Ethyl cellulose-chitosan complex particles stabilized W/O Pickering emulsion as a recyclable bio-catalytic microreactor

Water-in-oil (W/O) emulsions have numerous applications in many industries like foods, pharmaceuticals, in particular biphasic bio-catalysis. However, most of them are stabilized by surfactants or synthetic particles, which lead to limited uses in foods. Here, a W/O type Pickering emulsion was successfully prepared firstly by ordered ethyl cellulose-chitosan complex particles (ECCPs) and used for a recyclable biocatalytic micro-reactor. The performances of emulsions with different ethyl cellulose-chitosan ratios, water phase fraction and particle concentration were discussed. The type of emulsions could be shifted from W/O to W/O/W and O/W as water fraction increased. Interestingly, a recyclable bio-catalytic microreactor platform was constructed using such novel W/O emulsions, and the activity of lipase was significantly increased by encapsulating it into Pickering emulsions, and was 6.3-times higher than that of free lipase in biphasic system. In particular, the encapsulated lipase remained stable and could be recycled over 15 times without the loss of activity.