【作者】 谭景林；

【导师】 张长桥； 冯圣玉；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2014， 博士

【摘要】 有机硅表面活性剂是以硅氧/碳烷为疏水链节,连接一个或多个亲水基团组成的一类新型高效的表面活性剂。不但具有比烷烃类表面活性剂更优良的表面活性和“超铺展”性,而且具备有机硅材料的耐高低温、耐气候老化、无毒生理惰性等优异的性能。以其独特、优异的性能广泛应用于聚氨酯泡沫、涂料/农药/纺织助剂、日用品、油田化学品等领域。随着有机硅材料进一步发展和对有机硅下游产品深入的开发,有机硅表面活性剂的品种也将不断的增加,应用领域也会不断扩大,这都是有机硅表面活性剂的发展方向与研究热点。本文通过分子设计合成不同疏水结构、亲水结构、平衡离子的阳离子有机硅表面活性剂、比较系统的探索疏水基团、亲水基团、平衡离子对阳离子有机硅表面活性剂在水溶液中聚集行为的影响。以期望实现为有机硅表面活性剂的实际应用提供理论依据。本论文主要分为以下五部分工作：第一部分概述了有机硅表面活性剂的类型、特性及其合成方法。第二部分合成了一系列不同疏水基、亲水基、平衡离子的阳离子型有机硅表面活性,三硅氧烷季铵氯盐(Si3ACl)、三硅碳烷季铵氯盐(Si3C2ACl)、四硅氧烷季铵氯盐(Si4ACl)、四硅氧烷咪唑氯盐(Si4mimCl)、四硅氧烷吡咯氯盐(Si4pyCl)>四硅氧烷吡咯硝酸盐(Si4pyNO3)、四硅氧烷吡咯醋酸盐(Si4pyAc)。并用1HNMR、FT-IR、ESI-MS对其分子结构进行了表征。表明所合成的阳离子型有机硅表面活性剂均为目标产品。第三部分探讨阳离子有机硅表面活性剂亲水头基对其在水溶液中的聚集行为影响。通过表面张力、电导率和稳态荧光方法研究了SimimCl、Si4pyCl和Si4ACl三种阳离子有机硅表面活性剂在水溶液中的表面活性及其聚集行为。发现,Si4mimCl、Si4pyCl和Si4ACl能降低水的表面张力至约20mN·m-1,具有较高降低表面张力的效率和效能,表明这三种阳离子型机硅表面活性剂具有优良的表面活性。其CMC值大小顺序为Si4pyCl<Si4mimCl<Si4ACl。由电导率实验惊奇的发现,Si4mimCl和Si4ACl的反离子结合度(β)随着温度的上升而上升,主要是受表面活性剂头基与疏水基之间相互吸引力的影响。然而发现Si4pyCl的声是随着温度的升高而降低的,这跟烷烃类阳离子表面活性的规律是一致的。热力学函数的探讨发现,Si4mimCl, Si4pyCl和Si4ACl在水溶液的胶束化过程是自发的。Si4pyCl和Si4ACl的胶束化过程是熵驱动过程,而Si4mimCl是焓驱动的胶束化过程。头基对Si4mimCl和Si4ACl胶束内部微极性环境影响也很大,Si4mimCl中咪唑头基与芘存在π-π相互作用,导致芘分子停留在胶束的头基部分,即芘分子主要停留在胶束中靠近头基的栅栏层,直接导致Si4mimCl的11/13值比Si4pyCl和Si4ACl的高。第四部分运用表面张力、电导率法研究了Si4ACl,Si3ACl和Si3C2ACl三种阳离子有机硅表面活性剂在水溶液中的聚集行为。探讨了疏水基对阳离子有机硅表面活性剂表面活性及胶束化的影响。Si3ACl,Si3ACl和Si3C2ACl能降低水的表面张力至约21～24mN.m-1,表明这三种有机硅表面活性剂具有优良的表面活性,且具有较高的降低表面张力的效率与效能。Si3C2ACl疏水链中含有疏水的CH2基团,而Si4ACl含有三个Si(CH3)3基团,导致CMC值顺序为Si3C2ACl<Si4ACl<Si3ACl,,说明疏水基团对其CMC值等影响较大。热力学探讨发现,Si4ACl, Si3ACl和Si3C2ACl在水溶液的胶束化过程是自发的。Si4ACl的胶束化过程是熵驱动过程,而Si3C2ACl和Si3ACl是焓驱动的胶束化过程。相比Si3ACl, Si3C2ACl的△Cm,p0值更负,因为Si3C2ACl疏水链段中含有疏水的CH2基团,具有更强的疏水作用。而Si4ACl体系中由于存在头基与疏水基之间相互作用力,其△Cm,p0值为正值。卤代盐的加入能降低阳离子有机硅表面活性剂在水溶液中的CMC值,即增强了吸附效率。但是对阳离子有机硅表面活性剂γCMC及其在气/液界面的吸附(Γmax、Amin)基本没有影响或影响不大。且卤代钠的对其影响顺序为NaI>NaBr>NaCl。第五部分利用表面张力、电导率法、动态光散射(DLS)、透射电镜(TEM)研究三种有机硅离子液体,Si4pyAc,Si4pyCl和Si4pyNO3,在水溶液中的聚集行为,借此进一步探讨了平衡离子对阳离子有机硅表面活性剂表面活性及胶束化的影响。表面张力结果发现,Si4pyCl和Si4pyNO3能降低水的表面张力至约20mN.m-1,表明三种有机硅离子液体具有优良的表面活性,且具有较高的降低表面张力的效率与效能。平衡离子对有机硅离子液体的表面活性等性能有着很大的影响。水溶液中有机硅离子液体的聚集体形貌为圆形。热力学探讨发现,Si4pyAc,Si4pyCl和Si4pyNO3在水溶液中的聚集行为是自发的。Si4pyCl离子液体胶束的形成是熵驱动的过程。而Si4pyAc和Si4pyNO3离子液体胶束的形成是焓驱动的过程。同时探讨了NaBr和NaCl对有机硅离子液体聚集行为的影响。发现对有机硅离子液体γCMC及其在气/液界面的吸附(Γmax、Amin)基本没有影响或影响不大。更多还原

【Abstract】 Silicone surfactants consist of a permethylated siloxane/silane group coupled to one or more polar groups, which are a new class of surfactants with excellent surface active. They are widely used in industrial fields, such as agricultural adjuvant, polyurethane foam additives, paint additives, emulsifiers in cosmetics, and textile conditioning. This wide application is attributed to those properties of silicone surfactant:(i) its high surface activity and "super-spreading",(ii) its low toxicity and excellent association behavior and (iii) its low glass transition temperature even for higher molecular weight make it easier to use at room temperature. With the further development of silicone materials, silicone surfactants will be widely investigated and under the spotlight.In this dissertation, a series of cationic silicone surfactants with different hydrophobic groups, different hydrophilic groups and different counterion groups are designed and prepared. Their aggregation behaviors in aqueous solution have been investigated systematically in order to study the effect of hydrophobic groups, hydrophilic groups and counterion groups on aggregation behavior of cationic silicone surfactant. Our research is helpful to establish the dependence of aggregation behavior of cationic silicone surfactants on their structures. This dissertation is divided into5parts as follows:The first part, the types, synthesized methods and study progress of silicone surfactants are summaried.The second part, a series of cationic silicone surfactants with different hydrophobic groups, different hydrophilic groups and different counterion groups are designed and synthesized. The results of FT-IR,1H NMR, and ESI-MS indicate that these cationic silicone surfactants are all objective products.The third part, the surface activity and aggregation behavior of Si4mimCl, Si4pyCl and Si4ACl in aqueous solution was systematically investigated by surface tension, electrical conductivity, and steady-state fluorescence. Surface tension of water can be reduced almost to20mN·m-1with the addition of the cationic silicone surfactants. The results indicate that all the three surfactants exhibit admirable surface activity. Because of the effect of the headgroups, the critical micelle concentrations (CMC) values increase following the order Si4pyCl<Si4mimCl<Si4ACl, and Si4pyCl packs more tightly at the air/water interface compared with Si4mimCl and Si4ACl. Electrical conductivity measurements show that all the three cationic silicone surfactants have low degree of counterion binding (β) and the β values for Si4pyCl and Si4ACl increase with increasing the temperature in the investigated temperature range. Thermodynamic parameters (△Hm0,△Sm0, and△Gm0) of micellization indicate that the micellization for Si4mimCl in aqueous is enthalpy-driven, and that for both the Si4pyCl and Si+ACl is entropy-driven. The I1/I3value for Si4imimCl is larger compared with Si4pyCl which may be caused by the π-π interaction between the imidazolium and the pyrene, consequently, the pyrene molecules tend to stay near the head group region. While, intermolecular hydrogen bonds of headgroup for Si4ACl cause the pyrene to be solubilized in the palisade layer near the polar headgroups in micelles, and therefore, Si4ACl has the lowest values of I1/I3.The forth part, aggregation behavior of Si4ACl, Si3ACl and Si3C2ACl in aqueous solution was investigated by surface tension and electrical conductivity. The results show that all the three cationic silicone surfactants perform admirable surface activity. Because of the effect of the hydrophobic groups, the critical micelle concentrations (CMC) values increase following the order Si3C2ACl<Si4ACl<Si3ACl, and Si3C2ACl packs more compactly at the air/water interface compared with Si4ACl and SiaACl. Thermodynamic parameters (△Hm0,△Sm0, and△Gm0) of micellization derived from electrical conductivities indicate that the micellization for Si.C2AC and Si.ACl in aqueous solution both is enthalpy-driven, and that for the Si4ACl is entropy-driven. The heat capacities,△cm0,p, values are positive for Si4ACl, indicating that there is the attractive interaction between the nitrogen atom of one surfactant molecule and the oxygen atom of another surfactant molecule for Si4ACl. The addition of sodium halides in the aqueous solution decreases CMC remarkably, however, the surface tension at CMC keeps the same with the salt-free system.The fifth parts, the aggregation behavior of three silicone ionic liquids, Si4pyAc, Si4pyCl and Si4pyNO3, in aqueous solution was systematically investigated by surface tension, electrical conductivity, dynamic light scattering (DLS), and transmission electron microscope (TEM). Surface tension of water can be reduced almost to20mN·m-1with the addition of the silicone ionic liquids, indicating that all the three silicone ionic liquids exhibit excellent surface activity. The critical micelle concentrations (CMC) values of Si4pyNO3is less than that of Si4pyAc. Electrical conductivity measurements show that the degree of counterion binding (β) for Si4pyNO3is twice larger than that for Si4pyAc. Thermodynamic parameters (△Hm0, ASm0, and AGm0) of micellization derived from electrical conductivities indicate that the micellization for Si4pyNO3and Si4pyAc is enthalpy-driven process. The heat capacities,△cm,p0, are negative for two silicone ionic liquids (Si4pyNO3and Si4pyAc) relating to the removal of water accessible non-polar surfaces.更多还原