卟啉分子组装动力学对其结构的调控作用研究

发布时间：2018-02-02 10:09

本文关键词： 卟啉自组装反应/扩散协调结构多样性　出处：《哈尔滨理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：纳米材料的结构决定其性能，因此制备具有不同结构的材料对于材料性能的优化及开发具有十分重要的意义，另一方面，多样性和复杂性是材料结构的一个内在特征，这为材料结构的可控制备增加了难度，因此有效调控材料结构的方法及理论发展非常缓慢。考虑到很多复杂结构都是在远离热力学平衡态的条件下生成，动力学因素对材料结构具有重要的调控作用，因此本文以卟啉分子自组装过程为例，以组装分子的扩散和组装速率为调控手段，研究这两个动力学因素对自组装结构的调控作用和规律，为制备卟啉自组装光电材料提供相应的理论依据。通过调节溶液的pH值来调节四苯基卟啉（TPP）分子的组装速率，分别在溶液pH1.5，6.5，12.0条件下进行了卟啉分子组装。在低pH条件下，TPP质子化，静电排斥作用使卟啉分子沿着分子平面滑移，形成head-to-tail的聚集形式。在高pH条件下，质子化作用消失，分子间主要为π-π相互作用，此时分子堆叠方式为face-to-face。在pH接近中性时，π-π相互作用与静电排斥作用之间的竞争，使得分子间的排列方式产生新的规则，导致了分子的非对称性组装，因而形成管状结构。因此，在不同pH条件下，静电排斥力与π-π相互作用之间的竞争导致了分子聚集方式的差异，生成了不同结构的组装体。接下来，通过改变醇水溶液中乙醇与水的体积比，来调控卟啉分子的扩散速率，得到了带状、中空带状、中空管状和实心柱状结构的组装体。采用原位观测法观察了管状结构与柱状结构的生成过程，发现了不同醇水体系中TPP分子组装行为的差异， TPP分子在溶液中分布和扩散环境不同，会产生微观浓度场，导致卟啉分子沿着不同的方向优势组装，从而形成各种不同的结构。因此，分子扩散过程也是影响材料结构的一个重要原因。
[Abstract]:The structure of nanomaterials determines their properties, so the preparation of materials with different structures is very important for the optimization and development of material properties, on the other hand. Diversity and complexity is an inherent feature of material structure, which makes it more difficult to control the preparation of material structure. Therefore, the development of effective methods and theories of material structure control is very slow. Considering that many complex structures are formed far from the thermodynamic equilibrium state, the kinetic factors play an important role in regulating the material structure. In this paper, the self-assembly process of porphyrin molecules is taken as an example, and the diffusion and assembly rate of the assembled molecules are taken as the means to study the regulation of these two kinetic factors on the self-assembly structure. It provides a theoretical basis for the preparation of porphyrin self-assembly optoelectronic materials. By adjusting the pH value of the solution, the assembly rate of TPP was adjusted at pH 1.5 ~ 6.5, respectively. Porphyrin molecules were assembled under the condition of 12.0.The porphyrin molecules slid along the molecular plane by electrostatic repulsion under the condition of low pH and protonation of TPP. The aggregation form of head-to-tail was formed. At high pH, the protonation disappeared and the intermolecular interaction was mainly 蟺-蟺. When pH is near neutral, the competition between 蟺-蟺 interaction and electrostatic repulsion results in new rules of molecular arrangement. Therefore, the competition between electrostatic repulsion force and 蟺-蟺 interaction leads to the difference of molecular aggregation mode under different pH conditions. Different structures of the assembly were formed. Next, the diffusion rate of porphyrin molecules was regulated by changing the volume ratio of ethanol to water in alcohol aqueous solution, resulting in banded and hollow banded porphyrin molecules. In situ observation method was used to observe the formation process of tubular and columnar structures, and the difference of assembly behavior of TPP molecules in different alcohol-water systems was found. Different distribution and diffusion environment of TPP molecules in solution will produce microcosmic concentration field, leading porphyrin molecules to be assembled in different directions, thus forming a variety of different structures. The molecular diffusion process is also an important factor affecting the structure of materials.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O626;TB383.1

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