项目名称： 液滴形成中的渗透效应-以微流控双水相体系为模型的研究

项目编号： No.21476189

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 岑浩璋

作者单位： 香港大学深圳研究院

项目金额： 90万元

中文摘要： 目前的射流断裂及液滴生成理论只适用于完全非互溶的液液两相体系，此时渗透效应被忽略不计。对于存在显著渗透效应的部分不互溶的液液两相体系，虽然静态条件下的两相互渗透现象已被人们所知，但其对射流断裂及液滴生成机制尚未被研究。 本项目研究的主要目的是将现有液滴形成理论拓展到部分不互溶的液液两相体系中。我们将以微流控双水相体系为模型，以微流控装置为平台，通过定量改变两相间的渗透压，研究其对射流不稳定性、射流断裂和液滴生成的影响。我们还将考察存在溶质补偿扩散、外场螯合（机械振动、电场驱动）时等的液滴形成机制，开发适用于低界面张力体系的液滴乳化技术。综上所述，本项目以拓展液滴生成理论的范围为研究目标，深化液滴生成机制的科学理解，为优化液滴形成过程提供新的科学思路和技术手段。

中文关键词： 微流控；乳液

英文摘要： Osmotic effect between two immiscible phases is used to be negligible in the study of multi-phase fluid dynamics, considering the solubility of one solvent phase in the other phase is usually quite low. However, there are some exceptions in the partially miscible two-phase systems, where the osmotic effect cannot be neglected. Due to the non-zero solubility of solvent, the dispersed phase is inevitably undergoing a certain degree of osmosis/ diffusion/ dehydration during the process of droplet formation, yet the existing theory of jet breakup and droplet formation fails to address these new conditions. The purpose of this study is to broaden the scope of existing theory on the instability of an osmotic jet and formation of droplets. A model system of aqueous two-phase system is investigated on the platform of microfluidic devices. This system enables the variation in osmotic pressure in a well-controlled manner, thus we can systematically study the osmotic effect. We also intend to couple the mechanical vibration and the electric field to hydrodynamic forces, developing new emulsification technique for liquid/liquid system with low interfacial tension. In sum, our input will lead to a higher degree of understanding towards schematics of droplet formation, a better control over the formation of droplet, and hence would open up new opportunity for the field of osmosis triggered droplet formation.

英文关键词： microfluidics;emulsion