【作者】 陈贻建；

【导师】 徐桂英；

【作者基本信息】 山东大学 ， 化学， 2014， 博士

【摘要】 阴-非离子表面活性剂相比于非离子表面活性剂和阴离子表面活性剂,具有耐盐性能好,kraff点低,浊点高以及环境友好的优点。研究发现,该类阴-非离子表面活性剂都有很高的抗Ca2+能力,认为分子中的EO基团会与Ca2+离子发生络合作用,从而减小了Ca2+离子对极性头基的影响,表面活性剂分子不容易沉淀,因此提高了其抗Ca2+离子能力。为了得到EO基团与Ca2+离子相互作用的大小、EO数量对这种相互作用力的影响、EO基团的数量与表面活性剂分子抗Ca2+能力的关系以及不同种类阴-非离子表面活性剂抗Ca2+离子的差异等,通过分子动力学模拟的方法从微观上深入分析,考察了烷基硫酸盐和烷基磺酸盐随EO数的增加,对表面活性剂聚集行为及其与Ca2+离子相互作用的影响,以期对阴-非离子表面活性剂的实际应用和分子设计提供理论指导。十二烷基硫酸钠(SDS)是一种常见的阴离子表面活性剂,广泛应用于各种领域。第二章就选取了SDS分子以及十二烷基苯硫酸钠(SDBS)作为对比,通过分子动力学模拟研究了引入一个EO基团后,表面活性剂分子在气/液界面聚集行为的差异。EO基团的引入会降低极性头所带电量,它们之间的经典排斥力降低,有利于表面活性剂形成更为紧密的聚集结构。而头基负电性的降低,使其与Na+离子的相互作用降低,SDBS的体系降低幅度高于SDS. EO基团的存在可以增强极性头基的水化能力,且SDBS的体系增强幅度高于SDS。SDS与SDBS体系之间这些差异可能与苯环所带来的空间位阻效应有关。EO基团的引入会提高SDS和SDBS的水化能力,降低头基与Na+离子的相互作用。第三章中就进一步探讨了EO基团的引入对SDS和SDBS抗钙性的影响。在SDS和SDBS体系中,大多数Ca2+离子则位于表面活性剂分子中804头基的第二水化层。而在SDES和SDBES体系,部分Ca2+离子会进入EO基团和804头基的第一水化层,Ca2+离子与表面活性剂的相互作用增强,而进一步的分析表明,Ca2+离子只与804头基中与EO基团相连的O原子发生强的相互作用,而与其它三个O原子的相互作用力没有明显的增强。引入的EO基团会结合Ca2+离子,限制其迁移能力,降低了Ca2+离子对804头基的影响,因而降低了表面活性剂被沉淀的几率,提高其抗钙性能。一个EO基团的引入就可以提高SDS的抗钙性能,为了得到EO数量对它们抗钙性能的影响,第四章模拟研究了SDS、SDES、SDE2S、SDE3S和SDE4S在界面聚集行为和抗钙性能的差异。EO数增加,会降低表面活性剂与Na+离子相互作用力,而能提高其与Ca2+离子的结合能力,尤其是当EO数大于2时,提高的幅度更大,继续增加EO基团,对其抗钙性能的提高不明显。烷基磺酸盐类表面活性剂活性剂也是一类用途广泛的阴离子表面活性剂,作为与烷基硫酸盐的对比,第五章模拟了EO基团的引入对十二烷基磺酸钠(SDSn)和十二烷基苯磺酸钠(SDBSn)表面活性剂分子在气/液界面上的聚集行为及其抗钙性能的影响。EO基团的增多都可以增强SDSn和SDBSn表面活性剂分子、头基S03及Oe原子的水化能力。SDSn分子中的S03基团与反离子Na+的相互作用随着EO数的增加逐渐减弱,SDBSn分子则是引入第一个EO基团时,它们之间的相互作用增强,而随着进一步增加EO基团其相互作用又逐渐减小。SDSn分子中引入3个EO基团时,Ca2+离子对S03基团影响最小,EO络合Ca2+离子的能力最大,此时表面活性剂分子的抗钙性能最强。而SDBSn分子中引入2个EO基团后,表面活性剂分子的抗钙性能就大大提高,继续增加EO基团对其抗钙性能的提高不明显。表面活性剂与聚合物混合体系的研究一直是大家感兴趣的课题。目前对阴-非离子表面活性剂与聚合物混合体系的研究较为缺乏。第六章我们选择的模拟体系为含有三个EO基团的十二烷基聚氧乙烯醚磺酸钠(SDE3Sn)和十二烷基聚氧乙烯醚硫酸钠(SDE3S)分别与聚丙稀酰胺(PAM)以及PEO-PPO嵌段聚醚的混合体系,考察在含有CaCl2时,混合体系组分间的相互作用及其抗钙能力,结果发现含有SDE3Sn的混合体系的抗Ca2+性能优于含SDE3S者。更多还原

【Abstract】 Compared with non-ionic and anionic surfactant, there are many advantages of anionic-nonionic surfactants:a good resistance to salt, low Kraff point, high cloud point, and environmentally friendly. The anionic-nonionic surfactant has a high ability to resist Ca2+ions, EO group would combine Ca2+ions to form complexation, which reduces the effect of Ca2+ion on the polar groups, surfactant molecules precipitate hardly, thereby improving its ability to resist Ca2+ion. To get the interaction between EO group and Ca2+ion, EO number effects, the relationship of surfactant molecular anti-Ca2+capacity with number of EO units, and the differences of anti-Ca2+ions with different species anionic-nonionic surfactant, molecular dynamics simulation was used to study the aggregation behavior, interaction with Ca2+ion of alkyl sulfate and alkyl sulfonate with EO number of increased, With a view to the practical application of anionic-nonionic surfactant molecules and its molecular designed to provide theoretical guidance.Sodium dodecylsulfate (SDS) is a common type of anionic surfactants, widely used in various fields. In Chapter2, SDS and alkyl benzene sodium sulfate (SDBS); were compared by molecular dynamics simulations to investigate the differences of their interfacial aggregation behavior with EO group introduced. The EO group introduction will reduce the polarity of the charge, electrostatic repulsive force between them reduced, to form compact aggregates. Negative charge decreases of SO4group induce its interaction with Na+ions reduced. SDBS system reduces more than the SDS. EO groups exist to increase the hydration capacity of polar base and SDBS system increased more than SDS. These differences may be caused by steric effects of the benzene ring.Introduction of EO groups would increase the hydration capacity of SDS and SDBS, lower SO4group interactions with Na+ions. In Chapter3, the effect of EO group introduction is further explored on the anti-Ca2+capacity of SDS and SDBS. In SDS and SDBS systems, most Ca2+ions locate in the second hydration layer of surfactant molecules and SO4groups. In the SDES and SDBES system, part Ca2+ions would enter into their first hydration layer of SO4group and EO units, the interactions between Ca+ion with the surfactant enhanced, further analysis showed that the Ca2+ions only interact strongly with the O atom (SO4group connected with the EO groups), and its interaction with other three O atoms are rarely improved. The EO group would combine Ca+ions, limiting their migration, reduces effect of Ca2+ions on SO4group, thus avoiding the precipitation of surfactant, improving its anti-Ca2+capacity.Introduction of EO groups can increase the anti-Ca2+capacity of SDS, to get the effects of EO numbers on improving its anti-Ca2+capacity, in Chapter4, molecular dynamic simulations were used to compare the differences of the interfacial aggregation and their anti-Ca2+capacity of SDS, SDES, SDE2S, SDE3S and SDE4S. Increased number of EO, would lower surfactants interaction with Na+ions, and can improve the ability of its combination with Ca2+ions, especially when more than2EO units presence, there is a larger increase, while continues to increase the EO groups, its anti-Ca+capacity improvement is not evident.Alkyl sulfonate surfactants are also widely used in various fields, as compared with alkyl sulfates, in Chapter5, the interfacial aggregation behaviors and their anti-Ca2+capacity of SDSn and SDBSn were compared with EO groups increase. Introduction EO groups would enhance their hydration capacity of surfactant molecules, SO3and EO group. The interaction between SO3groups in SDSn molecules and Na+ions decreases with increasing EO. As for the SDBSn molecule, first EO group introduced will enhance the interaction between them, and as a further increase in EO group, their interaction decreases. SDSn molecule with3EO group introduced, Ca2+ion on SO3groups least affected, EO complexing capacity maximum of Ca2+ion, anti-Ca2+capacity of surfactant molecules is highest. As the SDBSn molecule with2EO groups introduced, anti-Ca2+capacity of surfactant molecules is greatly improved, continue to increase the EO groups, its anti-Ca2+capacity improvement is not evident.The mixtures of surfactant and polymer have always been a topic. While the researches on mixtures of anionic-nonionic surfactants and polymer are relatively lack. In Chapter6, the SDE3Sn and SDE3S are chosen to mix with polypropylene amide (PAM) and PPO-PEO polyether, respectively. When containing CaCl2, the interaction between the mixture system components and their ability to resist the Ca+were compared, the results found to contain SDE3Sn, Ca2+resistance of mixtue system with superior to contain SDE3S.更多还原