EAGER: Unravelling the Spatiotemporal Dynamics of Three-Phase Contact Line on Soft Surfaces by Transmission X-Ray Microscopy

EAGER：通过透射 X 射线显微镜揭示软表面三相接触线的时空动力学

• 批准号: 2133017
• 负责人: Jiangtao Cheng
• 金额: $ 18万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2133017&HistoricalAwards=false
• 关键词: EAGER; Unravelling; Spatiotemporal; Dynamics; Three

Understanding and controlling the complex dynamics of liquid droplets that impact and spread over solid surfaces has intrigued scientists for more than a century because of the potential applications these phenomena have in broad areas of technology, including fuel combustion, spray coating, pesticide deposition, and inkjet printing. However, most research has considered impact and spreading over rigid synthetic surfaces with uniform textures, which is not the case, for example, in most biological systems. As a result, it remains challenging to predict the behaviors and outcomes of droplet impact on soft surfaces, mainly due to the complexity of the dynamic processes that occur at the droplet rim and the three-phase (solid-liquid-air) contact zone. The goal of this EAGER project is to uncover the fundamental mechanisms that govern contact line dynamics on soft substrates. To examine the details of contact line motion, the researchers will use ultrafast transmission X-ray microscopy (TXM). As a powerful and non-destructive tool, TXM will provide unprecedented spatial and temporal resolutions by imaging multiphase topography and transport in otherwise opaque media. The outcome of this project will have a broad impact on a variety of fields. New research opportunities from this project will be integrated with educational endeavours involving underrepresented college students and high school students in western Virginia. Three-phase contact line dynamics on soft surfaces is a ubiquitous process, and its underlying mechanism is of significant scientific and technological importance. TXM offers unprecedented temporal and spatial resolutions, phase-contrast with the edge-enhancement capability, and ultrahigh and nondestructive penetrability to examine three-phase contact line dynamics on soft materials. Soft substrates with well-characterized flexibility and elasticity will be fabricated. Liquid droplet impact dynamics will be examined with TXM. By visualizing contact line topology and tracking its dynamic evolution, droplet interfacial dynamics including elasto-viscous effects, contact line friction and dissipation on soft surfaces will be revealed for complex, mobile, multiphase and soft liquid-solid interfaces. By imaging the air nanobubbles that may be trapped under an advancing contact line, the mechanism of contact line slip may be revealed. The proposed efforts could not only advance our understanding of the underlying physics governing multiphase interfacial transport on soft surfaces, but also open a new avenue to developing novel bio-inspired interfacial materials and provide guidelines on modifying elasto-viscous properties for controlling droplet impact behaviors.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.

一个多世纪以来，了解和控制液滴撞击和扩散到固体表面的复杂动力学一直吸引着科学家们的兴趣，因为这些现象在广泛的技术领域具有潜在的应用，包括燃料燃烧、喷涂、农药沉积和喷墨印刷。 然而，大多数研究都考虑了在具有均匀纹理的刚性合成表面上的影响和扩散，但在大多数生物系统中，情况并非如此。因此，预测液滴撞击软表面的行为和结果仍然具有挑战性，这主要是由于液滴边缘和三相（固-液-空气）接触区发生的动态过程的复杂性。该 EAGER 项目的目标是揭示控制软基底上接触线动力学的基本机制。为了检查接触线运动的细节，研究人员将使用超快透射 X 射线显微镜 (TXM)。作为一种强大的非破坏性工具，TXM 将通过对不透明介质中的多相形貌和传输进行成像来提供前所未有的空间和时间分辨率。该项目的成果将对各个领域产生广泛的影响。该项目的新研究机会将与涉及弗吉尼亚州西部代表性不足的大学生和高中生的教育事业相结合。软表面上的三相接触线动力学是一个普遍存在的过程，其潜在机制具有重要的科学和技术意义。 TXM 提供前所未有的时间和空间分辨率、具有边缘增强功能的相位对比以及超高的无损穿透性，用于检查软材料上的三相接触线动力学。将制造具有良好柔韧性和弹性的软基材。 将使用 TXM 检查液滴冲击动力学。通过可视化接触线拓扑并跟踪其动态演化，将揭示复杂、移动、多相和软液-固界面的液滴界面动力学，包括弹粘性效应、接触线摩擦和软表面上的耗散。通过对可能被困在前进的接触线下方的空气纳米气泡进行成像，可以揭示接触线滑移的机制。所提出的努力不仅可以增进我们对控制软表面上多相界面传输的基础物理的理解，而且还为开发新型仿生界面材料开辟了一条新途径，并为改变弹粘性特性以控制液滴撞击行为提供了指导。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Modeling liquid droplet impact on a micropillar-arrayed viscoelastic surface via mechanically averaged responses

通过机械平均响应模拟液滴对微柱阵列粘弹性表面的影响

• DOI: 10.1080/19942060.2023.2194949
• 发表时间: 2023-12
• 期刊: Engineering Applications of Computational Fluid Mechanics
• 影响因子: 6.1
• 作者: Li, Yang;Cheng, Jiangtao
• 通讯作者: Cheng, Jiangtao

Droplet Evaporation on Hot Micro-Structured Superhydrophobic Surfaces: Analysis of Evaporation from Droplet Cap and Base Surfaces

热微结构超疏水表面上的液滴蒸发：液滴帽和基表面的蒸发分析

• DOI: 10.1016/j.ijheatmasstransfer.2021.122314
• 发表时间: 2022-04
• 期刊: International Journal of Heat and Mass Transfer
• 影响因子: 5.2
• 作者: Huang, Wenge;He, Xukun;Liu, Cong;Li, Xiaojie;Liu, Yahua;Collier, C. Patrick;Srijanto, Bernadeta R.;Liu, Jiansheng;Cheng, Jiangtao
• 通讯作者: Cheng, Jiangtao