Fluorosurfactants and their application in droplet microreactors: An overview

Fluorosurfactants play a crucial role in ensuring the stability and uniformity of droplet microreactors, which significantly broaden their applications in chemical and biological research. This review covers structure diversity and functional versatility of fluorosurfactants. Fluorosurfactants can be divided into two basic types according to their structure, linear and dendritic types, which both provides individual advantages. Linear fluorosurfactants are easily synthesized and commercially available, whereas dendritic fluorosurfactants have a branched structure that greatly reduces molecular cross-talk between droplets. Based on the application point of view, fluorosurfactants can be further classified into two categories: reactive and responsive fluorosurfactants. The hydrophilic head of reactive fluorosurfactants contains a reactive functional group, making them very useful in other applications, such as microcapsule preparation or protein crystallization. In contrast, responsive fluorosurfactants would change their properties with respect to external stimuli, such as temperature or light, making them perfect candidates for the on-demand control of droplet behavior. Development of these new classes of fluorosurfactants has expanded the capabilities and applications of droplet microreactors that enables interdisciplinary challenges to be solved.