In flow-based technologies: A new paradigm for the synthesis and processing of covalent-organic frameworks

•Microfluidics can be used for up-scaled processing of covalent-organic frameworks.•Microfluidics offers an exquisite control over mixing regimes.•Mixing regimes can tailor the shape, morphology and surface integration of COFs.•Microfluidics can reveal morphogenesis of COFs via simulated microgravity. Nearly twenty years since the discovery of covalent-organic frameworks (COFs), most of the research on these materials has been focused on the rational design of new structures. Recently, the quest for discovering the functionalities and potential applications of these crystalline materials has attracted the attention of many researchers. While the number of reports regarding these two aspects within the COF research area is continuously growing, in order to achieve their full potential, the processability aspect of COFs also needs to be addressed. In this review article, we examine the opportunities that flow-based technologies offer regarding (a) the continuous synthesis of COFs, and (b) the processing of these materials into functional surfaces and devices (e.g. thin films and 3D structures), both aspects being ultimately amenable to industrial scale up.