Intensification of interfacial enzymatic reactions in oil-water systems using slug flow in adaptive microfluidic channels.

Lipase is a type of hydrolase that catalyzes reactions at the water-in-oil (O/W) interface and possesses significant applied value across various fields. This study introduces integrated reaction-separation system employing microfluidic slug in a water-in-oil (W/O) droplet flow, specifically designed to enhance lipase-catalyzed interfacial lipid hydrolysis. By incorporating spiral microchannels, the system significantly improves interfacial mass transfer through slug flow-induced mixing and turbulence. Tributyrin hydrolysis within a liquid paraffin/phosphate buffer biphasic system serves as the model reaction to investigate the mechanisms underlying the intensification of interfacial enzymatic catalysis. Under comparable conditions, the microfluidic slug droplet system achieves an enzymatic reaction rate approximately 20 times greater than that observed in conventional beaker-based systems and 1.36 times greater than that in straight microchannels. The effects of droplet size, total flow rate, and channel curvature on conversion efficiency and reaction kinetics are examined, demonstrating that these parameters significantly impact mass transfer behavior. The dynamic interfaces generated within the slug flow architecture increase the specific surface area and facilitate accelerated mass transport, thereby enabling more efficient oil-water biphasic catalysis. This platform offers considerable potential for advancing interfacial biocatalysis and optimizing enzymatic transformations across a broad range of industrial and biotechnological applications.