RII Track-4: NSF: Understanding Microstructure Evolution in Stimuli-Responsive Yield-Stress Fluid-Assisted 3D Printing: Linking Microstructures to Macroscale Rheological Properties

RII Track-4：NSF：了解刺激响应屈服应力流体辅助 3D 打印中的微观结构演化：将微观结构与宏观流变特性联系起来

• 批准号: 2229004
• 负责人: Yifei Jin
• 金额: $ 23.18万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 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: 2023-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2229004&HistoricalAwards=false
• 关键词: RII; Track; NSF; Understanding; Microstructure

Recently, an innovative three-dimensional (3D) printing method has been proposed and developed to fabricate parts with arbitrary architectures. In this method, a 3D structure is freeform printed within a unique liquid support bath with desired properties that are controllable by either printing conditions or working environments. Although this method presents a better printing capability than many current 3D printing approaches, the working mechanisms of unique support bath materials are still elusive, which has hampered the further development of this 3D printing method. The project aims to investigate the microstructure changes of a representative thermosensitive support bath material at different temperatures and printing conditions. The achievements of this project can guide the design of more support baths as well as fundamentally explain the working mechanisms of printing within a support bath. The proposed research will have a profound societal impact by accelerating the development of 3D printing technology to enhance the manufacturing capability in the United States. In addition, the project will promote the education of students from K-12 to graduate in the State of Nevada through diverse activities, including hands-on K-12 lab activities, research module-involved curricula, and mentorship of students from underrepresented backgrounds at the University of Nevada, Reno. This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows (RII Track-4) project would provide a fellowship to an Assistant professor and training for a graduate student at the University of Nevada Reno (UNR). Stimuli-responsive yield-stress fluids, developed on the basis of regular yield-stress materials, can change rheological properties/behaviors by responding to both applied shear stress and external stimuli. This dual-responsiveness makes stimuli-responsive yield-stress fluids promising for support bath-assisted 3D printing because a support bath material can be easily added during printing and removed after printing by applying external stimuli to achieve desired rheological properties, making it technically feasible to print 3D structures with arbitrary architectures. However, the interrelationships between microstructure evolution and macroscale rheology change of stimuli-responsive yield-stress fluids have so far remained elusive. Thus, the overarching goal of this project is to fundamentally understand the microstructure evolution of a representative stimuli-responsive yield-stress fluid—Pluronic F127-nanoclay nanocomposite—under different stress and temperature conditions through nanoscale material characterization, mathematical modeling, molecular dynamics simulation, and rheological testing. To achieve this goal, two integrated research objectives will be pursued: (1) characterize/establish static microstructure models in Pluronic F127-nanoclay nanocomposite via nanoscale material characterization techniques and mathematical modeling; and (2) explore temperature- and stress-induced microstructure evolutions via molecular dynamics simulation and rheological property testing. Completing the objectives will establish a paradigm for linking microstructures to macroscale rheological properties of support bath materials, promoting the development of more advanced stimuli-responsive yield-stress fluids for 3D printing applications in the future.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.

最近，已经提出并开发了一种创新的三维（3D）打印方法，以制造具有任意体系结构的零件。在这种方法中，3D结构是在独特的液体支撑浴室中自由形式印刷的，其所需属性由印刷条件或工作环境控制。尽管此方法比许多当前的3D打印方法具有更好的打印能力，但是独特的支撑浴材料的工作机制仍然难以捉摸，这阻碍了这种3D打印方法的进一步开发。该项目旨在研究在不同温度和印刷条件下代表性热敏浴室材料的微观结构变化。该项目的成就可以指导设计更多的支撑浴室，并从根本上解释支撑浴中印刷的工作机制。拟议的研究将通过加速3D打印技术的发展来增强美国的制造能力，从而产生深远的社会影响。此外，该项目将通过潜水员活动，包括动手的K-12实验室活动，研究模块的课程以及内华达大学内华达大学里诺大学代表性不足的学生的心态，促进从K-12到内华达州毕业的学生的教育。这项研究基础设施改进Track-4 Epscor Research Fellows（RII Track-4）项目将为内华达大学Reno大学（UNR）的一名研究生助理教授和培训提供奖学金。刺激反应性的屈服压力液基于常规的屈服压力材料开发，可以通过响应施加的剪切应力和外部刺激来改变流变特性/行为。这种双重响应性使刺激性响应性屈服压力液体有望提供支撑浴辅助的3D打印，因为在打印过程中可以轻松添加支撑浴材料，并在打印后通过应用外部刺激来实现所需的流变学特性，从而使其在技术上可比性的3D结构具有任意体系结构在技术上可行。然而，刺激反应性屈服液的微观结构演化与宏观流变学之间的相互关系仍然难以捉摸。这是这个项目的总体目标是从根本上了解代表性刺激性响应性产量压力 - 倍率F127-纳米粘土纳米复合材料的微观结构演变 - 通过纳米级材料表征，数学模型，分子动力学模拟和流变学测试，通过纳米级材料表征，通过纳米级材料进行不同的压力和温度条件。为了实现这一目标，将追求两个集成的研究对象：（1）通过纳米级材料表征技术和数学建模来表征/建立Pluronic F127-Nanoclay纳米复合材料中的静态微结构模型； （2）通过分子动力学模拟和流变学性能测试探索温度和应力诱导的微观结构演变。完成目标将建立一个范式，以将微观结构与支撑浴材料的宏观流变学特性联系起来，从而促进未来3D打印应用程序的更先进的刺激性屈服压力压力。该奖项反映了NSF的法定任务，并通过使用基金会的Merit进行了评估，并通过评估了Crcriatial和Broadial and tocrit and tocriat and tocrital and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia and Broadia。