One-step microfluidic production of gas-in-water-in-oil multi-cores double emulsions

•We firstly generated G/W/O multi-cores double emulsions with a one-step microfluidic approach.•We discussed two different flow patterns in the same device, which can be converted to each other.•We developed a new method to prepare porous microspheres by gas-in-water-in-oil double emulsions.

In this work, we generated gas-in-water-in-oil (G/W/O) multi-cores double emulsions with a one-step microfluidic device and found a new stable flow pattern, where multi-cores double emulsions were easily fabricated. The mechanism of the particular flow pattern was discussed. Moreover, we systematically studied the effects of the three flow rates on the size and structure of the double emulsions. We then developed mathematical models to predict the size and structure of the double emulsions. On this basis, porous polyacrylamide hydrogel microspheres were successfully fabricated by in situ UV polymerization method. This method provides a simple and novel approach to produce porous microspheres.

Graphical abstractWe generated gas-in-water-in-oil (G/W/O) multi-cores double emulsions with a one-step microfluidic device and found a new stable flow pattern, where multi-cores double emulsions were easily fabricated.Figure optionsDownload full-size imageDownload as PowerPoint slide