ABSTRACT
The interlayer space of 2D materials can be a slit reactor where transformations not typical for the gas phase occur. We report redox reactions involving acetonitrile and nitrogen oxide guests in galleries of fluorinated graphite. Fluorinated graphite intercalation compounds with acetonitrile are treated with dinitrogen tetraoxide and the synthesis products are studied by a set of experimental methods. Data analysis reveals that N2O4 dissociates in fluorinated graphite matrices to form nitrogen-containing species NO3, NO2, NO, and N2. The interaction of NO3 with acetonitrile yields HNO3, which predominates as a guest in the synthesis products independently of the fluorination degree of the matrix. This reaction is accompanied by the removal of fluorine atoms weakly bonded to the graphite layers, leading to partial defluorination of the matrices. Our work demonstrates the possibility of using fluorinated graphite as a test nanoreactor whose dimension can be controlled by fluorination of the layers.
ABSTRACT
Thin graphene/polymer sheet composites were fabricated using easily soluble expanded graphite (ESEG), and their field emission (FE) parameters were examined. Due to the high dispersability of ESEG, a stable graphene suspension was prepared by ultrasonication in toluene without the need for a surfactant. The suspension consisted of exfoliated graphene sheets with a thickness of 1 - 2 nm. Using a calendering process, the solution was further shear mixed with ethyl cellulose to obtain a well-dispersed graphene/polymer composite. The composite was screen printed onto a conducing substrate to fabricate the FE cathode layers. The FE measurements were taken in a diode configuration at an applied electrostatic field and inter-electrode distance of 1.7 to 6 V/microm and approximately 200 microm, respectively. The threshold turn-on-field was approximately 3.5 V/microm at a current density of approximately 10 microA/cm2 with a corresponding mean field enhancement factor of 1350 +/- 50. Emission occurred mainly from the edges and bends of the graphene layers. The luminescence uniformity of the composite cathode layers was examined using a phosphor-coated anode.