Aviation Week & Space Technology – Defense Technology Edition
Pat Toensmeier
Thu, 2016-04-07 04:00

Graphene maker touts commercial scale of its process capability.

The next “wonder material” that could bring major benefits to the aerospace and
defense industry is graphene. Work is underway at universities and research institutes to
fine-tune the composition and processability of the material, derived from graphite, for
diverse end-uses.

Graphene can be produced in different forms. One common representation shows it as a
densely packed, 2-D sheet of carbon atoms arranged in a honeycomb lattice one atom
thick. Technically, graphene is an allotrope of carbon in which each atom forms a
vertex through a covalent bond.

Laboratory-scale production is common around the world, but one company, Standard
Graphene of South Korea, maintains it is the only supplier that can provide graphene in
volume quantities for research, prototyping or production. The company has developed
a compact, modular plant that is fully automated, from production to packaging, with an
annual capacity of 1.1 metric tons (2,425 lb.) of graphene oxide (GO) or reduced GO
(rGO).

“No other company in the world can produce this much graphene,” CEO Joung-Hoon
Lee tells Aviation Week.

Because the plant is modular, increases in capacity are achieved by adding multiple
plants, each in a Production-Ready Graphene from South Korean Company production
cell. One cell requires floor space of 27 X 10 meters (88.5 X 32.8ft.) and is 3-4 meters
(9.8-13.1ft.) high.

Standard developed the synthesis technology it uses to make graphene in 2008, started a
pilot plant in 2009, and optimized the process in 2010. As with other graphene grades,
the material Standard produces has a number of high-value properties, including:
electrical conductivity that is 100 times greater than copper; thermal conductivity of
5,000 W/mK (watts per kelvin meter), twice as high as that of a diamond; breaking
strength 200 times greater than most steel; and tensile strength of 20 gigapascals.

The material is chemically inert and high in transparency since it absorbs just 2.3% of
light that falls on it. Standard’s graphene also has a high specific surface area, up to
2,630 sq. meters (28,309 sq. ft.) per gram. Chief Technology Officer Gunsoo Kim says
that 1 gram of graphene can cover a soccer field, which according to international
football rules is 110-120 yards long and 70-80 yards wide.

Standard produces six grades: four of rGO—V20-100, V21-100, V30-100 and V31-
100—and two of graphene oxide—V20-100 and V30-100. The lateral size of each is
more than 7 micrometers, while particle thickness is less than 5 nanometers. Grades
incorporate multiple layers, 3-5 in some versions and 7-8 in others. Kim says fewer
layers yield higher properties than graphene versions with dozens of layers.

The executives identified various aerospace and defense applications that would benefit
from using Standard’s graphene materials. These include:

• Supercapacitor electrodes. Adding graphene to the construction of these batteries
would result in faster charging and longer charge life, owing to the material’s high
electrical conductivity.

• Spray paint for aircraft body coatings. A 0.01% loading of graphene yields an
extremely hard coating that would not detach or chip off a surface.

• Structural diagnostics. Coating sensors with conductive graphene could be used to
create a monitoring system that detects the exact location of structural damage.

• EMI shielding. Adding 0.07% graphene to polyurethane (PUR) protects sensitive
electronics from electromagnetic interference.

• Sound-dampening. Tests in which PUR was blended with 0.07% graphene resulted in
25% average noise reduction.

• Weight reduction. Adding 0.2-0.375% graphene to the carbon-fiber-reinforced plastics
used in many cargo containers on military and civil transports would lower weight from
an average 250 lb. per container to 70 lb., while improving strength.

•Increasing tire strength. Adding 0.1% graphene to rubber in aircraft tires would
significantly raise their strength and extend service life, reducing replacement costs.

Standard has a mixing technology that reportedly assures consistent dispersion of
micro-scale graphene particles in blends. The company can assist in developing viable
manufacturing processes for customers.

The company has memos of understanding with Asian businesses including Avic and
has also signed a memorandum of understanding with Local Motors in the U.S., which
3-D prints electric cars. Standard, in fact, developed a formula containing graphene for
3-D printing, which it recently delivered to a Local Motors’ production plant in Oak
Ridge, Tennessee, for testing and evaluation.

standard graphene

standard graphene

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