聚醚类破乳剂的界面扩张流变性质

采用悬挂滴方法研究了不同结构聚醚类破乳剂与煤油间的界面张力及界面扩张流变性质. 结果表明, 4种聚醚类破乳剂均具有较强的降低界面张力能力, 且支链化程度越低分子在界面上排列越紧密, 直线型破乳剂在低浓度条件下界面张力最低. 破乳剂的分子尺寸较大, 慢弛豫过程控制界面膜性质, 吸附膜以弹性为主. 同时, 柔性聚氧乙烯链和聚氧丙烯链对界面膜性质的影响较大, 随着支链化程度增大, 界面分子间相互作用增强, 界面膜弹性增强, 黏性降低.     

疏水改性聚丙烯酰胺对原油组分界面扩张流变性质的影响

利用悬挂滴方法研究了疏水改性聚丙烯酰胺(HMPAM)对胜利采油厂高温高盐油藏采出原油中酸性活性组分和沥青质界面膜扩张流变性质的影响,考察了不同活性组分浓度条件下的界面扩张流变行为.实验结果表明:1750mg·L-1HMPAM能够在界面上形成网络结构,界面扩张模量数值高达100mN·m-1左右;油相中的酸性组分随着老化时间增加吸附到界面上,与HMPAM分子的疏水改性部分形成聚集结构,一方面通过快速的扩散交换过程大大降低扩张模量,另一方面通过与疏水改性部分的相互作用加强HMPAM分子间的缔合强度,增强网络结构的弹性.沥青质分子尺寸相对较大,分子间存在氢键等较强的相互作用,造成沥青质界面聚集体和HMPAM形成的网络结构共同决定界面膜性质,混合膜的扩张模量较单独HMPAM体系仅略有降低.     

短链烷基对多取代烷基苯磺酸盐界面性质的影响

利用悬挂滴方法研究了2,5-二乙基-4-壬基苯磺酸钠(292)、2,5-二丙基-4-壬基苯磺酸钠(393)和2,5-二丁基-4-壬基苯磺酸钠(494)在空气-水表面和正癸烷-水界面的扩张流变性质,考察了时间、界面压、工作频率及体相浓度对扩张弹性和粘性的影响。研究发现,在低表面活性剂浓度条件下,表面吸附膜类似弹性膜,其强度由膜内分子的相互作用决定;高浓度下体相与表面间的扩散交换过程控制表面膜的性质。油分子的插入导致界面吸附分子之间相互作用的削弱,扩散交换过程主导界面膜性质;但随着短链烷基长度增加,油分子的影响变小。表面膜的强度在吸附达到平衡前已经决定,而界面膜在吸附饱和后仍然随界面分子重排而变化。     

表面活性剂对驱油聚合物界面剪切流变性质的影响

利用双锥法研究了表面活性剂十二烷基苯磺酸钠(SDBS)和十六烷基三甲基溴化铵(CTAB)对油田现场用部分水解聚丙烯酰胺(PHPAM)和疏水改性聚丙烯酰胺(HMPAM)溶液的界面剪切流变性质的影响,实验结果表明:HMPAM分子通过疏水作用形成界面网络结构,界面剪切复合模量明显高于PHPAM.SDBS和CTAB通过疏水相互作用与HMPAM分子中的疏水嵌段形成聚集体,破坏界面网络结构,剪切模量随表面活性剂浓度增大明显降低.同时,界面膜从粘性膜向弹性膜转变.低SDBS浓度时,少量SDBS分子与PHPAM形成混合吸附膜,界面膜强度略有升高;SDBS浓度较高时,界面层中PHPAM分子被顶替,吸附膜强度开始减弱.阳离子表面活性剂CTAB通过静电相互作用中和PHPAM分子的负电性,造成聚合物链的部分卷曲,从而降低界面膜强度.弛豫实验结果证实了表面活性剂破坏HMPAM网络结构的机理.     

书刊征订

《界面膜原理与应用》界面无处不在。本书从基本原理出发,引用一些实际的体系和过程,系统介绍各种界面膜的概念、形成、状态、性质、稳定性、应用及其研究方法。着重介绍气液界面单分子膜,固液和液液界面膜,对于各种有序分子膜如LB膜、人工双层     

驱油体系化学剂间相互作用对界面吸附膜的影响

采用界面张力弛豫技术研究了不对称Gemini表面活性剂C12COONa-p-C9SO3Na、部分水解聚丙烯酰胺Mo-4000、疏水缔合水溶性聚丙烯酰胺(HMPAM)等驱油体系化学剂在癸烷/水界面上的扩张流变性质,考察了不同离子强度、不同类型电解质对体系界面流变性质的影响,计算得到界面扩张弹性模量和粘性模量的全频率谱,并通过归一化方法(cole-cole图)探讨了界面吸附膜的弛豫过程。研究发现,界面膜内分子重排和界面与体相间分子扩散交换是影响膜性质的主要弛豫过程。表面活性剂体相浓度增大有利于界面分子重排过程,而低频有利于扩散交换过程;不同结构聚合物以及不同离子强度、不同类型电解质对表面活性剂吸附膜有不同的影响。     

扩张流变法研究表面活性剂在界面上的聚集行为

近年发展起来的界面流变测定技术在研究界面性质方面具有许多独特之处.本文结合我们的工作,总结了近年来有关该技术在表面活性剂界面聚集行为研究中的应用,讨论了扩张频率、表面活性剂浓度及疏水链长、无机盐和温度对表面扩张流变行为的影响,同时探讨了小分子表面活性剂与高分子表面活性剂表面扩张流变行为的区别以及小分子表面活性剂在气/液界面与液/液表面的扩张流变性的差异.大量研究表明,借助于界面流变性的测定不仅可以研究发生在界面上和界面附近的微观弛豫过程,而且可以探讨界面上超分子聚集体的形成,进而为乳状液和泡沫等分散体系的稳定性提供依据.     

十二烷基硫酸钠对两性咪唑类离子液体表面活性剂1-磺丙基-3-十二烷基咪唑内盐界面聚集行为的影响

利用界面扩张流变技术,研究了两性咪唑类离子液体表面活性剂1-磺丙基-3-十二烷基咪唑内盐(C₁₂imSP)的界面聚集行为,探讨传统表面活性剂十二烷基硫酸钠(SDS)对C₁₂imSP界面聚集行为的影响机制。 结果表明,少量SDS的加入可以填补界面上疏松的C₁₂imSP分子间的空位,界面上形成表面活性剂混合吸附膜,界面张力显著降低;提高SDS的浓度,其分子从体相向界面层的扩散交换占优势,界面层分子逐渐达到饱和吸附,此后体系中有混合胶束形成。 体相胶束中富集的SDS分子对C₁₂imSP分子的“收纳”作用及进一步的“挽留”作用,加之C₁₂imSP分子本身相对较大的空间位阻效应导致界面上的C₁₂imSP分子一旦通过扩散作用被交换至体相,其很难再回复到表面层,即界面膜以SDS分子为主。 通过调节体系中SDS的含量,可以实现对混合体系SDS/C₁₂imSP/NaCl(0.1 mol/L)界面聚集行为的调控,进而实现对界面膜性质的调控。     

不同结构驱油聚合物的界面剪切流变性质

利用双锥法研究了油田现场用超高分子量部分水解聚丙烯酰胺(PHPAM)和疏水改性聚丙烯酰胺(HMPAM)溶液与航空煤油间的界面剪切流变性质,考察了时间、应变幅度和剪切频率对不同浓度PHPAM和HMPAM溶液界面剪切流变参数的影响.结果表明,只有在适宜的剪切频率条件下,流变数据才能反映界面膜的结构信息.HMPAM分子具有界面活性,能吸附在界面上,其界面膜的强度随时间变化逐渐增强,且在高浓度时以黏性为主;PHPAM分子不具有界面活性,其剪切流变参数没有时间依赖性,界面层以弹性为主.HMPAM能通过疏水作用形成界面网络结构,界面膜的剪切复合模量明显高于PHPAM界面层.HMPAM界面层中网络结构在剪切形变作用下的破坏与重组这一慢弛豫过程是其强度较高的原因.     

表面活性剂对分散体系粘度影响的特殊性

通过液体石蜡的水基化分散对影响分散体系粘度的粒子大小、表面活性剂胶束和界面膜等因素进行了研究.结果表明,表面活性剂胶束对分散体系粘度的影响极为有限,而在分散相粒子界面上由表面活性剂分子所形成的界面膜是导致分散体系粘度产生变化的重要因素.实验数据表明,对于分散体系的稳定性,存在一个表面活性剂浓度变化的临界值,而该临界值所对应的是表面活性剂分子在粒子表面以最紧密和规整的方式形成的界面膜,该种界面膜使分散体系粘度达到最大值,从而最大限度地保证了分散体系的稳定性.     

Enhanced heavy oil recovery by organic alkali combinational flooding solutions

Although alkaline/surfactant/polymer (ASP) flooding is successfully applied in oil fields, some disadvantages such as scales, corrosion effects, and viscosity reductions of polymer solutions appear. Usage of organic alkalis can avoid or decrease these disadvantages. In this paper, the physicochemical properties, including interfacial tension (IFT), and viscosity, of organic alkali combinational flooding solutions and their effectiveness as enhanced oil recovery agents are investigated. Monoethanolamine (MEA) is the optimal one for decreasing the IFT among the three organic alkalis studied in this paper. Although MEA cannot decrease the IFT as low as NaOH does, it has good compatibility with both surfactant and the polymer hydrolyzed polyacrylamide (HPAM). MEA not only helps a surfactant solution or HPAM/surfactant mixture attain ultralow IFT values, but can also promote better viscosity stability for HPAM or HPAM/surfactant solutions compared to NaOH. Moreover, core flood experiments show that adding MEA can obtain additional tertiary oil recovery of 6%–10% original oil in place (OOIP) on the top of HPAM or HPAM/surfactant flooding, although MEA has a lower enhanced oil recovery than NaOH. The experimental results show that MEA is a good choice to replace NaOH in enhancing heavy oil recovery.     

Interaction Between the Hydrophobically Modified Polyacrylamide and HPAM-Flooding Produced Liquid

In order to utilize the produced liquid of hydrolyzed polyacrylamide (HPAM) flooding to enhance oil recovery, the interaction between hydrophobically modified polyacrylamide (HMPAM) and the produced liquid of HPAM flooding was investigated. The viscous characteristic of HMPAM in aqueous solution was investigated by Ubbelohde viscometer. The results show the intrinsic viscosity of HMPAM in aqueous solution is higher than that of HPAM, indicating that HMPAM has better effect on increasing the viscosity of aqueous solution. The viscosity of the complex system consisted of HMPAM and the produced liquid from HPAM flooding is lower than that of the HMPAM system, but higher than that of the HMPAM/HPAM complex system in mineralized water. In order to investigate the major factor of the influence on the viscosity of the HMPAM/produced liquid complex system, the viscosities of HMPAM/HPAM (and hydrolyzed HPAM with different hydrolysis degree) in distilled water and in mineralized water were studied. The fluorescence spectrum and transmission electron microscopy measurements were carried out to investigate the interaction between HPMAM and produced liquid from a microscopic perspective. These results are useful for farther enhancing oil recovery after HPAM flooding.     

Molecular simulation studies on the interaction between different polymers in aqueous solution

A molecular dynamics simulation was performed to investigate the aggregates of mixing and the interaction between different polymers in aqueous solution. These polymers include partially hydrolyzed polyacryamide (HPAM), hydroxyethylcellulose (HEC) and polyvinylpyrrolidone (PVP). The structures of mixed aggregates were analyzed from the dihedral angle distribution of: (1) pure HPAM; (2) HPAM in aqueous solution; (3) HPAM with small segments of PVP or HEC in aqueous solution. At the same time, the simulated IR spectra and the calculated interaction parameters were used to distinguish the different interactions between HPAM and PVP or HEC. In order to confirm the validity of the simulated predictions, experimental IR spectra of polymer systems were made, and the specific viscosity of the HPAM and PVP or HEC system was measured using capillary viscometry. It can be seen from the viscosity measurements that the viscosity of the HPAM/PVP system in aqueous solution decreases linearly with an increase in concentration of PVP, whereas a maximum viscosity value appears with the increase in concentration of HEC in the HPAM/HEC system. The conclusion was drawn that the interaction between HPAM and HEC is stronger than the one between HPAM and PVP, and that molecular simulation can be considered as an adjunct to experiments and can provide otherwise inaccessible (or, not easily accessible) microscopic information that experimentalists can use.     

纳米SiO2/HPAM/NaCl分散体系的稳定性、流变性及驱油性能研究

利用纳米粒度及Zeta电位分析仪、流变仪和悬滴法对纳米SiO_2/HPAM/NaCl体系60℃的稳定性、流变性及油水界面张力进行了研究。结果表明,HPAM的加入使SiO_2悬浮液的Zeta电位更负、粒径明显增加,静置10 d无明显浑浊现象。加入纳米SiO_2后,HPAM溶液的黏度增加,耐温、耐盐和耐剪切性能得到改善。对于质量分数为0.18%的HPAM溶液,SiO_2质量分数小于0.5%时,随SiO_2质量分数的增加,体系的黏度、储能模量和损耗模量增加,临界线性应变减小,蠕变回复能力增强;SiO_2质量分数大于0.5%时,出现了相反的现象;这是因为SiO_2质量分数不同时,HPAM在SiO_2表面的吸附量、吸附构型及两者之间形成的网状结构不同。纳米SiO_2的加入同时强化了HPAM降低油水界面张力的性能,加入质量分数为0.2%和0.5%的SiO_2后,HPAM的采收率分别提高了4.5%和6.0%。     

油酸-油酸钠水溶液/原油间的瞬时界面张力

羧酸盐表面活性剂以其价格低廉、资源丰富和较高的界面活性而受到重视[1]．我们将廉价的天然核酸盐复配体系用于提高采收率研究，取得良好效果问．据最近报道问，用瞬时界面张力（l）评价驱油体系更符合实际采油过程．本文应用试剂级油酸，试图从理论上探讨不同因素对混合体系瞬时界面张力的影响规律，为驱油体系配方的选择提供依据．1实验部分1．1试剂油酸（R17C00H），分析纯收京长城化学试剂厂产品）．水解聚丙烯酸胶（HPAM），平均分子量为1．7X10’，平均水解度为20％，（美国辉瑞公司产品）．1．2方法按设计量在电子分析天平（精…     

The Influence on Interfacial Tension of the Combination of Anionic and Cationic Surfactants: Alkyl Sulfonate/Alkyltrimethylammonium Bromide

Mioellization of aqueous mixture of sodium octyl sulfonate ( C₈As )/ cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfonate (C₁₂As)( CTAB in the presence of sodium bromide has been studied by surface tension measurement. Nonideal solution theory has been used to calculate the molecular interaction parameters (β^M and β^s). The oil-aqueous interfacial tensions of C₁₂As/ CTAB, C₈As/CTAB, C₁₂As/dodecyl trimethylammonium bromide (DTAB) systems were also measured. We studied the influence of the surfactant concentration, surfactant molar fraction ratio, hydrocarbon chain length, added NaCl and alcohol concentration on the interfacial tension.     

聚丙烯酰胺的形态结构研究

本文用电子显微镜深入的研完了部分水解聚丙烯酰胺在水溶液中的形态。给出大分子的伸展网状结构是其稀溶液高粘度的结构本质。并详细讨论了聚合物的水解度、分子量、外加盐种类及波度与分子聚集状态的关系。     

Adsorption of Triton X-100 and cetyltrimethylammonium bromide mixture with ethanol at nylon-6–solution interface with regard to nylon-6 wettability: II. Work of adhesion and activity of surfactants at interfaces

On the basis of the values of the surface tension of the aqueous solutions of the Triton X-100 and CTAB mixture with ethanol, the surface tension of nylon-6 and the nylon-6–solution interfacial tension, the activity of the surfactant mixture and ethanol at the nylon-6–solution interface was calculated and compared to that at the solution–air one. For these calculations, the Sprow and Prausnitz equation was applied. The obtained values of the activity were used for the calculations of the work of adhesion of the solution to the polymer surface. The values of the work of adhesion obtained in this way were compared to those determined from the Young–Dupre equation by using the contact angle values of the aqueous solutions of the TX-100 and CTAB mixture with ethanol measured on the nylon-6 surface. The changes of the work of adhesion determined from the Young–Dupre equation were also considered as a function of the surface tension of the solution, its polar component and the interfacial interaction parameter.     

一些聚合物对中相微乳液物性的影响

研究了水解聚丙烯酰胺、黄原胶和木质素磺酸盐对中相微乳液相体积、粘度和界面张力的影响。实验结果表明: 含有聚丙烯酰胺时,中相微乳液的相态、增溶参数、中相与下相间界面张力及中相粘度均无明显变化。生物聚合物对中相微乳液的物理性质影响也不大。木质素磺酸盐则对微乳液的形成产生明显影响: 随着木质素磺酸盐浓度的增大,微乳液由中相转变为上相,相应的物理参数亦有变化。     

甲基丙烯酸3-磺酸丙酯钾盐苯乙烯共聚物负离子与N,N,N-三甲基十六烷基溴化铵相互作用研究

聚电解质与表面活性剂相互作用研究已有很多报道[1～4],由于在很多方面与生物膜中脂质体-蛋白质间相互作用相似,从而近年来备受关注[5～6].作为带电荷的水溶性高分子,聚电解质与带相反电荷的表面活性剂分子可以形成规整性非常好的聚电解质表面活性剂复合物.Ａｎｔｏｎｉｅｔｔｔｉ等报道聚丙烯酸与十六烷基三甲基溴化铵(ＣＴＡＢ)形成规整的介规相(Ｍｅｓｏｐｈａｓｅ)聚电解质表面活性剂复合物结构[7],漆宗能等在同一体系既观察到了热致液晶也观察到了溶致液晶[8].在研究甲基丙烯酸3磺酸丙酯钾盐(ＳＰＭＳ)的苯乙烯(Ｓｔ)共聚物(Ｐ(ＳＰＭ…