Experimental investigation and numerical simulation of the orientation processes in block copolymers on a macroscopic and a molecular level

宏观和分子水平上嵌段共聚物取向过程的实验研究和数值模拟

• 批准号: 263005595
• 负责人: Professor Dr. Marcus Müller
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/263005595?language=en
• 关键词: Experimental; investigation; numerical; simulation; orientation

The comprehensive goal of the continuation of this project is a better understanding of the influences like dynamic asymmetries and complex molecular topologies on the linear and nonlinear rheological properties of homopolymer and block copolymer melts. This goal is further divided into four working packages1) It shall be clarified if a dynamic asymmetry of the polymer blocks in block copolymer melts has some influence on the stability of the orientation of polymer lamellae. For identical mobilities, as it is the case in computer simulations or the polymer systems of the first application, the perpendicular orientation is found to be the stable one. However, for many experimental systems the parallel one is observed. The difference in mobility shall be increased in the experiment and in the simulations to evaluate its influence on the stability of the lamellae’s orientation. 2) Another question to answer is if there are differences in the orientation kinetics of lamellae in shear between lamellar diblock copolymers and lamellar triblock copolymers. It shall be clarified if the fixation of triblock copolymers in one lamella or the bridging by a fixation in two different lamellae shows a noticeable influence on the orientation kinetics of the observed system. 3) The influence of entanglements on the nonlinear rheology and on higher harmonics shall be investigated. First, less complex systems as homopolymer melts shall be investigated. In order to evaluate the influence of molecular weight and thus the amount of entanglements, the nonlinear behavior in simulations I planned to be investigated by simulations with slip-springs, which mimic entanglements of polymer chains, and simulations without these. 4) The influence of polymer topology is planned to be investigated. With an increasing number of sidechains the influence of entanglements on the dynamics of the polymer decreases. The number of sidechains is gradually increased in the simulations and in the experiments and the nonlinear behavior of the polymers’ melt is investigated. With this approach it is possible to clarify if higher harmonics result from entanglements or from a complex relaxation spectrum.

继续该项目的综合目标是更好地了解动态不对称性和复杂分子拓扑等对均聚物和嵌段共聚物熔体的线性和非线性流变性能的影响，该目标进一步分为四个工作包1）。澄清了嵌段共聚物熔体中聚合物嵌段的动态不对称性是否对相同迁移率的聚合物片层取向的稳定性有一些影响，就像计算机中的情况一样。在第一次应用的模拟或聚合物系统中，发现垂直取向是稳定的，但是，对于许多实验系统来说，在实验和模拟中观察到迁移率的差异以评估其。 2) 另一个需要回答的问题是，层状二嵌段共聚物和层状三嵌段共聚物之间的层状取向动力学是否存在差异。如果三嵌段共聚物在一个薄片中的固定或通过在两个不同薄片中的固定的桥接对所观察到的系统的取向动力学显示出显着的影响，则需要澄清。 3) 缠结对非线性流变学和高次谐波的影响。首先，应研究不太复杂的系统，例如均聚物熔体，以评估分子量以及缠结量和模拟中的非线性行为的影响。我计划通过模拟聚合物链缠结的滑弹簧模拟进行研究，并计划研究不使用滑弹簧的模拟。 4）计划研究随着侧链数量的增加，缠结对动力学的影响。在模拟和实验中，聚合物的侧链数量逐渐增加，并研究聚合物熔体的非线性行为，可以澄清高次谐波是由缠结还是由缠结引起的。来自复杂的弛豫谱。