Discovering the Mechanisms of Hydrogel Surface Weakening and Wear Under Applied Sliding Conditions

发现滑动条件下水凝胶表面弱化和磨损的机制

• 批准号: 1563087
• 负责人: Alison Dunn
• 金额: $ 29.55万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1563087&HistoricalAwards=false
• 关键词: Discovering; Mechanisms; Hydrogel; Surface; Weakening

Hydrogels are flexible plastic materials that have water integrated into the structure. This hydration helps make them slippery and biocompatible, so they are used as thin biomedical devices such as contact lenses and catheter coatings, as well as in the oil industry as soft particles. New chemistries of hydrogel are developed every day for targeted applications such as drug delivery, prosthetic soft devices, and synthetic soft tissues. However, retaining durability of soft, slippery materials in these intended applications when they are sliding against other materials is important for their success. The specific ways that hydrogels degrade under sliding is not yet known, so this award supports the fundamental discovery of connections between the hydrogel structure, sliding conditions, and surface durability. These connections will result in new mechanical design guidelines for manufacturing hydrogels, impacting health and industrial sectors. Because this research connects materials properties to mechanical performance, it is well-suited as the basis for interdisciplinary activities targeted to empower underrepresented minority students in science and engineering. The friction and lubrication properties at the interface of soft hydrated materials determine the collective behavior of dense microgel systems, but friction is often treated as a simple function of slip velocity or shear rate. Materials-based lubrication theories for soft hydrated matter have recently emerged, along with experimental evidence of hydrogel surface wear. The research goal of this project is to discover the mechanisms of surface degradation in soft interfaces due to surface shear by applying, measuring in situ, and mapping the progression of mechanical degradation in slipping, low-friction hydrogel interfaces. Instrumented micro-tribometry, optical- and force-based microscopy, and micro-indentation will be employed to measure the progression of degradation. This knowledge will contextualize competing theories of hydrogel lubrication and catalyze hypotheses regarding chemical and physical degradation of hydrogels for emerging scientific, technological, and engineering design problems

水凝胶是将水整合到结构中的柔性塑料材料。这种水合有助于使它们湿滑且具有生物相容性，因此它们被用作薄的生物医学设备，例如隐形眼镜和导管涂料，以及在石油工业中（作为软颗粒）。每天针对诸如药物输送，假体软设备和合成软组织等有针对性的应用开发水凝胶的新化学。但是，当这些预期的应用与其他材料滑动时，在这些预期的应用中保留了柔软的湿滑材料的耐用性对于它们的成功很重要。尚不清楚水凝胶在滑动下降解的特定方式，因此该奖项支持水凝胶结构，滑动条件和表面耐用性之间的连接的基本发现。这些连接将为制造水凝胶提供新的机械设计指南，从而影响健康和工业部门。由于该研究将材料属性与机械性能联系起来，因此它非常适合旨在赋予科学和工程中代表性不足的少数民族学生的跨学科活动的基础。软性水合材料界面上的摩擦和润滑特性决定了密集的微凝胶系统的集体行为，但是摩擦通常被视为滑动速度或剪切速率的简单功能。最近出现了针对软性水合物质的材料润滑理论，以及水凝胶表面磨损的实验证据。该项目的研究目的是通过施加，测量原位测量表面剪切而在软界面中发现表面降解的机理，并映射机械降解的进展，在滑动，低摩擦水凝胶界面中。仪器的微部件测量法，光学和基于力的显微镜以及将使用微观指示来测量降解的进展。这些知识将使竞争性的水凝胶润滑理论与竞争性理论相关，并催化有关用于新兴科学，技术和工程设计问题的水凝胶化学和物理降解的假设