Harnessing the power of polymer phase interactions in the design of supramolecular interpenetrating networks

非技术概述：生物材料通常具有复杂的组件，利用具有不同机械性能的相之间的相互作用来实现协同和高度可调的效果。将这种受自然启发的结构相互作用结合到合成聚合物系统中，提出了开发机械坚固和功能材料的建议。它们的结构和性质将在本项目中使用先进的仪器组合进行研究和关联。控制和调整复杂系统中分子和材料结构的能力解决了新材料开发中与机械自适应行为和控制运输相关的关键科学挑战。这样的系统在一系列应用中具有潜在的用途，包括生物医学运载工具、传感器、致动器和膜，并且可能在可加工性方面也具有潜在的优势。研究生和本科生将接触到跨领域的研究——从合成到加工——并在指导和社区推广领域利用这些进展。将支持为女学生和博士后，特别是来自代表性不足群体的女学生和博士后建立一个指导平台，就分享经验和职业道路进行对话。与一所K-12全女子私立学校扩大合作，将在为期两周的高中女生科学/工程暴露项目中提供动手示范、职业发展和安全/道德培训。技术概述：超分子缔合在弹性体、共混物和共聚物体系中得到了广泛的研究，并激发了人们在设计互穿聚合物网络（ipn）时利用动态缔合的兴趣。ipn提供了一个强大的平台来探索超分子基序作为增韧机制的作用，这是由于聚合物相的密切相互作用。该研究项目将阐明结构参数和指导原则，以直接制造具有可调界面相互作用，定制结构非均质性和协同力学行为的超分子ipn。我们将探讨三种超分子ipn，它们利用：(1)互补和正交超分子结合，重点关注不同相互作用强度/组织的基序如何影响微观结构的发展和动力学；(2)自互补和互补氢键结合，重点关注所产生的IPN形态、力学和超分子响应之间的相关性；(3)颗粒增强作为控制相粗化、力学行为和功能的方法。将利用一整套结构、热、机械和形态表征技术，包括变温核磁共振、荧光光谱、拉伸测试、动态力学分析、原子力显微镜、流变学、扫描电子显微镜、x射线和中子散射。

NON-TECHNICAL SUMMARY:Biological materials often feature complex assemblies that utilize the interaction between phases possessing disparate mechanical properties to achieve synergistic and highly tunable effects. Incorporation of this nature-inspired structural interplay into synthetic polymeric systems is proposed toward the development of mechanically-robust and functional materials. Their structures and properties will be studied and correlated in this project using a combination of advanced instrumentation. The ability to control and tune the molecular and materials architecture in complex systems addresses key scientific challenges related to mechanically adaptive behavior and controlled transport in new materials development. Such systems have potential use in a range of applications, including biomedical delivery vehicles, sensors, actuators, and membranes, and may potentially also offer advantages in terms of processability. Graduate and undergraduate students will gain exposure to cross-cutting research -- from synthesis to processing -- and utilize these advances in the areas of mentorship and community outreach. A mentoring platform for female students and post-docs, particularly from underrepresented groups, to engage in dialogue regarding shared experiences and career pathways will be supported. An expanded partnership with a K-12 all-female independent school will provide hands-on demonstrations, career development, and safety/ethics training during a two-week science/engineering exposure program for high-school girls. TECHNICAL SUMMARY:Supramolecular associations have been widely explored in elastomers, blends, and copolymer systems, and have motivated interest in the utilization of dynamic associations in the design of interpenetrating polymer networks (IPNs). IPNs provide a robust platform to explore the role of supramolecular motifs as a toughening mechanism due to the intimate interaction of the polymer phases. This research program will elucidate structural parameters and guiding principles to direct fabrication of supramolecular IPNs with tunable interfacial interactions, tailored structural heterogeneity, and synergistic mechanical behavior. Three classes of supramolecular IPNs will be explored that utilize: (1) complementary and orthogonal supramolecular associations with focus on how motifs of varying interaction strength/organization influence microstructure development and dynamics, (2) self-complementary and complementary hydrogen bonding associations with an emphasis on the correlation between the resulting IPN morphology, mechanics, and supramolecular response, and (3) particulate-reinforcement as an approach to control phase coarsening, mechanical behavior, and functionality. A full suite of structural, thermal, mechanical, and morphological characterization techniques will be utilized, including variable temperature nuclear magnetic resonance, fluorescence spectroscopy, tensile testing, dynamic mechanical analysis, atomic force microscopy, rheology, scanning electron microscopy, and X-ray and neutron scattering.