CDMR: Tuning the Mechanical Properties of Ordered Supramolecular Polymers and Their Networks

第一部分：非技术超分子聚合物代表了新一代聚合物材料，在加工、自我修复和回收方面具有优越的性能，作为电子活性材料和生物活性材料具有重要的技术应用。拥有能够在聚合物分子和网络水平上精确调整力学性能的基础知识，可能会导致超分子材料设计方式的重大转变。该项目属于计算和数据驱动材料研究(CDMR)的一般领域。它的目的是深入了解影响小分子构建单元与超分子聚合物的合作结合的各种因素，并利用所获得的知识来实现对单个聚合物及其3D网络的机械性能的精确控制。实验和计算方法的结合使用将有助于阐明这些构建单元的关键特征，以精确控制所产生的超分子聚合物的机械性能。利用分子模拟在多个长度尺度上对自组装路径进行了预测。这项工作产生的知识将影响先进材料的开发，用于有机电子和再生医学，其中聚合物长度和聚合物间缔合很重要，再生医学需要具有一定硬度的生物活性水凝胶。这两个PI为这个综合项目带来了互补的实验和理论/计算专业知识，并致力于在所有层面提供广泛的教育经验。第2部分：技术总结有序超分子聚合物(SPS)的形成，利用可以组装成高度有序和离散的一维(1D)纳米结构的小分子构建单元，导致了功能超分子材料的发展。该项目属于计算和数据驱动材料研究(CDMR)的一般领域，重点是深入了解影响小分子建筑单元合作缔合的各种因素。它旨在设计和合成一系列具有三个不同功能臂(两个疏水和一个亲水)的小分子微臂星形构筑单元(MASBU)，并阐明决定其生长动力学和最终有序SP力学性能的关键分子设计特征。具有主动反馈机制的实验和计算相结合的方法将被用来将每一臂的顺序变化与所产生的SP及其网络的机械特性(持续长度、轮廓长度、捆绑)相关联。具体地说，目标1和目标2将分别侧重于合成和研究具有异构烃和pi共轭链段的MASBU，目的是确定内部堆积顺序和持续长度之间的关系。目标3旨在通过改变能够形成分子间氢键的多肽片段中缔合作用的强度来建立生长动力学与轮廓长度之间的关联。目标4将试图确定决定由组装的SP形成的超分子网络的整体力学性质的关键因素，特别是观察持久性和轮廓长度以及SP束的影响。一个成功的结果将导致我们对有序SP体系结构-性质关系的基础知识的重大进展，并可能对超分子材料的产生产生重大影响。这两个个人投资促进机构为这一综合项目带来了互补的实验和理论/计算专门知识，并致力于在所有各级提供广泛的教育经验。

PART1: NON-TECHNICAL SUMMARYSupramolecular polymers represent a new generation of polymeric materials, offering advantageous properties in processing, self-healing, and recycling, and have important technological applications as both electronically and biological active materials. Possessing the fundamental knowledge that would enable the precise tuning of the mechanical properties at the polymer molecular and network level could lead to a significant shift in the way that supramolecular materials are designed. This project is in the general area of Computationally and Data-Driven Materials Research (CDMR). It aims to develop an in-depth understanding of the various factors that affect the cooperative association of small molecular building units into supramolecular polymers, and to use the knowledge gained to achieve precise control over the mechanical properties of individual polymers as well as their 3D networks. A combined use of experimental and computational methodologies will help elucidate the key features of these building units for precise control over the mechanical properties of the resulting supramolecular polymers. Prediction of the pathway of self-assembly is proposed with molecular modeling at multiple length-scales. Knowledge generated from this work will impact the development of advanced materials for applications in organic electronics, where the polymer length and inter-polymer associations are important, and in regenerative medicine, which requires biologically active hydrogels with defined stiffness. The two PIs bring complementary experimental and theoretical/computational expertise to this integrated project and are committed to providing a broad educational experience at all levels.PART 2: TECHNICAL SUMMARYThe formation of ordered supramolecular polymers (SPs), utilizing small molecular building units that can assemble into highly ordered and discrete one-dimensional (1D) nanostructures, has led to the development of functional supramolecular materials. This project is in the general area of Computationally and Data-Driven Materials Research (CDMR) and is focused on in-depth understanding of the various factors that affect the cooperative association of small molecular building units. It aims to design and synthesize a series of small-molecule mikto-arm star building units (MASBUs) possessing three distinct functional arms (two hydrophobic and one hydrophilic), and to elucidate the key molecular design features that define their growth kinetics and eventual mechanical properties of ordered SPs. A combined experimental and computational approach with an active feedback mechanism will be applied to correlate the sequential variation of each arm with the mechanical properties (persistence length, contour length, bundling) of the resulting SPs and their networks. Specifically, Objectives 1 and 2 will focus on the synthesis and study of MASBUs possessing isomeric hydrocarbons and pi-conjugated segments, respectively, aiming to determine the relationship between the internal packing order and the persistence length. Objective 3 aims to establish a correlation between the growth kinetics and the contour length by varying the strength of associative interactions within a peptide segment capable of forming intermolecular hydrogen bonding. Objective 4 will attempt to identify the key factors that determine the bulk mechanical properties of the supramolecular networks formed by the assembled SPs, in particular looking at the effect of the persistence and contour length and also the SP bundling. A successful outcome will lead to significant advances in our fundamental knowledge of structure-property relationships in ordered SP systems, and could have a substantial impact on the creation of supramolecular materials. The two PIs bring complementary experimental and theoretical/computational expertise to this integrated project and are committed to providing a broad educational experience at all levels.