【作者】 朱艳艳；

【导师】 徐桂英；

【作者基本信息】 山东大学 ， 胶体与界面化学， 2009， 博士

【摘要】 低聚表面活性剂（oligomeric surfactant）包括二聚（通常称为Gemini）、三聚、四聚以及具有更高聚合度的两亲分子,它是由两个或两个以上相同或几乎相同的两亲分子,在其头基或靠近头基处由连接基团（spacer）通过化学键连接在一起构成的。与传统的表面活性剂相比,低聚表面活性剂具备许多独特的物理化学性质,如:具有很高的表面活性、其水溶液具有特殊的相行为和流变性、而其形成的分子有序组合体往往具有一些特殊的性质和功能。低聚表面活性剂的分子量通常介于传统表面活性剂与高分子表面活性剂之间,它的出现填补了两者之间的空白,被誉为新一代表面活性剂,最有可能成为21世纪广泛应用的一类表面活性剂。目前,对低聚表面活性剂的研究大多集中在Gemini表面活性剂,尤其以季铵盐类阳离子类Gemini表面活性剂最多,而有关以聚氧乙烯基为亲水基团的非离子低聚表面活性剂的报道极少。本论文中,我们选择烷基酚聚氧乙烯醚的七聚非离子表面活性剂Tyloxapol为研究对象,采用表（界）面张力、界面流变、紫外光谱、荧光光谱、光散射、计算机模拟和透射电镜等方法研究了Tyloxapol的物理化学性质及其与十六烷基三甲基溴化铵（CTAB）、非离子聚合物（嵌段聚醚、聚乙二醇）、部分水解聚丙烯酰胺（HPAM）/CTAB的相互作用,探讨了Tyloxapol与不同的两亲分子相互作用本质,并与其相应单体异辛基酚聚氧乙烯醚（Triton X-100,TX-100）进行比较。以期为开拓低聚表面活性剂Tyloxapol在不同领域的应用提供基础数据和理论依据。论文主要包括五部分内容:论文的第一部分概述了低聚表面活性剂研究的意义,并综述了低聚表面活性剂的研究进展。论文的第二部分包括两部分。第一节研究了Tyloxapol/CTAB（十六烷基三甲基溴化铵）复配体系的表面张力和表面扩张粘弹性,并与TX-100/CTAB体系进行了比较。应用Clint、Rubingh、Rosen和Maeda理论分析了表面活性剂在胶束和表面吸附层中的相互作用。实验结果表明,Tyloxapol降低水表面张力的效率高于TX-100,而降低表面张力的效能低于TX-100,这是由于Tyloxapol分子在表面上呈“U”或者“V”构型所致。当混合体系中非离子表面活性剂摩尔分数较高时,Tyloxapol/CTAB复配体系在降低表面张力效率和效能两方面均产生协同增效作用,而TX-100/CTAB混合体系则仅产生降低表面张力效率的协同增效作用。Rubingh和Rosen理论计算结果均表明,两种混合表面活性剂体系的胶束中分子相互作用参数（β^m）和表面吸附层中分子相互作用参数（β^s）均为负值,说明Tyloxapol和CTAB,TX-100和CTAB之间均存在吸引作用。Tyloxapol/CTAB混合体系β^m的绝对值明显小于β^s;而TX-100/CTAB混合体系β^m和β^s相差不大。Tyloxapol/CTAB混合体系的β^m和β^s的绝对值大于TX-100/CTAB混合体系,说明Tyloxapol和CTAB之间的吸引作用更强。通过Maeda理论计算得到的疏水链间的相互作用（B₁）比头基之间的相互作用（β^m、β^s）弱,而且Tvloxapol/CTAB和TX-100/CTAB两混合体系的B₁值差别不大。在胶束和吸附层中非离子表面活性剂均为主导成分。Tyloxapol、TX-100和CTAB的表面扩张模量均随浓度增大出现先增大后减小的趋势,Tyloxapol具有最大的表面扩张模量。混合表面活性剂的扩张模量数值基本介于两种单一表面活性剂之间,而且与非离子表面活性剂的扩张模量数值更接近,Tyloxapol/CTAB混合体系的表面扩张模量值总是大于TX-100/CTAB混合体系的数值。第二节对比研究了Tyloxapol/CTAB和TX-100/CTAB混合体系对芘的增溶作用,实验结果表明,单一表面活性剂Tyloxapol对芘的增溶能力最强,CTAB次之,TX-100最弱;Tyloxapol/CTAB混合体系对芘的增溶能力强于TX-100/CTAB,当Tyloxapol/CTAB的摩尔比为5:1时,混合体系的增溶能力最强。论文的第三部分采用旋滴法研究了高温高矿化度条件下Tyloxapol/CTAB/HPAM（部分水解聚丙烯酰胺）混合体系与原油间的界面张力,并与TX-100/CTAB/HPAM体系进行了比较,同时考察了非离子表面活性剂种类、非离子表面活性剂/CTAB配比和HPAM浓度对界面张力的影响。结果表明,对于单一表面活性剂体系,CTAB降低界面张力的能力强于非离子表面活性剂;原油与Tyloxapol溶液之间的界面张力高于原油与TX-100溶液,这是由于Tyloxapol在界面上异常的聚集行为引起的;而原油与混合表面活性剂体系间的界面张力总是高于原油与CTAB溶液之间的界面张力;然而,不论是单一表面活性剂还是混合表面活性剂,它们与原油间的界面张力都不能达到超低水平。只有当混合体系中含有适量的HPAM后,其水溶液与原油间的界面张力方可达到超低水平,这是由于非离子表面活性剂/CTAB和HPAM分子在油/水界面共吸附而形成具有高活性聚合物/表面活性剂复合物PS_γ所致。混合体系中非离子表面活性剂/CTAB的质量比对油/水界面张力也有影响,当非离子表面活性剂/CTAB比例为1:1、3:1和5:1时,界面张力才可达到超低水平。Tyloxapol/CTAB/HPAM混合体系与原油之间的界面张力达到超低所需时间比TX-100/CTAB/HPAM要长;但是壬基酚聚氧乙烯醚NP-10/CTAB/HPAM和TX-100/CTAB/HPAM二种混合体系与原油达到超低界面张力所需时间差别不大,而壬基酚聚氧乙烯醚二聚体bis-（NP-10）/CTAB/HPAM混合体系与原油间达到超低界面张力所需时间比NP-10/CTAB/HPAM要短,这是因为尽管bis-（NP-10）扩散到界面的速度比NP-10要慢,但是前者界面活性比较高。论文的第四部分采用表面张力、表面扩张流变、荧光光谱、动态光散射和计算机模拟方法研究了Tyloxapol与F127(PEO₉₉PPO₆₅PEO₉₉)的相互作用,并与聚乙二醇（PEG10000）和TX-100进行了对比。表面张力和动态表面粘弹性实验结果均表明,Tyloxapol和TX-100与聚合物F127、PEG在表面上的相互作用机理相同。Tyloxapol和TX-100与F127在表面上形成混合吸附层,Tyloxapol和TX-100与PEG的混合体系表面上主要是表面活性剂分子吸附。当Tyloxapol溶液中存在F127时,芘在混合体系中的I₁/I₃值小于在单一F127和Tyloxapol中的数值,而且随着体系中F127浓度的不断增加,芘在混合胶束中的I₁/I₃值越来越小,这说明混合胶束中分子排列更加紧密。而对于Tyloxapol/PEG混合体系,芘在混合体系中的I₁/I₃值高于在单一Tyloxapol中的数值,这是由于PEG分子链段插入Tyloxapol胶束中使得表面活性剂分子排列疏松。光散射测定结果也表明,表面活性剂与F127形成混合胶束,而与PEG形成复合物,这种复合物的形成是PEG分子链段插入Tyloxapol胶束中。聚集体的结构与表面活性剂和聚合物的浓度和二者比例密切相关。光散射和DPD模拟结果表明,F127浓度较低时,Tyloxapol与F127的亲水链段通过氢键相互作用形成混合胶束;F127浓度较高时,二者的亲水和疏水链段均存在相互作用从而形成混合胶束。对于TX-100/F127混合体系,二者的亲水和疏水链段存在相互作用从而形成混合胶束。与TX-100相比,由于Tyloxapol分子的空间位阻作用和单体之间的相互作用使其与F127的相互作用较弱一些。PEG浓度很低时,其分子会缠绕在表面活性剂Tyloxapol和TX-100胶束周围;PEG浓度增大,其分子会在胶束间起到“桥联”作用。论文的第五部分通过紫外可见近红外光谱、拉曼光谱和高分辨透射电镜方法研究了Tyloxapol对碳纳米管（CNTs）的分散作用,并与TX-100做了比较。结果表明,随着溶液中Tyloxapol和TX-100浓度的增加,表面活性剂分散CNTs的量先增强后减弱。相比TX-100,Tyloxapol在较低的浓度下就表现出分散CNTs的能力。Tyloxapol分散CNTs的最大量略强于TX-100所分散的最大量。这是由于一方面每个Tyloxapol包含大约7个TX-100分子,Tyloxapol分子中的部分链段吸附在碳管上,另外一部分链段则有可能伸向水相,产生较大的空间位阻作用,从而有利于分散碳管;另一方面Tyloxapol分子本身的空间位阻效应也使其不易吸附在CNTs表面,而更倾向于在溶液中自聚集形成胶团,这不利于分散碳管。因此,Tyloxapol分散CNTs的最大量只是略高于TX-100所分散的最大量。更多还原

【Abstract】 Oligomeric surfactants are a new class of amphiphiles including dimeric（gemini）, trimeric,and tetrameric,etc.These surfactants are made up of two amphiphilic moieties connected at the level of the head groups or very close to the head groups by a spacer group. Oligomeric surfactants have more excellent physico-chemical properties than conventional surfactants,such as higher surface activity,special phase behavior and rheologial property. The molecular weight of oligomeric surfactants is between that of conventional and macromolecular surfactants,so they have filled the gap between conventional and macromolecular surfactant.Oligomeric surfactants are the most likely to be used in 21st century.People have paid much attention to the study on Gemini surfactants,especially on quaternary ammonium Gemini surfactants.However,a few studies on poly（ethylene oxide） nonionic oligomeric surfactants are reported.In this thesis,it is focused on the study of the nonionic oligomeric surfactant Tyloxapol,which can be considered as an oligomer of the non-ionic polyoxyethylene tert-octylphenyl ether（Triton X-100,TX-100）,with a polymerization degree below 7.The physicochemical property of Tyloxapol and its interactions with hexadecyltrimethylammonium bromide（CTAB）,polymer [(PEO₉₉PPO₆₅PEO₉₉,F127) and（poly ethylene glycol,PEG）]and partially hydrolytic polyacrylamide（HPAM）/CTAB are investigated via surface tension,surface dilational rheology,steady-state fluorescence,UV-vis spectrum,DLS（dynamic light scattering）, computer simulation and high-resolution transmission electron microscopy（HRTEM） method.For comparison,parallel measurement on TX-100 is made.The thesis aims to provide basic data and theoretical basis for developing Tyloxapol’s widely use in different areas.This thesis consists of five parts.In the first section,the importance and the progress of studies on oligomeric surfactant are summarized.The second section consists of two parts.In part one,surface tension and dilational viscoelasticity of water in the presence of surfactants Tyloxapol and TX-100 with CTAB are investigated.The surfactant interactions in the micelles and monolayers have been analyzed using the theories of Clint,Rubingh,Rosen,and Maeda with the aim to reveal the comparative performance of these mixtures.The results show that the surface tension reduction efficiency of Tyloxapol is higher than that of TX-100,however,the surface tension reduction effectiveness of the former is lower than that of the latter.The aberrant behavior of Tyloxapol is attributed to its "U" or "V" conformation at the air/water surface. It is noticeable that cmc andγ_cmc of the Tyloxapol/CTAB mixture is even lower than those of Tyloxapol at higher mole fraction of nonionic surfactant,indicating synergism in surface tension reduction effectiveness and efficiency.However,the TX-100/CTAB mixture only shows the synergism in surface tension reduction effectiveness.According to the Rubingh and Rosen theory,the results indicate that both interaction parameters for mixed micelle formation in an aqueous solutionβ^m and interaction parameters for mixed monolayersβ^s at the air/water interface are negative,predicting non-ideal mixing and attractive interaction between the constituent surfactants in the mixed micelle and layer.β^m is less negative thanβ^s in the Tyloxapol/CTAB mixed system,bothβ^m andβ^s are more or less the same for the TX-100/CTAB system.Furthermore,bothβ^m andβ^s are more negative for the Tyloxapol/CTAB mixture than that for the TX-100/CTAB one,indicating stronger attractive interaction between Tyloxapol and CTAB.The chain-chain interaction parameter B₁ is less negative thanβ^m andβ^s.The mixed micelles and monolayer are predominated by nonionic surfactants.The surface dilational viscoelasticity results show that the adsorption layer of Tyloxapol has the highest dilational modulus value among three single surfactants.Also,it indicates the surface dilational modulus maximum values of surfactant mixtures are usually between that of the single surfactant.Moreover,it is worth noting that the dilational modulus maximum values of Tyloxapol/CTAB mixtures are always higher than those of TX-100/CTAB ones.In part two,the solubility of pyrene in Tyloxapol and TX-100 with CTAB are investigated.For three single surfactants,the solubilization power increases in the order of TX-100＜CTAB＜Tyloxapol.Tyloxapol/CTAB has higher solubilization power than TX-100/CTAB.In addition,Tyloxapol/CTAB mixture has the highest solubilization power when the mole ratio of Tyloxapol to CTAB is 5:1.In the third section,interfacial tension（IFT） between Tyloxapol and TX-100 with CTAB in the presence of HPAM is investigated by spinning drop technology at high salinities and temperature.Effects of different nonionic surfactants,HPAM concentration and mass ratios of nonionic surfactant/CTAB on the dynamic IFT between crude oil and aqueous solution are studied in detail.For single surfactant systems,it is found that the ability of lowering IFT for CTAB is better than that for nonionic surfactant,while the IFT between Tyloxapol and crude oil is higher than that that between TX-100 and crude oil, which is attributed to the aberrant aggregation behavior of Tyloxapol at the crude oil/water interface.The IFTs between mixed surfactants systems and crude oil are always higher than that between CTAB and crude oil.However,IFTs between both single and mixed surfactants systems and crued oil can’t reach ultra-low level.Interestingly,the ultra-low IFT is obtained for all surfactant mixtures in the presence of appropriate HPAM,which is ascribed to the formation of polymer-surfactant complexes PS_γwith high surface-activity at interface by nonionic surfactant/CTAB and HPAM.Mass ratios of nonionic surfactant/CTAB in aqueous phase also have effect on IFT.Only proper mass ratios of nonionic surfactant/CTAB in aqueous phase could yield ultra-low IFT values,which are 1:1, 3:1 and 5:1.The time to reach ultra-low level for Tyloxapol/CTAB/HPAM mixed system is much longer than TX-100/CTAB/HPAM,but the time to reach ultra-low level for polyoxyethylene nonylphenyl ether NP-10/CTAB/HPAM and TX-100/CTAB/HPAM mixed system is almost the same.The time to reach ultra-low level for polyoxyethylene nonylphenyl ether dimer bis-（NP-10）/CTAB/HPAM mixed system is shorter than NP-10/CTAB/HPAM,this is because that the transport of bis-（NP-10） molecules to interface is slower,but it has high surface activity than NP-10.In the fourth section,the interaction between Tyloxapol and F127(PEO₉₉PPO₆₅PEO₉₉) is investigated via the surface tension,dynamic surface dilational viscoelasticity, steady-state fluorescence,DLS measurement and computer simulation method.For comparison,PEG and TX-100 are also selected.The results of both surface tension and dynamic surface dilational viscoelasticity testify that the interaction mechanism between Tyloxapol and TX-100 with F127 is the same.There is formation of mixed adsorption layer between Tyloxapol and TX-100 with F127 mixtures,while the surfactant molecules mainly adsorb on the surface for Tyloxapol and TX-100 with PEG mixtures.The I₁/I₃ value in Tyloxapol/F127 mixed micelle is smaller than in single Tyloxapol and F127 micelle.The I₁/I₃ value becomes smaller with increasing F127 concentration,indicating the packing of molecules in mixed micelle is denser.However,The I₁/I₃ value in Tyloxapol/PEG mixed micelle is higher than in single Tyloxapol micelle,which is due to penetration of PEG molecules into Tyloxapol micelle making the mixed micelle looser.The results of DLS measurement also show that there is formation of mixed micelle for surfactant and F127, while surfactant and PEG forms surfactant/PEG complex by the penetration of PEG molecules into surfactant micelle.The structure of aggregate is related to the ratio and concentration of surfactant and polymer.The results of dissipative particle dynamics（DPD） simulation and DLS measurement show that there is interaction between hydrophilic chains for and F127 mixture at low F127 concentration.However,there is interaction between hydrophilic and hydrophobic chain for Tyloxapol and F127 mixture at high F127 concentration.Compared to the interaction between TX-100 and F127,the interaction between Tloxapol and F127 is weaker due to Tyloxapol’s steric effect and the interaction between its monomers.When the PEG concentration is low,the molecule will wrap around the Tyloxapol and TX-100 micelle.When the PEG concentration is increased,the PEG molecules will act as a "bridge" between micelles.In the fifth section,the ability of dispersing carbon nanotubes（CNTs） in aqueous solutions by Tyloxapol is investigated in detail by UV-vis-NIR,Raman spectra and HRTEM observations.For comparison,TX-100 is also selected.The results show that the amount of the CNTs in surfactant solution first increases and then decreases with increasing surfactant concentration.Tyloxapol could disperse CNTs at rather low concentration compared with TX-100.The maximum dispersing amount of the CNTs in Tyloxapol solution is a little higher than in TX-100 solution.On one hand,this is because that some chains of Tyloxapol will adsorb on the CNTs,while the others can stretch into water phase and hence create steric repulsion effect,which is favorable to disperse CNTs;on the other hand,it is not easy for Tyloxapol to adsorb on the CNTs due to its steric repulsion effect,Tyloxapol will self-aggregate to form micelle in solution,which is unfavorable to disperse CNTs.As a result,the maximum dispersing amount of the CNTs in Tyloxapol solution is just a little higher than in TX-100 solution.更多还原