1. The document discusses research by SLINTEC on using Sri Lankan vein graphite to produce value-added carbon products like graphene oxide and graphene. 2. Raman spectroscopy and NEXAFS analysis shows the Sri Lankan graphite has properties similar to high-quality synthetic graphite, making it a suitable precursor. 3. The motivation is the abundance of high-quality Sri Lankan graphite and growing demand for carbon products, which SLINTEC's research can help meet by developing processes to produce graphene oxide, graphene and other materials from the graphite.

1. The SLINTEC initiatives

2. Introduction
Graphene is a one-atom-
thick planar sheet of
atoms that are densely
packed in a honeycomb
crystal lattice
Fullerene Graphite
Carbon
nanotubes
Graphene

3. SLINTEC carbon material research
Graphene Oxide
Graphite
Oxide
GNP
Graphite
CNT
Graphene

4. Our motivation
• Purest of graphite found in Sri Lanka; ideal
precursors for value added carbon products
• Strong resemblance of Sri Lankan graphite to
high quality man made graphite
• Vast number of established and potential
applications for carbon products
• High growth of demand for value added
carbon products

5. Graphite
• Amorphous graphite
• Flake graphite
• Vein graphite
– It is the most pure type of
graphite, with the highest
level of crystallinity of the
natural forms
1. Stacked carbon structure
2. Interlayer spacing is 3.354 Å
3. Excellent insulator and electrical
conductor
4. Excellent lubricator

6. Graphite-Applications

7. Graphite-Opportunity-Raman
• We observe strong resemblance of Sri Lankan
Vein graphite to high quality expensive
synthetic graphite
1000 1500 2000 2500 3000
D
G
2D
Vein Graphite
Ra-Gedara mine
Raman shift (cm
-1
)
1000 1500 2000 2500 3000
G
2D
HOPG
Raman Shift (cm
-1
)

8. Graphite-Opportunity-NEXAFS

9. Similarities
• From the data, we can see that:
– D/G ratio is ~ 0.0337 and more comparable to
pyrolytic graphite than commercial graphite
– This would suggest a large crystallite size, that is,
less boundaries, and hence less defects
– The graphene layers are not turbostratic, i.e. there
is a electronic correlation between the layers
(wide 2D peak)

10. Graphene oxide
Graphite oxide, formerly called graphitic oxide
or graphitic acid, is a compound of carbon,
oxygen, and hydrogen in variable ratios,
obtained by treating graphite with strong
oxidizers. The maximally oxidized bulk
product is a yellow solid with C:O ratio
between 2.1 and 2.9, that retains the layer
structure of graphite but with a much larger
and irregular spacing
Exfoliated graphite oxide
Chemical Oxidation
With an oxidant
Such as KMnO4 and
H2SO4 as an intercalant.
Oxidation of graphite matrix where
Peripheral carbon atoms at plane edges
And in defects bonded to oxygen containing
groups
Ultrasound
Graphite

11. Graphene oxide-Graphene precursor
Graphene oxide can be readily
reduced with strong reducing
agents to prepare Graphene
in large scale
thinnest imaginable material
Largest surface area (~3000 m2/g
Strongest material ever measured
Stiffest known material (> diamond)
Most stretchable and pliable
Record thermal conductivity (>diamond)
Highest current density at RT
(million times higher than Cu)
Completely impermeable
Highest intrinsic mobility (100 x Si)
Conducts electricity in the limit of no
electron
Lightest charge carriers (zero rest mass)
Longest mean free path at RT(>micron)

12. Graphite
Next generation
Electronics.
> 5 micron
Graphite
Oxide (GO)
Graphite
nanoplatelets
(GNP)
Graphene
Many layers of
graphene oxide
(1st product)
Research finished
(2nd product) (3rd product
Future !!!)
Reduction
C:O = 1:3
oxidation
Our work on graphene oxide

13. 13
40 µm
Graphite particles
Thick GO paper
t >>> 200µm
t = 0.5 µm
Thin GO paper
t >> 100 µm
oxidation
Self-
assembling
Unimpeded permeation for water
Size of a water molecule = 0.278 nm
Dilution Exfoliation
Full of nano-capillaries, Science, 335, 442, 2012
Graphene oxide membrane

14. Graphene oxide-Preparation
GO from Ragedara
graphite
We have successfully
prepared graphene oxide
and graphene from vein
graphite in Sri Lanka
Carbon nano structures based polyurethane
nano composites as flexible, light weight,
high modulus thermal insulate, electricity
conductive materials

15. 15
Transparent
conductive thin films
Graphene electronics Graphene
ultracapaciters
Sensors
Graphene
composites
Graphene
Graphene – Few applications
Biodevices
And many many more!!

16. 16
Aerospace Industry
Automotive
Defense
Energy and
Telecommunication
graphite
GNP
GNP – Few applications