Stacks of correlated polymer lamellar crystals as platform for functional assemblies

相关聚合物层状晶体的堆叠作为功能组装的平台

• 批准号: 410892664
• 负责人: Professor Dr. Günter Reiter
• 金额: --
• 依托单位: Department of Chemical Engineering
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410892664?language=en
• 关键词: Stacks; correlated; polymer; lamellar; crystals

Polymer lamellar crystals can be considered as part of the family of quasi-two-dimensional nano-sheets with tunable thickness and (functional) surface properties. Besides single-layer crystals, correlated stacks of multi-lamellar polymer crystals with unique orientation can be generated from solution or melt. It is generally accepted that the formation of new crystalline layers on top of the amorphous fold surface of a basal lamella requires a nucleation process. However, the mechanism responsible for stack formation and how the stacked layers are mutually connected is not yet clear. In this joint proposal, we aim to produce stacks of correlated polymer lamellar crystals, both from homopolymers and block copolymers. The thickness of the lamellar core and the interfacial layer, the number of lamellar layers and the areal density of connecting tie chains in the stacks will be tuned via systematic variation of characteristic polymer chain parameters and crystallization conditions. The effect of self-induced nucleation on the fold surface will be examined methodically and in detail. For the formation of stacks of correlated lamellae, a model accounting for the competition of nucleation, growth and diffusion will be developed. Furthermore, we will employ stacks of correlated polymer lamellar crystals as platform for functional anisotropic assemblies yielding composite materials exhibiting features of single crystals. For instance, we will synthesize end-functionalized polymer chains (e.g., using tetraphenylethylene) which emit light when the end-groups aggregate at high areal densities, leading to aggregation-induced emission. After crystallization of such end-functionalized polymers, the functional groups are confined within amorphous interlayers between crystalline lamellae. We will also attempt to incorporate quantum dots or small dyes molecules within the amorphous interlayers. The fluorescence behavior (orientation and polarization dependence) of the stacked lamellar crystals will be investigated in detail. In addition, lithium salts will be inserted into amorphous interlayers and the electric (transport) properties will be measured. We expect that the outcome of the joint project will not only deepen our understanding of the central mechanism of self-induced nucleation in polymer crystals leading to the formation of (high) stacks of correlated polymer lamellar crystals, but also provide new concepts for designing functional materials based on correlated stacks of two-dimensional polymer lamellar crystals.

聚合物层状晶体可以被认为是具有可调厚度和（功能）表面性质的准二维纳米片家族的一部分。除了单层晶体，具有独特取向的多层聚合物晶体的相关堆叠可以从溶液或熔体中产生。通常认为，在基底薄片的无定形折叠表面的顶部上形成新的结晶层需要成核过程。然而，负责堆叠形成的机制以及堆叠层如何相互连接尚不清楚。在这个联合提案中，我们的目标是从均聚物和嵌段共聚物中产生相关聚合物层状晶体的堆叠。层状核心和界面层的厚度、层状层的数量和堆叠中连接连接链的面密度将通过特征聚合物链参数和结晶条件的系统变化来调节。折叠表面上的自诱导成核的效果将被系统地和详细地检查。为了形成相关薄层的堆叠，将开发一个模型，该模型考虑成核、生长和扩散的竞争。此外，我们将采用堆叠的相关聚合物层状晶体作为平台的功能各向异性组件产生复合材料表现出单晶的功能。例如，我们将合成末端官能化的聚合物链（例如，使用四苯乙烯），当端基以高面密度聚集时发光，导致聚集诱导的发光。在这种末端官能化的聚合物结晶后，官能团被限制在结晶层之间的无定形夹层内。我们还将尝试将量子点或小的染料分子内的无定形夹层。堆叠的层状晶体的荧光行为（取向和偏振依赖性）将被详细研究。此外，锂盐将被插入到无定形夹层和电（传输）性能将被测量。我们期望，该联合项目的成果不仅将加深我们对聚合物晶体中自诱导成核导致相关聚合物层状晶体（高）堆叠形成的中心机制的理解，而且还将为基于二维聚合物层状晶体相关堆叠设计功能材料提供新的概念。