Graphene oxide is hydrophilic by virtue of its functionalized basal plane bonded to polar organic moieties. P. M. Ajayan and co-workers at Rice University and the MD Anderson Cancer Center in Houston discuss the synthesis of fluorinated graphene oxide through the oxidation of the basal plane in fluorinated graphite in new work presented in Particle & Particle Systems Characterization. This enables graphene oxide with a tunable hydrophobity to be produced by varying the C/F and C/O ratios during synthesis.
The authors discuss a chemical scheme whereby bulk quantities of 2D nanoflakes are produced in a one-pot synthesis that consistently yields two discrete solid products with different C/O and C/F ratios, fluorinated graphene oxide (FGO) and highly fluorinated gaphene oxide (HFGO).
The ease of solution processing of these materials lends them to be suitable for the production of inks that can be sprayed on a variety of surfaces from metals to fabrics at a pinhole-free, nanometer-thick level. These films can repel both water and organic solvents. This method is much easier and technologically less demanding than other methods of producing materials that are both hydrophobic and lipophobic.
The use of 13C MAS NMR spectroscopy is described to characterize the structure of both the FGO and HFGO.