Architectural design of active adhesives

活性粘合剂的结构设计

• 批准号: 2403716
• 负责人: Sergei Sheiko
• 金额: $ 49.5万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2403716&HistoricalAwards=false
• 关键词: Architectural; design; active; adhesives

PART 1: NON-TECHNICAL SUMMARYAdhesives are ubiquitous materials not only in our daily lives but also for advanced and specialized applications such as wearable electronics, biomedical adhesives, and soft robotics. Current approaches to meet such a diverse scope of functions rely on exploratively blending assorted polymers with large quantities of tackifiers, plasticizers and other additives as needed. This mixing-based approach toward property control is ineffective and imprecise. Furthermore, loose additives are prone to leaching and migration, which leads to property variation over time along with inevitable surface contamination, thus prohibiting their use in sensitive applications such as art restoration, biomedical devices, and microelectronics. The proposed adhesion-by-architecture platform will empower the design of additive-free adhesives with tailored property combinations that can be switched on demand. The platform is based on brush-like polymer networks with dynamic molecular linkers, which provide various pathways for molecular-scaffold reconfiguration without losing material integrity. The abundance of structural parameters in molecular brush networks allows for the programmable variation of distinct physical characteristics independent of chemical composition and one another. Developing structurally programmable adhesives with actively modulated performance will offer a breakthrough in soft matter engineering, yielding active adhesives with exceptional property combinations and switching on-demand capability. The design of advanced materials will provide ample opportunities for interdisciplinary training of graduate students with diverse backgrounds through integration of precision chemistry, soft-matter physics, and emerging technologies.PART 2: TECHNICAL SUMMARYAdhesive performance results from an interplay of bulk and interfacial deformation mechanisms, both viscoelastic in nature. Understanding how molecular brush architecture controls this interplay represents the intellectual focus of this proposal. The proposed research will address the following fundamental problems. The first is the hierarchical relationship between adhesion and molecular network architecture, spanning different length and time scales. Understanding how an individual element of the brush structure contributes to the viscoelastic response is a crucial milestone towards programmable control of the performance of pressure-sensitive adhesives (PSAs). The second is the inherent reliance of adhesion on chemical composition and the interdependence of distinct adhesive characteristics such as tack, stretch, and work of adhesion. The design-by-architecture approach will allow breaking these conventional rules to allow for the variation of physical characteristics independent of chemistry and one another. The third is the current inability to switch the adhesion strength of pressure-sensitive adhesive materials on demand without perturbing the integrity and shape of a device. This challenge will be addressed by strategically incorporating dormant functionalities that can be activated by an external stimulus to trigger internal rearrangement of the network topology..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.

第1部分：非技术性粘合剂不仅在我们的日常生活中普遍存在，而且在可穿戴电子产品、生物医学粘合剂和软机器人等高级和专业应用中也是普遍存在的材料。目前满足这种不同功能范围的方法依赖于根据需要探索性地将各种聚合物与大量增粘剂、增塑剂和其他添加剂混合。这种基于混合的房地产控制方法是无效和不精确的。此外，松散的添加剂容易渗出和迁移，这会导致性能随时间变化以及不可避免的表面污染，从而阻止它们在艺术修复、生物医学设备和微电子等敏感应用中的使用。拟议的建筑粘合平台将使无添加剂粘合剂的设计具有可按需切换的量身定制的性能组合。该平台基于刷状聚合物网络和动态分子连接物，为分子支架的重构提供了不同的途径，而不会损失材料的完整性。分子刷网络中丰富的结构参数允许不同的物理特性的可编程变化，而不依赖于化学成分和彼此。开发具有主动调节性能的结构可编程胶粘剂将提供软物质工程方面的突破，产生具有特殊性能组合和按需切换能力的活性胶粘剂。先进材料的设计将通过整合精密化学、软物质物理和新兴技术，为不同背景的研究生提供大量的跨学科培训机会。第二部分：技术总结粘性性能是体相和界面变形机制相互作用的结果，两者都是粘弹性的。理解分子刷结构如何控制这种相互作用代表了这一提议的智力重点。拟议的研究将解决以下基本问题。第一个是粘附性和分子网络结构之间的层次关系，跨越不同的长度和时间尺度。了解刷子结构的单个元素如何影响粘弹性响应是实现压敏胶粘剂(PSA)性能可编程控制的重要里程碑。第二种是粘合对化学成分的内在依赖，以及不同粘合特性的相互依赖，如粘性、拉伸和粘附功。按架构设计的方法将允许打破这些常规规则，允许物理特性的变化独立于化学和彼此。第三个问题是，目前无法在不影响设备完整性和形状的情况下按需切换压敏粘合材料的粘合强度。这一挑战将通过战略性地整合休眠功能来解决，这些功能可以由外部刺激激活以触发网络拓扑的内部重新安排。该奖项反映了NSF的法定使命，并已通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。