Fluoropolymer‐Coated PDMS Microfluidic Devices for Application in Organic Synthesis

In recent years there has been huge interest in the development of microfluidic reactors for the synthesis of small molecules and nanomaterials. Such reaction platforms represent a powerful and versatile alternative to traditional formats since they allow for the precise, controlled, and flexible management of reactive processes. To date, the majority of microfluidic reactors used in small‐molecule synthesis have been manufactured using conventional lithographic techniques from materials such as glasses, ceramics, stainless steel, and silicon. Surprisingly, the fabrication of microfluidic devices from such rigid materials remains ill‐defined, complex, and expensive. Accordingly, the microfluidic toolkit for chemical synthesis would significantly benefit from the development of solvent‐resistant microfluidic devices that can be manufactured using soft‐lithographic prototyping methods. Whilst significant advances in the development of solvent‐resistant polymers have been made, only modest steps have been taken towards simplifying their use as microfluidic reactors. Herein, we emphasize the benefits of using a commercially available, amorphous perfluorinated polymer, CYTOP, as a coating with which to transform PDMS into a chemically inert material for use in organic synthesis applications. Its efficacy is demonstrated through the subsequent performance of photooxidation reactions and reactions under extremely acidic or basic conditions. It′s a clean machine: for fabricating solvent‐resistant PDMS microfluidic devices using the commercially available, amorphous perfluorinated polymer, CYTOP has been demonstrated. We provide proof‐of‐concept verification of the use of the CYTOP‐coated microfluidic reactors in photooxidation reactions and reactions under extremely acidic or basic conditions.