A novel helical descending liquid‐bridge for continuous demulsification

Abstract Existing physical demulsification methods are expensive and offer low separation efficiencies. Therefore, the development of efficient and green continuous demulsification processes has garnered research attention. Inspired by the novel helical liquid bridge flow realized previously by our group, a continuous demulsification method featuring a helically descending liquid bridge was established in this study to treat oil‐in‐water emulsions with low oil contents. First, the formation of the liquid bridge flow was verified. Then, the continuous demulsification of the helically descending liquid bridge was monitored using a high‐speed camera, which helped elucidate the demulsification mechanism. Furthermore, the surface of the helical string was modified to make it oleophilic for improving the demulsification efficiency. The results showed that the helical liquid descent achieved with surface modification led to a competitive separation efficiency of up to 52.94%, which was 27.94% higher than that of other helical microchannel devices with hydrophobic surfaces.