In Situ Radical Polymerization and Grafting Reaction Simultaneously Initiated by Fluorinated Graphene.

Fluorinated graphene (FG) showed interesting electrochemical, electronic, and mechanical properties, as well as chemical reactivity for multifarious functionalization of graphene material. This work reported a free radical polymerization and grafting from polymerization of a styrene monomer directly initiated by FG, which simultaneously provided free polymers and functionalized graphene with polymer chains grafted. The FG exhibited an almost comparative initiation efficiency to equivalent commercial initiator azodiisobutyronitrile under similar conditions, resulting in a high yield of free polystyrene (40.9%) with a high molecular weight ( Mn = 114.7 kg/mol). It was demonstrated that FG-triggered polymerization presented some special characteristics, such as a long lifetime of chain radical centers even when the reaction was stopped and insensitivity to oxygen molecules. The mechanistic study indicated that the polymerization was initiated by single-electron transfer reaction between FG and a monomer leading to formation of primary radicals; in addition, FG also played an important role in chain transfer and termination reactions during the polymerization process.

The Friedel-Crafts reaction of fluorinated graphene for high-yield arylation of graphene.

Herein, we report the Friedel-Crafts reaction of fluorinated graphene with aryl molecules including methylbenzene, chlorobenzene and polystyrene. The reaction achieved the high-yield arylation functionalization of graphene under mild reaction conditions and extends the range of the Friedel-Crafts reaction to the field of two-dimensional materials.

Chemical reactivity of C-F bonds attached to graphene with diamines depending on their nature and location.

The attachment of fluorine to graphene is a facile means to activate the carbon bonds for subsequent covalent bonding to other molecules for the preparation of desired graphene derivatives. Therefore, an insight into the chemical reactivity of fluorinated graphene (FG) is very essential to enable precise control of the composition and structure of the final products. In this study, FG has been treated with various mass amounts of poly(oxypropylene)diamine (PEA) ranging from starvation to saturation to explore the dependence of a substitution reaction of diamines on the nature and location (attached onto the basal planes or along defects or edges) of C-F bonds. X-ray photoelectron spectroscopy directly tracked the atomic percentage of fluorine present and the carbon 1s bonding state, showing that the grafting ratio of diamines gradually increases with increased diamine mass ratio. The varying of the types and orientation of C-F bonds characterized by polarized attenuated total reflectance Fourier transform infrared spectroscopy indicates that "covalent" C-F bonds are more sensitive to the substitution reaction of diamines than ''semi-ionic'' C-F bonds, and the C-F bonds attached onto basal planes more preferably participate in the functionalization reaction of diamines than that of C-F bonded on non-coplanar regions (edges or defects). The one-dimensional expansion along the graphene c-axis shown by wide angle X-ray diffraction provides further evidence on the preferred functionalization reaction of C-F attached on the basal planes, resulting in a change of the average intersheet distance by various magnitudes.