Collaborative Research: Multi-Scale Micromechanical Properties of Hierarchical Coatings and Interfaces Fabricated by Self-Limiting Electrospray Deposition

合作研究：自限性电喷雾沉积制备的分层涂层和界面的多尺度微机械性能

• 批准号: 2019928
• 负责人: Jae-Hwang Lee
• 金额: $ 30.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2019928&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; Scale; Micromechanical

Porous materials are ubiquitous in applications ranging from filtration and construction to ones in extreme environments, such as the Arctic, deep sea, and space. The methods of manufacturing these materials often require bulk processing techniques, and it can be difficult to deterministically tune the structure and composition independently. This collaborative research employs self-limiting electrospray deposition (SLED) to create controlled libraries of porous microfilms, enabling rapid screening of their characteristic material and architecture parameters while facilitating customized property tunability. Mechanical analysis covering testing conditions from quasi-static to ballistic impact at room or elevated temperatures are undertaken, allowing probing of the materials’ mechanical response to thermomechanical stimulus. For ballistic analysis, laser-induced particle impact testing (LIPIT), an innovative method of using laser-propelled microparticles to create controlled microballistic impact, is used. These experiments inform a semi-empirical model that in turn guides the direction of future experiments, ultimately leading to a platform to design and optimize porous materials for myriad applications, including exploration of SLED thin films as low-thickness alternatives to bulkier coatings. The project team consists of experts in SLED fabrication, nanomechanical testing and modeling, and microballistic analysis. This award allows for a new level of understanding and control of the synthesis of critical porous materials aiding in US competitiveness and prosperity. SLED utilizes the repulsion of the charged electrostatic spray to create level thin films of controlled thickness. Spray parameters control different aspects of the final porous morphology. The flow rate controls the characteristic scale of the porous structure; the solids loading controls the fill fraction of the pores; the spray temperature controls the degree of fusion of the pores; and the materials selection controls the composition of the material. Evaluation of model plastic with and without particle and rubber reinforcement, along with crosslinked porous epoxies, will be performed. During the strain rate testing in LIPIT, a ceramic microsphere is accelerated to at most 1,000 m/s by laser-induced rapid gas expansion and is tracked using ultrafast stroboscopic microscopy. An intense mechanical impulse is thereby applied to the specimen through the collision of the microsphere and can then be analyzed for energy dissipation and damage mechanisms. Moreover, using slower mechanical stimuli methods, nanoimpact (1-20 mm/s) and nanoindentation (10-1,000 nm/s), on the same specimens allows comparison between the deformation-rate-dependent characteristics of the SLED coatings over the different ranges. Each stage of these studies is supported by multiscale computational simulations to create predictive models to guide both the course of the experiments and the design of future materials.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.

在极端环境（例如北极，深海和空间）中，多孔材料无处不在。制造这些材料的方法通常需要大量的处理技术，并且很难独立调整结构和组成。这项合作研究员工的自限制电喷雾沉积（Sled）创建了可控的多孔缩微胶片库，从而在支持自定义的属性可突可线性的同时，可以快速筛选其特征材料和架构参数。进行了机械分析，涵盖了从准静态到房间或温度升高的测试条件，从而探测了材料对热机械刺激的机械响应。为了进行弹道分析，使用了激光诱导的颗粒撞击测试（LIPIT），这是一种使用激光螺旋形的微粒来产生受控的微生物影响的创新方法。这些实验为一个半经验模型提供了信息，该模型反过来又指导了未来的实验方向，最终导致了为无数应用设计和优化多孔材料的平台，包括探索雪橇薄膜作为块状涂层的低厚度替代品。项目团队由雪橇制造，纳米力学测试和建模以及微型分析的专家组成。该奖项允许新的理解和控制关键多孔材料的合成，以帮助美国的竞争力和繁荣。雪橇利用电荷静电喷雾的排斥来产生控制厚度的水平薄膜。喷雾参数控制最终多孔形态的不同方面。流速控制多孔结构的特征尺度；固体加载控制孔的填充分数；喷雾温度控制孔的融合程度；材料选择控制材料的组成。将进行具有和没有颗粒和橡胶加固的模型塑料以及交联的多孔环氧树脂的评估。在脂质的应变速率测试过程中，通过激光诱导的快速气体膨胀将陶瓷微球加速至最多1,000 m/s，并使用超快频镜显微镜进行跟踪。因此，通过微球的碰撞将强烈的机械冲动应用于样品，然后可以分析能量耗散和损坏机制。此外，使用较慢的机械刺激方法，纳米IMPACT（1-20 mm/s）和纳米识别（10-1,000 nm/s），在相同的标本上可以比较不同范围内雪橇涂层的变形率依赖性特性。这些研究的每个阶段都得到了多尺度计算模拟的支持，以创建预测模型，以指导实验和未来材料的设计。该奖项反映了NSF的法定任务，并通过基金会的智力优点和更广泛的影响通过评估来诚实地支持支持标准。

项目成果

Enhanced mechanical energy absorption via localized viscoplasticity of nano-cellular polymer coating under supersonic impact loading

• DOI: 10.1016/j.giant.2023.100180
• 发表时间: 2023-07
• 期刊: Giant
• 影响因子: 7
• 作者: Zongling Ren;Robert Green-Warren;Noah McAllister;Ara Kim;Asaad Shaikh;A. Pelegri;J. Singer