Two-way shape-memory polymer design based on periodic dynamic crosslinks inducing supramolecular nanostructures

基于周期性动态交联诱导超分子纳米结构的双向形状记忆聚合物设计

• 批准号: 2342272
• 负责人: Zhenan Bao
• 金额: $ 45万
• 依托单位: Stanford University
• 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: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2342272&HistoricalAwards=false
• 关键词: Two; way; shape; memory; polymer

PART 1: NON-TECHNICAL SUMMARY Shape memory polymers (SMPs) have many potential applications, including aerospace, biomedical, soft robotics, and others. Current limitations of SMPs including low energy density, which means the material cannot be subjected to a large load. Furthermore, they do not have high robustness and have poor reversibility. The PI's work addresses limitations of SMPs through a new mechanism of strain-induced long-range ordered nanostructures formed from supramolecular assembly. The PI and her group will advance the state of knowledge in materials chemistry and polymer science through understanding novel materials design and structure-property relationships specific to two-way SMP (2WSMP) design. By integrating synthesis, processing, and advanced characterization, they will aim to enable a new generation of 2WSMPs with unprecedented energy densities synthesized from low-cost and scalable commercial starting chemicals. Compared to current widely used liquid-crystal elastomer shape-actuation materials, these 2WSMPs would actuate under much larger loads at a much lower material cost. This should allow more widespread testing and adoption, and help advance research on soft actuators. The collection of curated, high-quality experimental datasets produced from this project can potentially be used to benchmark theory and simulation models. With the potential applications and visual effects of 2WSMP behaviors, this work also offers appealing opportunities for recruiting and training students as next-generation workforce and research leaders. PART 2: TECHNICAL SUMMARY Polymer networks formed through dynamic noncovalent or covalent bonds exhibit a range of interesting and tunable mechanical properties (e.g., tough, elastic, self-healable, stimuli-responsive, and reconfigurable). In nature, hierarchically ordered structures are formed through weak but cooperative interactions to perform precise functions. This work will investigate a new molecular design concept of high energy-density shape memory polymers through strain-induced large range order of supramolecular nanostructure formation. The hypothesis is that the ability to form strain-induced supramolecular structures in periodic dynamic polymers (PDPs) may stabilize polymer chain alignment under large strains through non-covalent and covalent crosslinks and as a result crystallite alignment in the prepared two-way shape memory polymers (2WSMPs). The planned work will focus on addressing fundamental questions related to molecular design, polymer thin film and fiber morphology control and crystalline domain orientation, and ultimately their impact on the new designs of SMP behaviors. This study will lead to high energy density 2WSMPs synthesized from low cost and scalable reagents. The resulting 2WSMPs are aimed to have high stroke, actuation under large loads, and minimal cycling hysteresis..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：非技术摘要形状记忆聚合物（SMP）具有许多潜在的应用，包括航空航天，生物医学，软机器人技术等。 SMP的当前局限性包括低能密度，这意味着材料不能承受较大的负载。此外，它们没有很高的鲁棒性且可逆性差。 PI的工作通过由超分子组件形成的应变诱导的长期有序的纳米结构的新机制来解决SMP的局限性。 PI和她的小组将通过了解新颖的材料设计和特定于双向SMP（2WSMP）设计的新型材料设计和结构 - 质地关系来推进材料化学和聚合物科学的知识状态。通过整合综合，加工和高级表征，它们将旨在使新一代的2WSMP具有从低成本和可扩展的商业起始化学品中合成的前所未有的能量密度。与当前使用广泛使用的液晶弹性体形状输入材料相比，这些2WSMP将以更大的材料成本下的较大载荷下攻击。这将允许更多的广泛测试和采用，并帮助推进对软执行器的研究。 该项目产生的精心策划的高质量实验数据集的收集可能可用于基准理论和仿真模型。借助2WSMP行为的潜在应用和视觉效果，这项工作还为招聘和培训学生作为下一代劳动力和研究领导者提供了吸引人的机会。 第2部分：通过动态非共价或共价键形成的技术摘要聚合物网络具有一系列有趣且可调的机械性能（例如，坚韧，弹性，可自我修复，刺激性，反应性和可重新配置）。在本质上，层次有序结构是通过弱但合作的相互作用来执行精确功能的。这项工作将通过应变诱导的大分子纳米结构形成的大范围顺序研究高能密度形状组合聚合物的新分子设计概念。假设是，在周期性动态聚合物（PDPS）中形成应变诱导的超分子结构的能力可以通过非共价和共价交联在大型菌株下稳定聚合物链对准，并因此在准备好的双向双向记忆聚合物（2WSMP）中稳定了结晶石对齐。 计划的工作将着重于解决与分子设计，聚合物薄膜和纤维形态控制和晶体域取向相关的基本问题，并最终对SMP行为的新设计产生了影响。这项研究将导致高成本和可扩展试剂合成的高能量密度2WSMP。由此产生的2WSMP的目的是进行高中风，在大负荷下进行驱动以及最少的骑行滞后。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的评估和更广泛影响的评估来评估的。