPS,BS和FAPE与聚丙烯酰胺(KYPAM-2)组成二元复合体系,测试了KPS/KYPAM-2,BS/KYPAM-2和FAPE/KYPAM-2二元体系与1227溶液对原油的界面张力,并计算了它们剥离岩石表面油滴所需克服的粘附功,最后利用上述二元体系与1227溶液进行了驱油效率的考察。结果表明:4种表面活性剂溶液均能使岩石表面的可润湿性由油性润湿向中性或水性润湿反转;其中BS的粘附功为0.018 J,静态洗油效率为85.7%,BS/KYPAM-2二元体系水驱后提高采收率12.7%,在4种表面活性剂里性能最好。     

不同反离子双癸基季铵盐对聚四氟乙烯表面的吸附行为

利用座滴法研究了系列反离子双癸基季铵盐和Gemini型季铵盐表面活性剂对超疏水材料聚四氟乙烯(PTFE)表面的吸附行为。考察了表面活性剂的表面活性、类型和浓度对接触角的影响规律,并探讨了铺展系数、黏附张力和黏附功的变化规律。研究表明:双癸基季铵盐表面活性剂在PTFE表面的接触角随着反离子基团的增大呈现先减小后增大的趋势,其中反离子最大的双癸基二甲基戊酸铵(DDAV)在PTFE表面的润湿效果最好;铺展系数(S)随着反离子有机酸基团的增大呈现先减小后增大的趋势;当表面活性剂的质量浓度低于cmc时,粘附力和表面张力之间呈现出良好的线性关系;当质量浓度大于cmc时,反离子基团小的表面活性剂溶液在固-液界面和气-液界面形成了饱和吸附层。反离子基团较大的表面活性剂在气-液界面达到饱和吸附,但在固-液界面上没有达到饱和,随着浓度的增加继续吸附,润湿性能增强。     

盐22块砂砾岩油藏复合增注技术实验研究

针对胜利油田低渗透和特低渗透砂砾岩油藏开发中存在的产能下降快、注水压力高和解堵效果差,严重影响储量有效动用的问题,以盐22块油层为对象,研究了缓速酸解堵、表面活性剂及润湿反转剂增注复合降压增注技术。实验研究了在模拟地层条件下油层岩石结构、酸溶蚀率、解堵性、化学剂耐温耐盐及表界面性、表面活性剂溶油性、润湿反转剂润湿性和表面活性剂-润湿反转剂对水相渗透率的影响。实验结果表明,复合降压增注技术可降压20%以上,大幅度提高水相渗透率,为实现该类型油藏有效注水提供参考。     

A new method for the characterisation of the wettability of powders

The wetting characteristics of fine powders play an important role in a variety of processes. The most important way of characterising the wettability of a fluid/fluid/solid system is to measure the contact angle. This paper describes a relatively simple method for the determination of the contact angle on powdery materials. The technique involves the measurement of the dynamic contact angle which is formed when a liquid drop is placed on a horizontal porous surface. On the basis of the measured dynamic contact angle as a function of time an “apparent” static contact angle has been defined, which gives a measure of the wettability of porous solid systems by analogy with the wetting of non-porous solids. Determinations with glass beads and NaCl-powders as the test materials indicate that the measured value depends on the particle size of the powder, the porosity and the temperature. It was concluded that the capillary penetration of the liquid droplet into the porous media itself influences the wetting characteristics.     

Assessment of the Wettability of Porous Electrodes for Lithium-Ion Batteries

The wettability of lithium cobalt oxide (LiCoO₂) and mesocarbon microbead electrodes in nonaqueous electrolyte is analyzed by a mathematical model of capillary liquid movement. Results show that wetting in the LiCoO₂ electrodes is difficult as compared with the MCMB electrodes at the same electrolyte composition. Wetting in the porous electrodes is controlled mainly by electrolyte penetration and spreading in pores. Electrolyte penetration is determined by viscosity. On the other hand, electrolyte spreading is controlled by surface tension. Organic solvent composition and lithium salt concentration may influence the wettability of porous electrodes due to changes in the viscosity and surface tension of the electrolyte. Increasing the amount of EC and/or lithium salts can cause poorer electrolyte spreading and penetration. Furthermore, careful pressure control has a positive effect on increasing the surface area of the solid–liquid interface. AC impedance data show that batteries with vacuuming prior to electrolyte filling may reach a maximum wetting in a few hours. If no vacuuming is applied, a few days are required to obtain sufficient wetting.     

Surfactant-Induced Wettability Alteration of Oil-Wet Sandstone Surface: Mechanisms and Its Effect on Oil Recovery

Different analytical methods were utilized to investigate the mechanisms for wettability alteration of oil-wet sandstone surfaces induced by different surfactants and the effect of reservoir wettability on oil recovery. The cationic surfactant cetyltrimethylammonium bromide (CTAB) is more effective than the nonionic surfactant octylphenol ethoxylate (TX-100) and the anionic surfactant sodium laureth sulfate (POE(1)) in altering the wettability of oil-wet sandstone surfaces. The cationic surfactant CTAB was able to desorb negatively charged carboxylates of crude oil from the solid surface in an irreversible way by the formation of ion pairs. For the nonionic surfactant TX-100 and the anionic surfactant POE(1), the wettability of oil-wet sandstone surfaces is changed by the adsorption of surfactants on the solid surface. The different surfactants were added into water to vary the core surface wettability, while maintaining a constant interfacial tension. The more water-wet core showed a higher oil recovery by spontaneous imbibition. The neutral wetting micromodel showed the highest oil recovery by waterflooding and the oil-wet model showed the maximum residual oil saturation among all the models.     

羟基和酯基型Gemini双季铵盐表面活性剂在煤沥青表面的润湿特性

以自制的羟基和酯基型Gemini双季铵盐表面活性剂为研究对象,在考察其表面活性的基础上,进一步研究了表面活性剂在煤沥青表面的润湿性。研究表明,羟基型Gemini表面活性剂在煤沥青表面的接触角随疏水链长度的增长呈先减小后增大趋势,其中C₁₂-OH在煤沥青表面的润湿效果最好;对于m-n-m酯基型Gemini表面活性剂而言,接触角随疏水链长度的增长而降低。当疏水链长度一定时,m-6-m在煤沥青表面的润湿效果比m-2-m好。在一定浓度范围内,C₁₀-OH、C₁₂-OH和12-2-123种Gemini表面活性剂的表面张力与其在煤沥青表面黏附张力呈线性关系。煤沥青表面的Zeta电位随Gemini表面活性剂浓度的增大呈先增大后趋于平稳的趋势。     

Pore diameter-dependence wettability of porous anodized aluminum oxide membranes

Porous anodized aluminum oxide membranes with different diameters are fabricated and characterized, and the relation between the pore diameters and the wettability is investigated. The results indicate that changing the diameter of the porous anodized aluminum oxide from 15 to 220 nm causes the wettability on the surface of porous anodized aluminum oxide within the range from hydrophilicity to hydrophobicity. The presence of nanopores is recognized as one of the main causes of the transform of the wettability on the surfaces of the porous anodized aluminum oxide. The wettability-controllable anodized aluminum oxide surface can be an excellent platform on which to elucidate the physical nature of the wetting phenomenon related to the nanostructure and has promising potential in technological applications.     

表面活性剂吸附对促进甲烷水合物生成效果的影响

基于表面活性剂固-液界面吸附理论,在无搅拌条件下研究了十二烷基硫酸钠（SDS（、脂肪醇聚乙烯醚硫酸钠（AES（、脂肪醇聚乙烯醚（AEO（3种表面活性剂在不锈钢反应釜中对甲烷水合物生成的促进效果。结果表明：水合物的生成形态与表面活性剂吸附金属表面形态有良好的对应关系;SDS与AES在金属表面的吸附作用可使水合物成核速率提高,成核位置增多。由于AEO不能在金属壁面发生吸附,导致对水合物生成促进效果降低,在浓度为300 mg·L^-1的SDS、AES和AEO溶液中,水合物储气密度及平均储气速率分别为131.4、128.3、12.3（体积比（和5.8、7.6、0.07 mmol·min^-1;逐步提高SDS溶液浓度（80~1200 mg·L^-1（和AES溶液浓度（60~1350 mg·L^-1（,水合物储气密度首先增大然后减小,储气速率线性增大。因此,合理选择表面活性剂种类及浓度,可显著促进水合物生成。     

Wetting behavior of human hair fibers

The wetting behavior of human hair in water has been investigated using a technique based on the Wilhelmy balance principle. The experimental technique makes it possible to study the relaxation effects occurring at the solid–liquid–air interface. The results strongly suggest that interactions between the solid and the liquid make important contributions to wettability of the solid surface because of reversible reorientation of polar groups at the interface. The effects of scale structure, weathering, and mechanical damage on wettability of the fiber surface are discussed. Surface roughness of the fiber plays an important role in wetting hysteresis.     

Contact angle of surfactant solutions on precipitated surfactant surfaces. III. Effects of subsaturated anionic and nonionic surfactants and NaCl

The contact angles of saturated calcium dodecanoate (CaC₁₂) solutions containing a second subsaturated surfactant on a precipitated CaC₁₂ surface were measured by using the drop shape analysis technique. The subsaturated surfactants used were anionic sodium dodecylsulfate (NaDS), anionic sodium octanoate (NaC₈), and nonionic nonylphenol polyethoxylate (NPE). Comparing at the critical micelle concentration (CMC) for each surfactant, NaC₈ was the best wetting agent, followed by NaDS, with NPE as the poorest wetter (contact angles of 32⁰, 42⁰, and 62⁰, respectively). Surface tension at the CMC increased in the order NaC₈<NPE<NaDS, and subsaturated surfactant adsorption increased in the order NPE≪NaDS (1.4 vs. 84 μmole/g); adsorption of the NaC₈ was not measurable. Interfacial tension (IFT) reduction at the solid-liquid interface due to subsaturated surfactant adsorption is an important contribution to contact angle reduction, in addition to surface tension reduction at the air-water interface. Surfactant adsorption onto the soap scum solid is crucial to solid-liquid IFT reduction and to good wetting. The fatty acid was the best wetting agent of the three surfactants studied, probably because calcium bridging with the carboxylate group synergizes surfactant adsorption onto the solid of the higher molecular weight soap. NaCl added to NaDS surfactant results in depressed CMC, lower surface tension at the CMC, decreased NaDS adsorption onto the solid, and decreased reduction in solid-liquid IFT. The contact angle is not dependent on the NaCl concentration for NaDS. The NaCl causes an increased tendency to form monolayers, which decrease air-water surface tension, but a decreased tendency to form adsorbed aggregates on the solid; the two trends offset each other, so wettability is not affected by added salt. The Zisman equation does not describe the wetting data for these systems well except for NaDS, further emphasizing the danger of ignoring solid-liquid IFT reduction in interpreting wetting data in these systems.     

Modification of a Poly(tetrafluoroethylene) Porous Membrane to Superhydrophilicity with Improved Durability

The commercial fluorocarbon surfactant (FCS) DuPont? Zonyl 321 fluorinated cationic surfactants, was employed to modify both flat‐sheet and hollow‐fiber poly(tetrafluoroethylene) (PTFE) porous membranes. The variation of morphology, wettability, and hydrophilicity durability to acid and alkali as well as the filtration performance of both membranes were investigated. Such superhydrophilic membranes showed better wetting stability and higher resistance to acid and alkali solutions. Moreover, both membranes exhibited good filtration performance.     

Partial wetting in porous catalysts: wettability and wetting efficiency

Qualitative changes in the local (pore level) wetting efficiency of a porous catalyst as a function of catalyst wettability are proposed based on monitoring the 1-D motion of the solid-liquid-gas contact line. As catalyst wettability is increased, the resulting wetting efficiency is likely to show two distinct transitions viz., (1) a sudden decrease that is inspired by coalescence of neighboring rivulets and, (2) a sudden increase that is inspired by porous nature of the catalyst. As catalyst wettability decreases, the wetting efficiency is likely to decrease in the beginning but can then be held constant due to pinning or holding of the retracting contact line by liquid-filled pores. This will result in comparatively much higher wetting efficiencies. It is further proposed that under favorable circumstances this pinning can disappear and will, thus, allow the contact line to retract and wetting efficiency to decrease. In the end, the effect of catalyst geometry on the relation between wetting efficiency and wettability is presented.