| Abstract: | Biodiesel inherently contains more water than mineral diesel and as a result microbial contamination is a major problem that hinders its widespread application. The current method of removing the microbial contamination is direct addition of biocide. However, this method cannot enrich the water phase with biocide rapidly enough, leading to unavoidable overdosing of biocide and environmental issues. Here, biocide is encapsulated within hydrogel microparticles with a water‐triggered release feature to improve antimicrobial efficiency of biocide in biodiesel. To demonstrate the water‐triggered release mechanism, a green dye is encapsulated within the microparticles. The encapsulated dye remains inside the microparticles for more than 6 weeks when the microparticles are stored in oil phase; however, the dye releases in 4 min when the microparticles contact water. Using this water‐triggered release strategy, biocide is successfully delivered to the water phase in biodiesel. The encapsulated biocide shows higher antimicrobial efficacy than that of free biocide, in both short‐term and long‐term experiments. The possibility of scaling up the production of hydrogel microparticles using bulk emulsification method is also explored. Moreover, the water‐triggered release strategy can be used for releasing other water‐soluble functional materials. This opens opportunities for a wide range of encapsulation and controlled delivery applications. |
