Connecting Bond-breaking and Healing Kinetics to the Deformation and Fracture of Tough Hydrogels

将断键和愈合动力学与坚韧水凝胶的变形和断裂联系起来

• 批准号: 1903308
• 负责人: Chung-Yuen Hui
• 金额: $ 63.78万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903308&HistoricalAwards=false
• 关键词: Connecting; Bond; breaking; Healing; Kinetics

A hydrogel is a soft material that is mostly water. One can think of a hydrogel as a three dimensional "fishnet" consisting of gelatin molecular chains (network) swollen by water drawn into the net. Hydrogels have many current applications such as contact lenses and as scaffolding materials for tissue engineering. Potential future applications may include artificial cartilage and "muscles" for soft robots. A shortcoming of simple hydrogels is that they are easy to fail; this severely limits their practical use in load bearing components. In recent years, chemists have invented hydrogels that are highly resistant to fracture. The network of this new class of hydrogels consists of molecular chains linked to each other by different types of connectors (bonds). These connectors can be permanent or temporary. Temporary connectors can break and reform. This process dissipates energy which contributes to resistance to fracture and they also allow the gel to heal. Currently, engineers do not have the predictive tools to determine how components made of these hydrogels change shape under load and when they break. This project will develop such predictive tools. The end product will be a quantitative method and a computer code which allows engineers to design and analyze components made of these hydrogels. Two long standing problems in the time dependent mechanics of deformation and fracture of soft materials are: (1) three dimensional large deformation nonlinear viscoelasticity and (2) efficient integration of these three dimensional nonlinear viscoelastic equations. A new idea to be explored by this research is that nonlinear viscoelasticity shields the crack from high stresses and thus enhances toughness. This project will address these issues by: (a) performing experiments on a tough Polyampholyte hydrogel, (b) developing quantitative models relating nonlinear viscoelastic behavior to bond breaking and reformation kinetics, (c) developing experimental methods to discover and to quantify crack shielding and (d) developing efficient time integration schemes to solve the nonlinear viscoelastic equations. The project will advance the field of mechanics by building a framework for development of time dependent constitutive and fracture models that are linked directly to the microstructure and that can be used in practical finite element simulations.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.

水凝胶是一种柔软的材料，主要是水。 人们可以将水凝胶视为三维“渔网”，由明胶分子链（网络）组成，这些水被抽入网中的水肿胀。 水凝胶有许多当前的应用，例如隐形眼镜和用于组织工程的脚手架材料。 潜在的未来应用可能包括用于软机器人的人造软骨和“肌肉”。 简单水凝胶的缺点是它们很容易失败。这严重限制了它们在负载轴承组件中的实际使用。 近年来，化学家发明了对裂缝高度抗性的水凝胶。 这类水凝胶的网络由不同类型的连接器（键）相互关联的分子链组成。 这些连接器可以是永久的或临时的。 临时连接器可以破坏和改革。 这个过程消除了能量，从而有助于骨折，并且还使凝胶愈合。 当前，工程师没有预测工具来确定这些水凝胶制成的组件如何在负载下以及何时破裂的形状变化。 该项目将开发此类预测工具。 最终产品将是一种定量方法和计算机代码，它允许工程师设计和分析由这些水凝胶制成的组件。 在时间依赖性的变形和软材料断裂的机制中，两个长期存在的问题是：（1）三维大变形非线性粘弹性和（2）这三维非线性粘弹性方程的有效整合。 这项研究要探索的一个新想法是，非线性粘弹性使裂缝免受高应力，从而增强了韧性。 该项目将通过以下方式解决这些问题：（a）对坚硬的多型水解水凝胶进行实验，（b）开发有关非线性粘弹性行为与键合和改革动力学相关的定量模型，（c）开发发现和量化的实验方法，以量化Crack Shielding和（d）开发有效的时间集成计划以开发有效的时间集成方程，以开发非线性粘层方程。 该项目将通过建立一个依赖时间的本构和断裂模型的框架来推动机械师的领域，这些框架直接链接到微观结构，并可以用于实用有限元模拟中。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子的知识和广泛的影响来评估Criteria criteria criteria criteria criteria。

项目成果

Size effect on elastic stress concentrations in unidirectional fiber reinforced soft composites

• DOI: 10.1016/j.eml.2019.100573
• 发表时间: 2019-11-01
• 期刊: EXTREME MECHANICS LETTERS
• 影响因子: 4.7
• 作者: Hui, Chung-Yuen;Liu, Zezhou;Phoenix, S. Leigh
• 通讯作者: Phoenix, S. Leigh

Delayed fracture caused by time-dependent damage in PDMS

• DOI: 10.1016/j.jmps.2023.105459
• 发表时间: 2023-10
• 期刊: Journal of the Mechanics and Physics of Solids
• 影响因子: 5.3
• 作者: Jikun Wang;Bangguo Zhu;Chung-Yuen Hui;A. Zehnder

Load transfer between permanent and dynamic networks due to stress gradients in nonlinear viscoelastic hydrogels

由于非线性粘弹性水凝胶中的应力梯度导致永久网络和动态网络之间的负载传递

• DOI: 10.1016/j.eml.2022.101928
• 发表时间: 2023
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: Wang, Jikun;Cui, Kunpeng;Zhu, Bangguo;Gong, Jian Ping;Hui, Chung-Yuen;Zehnder, Alan T.
• 通讯作者: Zehnder, Alan T.

Metamodeling of constitutive model using Gaussian process machine learning

• DOI: 10.1016/j.jmps.2021.104532
• 发表时间: 2021-09
• 期刊: Journal of the Mechanics and Physics of Solids
• 影响因子: 5.3
• 作者: Jikun Wang;Tianjiao Li;Fan Cui;C. Hui;Jingjie Yeo;A. Zehnder

Energy release rate of a single edge cracked specimen subjected to large deformation

单边裂纹试件大变形能量释放率

• DOI: 10.1007/s10704-020-00479-7
• 发表时间: 2020
• 期刊: International Journal of Fracture
• 影响因子: 2.5
• 作者: Liu, Zezhou;Zakoworotny, Michael;Guo, Jingyi;Zehnder, Alan T.;Hui, Chung-Yuen
• 通讯作者: Hui, Chung-Yuen