含胆酸钠的混合表面活性剂体系分子自组装热力学

发布时间：2018-06-04 01:25

本文选题：热力学 + 胆酸钠　；参考：《河南师范大学》2016年硕士论文

【摘要】：超分子聚集体囊泡为具有可调控性的软纳米粒子,由于其与细胞类似的双分子层膜结构,为细胞仿生研究提供了模型体系。小分子表面活性剂囊泡作为仿生研究及实际应用的系统,如缓释或定向释放的药物载体,在保持软材料性质的前提下提高双分子层稳定性是关键课题之一。本工作的目的是采用胆酸钠改性的葡聚糖聚合物对表面活性剂囊泡的修饰,提高囊泡的稳定性。本论文以等温滴定量热(ITC)为主要研究手段,结合冷冻透射电镜(cryo-TEM)、浊度、电导和动态光散射(DLS)等分析技术,以胆酸钠(NaCA)和含胆酸钠侧链的改性聚合物为研究主线,探讨它们与阴、阳离子表面活性剂的混合体系和阴阳离子混合囊泡之间的一系列分子自组装热力学和相行为。详细分析了双亲分子疏水侧链性质、电荷、溶液的组成和浓度等因素对复杂体系中分子聚集过程的影响,讨论了各种双亲分子间的协同效应。由此从宏观热力学特性和分子结构方面,解释胆酸钠组分对囊泡聚集体转变的调控作用以及此类复杂体系中分子间相互作用的热力学行为。论文工作包含以下主要内容:1.胆酸钠在水溶液中的胶束化热力学以等温滴定量热和电导率测定方法,研究了胆酸钠的浓度变化对其胶束化过程的影响。测量了胆酸钠的临界预胶束浓度和临界胶束浓度及其相应过程的相变焓。尤其是对于胆酸钠的预胶束形成,首次得到了有明确定义的预胶束化焓。2.建立了相同电荷的表面活性剂混合体系——NaCA/十二烷基硫酸钠(SDS)得到了在不同SDS初始浓度下相同电荷的NaCA和SDS之间的相互作用能。结果表明ITC对于相同电荷混合表面活性剂非常弱的协同效应以及疏水作用能量研究是最为直接准确的手段。3.建立了相反电荷的表面活性剂混合体系—NaCA/双子表面活性剂(12-10-12Br2)深入研究了这类混合体系从胶束到液晶,再到混合胶束的转变过程热力学和相行为。得到了混合体系胶束相与液晶相的浓度范围,详细讨论了双子表面活性剂浓度对混合体系聚集行为的影响。4.NaCA对于阴阳离子混合表面活性剂囊泡聚集行为的调控作用建立了含有三种表面活性剂分子的复杂体系。通过等温滴定量热与浊度、动态光散射、低温透射电镜等手段结合,研究了NaCA诱导的囊泡从溶胀到破裂过程的形态变化及聚集热力学,并得到了囊泡破裂的临界浓度和焓变。5.含有NaCA侧链的改性聚合物(Dex-xCACOONa)与囊泡的相互作用基于前面工作的基础,论文工作进一步在混合表面活性剂囊泡体系中加入侧链带有胆酸钠的改性聚合物,旨在调控囊泡的稳定性和聚集行为。首先利用ITC方法表征了双亲聚合物在水溶液中的自组装热力学性质和聚集能力。进而建立疏水聚合物与囊泡的混合体系,聚合物的NaCA改性侧链及替代度对囊泡聚集行为的影响被详细地讨论。这些结果对于我们进一步深入扩展此类复杂体系的研究和应用,有着重要的指导意义。论文工作得到国家自然科学基金项目(No.21273061和No.21327003)的支持。研究生期间关于同电荷表面活性剂体系的工作已经发表在国际专业杂志J.Chem.Thermodynamics,(100(2016)131-139)上。发表国内外会议论文(3篇)。两篇工作在整理中,一篇为胆酸钠与混合囊泡的相互作用,另一篇为疏水改性聚合物对囊泡聚集行为的调控及其相互作用热力学。
[Abstract]:The supramolecular aggregate vesicle is a controllable soft nanoparticle, which provides a model system for biomimetic research due to its similar bimolecular membrane structure. Small molecular surface active agent vesicles are used as biomimetic research and practical applications, such as sustained release or directional release drug carriers, before maintaining the properties of soft materials. It is one of the key issues to improve the stability of the biolecular layer. The aim of this work is to improve the stability of the vesicles by using sodium cholate modified glucan polymer to modify the vesicles of the surfactant. In this paper, the isothermal drop quantitative heat (ITC) is used as the main research method, combined with the cryopreservation transmission electron microscopy (cryo-TEM), turbidity, conductivity and dynamic dispersion. A series of molecular self-assembly thermodynamics and phase behaviors between the mixed systems of anion and cationic surfactant and the mixed vesicles of yin and yang ions are discussed with DLS and other analytical techniques. The properties of the hydrophobic side chain of the parents, charge and solution are detailed and analyzed. The effects of composition and concentration on the molecular aggregation process in complex systems are discussed, and the synergistic effects of various parents are discussed. From the macroscopic thermodynamic properties and molecular structures, the regulation of the sodium cholate component to the vesicle aggregates transformation and the thermodynamic behavior of intermolecular interaction in such complex systems are explained. The work includes the following main contents: 1. the micellization thermodynamics of sodium cholate in aqueous solution, the influence of the concentration change of sodium cholate on the micellization process of the isothermal drop quantitative heat and electrical conductivity. The critical Premicelle concentration and critical micelle concentration of sodium cholate and the enthalpy of the corresponding process are measured. In the formation of pre micelle of sodium cholate, a clearly defined premicellar enthalpy.2. has been obtained for the first time to establish a mixed system of surfactants with the same charge - NaCA/ twelve alkyl sulfate (SDS). The interaction energy between NaCA and SDS at the same charge at different initial SDS concentrations is obtained. The results show that ITC is the same charge mixing table. The very weak synergistic effect and the study of hydrophobic energy are the most direct and accurate means for.3. to establish a surface active agent, NaCA/ Gemini Surfactants (12-10-12Br2), to study the thermodynamics and phase behavior of the transition process from micelles to liquid crystals and then to mixed micelles. The concentration range of the micell phase and liquid crystal phase of the mixed system was obtained. The effect of the concentration of Gemini Surfactant on the aggregation behavior of the mixed system was discussed in detail. The complex system containing three kinds of surfactant molecules was established in the regulation of the aggregation behavior of the mixed surfactant in the mixture of yin and Yang. By the isothermal titration calorimetry (.4.NaCA) Combined with turbidity, dynamic light scattering and low temperature transmission electron microscopy, the morphological changes and aggregation thermodynamics of NaCA induced vesicles from swelling to rupture were studied. The interaction between the critical concentration and enthalpy of the vesicle rupture and the interaction of the modified polymer (Dex-xCACOONa) with the NaCA side chain (Dex-xCACOONa) with the vesicle was obtained based on the previous work. In this paper, a modified polymer of side chain with sodium cholate was added to the mixed surfactant vesicle system to regulate the stability and aggregation behavior of the vesicles. First, the ITC method was used to characterize the self assembly thermodynamic properties and the aggregation energy of the amphiphilic polymer in aqueous solution. The effects of the NaCA modified side chain and the substitution degree of the polymer on the vesicle aggregation are discussed in detail. These results have important guiding significance for us to further expand the research and application of such complex systems. The work has been supported by the National Natural Science Foundation Project (No.21273061 and No.21327003). The work on the same charge surface active agent system was published in the international professional journal J.Chem.Thermodynamics, (100 (2016) 131-139). Published in the domestic and foreign Conference Papers (3). Two work was in the arrangement, one for the interaction between sodium cholate and mixed vesicles, and the other for the aggregation of the vesicles by the hydrophobic modified polymer. Regulation and interaction thermodynamics.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O647.2

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