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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746768
• 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很重要的软的可变形材料。由于它们柔软且无毒，它们通常用于小型“器官芯片”设备中，以保持和培养可以生长为功能组织和器官的细胞。另一个应用是石油和天然气行业。天然气和油井威尔斯的钻探和密封需要将更稠更硬的液体泵入井中以置换水。水凝胶是这种液体的良好候选者，因为它是一种柔软的固体，在泵送时变成流动的液体。因此，其液体-固体二元性在这些应用中发挥着独特的作用。为了设计和优化这些技术，我们需要了解水凝胶如何流动以及它们如何熔化和固化。由于其复杂的内部结构，其物理学变得复杂。水凝胶是由链状分子组成的，称为聚合物，它们交联在一起形成网络，并用水溶胀。取决于外力、温度和化学试剂，凝胶可以可逆地熔化或固化。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-液体分层流动场景。例如，凝胶溶液可以在凝胶化之前被泵入到位，或者固体凝胶可以由另一种液体携带到期望的位置。水凝胶如何与流动的液体发生机械相互作用？流动如何影响凝胶的溶胀/收缩和熔化？如何使用液体流动来控制凝胶-流体界面？这样的问题很少被提出来，实际应用大多通过试验和错误来进行。这些问题的答案不仅是推进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液体材料。此外，我们的目标是开发计算方法和软件，工程师可以用来预测水凝胶-液体混合物系统的流动和结构。这项工作的性质将主要是数学和计算;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产生最大的社会影响。基于水凝胶的器官芯片设备可用于复制关键的组织和器官功能;这些可以实现药物测试和组织工程的突破，甚至可能导致植入式设备。使用凝胶包裹药物颗粒为我们提供了一种新的方法，可以将药物输送到人体的目标区域，并在很长一段时间内控制药物的释放。因此，拟议的工作不仅将推进科学研究领域，而且将对加拿大和其他地区产生深远的影响。