项目名称： 分叉双层微流控系统中液滴分裂机理与乳化制备微粒性能的研究

项目编号： No.51506103

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 任勇

作者单位： 宁波诺丁汉大学

项目金额： 20万元

中文摘要： 乳状液在我们生活和生产中有着重要的应用价值。由微流控形成乳状液，具有良好单分散性，可作为模板制备各种功能材料如微粒，应用于生物化学分析和制药等领域。微液滴分裂是微流控乳化中核心支撑技术，而相关领域日益涉及复杂结构如收缩分叉及多孔介质，这对微粒合成及其在给药体系的应用提出新挑战。分析研究在该微型系统内微液滴分裂机理及其对乳化影响，尤为迫切和重要。在这个项目中，我们提出一种新颖分叉双层微通道设计，形成缩颈结构，采用实验和数值模拟相结合的方法，对微液滴分裂机理开展研究。并以此为平台，研究液滴速度，轨迹，变形，屈曲和分裂。我们将形成高阶乳状液，制备满足不同剂量需要的单分散微粒，通过流固耦合分析，研究微粒释放动力特性,并应用于给药体系。我们将提供模型系统，以了解药物在毛细血管或生物组织多孔介质内如何实现精确递送。这些研究将对我们以乳状液液滴为平台在生物医学、能源方面的应用有着重要的价值和意义。

中文关键词： 微流控；多相流流动；微液滴分裂；乳化；给药体系

英文摘要： Emulsions are ubiquitous in our daily life and widely involved in industries related with drugs, foods, cosmetics, and oil products. Emulsions can be formed by microfluidic technologies, which enable spatial and temporal control over size, shape, and concentration of droplets. The formed emulsions can act as template to prepare monodispersed functional materials for applications ranging from biochemical assays to pharmaceutical industry. Droplet fission is indispensable microfluidic emulsification operation, as it leads to formation of emulsion with a large number of droplets, this is particularly important when large-scale complex biological and chemical assays are needed. However, full exploitation of microfluidic production and control of emulsion is challenged by (1) lack of thorough understanding of the stability and break-up of individual emulsions as they flow through constrictions or pores, especially when the interactions among the emulsions are important; and (2) limited number of different dosages of droplets produced by existing technology. Specifically, we focus on constrictions with bifurcated junction because the encapsulated drugs must go through such complex structures in blood capillaries or the porous tissue material during drug delivery process. Therefore, understanding of the unique phenomena in such a microscale systems is urgently needed. In this project, we aim to devise a new microfluidic droplet fission and emulsification approach to address the challenge. We will characterize the droplet fission and associated breakup dynamics in bilayer microchannels with constrictions formed by bifurcated junction, in which droplets can deform significantly on account of the confining geometric boundaries, and the flow of the surrounding viscous liquid, both of which control the speed, trajectory, deformation, buckling and breakup of each droplet. The physics of droplet breakup dynamics behind this novel microstructure is highly fascinating, and will lead to different physical phenomena, which will be investigated numerically and experimentally. The mechanism of droplet fission, fluid structure interaction, and release kinetics will be investigated and applied in fabrication of higher order emulsions, which will be used to synthesize microparticles for drug delivery applications. The understanding of the droplet fission and emulsification in the novel microstructure will enable more versatile control over the emulsion formation, and the release kinetics in the emulsion-templated microparticles involved applications. Our study will provide model systems to understand how the drug delivery can be controlled precisely in media with complex constrictions, such as blood capillaries or the porous material of a tissue structure. The higher order emulsions with custom-made volume and shape formed by our novel approach can be widely used in biomedical and industrial applications, and inspire novel opportunities in these applications.

英文关键词： microfluidics;multiphase fluid dynamics;droplet fission;emulsification;drug delivery system