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.

该项目延续的全面目标是更好地理解影响的影响，例如动态不对称和复杂的分子拓扑，对均聚物和块共聚物融化的线性和非线性流变特性的复杂分子拓扑。该目标进一步分为四个工作包1）如果块共聚物融化中聚合物块的动态不对称性对聚合物层层的方向的稳定性有一定影响，则应阐明。对于相同的迁移率，在计算机模拟或第一个应用程序的聚合物系统中就是这种情况，垂直方向被认为是稳定的。但是，对于许多实验系统，观察到平行系统。在实验和模拟中，应提高迁移率的差异，以评估其对薄片方向稳定性的影响。 2）要回答的另一个问题是，薄片二嵌段共聚物和层状三嵌段共聚物之间的剪切片的方向动力学差异。如果将三嵌段共聚物固定在一个层状中，或者在两个不同的薄片中固定在一个固定物中固定固定，则对观察到的系统的方向动力学产生了明显的影响。 3）应研究纠缠对非线性流变学和更高谐波的影响。首先，应研究不太复杂的系统作为均聚物熔体。为了评估分子量和这种纠缠量的影响，我计划通过带有滑动弹簧的模拟来研究的模拟中的非线性行为，这些模拟模仿了聚合物链的纠缠以及没有这些的模拟。 4）计划研究聚合物拓扑的影响。随着Sidechain的数量，纠缠对聚合物动力学的影响减少。在模拟和实验中，侧级技术的数量逐渐增加，并研究了聚合物熔体的非线性行为。通过这种方法，可以澄清较高的谐波是由纠缠或复杂的放松频谱引起的。