嵌段共聚物自组装有序结构的调控及动力学研究

发布时间：2018-06-27 01:55

本文选题：嵌段共聚物 + 圆柱受限　；参考：《山西师范大学》2017年博士论文

【摘要】：嵌段共聚物在不同的调控手段下能够形成丰富的多尺度有序结构,而结构决定性质,这些新奇结构所展现的特有的功能性质使得聚合物体系拥有十分重要的潜在应用价值。本文围绕嵌段共聚物自组装有序结构的调控及其动力学机理进行研究。我们采用元胞动力学方法(CDS)和布朗动力学方法(BD)来研究振荡剪切场和圆柱受限共同作用下、不同表面化学以及不同性质纳米棒诱导下对称/非对称嵌段共聚物的自组装行为及其动力学过程。主要包括以下几个方面的内容:第一章主要介绍了在本体、圆柱受限、外场、以及纳米粒子诱导下嵌段共聚物体系自组装的研究进展。同时对聚合物体系的相分离热力学理论、动力学理论以及元胞动力学(CDS)方法、布朗动力学(BD)方法做了简要介绍。第二章采用元胞动力学方法研究了在振荡剪切场和圆柱受限共同作用下嵌段共聚物的自组装行为。预测了嵌段共聚物圆柱受限体系在振荡剪切场中的微相结构。通过改变其受限程度D/L0(D为圆柱纳米孔的直径,L0为体相周期)、剪切振幅和剪切频率,研究了在不同受限环境下,剪切频率和剪切振幅对嵌段共聚物相行为的影响。同时进一步探讨了在不同受限程度下,嵌段共聚物随振幅和频率发生微相转变的动力学机理。发现在小管径下,受限效应占主导;大管径下,场效应占主导;而在中管径下,最终的相形貌是由受限效应和场效应相互竞争的结果。为实验上用两种不同调控手段相结合的方式制造无缺陷有序的纳米结构提供了一定的理论基础。第三章采用元胞动力学以及布朗动力学联用的方法探讨了对称两嵌段共聚物在不同表面化学纳米棒诱导下的微相转变。通过改变不同表面化学纳米棒的数目,我们得到了规整的平行层状结构,而纳米棒则以边对边的排列方式垂直分布在相界面上。对于不同数目纳米棒诱导下所发生的从无序到平行层状再到斜层状结构的微相转变,通过畴尺寸的动力学演化过程以及微观畴的取向序随时间的变化做了进一步的分析及验证。同时还对所得到的完美平行层状结构的形貌演化过程及其畴的生长动力学进行了探讨。另外,还研究了纳米棒的性质、棒-相相互作用(浸润强度)、棒-棒相互作用、棒长以及嵌段共聚物的聚合度对聚合物纳米复合材料相行为的影响。所得结果为如何在纳米尺度上得到有序的相结构,以及如何提高聚合物纳米复合材料的功能性提供了有益的指导。第四章研究了不对称两嵌段共聚物在不同性质纳米棒诱导下的相行为。通过改变浸润A相的棒长,聚合物体系发生了从斜层状结构到平行层状结构,再到垂直层状结构,最后到海岛状结构的相转变。其中纳米棒由端对端平行于相界面的排列方式转变为边对边垂直于相界面的排列方式,最后转变为钉扎于岛状A相中的聚集排列。对于该相转变,我们从畴尺寸的动力学演化做了进一步的分析及验证。同时,还对平行层状结构及垂直层状结构做了形貌演化及畴生长的动力学过程分析。另外我们还研究了单浸润纳米棒的数目对聚合物体系相行为的影响,发现浸润B相的纳米棒比浸润A相的纳米棒更容易诱导非对称嵌段共聚物形成层状结构。除此之外,我们还探讨了棒-相相互作用强度、棒-棒相互作用强度、以及聚合度对单浸润纳米棒诱导的非对称嵌段共聚物体系相行为的影响。最后,在第五章中,我们对本文的主要结论做了总结,并对今后的研究工作进行了展望。
[Abstract]:The block copolymers can form rich multiscale ordered structures under different regulatory means, and the structure determines their properties. The unique functional properties of these novel structures make the polymer system have a very important potential application value. In this paper, the regulation and dynamics mechanism of the self-assembled structure of block copolymer and its kinetic mechanism are discussed in this paper. We use the cellular dynamics (CDS) method and Brown dynamics method (BD) to study the self assembly behavior and dynamic process of symmetric / asymmetric block copolymers under the interaction of oscillating shear field and cylinder confinement, with different surface chemistry and different properties of nanorods. The main contents are as follows: In the first chapter, the progress in self assembly of block copolymer system under the induction of body, cylinder confinement, external field and nanoparticles is introduced. The phase separation thermodynamics theory, kinetic theory, CDS method and Brown dynamic (BD) method of polymer system are briefly introduced. The second chapter adopts cellular dynamics. The self-assembly behavior of block copolymers under the joint action of oscillating shear field and cylinder confinement was studied by the method of study. The microphase structure of the block copolymer cylindrical confinement system in the oscillating shear field was predicted. The shear amplitude and shear frequency were studied by changing the confinement degree D/L0 (D is the diameter of the cylindrical nanoscale, L0 phase period), and the shear amplitude and frequency. The effect of shear frequency and shear amplitude on the phase behavior of block copolymers under different confinement conditions. At the same time, the kinetic mechanism of microphase transition of block copolymers with amplitude and frequency under different restrictions is further explored. It is found that the confinement effect is dominant under the tube diameter; the field effect is dominant under the large diameter of the tube; The final phase appearance is the result of the competition between the confinement effect and the field effect. It provides a certain theoretical basis for the fabrication of non defective and ordered nanostructures by the combination of two different means of regulation in the experiment. The third chapter discusses the symmetric two block copolymers by the method of cellular dynamics and Brown dynamics. The microphase transition induced by different surface chemical nanorods. By changing the number of different surface chemical nanorods, we get a regular parallel layered structure, while the nanorods are vertically distributed on the phase interface by the arrangement of edge to side. The microphase transformation of the structure is further analyzed and verified by the dynamic evolution of the domain size and the change of the orientation sequence of the micro domain. Meanwhile, the evolution process of the perfect parallel layered structure and the growth kinetics of the domain are also discussed. In addition, the properties of the nanorods are also studied. The effect of phase interaction (infiltration strength), rod and rod interaction, rod length and the degree of polymerization of block copolymers on the phase behavior of polymer nanocomposites. The results provide useful guidance on how to obtain orderly phase structure on nanoscale and how to improve the functionality of polymer nanocomposites. Fourth chapters The phase behavior of asymmetric two block copolymers is induced by different properties of nanorods. By changing the length of the rods infiltrating the A phase, the polymer system takes place from the diagonal layer to the parallel layered structure, then to the vertical layered structure, and finally to the phase transition of the island structure. The arrangement of edge to side perpendicular to the phase interface was changed to the aggregation arrangement in the island A phase. For the phase transition, we further analyzed and verified the dynamic evolution of domain size. At the same time, the dynamics of the morphology and domain growth of the parallel layered structure and the vertical layered structure were also analyzed. In addition, we also studied the effect of the number of single infiltrating nanorods on the phase behavior of the polymer system. It was found that the nanorods infiltrating the B phase were more likely to induce the asymmetric block copolymers to form a layered structure than the nanorods infiltrating A phase. In addition, we also discussed the strength of the rod phase interaction, the rod and rod interaction strength, and the degree of polymerization. The effect of the phase behavior of asymmetric block copolymer system induced by single infiltrating nanorods. Finally, in the fifth chapter, we summarize the main conclusions of this paper and look forward to the future research work.
【学位授予单位】：山西师范大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O631.1

【相似文献】