Thermal Effect on Deformation of Nanofluid-Encapsulated Double Emulsion Droplets Flowing in a Constricted Microchannel

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.