共查询到19条相似文献,搜索用时 156 毫秒
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水相和特殊介质中有序聚集体的结构、性质和应用(Ⅰ)——表面活性剂在水相和离子液体中的有序聚集体 总被引:5,自引:2,他引:3
首先介绍了表面活性剂溶液性质和各种聚集体结构,其中包括胶束、微乳液、囊泡和溶致液晶等,以及聚集规则———临界堆积参数等。同时介绍了表面活性剂在离子液体中形成的各种典型有序聚集结构,特别阐明在室温下表面活性剂在水溶液和离子液体中聚集形成的有序聚集体的异同点;另外还介绍了利用表面活性剂在离子液体中形成的聚集体作为模板制备微纳颗粒。 相似文献
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介绍了黏弹性表面活性剂溶液的性质,确定黏弹性表面活性剂性质的测试方法和实验手段,以及其内部微观结构和流变特性等方面的研究成果。当黏弹性表面活性剂溶液浓度增加到某一临界浓度时,球形胶束开始向蠕虫状胶束转变,溶液黏度突然增大,随着浓度的进一步增大,蠕虫状胶束快速生长、增长并形成线型柔性棒状胶束,柔性棒状胶束相互缠绕、粘附甚至融合,形成某种超分子三维网状结构,溶液黏度急剧增加,并表现出较强的黏弹性。概述了黏弹性表面活性剂在油田中的应用,特别是在压裂液、酸液、钻井液及提高采收率等方面的应用,指出了黏弹性表面活性剂广泛运用的前景和尚未解决的问题。 相似文献
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《日用化学工业》2015,(9)
阴、阳离子表面活性剂之间强烈的相互作用利于形成自由弯曲的蠕虫状胶束。本文利用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和阴离子表面活性剂油酸钠(NaO A)制备了CTAB/NaO A蠕虫状胶束,研究了两表面活性剂的混合比和表面活性剂总浓度的变化对蠕虫状胶束体系稳态流变性及动态黏弹性的影响。结果表明,蠕虫状胶束在剪切过程中的解缠、拟网状结构的破坏以及最终沿剪切速度方向取向等是蠕虫状胶束产生剪切稀释特性的原因。两表面活性剂的混合比和表面活性剂总浓度的变化导致表面活性剂之间的静电作用、疏水作用发生较大的变化,最终引起体系内部表面活性剂聚集体形态的差异。体系内蠕虫状胶束长度、体系结构复杂程度、蠕虫状胶束形成的网络结构的致密度等都影响着体系的流变行为。在混合比R=3.6、总浓度cT=0.24 mol/L时,体系中蠕虫状胶束最长,网络结构最为紧密,体系的零剪切黏度达到最大值。表面活性剂浓度一定时,混合比的提高有助于蠕虫状胶束的定向生长,弛豫时间τR和储能模量高频区平台模量G0提高,R=3.6时两者皆达到极大值,此后由于蠕虫状胶束的分枝化及(或)胶束破裂导致τR及G0下降。在表面活性剂混合比一定(R=3.6)时,表面活性剂浓度的提高利于蠕虫状胶束的增长或者分枝化,增加了胶束网络结构缠绕(融合)点的密度,导致G0逐渐增大。Cole-Cole图证实本文研究的蠕虫状胶束体系是符合Maxwell模型的线性黏弹性流体。 相似文献
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第一讲 微乳液的形成和相态 总被引:1,自引:0,他引:1
一、表面活性剂溶液油-水-表面活性剂所构成的体系叫做胶体缔合结构,又称缔合胶体,广泛应用在日常生活和工业生产。这些体系包括胶束、微乳液、溶致液晶和乳状液等。当表面活性剂溶于水中,吸附在气-液界面上,随着浓 相似文献
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该文以2-氯乙胺盐酸盐和十八烷基叔胺为原料,合成了一种胺基型阳离子表面活性剂——N-十八烷基-N,N’-二甲基-乙基-1,2-胺,通过IR和1HNMR对其结构进行了确证,并得到了优化的合成条件:物料比nb/na 为1.20,反应温度为70 oC,反应时间为7 h,pH为7。此外,采用电导法测定了该种表面活性剂的临界胶束浓度(CMC)随着pH的降低而减小。该表面活性剂在NaSal质量百分浓度为1%条件下,能形成蠕虫状胶束。流变性能测试表明,体系具有蠕虫状胶束的剪切稀释性特征和凝胶特性,同时具有pH响应,能在酸性条件下增黏,是一种智能型蠕虫状胶束体系。 相似文献
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Wormlike Micelles in Mixed Amino Acid‐Based Anionic Surfactant and Zwitterionic Surfactant Systems
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Haiwei Lu Minjia Yuan Bo Fang Jinshuang Wang Yiguang Guo 《Journal of surfactants and detergents》2015,18(4):589-596
The formation of wormlike micelles in aqueous solutions of an amino acid‐based surfactant, sodium lauroyl sarcosinate (LS) and a zwitterionic surfactant, cocamidopropyl betaine (CAPB) has been investigated. Holding the total concentration of LS and CAPB constant at 12 wt%, the synergistic effects of mass ratio of CAPB and LS and pH of the micelle solution on rheological behaviors of CAPB/LS micelles were studied. The viscosity of CAPB/LS micelle systems with a mass ratio from 4:8 to 9:3 increases to maximum values and then decreases as pH increases from 4.0 to 5.6. The maximum viscosity of the transparent CAPB/LS micelle solution is nearly 5500 mPa·s with a mass ratio of CAPB/LS = 8:4 at pH 5.10. It is suggested that the proper pH for CAPB and LS to form wormlike micelles should be close to the isoelectric point of the CAPB/LS solution. The results of thixotropy measurements show that the appropriate mass ratio of CAPB/LS can improve the stability of the network structure of wormlike micelles. In addition, viscosity curves of CAPB/LS wormlike micelles follow a nonlinear co‐rotational Jeffreys model, and the linear viscoelasticity of CAPB/LS wormlike micelles can be described by a linear viscoelastic Jeffreys model. The network of wormlike micelles is confirmed by Cryo‐TEM images. 相似文献
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Qing You Yan Zhang Huan Wang Hongfu Fan Jianping Guo Ming Li 《International journal of molecular sciences》2015,16(12):28146-28155
Wormlike micelles are typically formed by mixing cationic and anionic surfactants because of attractive interactions in oppositely charged head-groups. The structural transitions of wormlike micelles triggered by pH in ionic liquids composed of N-alkyl-N-methylpyrrolidinium bromide-based ILs (ionic liquids) and anthranilic acid were investigated. These structures were found responsible for the variations in flow properties identified by rheology and dynamic light scattering, and account for the structures observed with cryogenic transmission electron microscopy (Cryo-TEM). High-viscosity, shear-thinning behavior, and Maxwell-type dynamic rheology shown by the system at certain pH values suggested that spherical micelles grow into entangled wormlike micelles. Light scattering profiles also supported the notion of pH-sensitive microstructural transitions in the solution. Cryo-TEM images confirmed the presence of spherical micelles in the low-viscosity sample and entangled wormlike micelles in the peak viscosity sample. Nuclear magnetic resonance spectroscopy analysis revealed that the pH sensitivity of ionic liquid systems originated from the pH-dependent binding ability of anthranilic acid to the cationic headgroup of ionic liquids. 相似文献
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Hydrophobically modified polymers were synthesized via esterification reactions between a commercial triblock copolymer composed of ethylene oxide (EO) and propylene oxide (PO) segments (EO20PO70EO20) and lauric and oleic acids. Rheological studies of aqueous systems containing the original copolymer and the synthesized products were performed to evaluate the effects of chemical modification, the presence of salt, and temperature on the rheology of the systems due to changes in the micellar structures. It was verified that the systems containing the synthesized products presented shear‐thinning behavior even in the absence of salt. In addition, increasing the temperature and salt concentration enhanced the hydrophobic character of the poly(propylene oxide) segment and reduced the hydration of the poly(ethylene oxide) segment; this favored the adequate packing needed to form long, wormlike micelles and resulted in pronounced shear thinning. The formation of a complex micelle structure probably occurred in the systems above the critical micellar temperature of the original copolymer because under this condition the molecules presented three alternate hydrophobic segments that had to dive into the micelle structure. The formation of long, wormlike micelles was also evidenced by the Maxwellian behavior observed in rheological oscillatory measurements. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Sudheesh Parathakkatt Jinu George Sajeev Moothandassery Sankarakutty Lisa Sreejith 《Journal of Polymer Research》2009,16(5):577-582
The effect of octanol on the interaction of polyethylene glycol (PEG) and cetylpyridinium chloride (CPC) were investigated
by viscosity, conductivity, differential scanning calorimetry (DCS), polarizing microscopy, Fourier transform infrared spectroscopy
(FTIR) and rheology analysis. The aggregation of polymer-surfactant micelles takes place at a surfactant concentration higher
than the critical micelle concentration. The long chain aliphatic alcohol (n-octanol) induced rapid structural transformation
in the mixed micellar system by unusual cooperative micellization. The rheological behavior of the viscoelastic system reveals
the presence of giant aggregates in this system. The lyotropic nature of the giant aggregates was monitored by DSC and polarizing
microscopic studies, and which was confirmed by cryo-TEM. 相似文献
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Brahim Lakhrissi Loubna Lakhrissi Mohamed Massoui El Mokhtar Essassi Francesc Comelles Jordi Esquena Conxita Solans Carlos Rodríguez-Abreu 《Journal of surfactants and detergents》2010,13(3):329-338
The surface and self-aggregation properties in water of a new series of amphiphilic homologues, bis-benzimidazolone derivatives
of d-glucose, were investigated. Parameters such as the maximal surface excess concentration, minimal area per molecule at the
interface, and critical micelle concentration (CMC) were found to be significantly dependent on the hydrophobic alkyl chain
length. The synthesized compounds form micelles at remarkably low concentrations, and CMCs derived from surface tension measurements
show a minimum as a function of the alkyl chain length; this unusual trend can be attributed to the formation of submicellar
aggregates in compounds with long alkyl chains, as evidenced from fluorescence probe spectroscopy data. At high surfactant
concentrations, lyotropic liquid crystalline phases with hexagonal structure are formed. Small angle X-ray scattering measurements
indicate that the characteristic nanoscopic lengths increase with water swelling and alkyl chain length. 相似文献
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Mingwei Zhao Zhibin Gao Caili Dai Xin Sun Yue Zhang Xiujie Yang Yining Wu 《Journal of surfactants and detergents》2019,22(3):587-595
Enhancing the viscoelastic properties of wormlike micelles by adding nanoparticles has been widely reported. Various mechanisms have been proposed to explain how nanoparticles strengthen the network formed by wormlike micelles. It remains unclear whether nanoparticles produce the same effect on systems with different entanglement degrees. To clarify this issue, the concentration of potassium chloride was used to control the entanglement degree of wormlike micelles. The rheological behavior of different nanoparticle-enhanced wormlike micellar systems (NEWMS) was investigated using rheology. Three critical parameters including zero-shear viscosity (η0), relaxation time (τR), and contour length (L) were calculated to analyze the effect of nanoparticles on the different wormlike micellar systems. An appropriate mechanism describing the interaction between nanoparticles and wormlike micelles with different structures was proposed. 相似文献
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阳离子双子表面活性剂C18-4- C18•2Br的流变性 总被引:2,自引:0,他引:2
对阳离子双子表面活性剂四亚甲基-1,2-双(十八烷基二甲基烷基溴化铵)(C18-4-C18.2Br)的流变特性进行了研究,考察了表面活性剂质量分数、水杨酸钠质量分数及温度对表面活性剂溶液黏度和黏弹性的影响。C18-4-C18.2Br溶液的黏度随着质量分数的增加而增加。随着水杨酸钠质量分数的增加,C18-4-C18.2Br溶液的黏度和黏弹性出现先增加后下降的过程。温度对C18-4-C18.2Br溶液的黏度有较大影响,水杨酸钠的加入可明显提高C18-4-C18.2Br溶液的抗温性。TEM结果表明,适量的水杨酸钠能够促进C18-4-C18.2Br胶束从球形向蠕虫状转变,过量的水杨酸钠又会使蠕虫状胶束向囊泡转变。 相似文献
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分别通过稳态、动态流变的方法和冷冻蚀刻透射电镜、室内模拟驱油实验和平板夹砂微观模型驱油实验,研究了由碳酸钠诱导形成的油酸钠蠕虫状胶束的流变学性质及形貌和蠕虫状胶束驱油配方的驱油效果及驱油微观机理。结果表明,在油酸钠(NaOA)溶液中,加入一定量的Na2CO3能够形成蠕虫状胶束;孤岛东区稠油注聚驱后,蠕虫状胶束驱油配方(w/%,1.83 NaOA 4.24 Na2CO3)的室内模拟驱油可提高采收率25%原始石油地质储量(OO IP);平板夹砂微观驱油模型显示蠕虫状胶束驱油体系进入模型中,能够使注聚后束缚残余油重新启动、变形,渐渐形成油墙向出口处运移,蠕虫状胶束驱油体系能够有效扩大波及体积,提高洗油效率,从而提高驱油效率。 相似文献