Solution spraying of poly(methyl methacrylate) blends to fabricate microtextured, superoleophobic surfaces

We describe a simple technique to prepare superhydrophobic and superoleophobic microtextured surfaces by spray coating a blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS, γ_sv ≈ 10 mN/m) using an air brush with a pressurized nitrogen stream. Scanning electron micrographs show the formation of microtextured surfaces possessing re-entrant curvature; a critical feature for obtaining liquid repellency with low surface tension liquids. The surface morphology can be tuned systematically from a corpuscular or spherical microstructure to a beads-on-string structure and finally to bundled fibers by controlling the solution concentration and molecular weight of the sprayed polymer. The oleophobicity of the resulting structures is characterized by advancing and receding contact angle measurements with liquids of a range of surface tensions.     

水溶性分散剂苯乙烯——马来酸酐（SMA）的合成及应用性能研究

通过溶液聚合的方法合成了苯乙烯--马来酸酐型（SMA）水溶液分散剂，用乌式粘度计对共聚物进行了表征，并用吊环法测定了共聚物的表面张力，当其水溶液浓度为0.3g/L时，表面张力下降为37.74mN/m，并用分光光度计表征其分散性能。     

Surfactant properties of low molecular weight phospholipids

Surface tensions, critical micelle concentrations (CMCs), contact angles on hydrophobic polyethylene, and foaming characteristics of phosphatidic acids, phosphatidylcholines, phosphatidylethanolamines, and phosphatidylglycerols were measured to determine their suitability as substitutes for traditional surfactants. These phospholipids have fatty acid chains of 5 to 12 carbon atoms, a range over which they are soluble at room temperature. Their surface tensions decrease with increasing concentrations until their CMCs are reached, above which their plateau surface tensions are as low as 21 mN/m, indicating excellent surface activities. In general, plateau surface tensions decrease with increasing chain length within each phospholipid type. The classical relationship for In CMC vs. chain length is followed with slopes typical of anionic surfactants for phosphatidic acids and phosphatidylglycerols and resembling zwitterionic surfactants for phosphatidylcholines and phosphatidylethanolamines, consistent with the charge on the hydrophilic group. The wetting capabilities of aqueous solutions on polyethylene are good and foam heights and stabilities are high, the latter two properties being comparable to traditional anionic (sodium dodecylsulfate) and nonionic (octylphenol polyethoxylate) surfactants. Some anomalies are observed regarding the effect of chain length on wetting and foaming, probably due to the depletion effect. Many phospholipids slowly degrade in aqueous solution. We conclude that short-chain phospholipids exhibit excellent surfactant properties and may be useful in many applications.     

新型阴离子孪连表面活性剂的合成

系列长链环氧烷与不同短链二醇在75~80℃、NaH作用下合成了系列中间体孪连长链二醇,此中间体再与1,3-丙烷磺酸内酯在THF、NaH中反应得到了疏水链长度和连接基长度不同的7种磺酸盐孪连表面活性剂。核磁共振氢谱及红外光谱的结构分析证实了它们的结构。它们的表面张力为26.5~34 mN/m,临界胶束浓度为0.001~0.01 mmol/L,结果表明,它们的表面活性比相应碳链的常规表面活性剂强很多。疏水链长度和连接基长度的增长,有助于表面活性的提高。     

脂肪酸单乙醇酰胺硫酸酯盐的物化性能

用滴体积法测定了纯化脂肪酸单乙醇酰胺硫酸酯盐(MSN)系列产品水溶液的表面张力,发现当MSN疏水基碳数(n)由10增至16时,其表面过剩浓度(Γm)由2.37×10-6mol/m2增至2.88×10-6mol/m2,临界表面张力(γCMC)由28.79 mN/m降至23.86 mN/m,降低表面张力20 mN/m所需浓度的负对数(pC20)由3.53升为5.54,临界胶束浓度(CMC)由1.40×10-3mol/L降为0.52×10-3mol/L。在所测定的温度(25℃)下,logCMC=-2.13-0.07n;在胶束化过程中,TΔS0m ic对ΔG0m ic的贡献比ΔH0m ic大,MSN胶束化的主要驱动力是熵变。     

居贝特十四醇聚氧乙烯醚羧酸钠盐的合成及表面性能

以正庚醇为起始原料,经过Guerbet、Williamson等一系列反应合成出了具有支链结构的居贝特十四醇聚氧乙烯醚羧酸钠盐[C14GA(EO)nCH2COONa,n=1-4]。用IR、NMR测定了所合成的表面活性剂的结构;用滴体积法测定了其表面张力。结果表明:该类表面活性剂有比较好的表面性能,并且随着分子中氧乙烯(EO)单元数的增多,该系列表面活性剂[C14GA(EO)nCH2COONa,n=1-4]的临界胶团浓度(CMC)以及临界胶团浓度时的表面张力(γCMC)降低,分别为:10．50 mmol/L,27．87 mN/m;0．85 mmol/L,26．00 mN/m;0．75 mmol／L,25．20 mN/ m:0．59 mmol/L,25．18 mN/m。讨论了该类表面活性剂的结构与表面活性的关系。     

季铵盐双子表面活性剂的合成和表面活性

以吗啉和溴代烷为原料,合成了两种季铵盐双子表面活性剂(m-6-m,m=10,12),并用IR和1HNMR表征了其结构。测得28℃时,12-6-12和10-6-10的表面张力(γCMC)分别为26.45 mN/m和25.55 mN/m;临界胶束浓度(CMC)分别为1.0 mmol/L和3.1 mmol/L;pC20值分别为3.48和3.03;比表面过剩(Γmax)分别为2.72×10-6mol/m2和2.80×10-6mol/m2;分子最小截面积(Amin)分别为0.611 nm2和0.593 nm2。结果表明,该季铵盐双子表面活性剂与相同离子头基及烷基链的单季铵盐表面活性剂相比,CMC低一个数量级,γCMC相差不大。     

Characterizations of surfactant synthesized from Jatropha oil and its application in enhanced oil recovery

Surfactants are frequently used in chemical enhanced oil recovery (EOR) as it reduces the interfacial tension (IFT) to an ultra‐low value and also alter the wettability of oil‐wet rock, which are important mechanisms for EOR. However, most of the commercial surfactants used in chemical EOR are very expensive. In view of that an attempt has been made to synthesis an anionic surfactant from non‐edible Jatropha oil for its application in EOR. Synthesized surfactant was characterized by FTIR, NMR, dynamic light scattering, thermogravimeter analyser, FESEM, and EDX analysis. Thermal degradability study of the surfactant shows no significant loss till the conventional reservoir temperature. The ability of the surfactant for its use in chemical EOR has been tested by measuring its physicochemical properties, viz., reduction of surface tension, IFT and wettability alteration. The surfactant solution shows a surface tension value of 31.6 mN/m at its critical micelle concentration (CMC). An ultra‐low IFT of 0.0917 mN/m is obtained at CMC of surfactant solution, which is further reduced to 0.00108 mN/m at optimum salinity. The synthesized surfactant alters the oil‐wet quartz surface to water‐wet which favors enhanced recovery of oil. Flooding experiments were conducted with surfactant slugs with different concentrations. Encouraging results with additional recovery more than 25% of original oil in place above the conventional water flooding have been observed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2731–2741, 2017     

三次采油用表面活性剂结构对油/水界面性能的影响

测定了几种不同分子结构的磺酸盐类阴离子表面活性剂、两性表面活性剂和非离子表面活性剂水溶液与国内某油田原油间的界面张力。结果表明:磺酸盐类表面活性剂降低油水界面张力的能力相对较高,且磺酸盐的烷链长度、芳环种类对界面张力的影响较大,调整磺酸盐的分子结构可以使油水界面张力降低到10~(-2)mN/m数量级;醇/酚醚类非离子表面活性剂以及两性表面活性剂仅能使油水界面张力降低至0.1 mN/m~10 mN/m数量级。     

Biosurfactant production from n-paraffins by an air isolate Pseudomonas aeruginosa OCD1

The potential production of biosurfactant was investigated with a strain of Pseudomonas aeruginosa OCD(1), which was isolated from air in our laboratory. The degradation of different hydrocarbons was studied with this microorganism. The values of surface tension and emulsification index of culture broth were very promising when n-octadecane was used as substrate. Characterization of biosurfactant revealed that the biosurfactant was rhamnolipid in nature. The surface tension of water was reduced to 31.5 mN/m from 72 mN/m with the critical micelle concentration of 35 mg/L. A low rhamnolipid concentration (< 5 mg/L) had a strong effect on reduction of surface tension.     

Adhesion of Streptococcus sanguis to porous and non-porous substrates with well-defined surface energies

Adhesion of the oral bacterium Streptococcus sanguis was investigated on two series of surfaces, one solid, non-porous and one porous with a pore diameter centered around 0.2 μm. Each series consisted of four substrates with varying surface free energies: pure aluminum oxide, poly(ethylene glycol) (PEG)-modified aluminum oxide, and two types of silanized aluminum oxide. The surface composition was analyzed by ESCA and the surface free energy and acid-base character were determined by contact angle measurements using water, formamide, and diiodomethane according to van Oss and Good. Contact angle measurements were conducted on non-porous substrates which had been subjected to the same silanization procedure as the porous ones. Untreated aluminum oxide and PEG-modified aluminum oxide were both hydrophilic and gave water contact angles of less than 10°. One silanization procedure gave a surface of intermediate hydrophobicity, with a γ^tot of 47.5 mN/m; the other gave a strongly hydrophobic surface of γ^tot = 27.4 mN/m. Adhesion of S. sanguis was measured by using radiolabelled bacteria. It was demonstrated that more bacteria adhered to the porous than to the non-porous substrate and that the PEG treatment, as well as the two silanization procedures, resulted in a decrease in bacterial adhesion, in relation both to the controls treated with aqueous buffer and to surfaces treated with fresh saliva.     

N-丙基-N-全氟辛基磺酰基甘氨酸盐类表面活性剂的合成方法改进及性能

以国产全氟辛基磺酰氟为原料 ,与正丙胺在异丙醚中 5 0℃下反应制得到N 丙基全氟辛基磺酰胺 ,再与氯乙酸乙酯在碱性条件下回流缩合得N 丙基 N 全氟辛基磺酰基甘氨酸乙酯 ,水解后得到N 丙基 N 全氟辛基磺酰基甘氨酸 ,总产率 79%。其锂、钠、钾盐的CMC值分别是 6 72mg/L、2 1 66mg/L及 3 0 79mg/L ,在质量浓度为 80mg/L时表面张力均降至 2 0mN/m以下 ,说明该类产品具有良好的表面活性     

Biochar as a filler in mixed matrix materials: Synthesis,characterization, and applications

The use of mixed-matrix materials (MMM) has become a major topic of research in recent years, due to unique properties achieved in these composites. In this work, biochar from sunflower seed hull pyrolysis and biochar/polysulfone (PSF) MMMs were produced and characterized. The optimal pyrolysis temperature for biochar production was determined to be 500 °C. The resulting biochar properties were an iodine number of 203 mg/g and a pore volume of 0.595 mL/g. In MMM fabrication, the use 4% ethanol as nonsolvent in the wet phase inversion process increased the glass transition temperature by 8 °C, indicating improved biochar/PSF interaction. The presence of biochar was shown to create pores in otherwise dense surfaces. The critical surface energy was also increased by the addition of biochar from 28.6 mN/m in pristine PSF to 35.7 mN/m in biochar/PSF MMMs. We identified and discussed several potential applications based on the determined properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48027.     

机油乳油提高药液对紫茎泽兰叶片润湿性研究

测定添加机油乳油的氨氯吡啶酸药液和甲嘧磺隆药液的表面张力,得到了机油乳油可以很明显地降低市售的氨氯吡啶酸、甲嘧磺隆制剂药液的表面张力的结论。氨氯吡啶酸的表面张力可由80mN/m左右降低到37mN/m左右,甲嘧磺隆可从90mN/m左右降低到40mN/m左右。通过氨氯吡啶酸药液和甲嘧磺隆药液与紫茎泽兰叶片接触角随时间变化规律的研究,确定液滴与叶片达到平衡的时间,即接触角测定的最佳时间。在药液与叶片达到平衡时,测定添加不同浓度机油乳油的氨氯吡啶酸药液与甲嘧磺隆药液与紫茎泽兰叶片的接触角,找出接触角较小时机油乳油的最低浓度,探索出提高药液在紫茎泽兰叶片润湿性的最小机油乳油添加浓度,以期为野外紫茎泽兰的化学防除工作提供参考。结果表明,液滴与紫茎泽兰叶片平衡时间为50s;农药与助剂最佳搭配为:0.2～0.4g/L氨氯吡啶酸+0.020%～0.040%机油乳油,0.4～0.8g/L氨氯吡啶酸+0.004%～0.040%机油乳油,0.8～1.6g/L氨氯吡啶酸+0.004%机油乳油;0.1～0.2g/L甲嘧磺隆+0.020%机油乳油,0.2～0.4g/L甲嘧磺隆+0.020%～0.040%机油乳油、0.4～0.8g/L甲嘧磺隆0.020%～0.040%机油乳油。     

沥青质模型油/MD膜驱剂溶液的界面张力

从MD膜驱剂与原油界面活性组分沥青质模型油的界面张力出发,考察了作用时间、水相pH、MD膜驱剂质量浓度、盐浓度、沥青质含量、芳香度、温度等对模型油/水界面张力的影响,并根据扩散控制机理解释了动态界面张力初期过程,进一步揭示了MD膜驱油技术的机理。结果表明,沥青质模型油/MD膜驱剂溶液的界面张力先随时间增加而降低,约15min后达到平衡,达到平衡之前的过程基本上符合扩散控制过程;MD膜驱剂的加入并不能改变pH对模型油/水界面张力的影响趋势;在所考察的条件范围内,沥青质模型油/水溶液的界面张力不随MD膜驱剂质量浓度增加而改变,其值约为19 65mN/m;NaCl对界面张力的影响不明显;沥青质质量浓度从0增加到1000mg/L时,模型油/水和模型油/MD膜驱剂溶液的界面张力分别从23 4mN/m和22 0mN/m逐渐下降至20 0mN/m和18 8mN/m;温度从25℃升高到45℃时,模型油/水溶液的界面张力降低;但芳香度从0增加到100%时,其界面张力均从21 0mN/m增加至31 5mN/m。MD膜驱剂是表面非活性物质,在驱油时不存在低界面张力提高采收率的机理。     

表面活性剂的复配及对甲维盐微乳剂物理稳定性的影响

通过测定不同类型的单一及复配型表面活性剂水溶液的临界胶束浓度和表面张力,研究了它对w(甲维盐)=1％的微乳剂物理稳定性的影响。膦酸酯类阴离子表面活性剂A的临界胶束浓度为1．79×10-4 mol／L,表面张力为28．90 mN/m;苄基酚聚氧乙烯聚氧丙烯醚嵌段型非离子表面活性剂B(EPE型)的临界胶束浓度为 1.91×10-4 mol/L,表面张力为20．70 mN/m;按m(A):m(B)=2:3形成的复配型表面活性剂2#的水溶液的临界胶束浓度为9．30×10-5 moL/L,表面张力为25．66 mN/m。当w(2#)=10％时,配制w(甲维盐)=1％的微乳剂物理稳定性最佳,各项指标均合格。     

Foam fractionation of spent sulphite liquor: Part I: Separation of surfactants

The surface activity of spent sulphite liquor (SSL) and the separation of surface active components by foam fractionation were studied. The maximum activity (lowest surface tension) of SSL was observed at a high pH. The surface tension was found to be 42 mN/m and 38 mN/m at acidic and basic pH values, respectively, and also a maximum foaminess (Σ) of 7 min was observed at pH 10. Foam fractionation reduced the surfactant concentration by 90% at an optimum pH of 10. The surfactants were concentrated in the collapsed foam as shown by the fact that the critical micelle concentrations of the unfractionated SSL and foam were 70% (v/v) and 10% (v/v), respectively. The removed surfactants were concentrated in 20% of the original liquid volume.     

Surface modification of poly(propylene) by photoinitiators: Improvement of adhesion and wettability

Different benzophenone‐type photoinitiators were photografted onto poly(propylene) (PP). The polymer surfaces were analyzed by means of contact angle measurements, UV spectroscopy, and FTIR‐ATR. The modified samples showed a better wettability and higher surface energies, increasing from 26 mN/m for pure PP to 36 mN/m for the modified samples. The UV spectrum of the modified PP films showed two absorption bands that could be related to the grafted initiator. The effect of irradiation time and photoinitiator concentration was investigated. Different acrylates were grafted efficiently onto the modified polymer surfaces. FTIR‐ATR and contact angle measurements confirmed the presence of the grafted chains. The surface energy of the grafted surfaces of samples increased to 70 mN/m, depending on the type of acrylate used. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2341–2350, 2004     

Bubble point pressures of binary methanol/water mixtures in fine‐mesh screens

Binary methanol/water mixture bubble point tests involving three samples of fine‐mesh, stainless steel screens as porous liquid acquisition devices are presented in this article. Contact angles are measured as a function of methanol mass fraction using the Sessile Drop technique. Pretest predictions are based on a Langmuir isotherm fit. Predictions and data match for methanol mole fractions greater than 50% when pore diameters are based on pure liquid tests. For all three screens, bubble point is shown to be a maximum at a methanol mole fraction of 50%. Model and data are in disagreement for mole fractions less than 50%, which is attributed to variations between surface and bulk fluid properties. A critical Zisman surface tension value of 23.2 mN/m is estimated, below which contact angles can be assumed to be zero. Solid/vapor and solid/liquid interfacial tensions are also estimated using the equation of state analysis from Neumann and Good. Published 2013 American Institute of Chemical Engineers AIChE J 60: 730–739, 2014