Liquid Crystal-Driven Chemical Feeding Accelerates Condensation Reactions in Droplet Microreactors.

Droplet microreactors have gained significant attention as confined spaces for chemical reactions, offering enhanced reaction rates and control. However, the impact of mass transfer induced by chemical feeding within these microreactors remains largely unexplored. In this study, a novel approach is demonstrated using liquid crystal (LC) phase transitions to feed chemicals from a bulk LC film to droplet microreactors situated on the LC film. By manipulating LC mesophases, precise control is achieved over the solubility of chemicals within the bulk LC, enabling both in situ loading and controlled release. The results reveal that while droplet confinement inherently enhances reaction rates, the chemical feeding further improves mass transport within the droplet microreactors. This synergistic effect leads to a remarkable acceleration of chemical reactions, with conversion rates up to nine times higher than conventional bulk reactions. Furthermore, the broad applicability of this approach is demonstrated across various aldehyde reactions, the reusability of the LC films for multiple reaction cycles, and multi-step microscale synthesis within a single droplet microreactor. These findings establish the LC system as an innovative platform for chemical feeding, substantially expanding the performance and utility of droplet microreactors for diverse chemical applications.