Hydrogel two-phase flows: hydrodynamics and applications

水凝胶两相流：流体动力学和应用

• 批准号: RGPIN-2019-04162
• 负责人: Feng, James
• 金额: $ 2.84万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=737451
• 关键词: Hydrogel; two; phase; flows; hydrodynamics

Hydrogels are soft deformable materials important to many emerging technologies. Because of their softness and lack of toxicity, they are often used in small "organ-on-chip" devices to hold and nurture cells that can grow into functional tissues and organs. Another application is in the oil and gas industry. The drilling and sealing of gas and oil wells require pumping a thicker and stiffer liquid into the well to displace water. Hydrogel is a good candidate for such a liquid, as it is a soft solid that becomes a flowing liquid when pumped. Thus, its liquid-solid duality serves a unique role in these applications. For the design and optimization of such technologies, we need to understand how hydrogels flow and how they melt and solidify. The physics of this turns out to be complex thanks to their complex inner structure. Hydrogels are made of chain-like molecules, called polymers, that are cross-linked together into a network, and swollen with water. Depending on external forcing, temperature and chemical agents, a gel can melt or solidify reversibly. Besides, in most applications, hydrogels are deployed using liquids, thus generating a hydrogel-liquid layered flow scenario. For example, a gel solution may be pumped into place before gelation, or solid gels may be carried by another liquid into desirable locations. How does a hydrogel interact mechanically with a flowing liquid? How does flow influence the swelling/shrinking and melting of the gel? How to use liquid flow to control the gel-fluid interface? Such questions have rarely been raised, and practical applications mostly proceed through trial and error. The answers to these questions will not only be key to advancing our scientific understanding of these fascinating materials, but also important to the technological applications mentioned above. We propose to establish a theoretical framework for describing and predicting this highly complex hydrogel-liquid material. Moreover, we aim to develop computational methods and software that engineers can use to predict the flow and the structure of the hydrogel-liquid mixture system. The nature of this work will be mostly mathematical and computational; it will quantify our understanding of these complex fluids and link that knowledge to applications in emerging technologies. The research will likely have its greatest societal impact in the fields of biomedical engineering and drug delivery. Hydrogel-based organ-on-chip devices can be used to reproduce key tissue and organ functions; these can enable breakthroughs in drug testing and tissue engineering, and may even lead to implantable devices. Using gels to encapsulate drug particles gives us a new way to deliver drugs into target areas in the human body and to control the release of the drugs over a long period of time. Therefore, the proposed work will not only advance an area of scientific research, but also have far-reaching benefits for Canada and beyond.

水凝胶是对许多新兴技术重要的柔软变形材料。由于它们的柔软性和缺乏毒性，它们通常用于小型的“芯片”设备中，以固定和培养可以生长成功能性组织和器官的细胞。另一个应用是石油和天然气行业。气和油井的钻孔和密封需要将较厚和更硬的液体抽入井中以取代水。水凝胶是这种液体的好候选者，因为它是一种柔软的固体，在抽水时会变成流动的液体。因此，其液体固定双重性在这些应用中起着独特的作用。为了设计和优化此类技术，我们需要了解水凝胶如何流动以及它们如何融化和凝固。由于其复杂的内部结构，因此物理学的物理学变得很复杂。水凝胶由称为聚合物的链状分子制成，它们共同连接到网络中，并用水肿胀。根据外部强迫，温度和化学剂，凝胶可以可逆地融化或固化。此外，在大多数应用中，使用液体部署水凝胶，从而产生水凝胶层层状流动方案。例如，在凝胶化之前，可以将凝胶溶液泵入到位，或者可以由另一种液体将固体凝胶携带到理想的位置。水凝胶如何与流动液体机械相互作用？流动如何影响凝胶的肿胀/收缩和融化？如何使用液体流以控制凝胶流体界面？这些问题很少提出，实际应用主要是通过反复试验进行的。这些问题的答案不仅是我们对这些迷人材料的科学理解的关键，而且对上述技术应用也很重要。我们建议建立一个理论框架来描述和预测这种高度复杂的水凝胶材料。此外，我们旨在开发工程师可以用来预测水凝胶 - 液体混合系统的流量和结构的计算方法和软件。这项工作的性质主要是数学和计算。它将量化我们对这些复杂流体的理解，并将这些知识与新兴技术中的应用联系起来。这项研究可能会在生物医学工程和药物输送领域具有最大的社会影响。基于水凝胶的器官芯片设备可用于再现关键组织和器官功能。这些可以在药物测试和组织工程方面取得突破，甚至可能导致可植入的设备。使用凝胶封装药物颗粒为我们提供了一种将药物输送到人体目标区域并在很长一段时间内控制药物释放的新方法。因此，拟议的工作不仅将推进科学研究领域，而且还会为加拿大及其他地区带来深远的好处。