Microencapsulation of solid cores to prepare double emulsion droplets by microfluidics

We herein present an effective microfluidic method based on facile glass capillary assembly for encapsulating solid cores to prepare double emulsions. Visualization experiments are conducted to verify the effectiveness of the presented microfluidic device. It is indicated that, via the presented microfluidic device, solid cores can be controllably encapsulated into every generated double emulsion droplets under wide operating range of flow rate. The number of the encapsulated solid cores can be well manipulated by adjusting the flow rate of different phases. Particularly, by employing multiple injection microchannels, multiple kinds of solid cores can be encapsulated into a single droplet in different combinations. This microfluidic methods show good applicability to generate both solid-in-oil-in-water (s/o/w) and solid-in-water-in-oil (s/w/o) double emulsion droplets. We believe that the current microfluidic methods are capable to extend the application of microencapsulation in microcapsule preparation, drug detection, food delivery, single cell analysis, and synthesis of nanomaterials, etc. (C) 2019 Elsevier Ltd. All rights reserved.