Influence of Double Network, Internetwork Connectivity and Sacrificial Bonds on the Frictional Characteristics of Double Network Hydrogels: Experiments and Modeling

双网络、网络连通性和牺牲键对双网络水凝胶摩擦特性的影响：实验和建模

• 批准号: 2154530
• 负责人: Rosa Espinosa-Marzal
• 金额: $ 42.43万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154530&HistoricalAwards=false
• 关键词: Influence; Double; Network; Internetwork; Connectivity

This grant will support research that will advance the knowledge related to a structure-property relation for double network hydrogels, promoting the progress of science. The exceptional lubrication behavior of biological tribosystems stems from its biphasic composition, a complex macromolecular network with a water-based lubricant. As a prominent example, articular cartilage balances lubricity with strength. To date, there is an urgent need to generate tribological understanding and models for novel biomaterials that can serve as replacement for cartilage. Double network (DN) hydrogels consist of two interpenetrating polymer network that resemble cartilage, are strong and tough, and have thus emerged as promising biomaterials. This research will advance the understanding of the mechanics associated with DN hydrogels, and specifically how double networks afford control of friction. The implications of this work go beyond fundamentals of soft matter tribology and extend to biomedical applications and soft robotics, where the processes occurring at the migrating hydrogel interface are relevant. Furthermore, the collaborative project will help develop the workforce in the U.S., broaden the participation of underrepresented groups in research, and positively impact engineering education.The overall objective of this research is to provide a fundamental understanding of the relation between microstructure of DN hydrogels and their frictional characteristics via experiments and modeling. Two major lines of research are proposed here: one combining physically and chemically crosslinked networks and a second one combining two chemically crosslinked networks, which lead to intrinsically different microstructures. The intellectual merit of this research will include: (1) thorough data of friction, structural, and mechanical properties of DN hydrogels as a function of composition via (novel and improved) experimental toolsets and a new mechanics model to quantify friction; (2) advances in the fundamental understanding of the effect of double network, sacrificial bonds, internetwork connections and charge on frictional dissipation mechanisms; and (3) discovery of hydrogel materials, capable of achieving low friction coefficients and augmented wear resistance through the precise control of their microstructure. To examine lubrication mechanisms, friction, adhesion and rheological measurements will be carried out on hydrogels to probe multiple dissipation mechanisms. The comparison between experimental and modeling results will enable us to elucidate the underlying mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该赠款将支持研究，以推动与双网络水凝胶的结构 - 质地关系相关的知识，从而促进科学的进步。生物扭转系统的特殊润滑行为源于其双相组成，这是一种具有水基润滑剂的复杂大分子网络。作为一个突出的例子，关节软骨将润滑性与强度平衡。迄今为止，迫切需要为新型生物材料产生摩擦学理解和模型，以替代软骨。双网络（DN）水凝胶由两个类似软骨，坚固而坚固的互穿聚合物网络组成，因此已成为有前途的生物材料。这项研究将提高人们对与DN水凝胶相关的力学的理解，特别是双重网络如何提供对摩擦的控制。这项工作的含义超出了软物质摩擦学的基本原理，并扩展到生物医学应用和软机器人技术，在迁移水凝胶界面上发生的过程是相关的。此外，该协作项目将有助于发展美国的劳动力，扩大了代表性不足的研究小组的参与，并对工程教育产生积极影响。这项研究的总体目的是提供对DN水凝胶的微观结构与DN水凝胶的微观结构及其通过实验和模型的摩擦特征之间的基本了解。这里提出了两种主要研究线：一种结合了物理和化学交联的网络，第二个结合了两个化学交联的网络，这导致了本质上不同的微观结构。这项研究的智力优点将包括：（1）DN水凝胶的摩擦，结构和机械性能的详尽数据作为通过（新颖和改进的）实验工具集组成的函数，以及一种量化摩擦的新力学模型； （2）在对双网络，牺牲债券，互联网连接以及对摩擦耗散机制的指控的基本理解方面的进步； （3）发现水凝胶材料，能够通过精确控制其微观结构来实现低摩擦系数和增强耐磨损性。为了检查润滑机制，将在水凝胶上进行摩擦，粘附和流变学测量，以探测多种耗散机制。实验结果和建模结果之间的比较将使我们能够阐明基本机制。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估标准通过评估来支持的。