Abstract

Double emulsions have been intensively used as a template to form core/shell structured microcapsules encapsulating and releasing a substance of interest in a controllable way for wide spectrum of chemical and biological applications. Herein a numerical model was established to investigate the thermal effect on breakup dynamics of a double emulsion flowing through a microchannel with a constricted segment which mimics the structure of microcapillaries using two groups of cases. In the first group, double emulsion was formed with water dispersed in oil which is surrounded by water (W/O/W); and in the second group, double emulsion was formed with water dispersed in oil which is surrounded by nanofluids where single-wall carbon nanotubes (SWCN) was dispersed in an ethylene glycol (EG) solution with volume fraction of 0.05% (W/O/SWCN-EG). In both groups, the thermal effect study was extended to other temperature dependent physical properties such as viscosity, density, and thermal conductivity. Thermal effects on the shear stress distribution in the constricted microchannel will lead to significant difference in deformation between the two groups. The investigation provides new insights to understanding the thermal effect in multiphase flow through complex microstructures where nanofluids have found significant increase in biomedical applications.

摘要

双重乳液已被广泛用作模板以形成核/壳结构的微胶囊，以可控的方式封装和释放感兴趣的物质，用于广泛的化学和生物应用。本文建立了一个数值模型，以研究双乳液流过微通道的热效应对破裂动力学的影响，该微通道具有模拟微毛细管结构的收缩段，使用两组案例。第一组，水分散在油中形成双乳液，油中被水包围（W/O/W）；在第二组中，水分散在油中形成双乳液，油中被纳米流体包围，其中单壁碳纳米管 (SWCN) 分散在体积分数为 0.05% (W/O/) 的乙二醇 (EG) 溶液中。 SWCN-EG)。在这两组中，热效应研究扩展到其他与温度相关的物理特性，例如粘度、密度和热导率。收缩微通道中剪切应力分布的热效应将导致两组变形的显着差异。该研究为理解多相流中的热效应提供了新的见解，通过复杂的微结构，纳米流体在生物医学应用中的应用显着增加。