Halogen-Bond Driven Self-Assembly of Perfluorocarbon Monolayers

TL;DR

This paper demonstrates a novel halogen-bond driven method to self-assemble stable, ultra-low energy perfluorocarbon monolayers on various substrates, with potential applications in biosensing, electronics, and microfluidics.

Contribution

It introduces a new, simple approach for forming highly compact perfluorocarbon monolayers using halogen bonding, outperforming traditional surface functionalization methods.

Findings

Achieved the lowest surface energy of 2.6 mJ/m² for a perfluorododecyl iodide monolayer.

Successfully functionalized surfaces with inert perfluorinated solvents.

Enabled stabilization of surfaces like perovskites in organic solvents.

Abstract

The self-assembly of a single layer of organic molecules on a substrate is a powerful strategy to modify surfaces and interfacial properties. The detailed interplay of molecule-to-substrate and molecule-molecule interactions are crucial for the preparation of stable and uniform monomolecular coatings. Thiolates, silanes, phosphonates and carboxylates are widely used head-groups to link organic molecules to specific surfaces study we show that self-assembly of stable and highly compact monolayers of perfluorocarbons. Remarkably, the lowest ever reported surface energy of 2.6 mJ m-2 was measured for a perfluorododecyl iodide monolayer on a silicon nitride substrate. As a convenient, flexible and simple method, the self-assembly of halogen-bond driven perfluorocarbon monolayers is compatible with several applications, ranging from biosensing to electronics and microfluidics. Compared to other methods used to functionalise surfaces and interfaces, our procedure offers the unique advantage to work with extremely inert perfluorinated solvents. We demonstrate that surfaces commonly unstable in contact with many common organic solvents, such as organic-inorganic perovskites, can be functionalized via halogen bonding.