微通道内卫星液滴生成—惯性分离一体化原理及并行放大准则

Due to the nonlinear dynamics, the rupture process of liquid-liquid interface often accompanies the production of satellite droplets, which challenges the uniformity and precision of droplet-based microfluidics technology. In this project, the mechanism of satellite droplet formation is revealed, according to the complex dynamics of interfacial instability in microfluidics. Based on the new concept of the inertial microfluidics, the mechanism of the separation of satellite droplet by using the inertial microfluidics is highlighted. The integration principle of generation – inertial microfluidics separation for the satellite droplet is proposed, as well as the parallelization criterion for the corresponding numbering-up. Based on the principle of interfacial dynamics, self-similarity, inertial microfluidics and numbering-up strategy of parallelized microchannels, the advanced measurement methods such as high-speed camera and micro-particle image velocimetry, combined with the dissipative particle dynamics and volume of fluids method, the influences of the configuration and size of microchannel, flow rate of fluid, physical properties of fluid such as viscosity and rheology, surface tension and surfactant concentration on the generation process, inertial separation and microfluidic parallelization during the numbering-up of integrated generation-inertial separation for satellite droplet are studied, and the predictive model and manipulation rule of the corresponding process are constructed. The implementation of this project is beneficial to realize the target of precision in producing monodisperse droplets with microfluidics technology, and to lay a solid foundation for the interfacial dynamics and regulation of microfluidics and complex fluids.

由于非线性动态特征，液液界面破裂过程常伴随卫星液滴的产生，对基于液滴的微流体技术均一性和精准化目标提出了挑战。本项目针对微流体界面失稳复杂动力学特征，阐释卫星液滴的生成机制。结合惯性微流体新概念，探究卫星液滴的惯性分离机制。提出卫星液滴生成—惯性微流体分离一体化方法，并构建相应过程的并行放大准则。基于界面动力学、自相似性原理、惯性微流体基本原理、并行微通道数目放大准则，采用高速摄像仪、微粒子图像测速仪等先进测量手段，结合耗散粒子动力学及流体体积法等模拟方法，考察微通道构型与尺寸、流体流量、流体物性如黏度及流变性、表面张力及表面活性剂浓度等对卫星液滴生成、惯性分离及生成—惯性分离微流体并行放大过程的影响，构建相应过程的预测模型和调控准则。本项目的实施，有利于实现微流体技术生产单分散性液滴的精准化目标，为微流体与复杂流体相关的界面动力学行为与调控夯实基础。

由于非线性动态特征，液液界面破裂过程常伴随卫星液滴的产生，对基于液滴的微流体技术均一性和精准化目标提出了挑战。本项目针对微流体界面失稳复杂动力学特征，阐释卫星液滴的生成机制。结合惯性微流体新概念，探究卫星液滴的惯性分离机制。提出卫星液滴生成—惯性微流体分离一体化方法，并构建相应过程的并行放大准则。本项目采用可视化实验、模拟及理论分析相结合的方法，探究了微通道内牛顿/非牛顿流体液液两相流及卫星液滴的生成调控、惯性分离及微通道的并行化数目放大机制。主要研究内容及结果为：1）探明了不同构型微通道中牛顿及非牛顿流体液滴生成时界面动态演化规律；2）阐明了卫星液滴生成机理及动力学机制，并提出了相应的调控方法；3）针对不同构型的微通道提出了并行放大及制备均一性液滴的指导性准则，构建了相应过程的预测模型。基于相关成果，发表了国内外学术论文18篇，其中SCI论文12篇，AIChE J 2篇、CES 2篇、《化工学报》6篇。参加了国内外学术会议9人次。培养了博士生1名，硕士生8名。本项目的实施，将为微流体与复杂流体相关的界面动力学行为及调控奠定良好的基础，为基于液滴的微流体技术的精确性和精准化发展夯实坚实的理论基础。