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NEOCLASSICAL THEORY OF INTERACTION 101

DC or AC bias voltage (in the range of several volts) applied to the sheets, the shielding can be
optimized for specific applications and even be modulated by volume or frequency. Besides,
the attenuation is almost independent of the angle of EM wave incidence allowing
unprecedented electrostatic confinement. A similar effect can be reached by magnetizing the
graphene layers.

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2.9.5 Conductive Graphene NanoRibbon (GNR) Thin Film as Deicing Coating
Icing-protection systems are widespread in large structures like glass buildings and house
windows, car windshields, cables and power line wires, aircraft, radar radomes, antenna
apertures, solar panels, wind turbine blades,
offshore oil platform, etc. They can be
categorized as either anti-icing heaters
(preventing ice accumulation) or deicing
heaters (removing ice after accumulation).
Graphene is the excellent material for the heater
composite made of conductive graphene
nanoribbons (GNRs). This metal-free, ultra-

Figure 2.9.8 Graphene nanotube light, robust and scalable graphene-based RF
unzipping and optical transparent conductive coating
could significantly reduce the size and cost of
de-icing/anti-icing coating and could be substantial in many aviation and military applications.
Thin conductive graphene films of different thickness and conductivity can be produced using
high aspect ratio (graphene monolayer with a high ratio of the width to the length) GNRs
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obtained by splitting carbon nanotubes with or sodium-potassium alloy (Na-K). Figure 2.9.8
schematically illustrates this process. Then GNR conductive film up to 100 nm thick can be
formed by using randomly dispersed GNRs on the
supportive substrate. Figure 2.9.9 depicts the scanning
electron microscope image of these graphene
nanoribbons. Such randomly dispersed GNRs with a
large number of graphene monolayers create isotropic or
very close to isotropic conductive films. By controlling
the spraying time or GNRs concentrations of solution ,
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the thicknesses of the GNR films can be monitored,
Figure 2.9.9 Scanning electron thereby changing the DC-resistance of the films as
microscope image shown in Figure 2.9.10a. Note that so wide variation of
sheet resistivity opens the way for a vast and diverse
range of applications of GNR. In particular, applying the DC-voltage to GNR sheet, as Figure
2.9.10b demonstrates, we can heat the layer and melt the snow or ice accumulated on its surface
while RF signal goes through unharmed. Calculations and experiment show that about 0.4
W/cm of heat power is quite enough for effective deicing. The deicing of the large surface of
2
antenna array or redomes covering such antennas requires the high transparency in RF
frequency range, etc. The efficacy and applicability of GNR films for any of such application

28 This section is based on publication: V. Volman, J. M. Tour, Yu Zhu, Abdul-Rahman O. Raji,
“Conductive Graphene Nanoribbon Thin Film as Heat Circuit for Antennas and Radomes,”
29 Public Domain Image, source: D. V. Kosynkin, A. L. Higginbotham, A. Sinitskii, J. R. Lomeda , A.
1
Dimiev, B. K. Price, James M. Tour, “Longitudinal unzipping of carbon nanotubes to form graphene
nanoribbons,” Nature 458, 16 April 2009.
30 Concentration of solution is a chemical term defined as the amount of solute dissolved in a specific
(fixed) amount of solvent.