【作者】 周朝辉；

【导师】 赵濉；

【作者基本信息】 中国科学院研究生院（理化技术研究所） ， 物理化学， 2009， 博士

【摘要】 表面活性剂分子设计对于表面活性剂在特定领域的应用研究具有重要的理论价值和实践意义。大量研究表明,具有支链结构的表面活性剂可以大大降低水溶液的表面张力,而离子型表面活性剂结构中引入EO基团能大大改善其表面活性,这为设计三次采油用表面活性剂开辟了新的思路。支链含EO基团的双链烷基苯磺酸盐阴离子表面活性剂研究得较少,人们对于位于疏水支链上的EO基团对表面活性剂性质的影响亦缺乏系统认识。已有的少量研究显示,引入EO基团的烷基苯磺酸盐阴非离子表面活性剂表现出更优的界面活性和耐温耐盐性能,在三次采油中具有广泛的应用前景。本论文选择支链含EO基的双链烷基苯磺酸盐阴离子表面活性剂—辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠为模型化合物,制备并系统研究了它们的理化性能。主要研究内容和结果如下:以正辛酸、苯酚、多缩乙二醇和溴代烷烃为原料,经酰化、酯化、Fries重排、催化加氢、威廉逊醚化及磺化等反应,首次合成出8种辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠表面活性剂,用FT-IR、1H NMR、ESI-MS等测试手段对其结构进行了鉴定,所合成的表面活性剂结构明确,纯度较高。采用Wilhelmy吊片法和旋转滴法测定了辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠水溶液的表/界面张力,系统研究了EO及烷基链长改变对其表/界面性能的影响。我们发现辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠具有优异的表面活性,临界胶团浓度(CMC)达10-5mol/L数量级,γCMC在25.79-31.62mN/m之间,降低表面张力的能力和效率出众。在纯水溶液中,随EO数的增加,CMC先减小后变化不大,而饱和吸附量则先增加后降低,相应地,γCMC先减小后增加,合适的EO链长度是辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠达到最优性能的关键因素;固定EO数为4,支链烷基链长的增加,CMC降低,饱和吸附量增加,γCMC降低。EO数对界面张力影响显著,含辛基-[ω-辛氧基-二氧乙烯]基-苯磺酸钠(EO=2)0.05wt%的弱碱驱油体系即可与胜利原油产生超低界面张力,体现出高效的降低油水界面张力的能力和效率。采用Langmuir槽法利用小幅周期振荡和界面张力弛豫法研究了辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠表面活性剂的表面扩张粘弹性质。结果表明,辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠的表面扩张性质随频率和表面活性剂浓度的变化均呈现规律性的变化:频率增加,扩张模量增加,粘性增强;浓度增加,扩张模量在CMC之前通过最大值后降低;辛基-[ω-辛氧基-聚(氧乙烯)]基-苯磺酸钠随EO数的增加,0.1Hz模量最大值先增加后降低,在EO=2时最大,而烷基链长的增加则使得扩张模量增强。界面张力弛豫研究表明辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠可能主要存在三个驰豫过程:体相与表面间的扩散交换过程,分子疏水支链的构象变化,表面吸附膜大量分子的重排过程。采用气流法测定了辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠表面活性剂的泡沫性能,并考察了不同物化条件及结构对泡沫性质的影响。实验发现,随着表面活性剂浓度的升高,其起泡能力和泡沫稳定性均逐渐增强,达到一定的浓度后泡沫性能趋于稳定;EO链增加,起泡性能先增加,EO数大于2后变化不大,而泡沫稳定性随EO数的增加显著增强;烷基链长增加,起泡性能降低而泡沫稳定性增加;温度升高,辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠的起泡能力有所增强,但泡沫稳定性变差;电解质的加入显著降低辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠水溶液的泡沫稳定性,但EO的引入能降低电解质的对表面活性剂稳定性的影响,表现出一定的非离子表面活性剂的性质。采用自发射荧光法及荧光自猝灭技术测定了辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠的胶团聚集性质,我们发现,辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠含有苯氧基荧光生色基团,利用其自发射荧光可用来测定CMC,所得结果精确度较高且与表面张力法结果吻合;利用甲基紫精(MV2+)猝灭辛基-[ω-烷氧基-聚(氧乙烯)]基-苯磺酸钠分子发射的荧光可用来测定胶团平均聚集数N,辛基-[ω-辛氧基-聚(氧乙烯)]基-苯磺酸钠随着EO数的增加,从0到1胶束聚集数N先减小,而从1到4则变化不大。更多还原

【Abstract】 It is valuable in theory and practice to design surfactants for special application fields. Many researches had shown that surfactants with branches can reduce surface tension obviously and the anionic surfactants with oxyethylene can also highly improve the surface property, which may break a new path to design surfactants for Enhanced Oil Recovery (EOR). The studies on anionic surfactants with oxyethylene in the branches are rarely reported, which leads to lacking systematical knowledge in the relationship of the molecular structure and performance of this kind of surfactants. The few researches have indicated that the anionic-nonionic arylalkyl sulfonates, containing oxyethylene in the branches, performed better interfacial properties, which made them potential candidates for a wide variety of surfactant applications in EOR. In the dissertation, the anionic arylalkyl sulfonated surfactants with oxyethylene in the branches, sodium octyl-[ω-octyloxy-poly(oxyethylene)]yl-benzene sulfonates ,have been synthesized and their properties have been studied systematically. The experiments and results are as following:The sodium octyl-[ω-octyloxy-poly(oxyethylene)]yl-benzene sulfonates were synthesized from fatty , phenol ,multiethylene glycol and alkyl bromide through several processes, including acylation, esterification, Fries rearrangement, Pd-catalyzed hydrogenation, Williamson ether synthesis and sulfonation. The structures were characterized by FT-IR, 1H NMR, and ESI-MS methods. The results suggested that the structures of the compounds with high purity are definite.The surface and interfacial tensions of sodium octyl-[ω-octyloxy-poly(oxyethylene)] -yl-benzene sulfonates in aqueous solutions have been investigated by Wilhelmy plate method and spinning drop method respectively to study the effect of the length of hydrophobic group and the number of EO units on their properties. It was discovered that the surface performance of these surfactants is greatly outstanding: the values of critical micelle concentration reached to be of the order of magnitude of 10-5 mol/L, the values of theγCMC is between 25 to 31 mN/m.and the efficiency of surface tension reduction is excellent. With the increasing in EO chain length, the CMC slightly changed after the first decrease, On the other hand, theΓmax decreased after the first increase andγCMC increased after the first decrease accordingly.The appropriate EO chain length is the key facter to get the best physicochemical properties.The carbon number of alkyl increased with 4 EO units in octyl-[ω-octyloxy-poly(oxyethylene)]-yl -benzene sulfonate ,however, the CMC andγCMC decreased and theΓmax increased.The interfacial tension is greatly affected on the EO chain length and the ultra low interfacial tension could be achieved in the water-crude oil weak alkali system with 0.05wt% sodium octyl-[ω-octyloxy-poly(oxyethylene)]-yl-benzene sulfonate containing 2 EO units,which proved its excellent effectiveness and efficiency of interfacial tension reduction.The dilational viscoelastic properties of sodium octyl-[ω-octyloxy-poly(oxyethylene)] -yl-benzene sulfonates at air-water were investigated by means of two methods: the interfacial tension response to sinusoidal area variations and interfacial tension relaxation method respectively. The dilational modulus and phase angle changed regularly with changing of concentration and frequency: the dilational modulus and viscosity increased with the frequency increasing as well as the surface dilational modulus passes through a maximum value with the increasing concentration. The max dilational modulus values of sodium octyl-[ω-octyloxy-poly(oxyethylene)]yl-benzene sulfonates at 0.1Hz passes through a maximum value (EO=2) with the increasing of EO chain and continue increase with length of alkyl group increasing. The results of interfacial tension relaxation showed that there will be three relaxed process: the exchange between surface and bulk, the conformational change of hydrophobic branch, the rearrangement of surface adsorbed film. The foam properties of sodium octyl-[ω-octyloxy-poly(oxyethylene)]yl-benzene sulfonates in the aqueous solution at different physicochemical condition were measured by air flowing method. It was found that the foam ability and foaming stability increase sharply with increasing surfactant concentration and then generally reached a plateau. The foam ability increased first and slightly changed (EO=2) while the foam ability continues increased with increasing of EO chain length.The foam ability decreased with the increasing of alkyl chain length,. however, the foam stability is on the contrary way. The foaming ability increased with the temperature increasing, while the foaming stability showed opposite tendency. The foaming stability was greatly decreased when NaCl was added, while the effect can improved by the introducing of the EO chian to the surfactant molecular.The micellezation and aggregation properties of sodium octyl-[ω-octyloxy-poly(oxy -ethylene)]yl-benzene sulfonates in aqueous solutions were investigated by fluorescence spectra of intrinsic probe. It’s shown the CMC got by fluorescence spectra of intrinsic probe method is accordance with the CMC measured by surface tension method. The aggregation number N, characterized by quenching the fluorescence spectra with methyl viologen (MV2+) as the extrinsic quencher, gradually decreased first(from 0 to1) and then slight changed (from 1 to 4)with increasing of EO chain length.更多还原