Fluorinated graphene oxide for enhanced S and X-band microwave absorption

Abstract

Here we report the microwave absorbing properties of three graphene derivatives, namely, graphene oxide (GO), fluorinated GO (FGO, containing 5.6 at. % Fluorine (F)), and highly FGO (HFGO, containing 23 at. % F). FGO is known to be exhibiting improved electrochemical and electronic properties when compared to GO. Fluorination modifies the dielectric properties of GO and hence thought of as a good microwave absorber. The dielectric permittivities of GO, FGO, and HFGO were estimated in the S (2 GHz to 4 GHz) and X (8 GHz to 12 GHz) bands by employing cavity perturbation technique. For this, suspensions containing GO/FGO/HFGO were made in N-Methyl Pyrrolidone (NMP) and were subjected to cavity perturbation. The reflection loss was then estimated and it was found that À37 dB (at 3.2 GHz with 6.5 mm thickness) and À31 dB (at 2.8 GHz with 6 mm thickness) in the S band and a reflection loss of À18 dB (at 8.4 GHz with 2.5 mm thickness) and À10 dB (at 11 GHz with 2 mm thickness) in the X band were achieved for 0.01 wt. % of FGO and HFGO in NMP, respectively, suggesting that these materials can serve as efficient microwave absorbers even at low concentrations. V

Fluorographene: Synthesis and sensing applications

“…34 It was stated that low level inhomogeneous F on graphene can induce partial positive surfaces on graphene and it can prevent thromboembolism. 13 Further, F doping can greatly enhance the lipophilicity of the drug carrier, an important criterion while designing in vivo drug carrier platforms. 13 FGO is also shown to be promising for ultrasound imaging and MRI contrast enhancement due to its paramagnetic centers (first carbons based nanoparticle free contrast enhancement agent) 35 along with its capability of carrying drug molecules due to the presence of oxygen functionalities.…”

“…13 Further, F doping can greatly enhance the lipophilicity of the drug carrier, an important criterion while designing in vivo drug carrier platforms. 13 FGO is also shown to be promising for ultrasound imaging and MRI contrast enhancement due to its paramagnetic centers (first carbons based nanoparticle free contrast enhancement agent) 35 along with its capability of carrying drug molecules due to the presence of oxygen functionalities. Further, electrocatalytic studies on FGO and FG show that F centers drastically change the spin and charge density distributions in graphene and C-F bond can make graphene as electrocatalytically active toward various reactions [Figs.…”

“…[8][9][10][11][12] It is found that these functional derivatives can abruptly change the electronic properties and low temperature fluctuations in graphene depending upon the nature of the chemical modifications, and hence this can bring exotic properties such as localized magnetic moments, high electric polarization, low surface energy along with specificity in adsorption of molecules by tuning the interactions. [13][14][15][16] Hence graphene can be chemically and/or structurally modified to tune its functionality, and henceforth its numerous applications. Moreover, graphene can be derived from graphite, an abundant material at the earth's surface, make it as a potential candidate not only for basic studies but for practical applications such as electronic devices and chemical sensors too.…”

Fluorinated Boron Nitride Quantum Dots: A New 0D Material for Energy Conversion and Detection of Cellular Metabolism

“…The inception of 2D materials marked by graphene brought several ambitious ideas into reality, primarily due to their unique properties provided by the absence of the third dimension for the lattice . In the pool of different 2D materials having similar structure, a wide range of electronic, optical, thermal, and magnetic properties are perceived . When these 2D materials are further confined to atomic scale quantum dots (QDs), size less than the Bohr radius of charge carriers, the confinement in space raises their energy and the electronic states become discrete, exhibiting properties strikingly different from the bulk material .…”

Metal-free carbon nanotubes: synthesis, and enhanced intrinsic microwave absorption properties

“…In order to explore high efficiency core/shell carbon-based nanohybrids, the EM parameters and microwave absorption properties of CNMs and graphene should be understood truly. Therefore, graphene and their derivatives were investigated intensively as potential microwave absorbers recently1920. However, as we all know that CNMs such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) are usually synthesized by the methods of electric arc discharge, laser evaporation and catalytic chemical vapor deposition212223.…”