The miracle material "Graphene". This presentation has information regarding Graphene Technology and its applications in Water Treatment.

1. Graphene and Water Treatment
Group members:
Mani (079)
Manisha(080)
Manoj(081)
Meman(082)
Nabin(083)
Narace(084)
Tutor:
Asst. Prof. Shukra Raj Paudel
Department of Civil Engineering
IOE, Tribhuvan University
2019-02-20

2. Objectives of Presentation
1. To learn about Graphene and its fundamentals
2. To know about uses of graphene in water treatment
3. To learn about use of graphene in desalination
4. To learn about limitations of graphene technology
2

3. Presentation Outline
1. Introduction
2. Fundamental science
3. Description of components
4. Application and suitability
5. Performance
6. Limitations
3

4. 1. Introduction
• Graphene is one-atom thick
layer of carbon arranged in a
honeycomb (hexagonal)
lattice.
• 2-D crystalline allotrope of
carbon.
• It is the thinnest, lightest,
strongest, best heat and
electricity conducting material
ever discovered
4
https://www.graphenesq.com/whatis/how.asp

5. 5
1. Stronger than diamond
2. 200 times harder than steel
3. High electrical conductivity
4. Ultrafiltration properties
5. High specific area
6. Barrier properties
7. Bactericidal applications
8. Eco friendly

6. Interesting facts about graphene
Graphene is made of same material
which makes our pencil lead yet it is
200 times stronger than steel
Filters made from graphene can be stronger and durable
Graphene can be made from simple and
eco friendly material as simple as soya
bean oil
Filters made from graphene can be eco
friendly and affordable

7. Discovery of graphene
• Single layer of graphene was
explored theoretically by P.R.
Wallence in 1947.
• And then unambiguously produced
and identified in 2004 by group of
Andre Geim and Konstantin
Novoselov.
• In 2010, they were awarded the
Nobel prize in Physics at UK’s
University of Manchester.
7
https://www.google.com/sear
ch?q=inventors+of+graphen

8. 2. Fundamental Science
Basically graphene is a one atom thick layer of carbon
Although graphene is one atom thick, its interesting
property is its impermeability
8
Graphene pie orbitals form a dense delocalized cloud that
blocks the gap between the aromatic rings, preventing
even the smallest materials like hydrogen and helium to
pass through it when 1-5 atm pressure is imposed on it at
room temperature.

9. Initially, graphene is hydrophobic, that is it repeals water.
This repulsion towards water is converted into affinity
towards water by producing artificial pores in graphene to
increase its permeability and permeation selectively.
When functionalized with nitrogen to create artificial
pores, a pore size of 3 angstrom is formed which allows
selective passage of H2 gas and blocks Ch4 gas.
When functionalized with oxygen( graphene oxide)
artificial pores can be formed such that it selectively
permeates water
9

10. https://arxiv.org/ftp/arxiv/papers/1402/1402.1014.pdf
10

11. https://en.wikipedia.org/wiki/Kinetic_diameter
11

12. https://arxiv.org/ftp/arxiv/papers/1402/1402.1014.pdf
12
https://arxiv.org/ftp/arxiv/papers/1402/1402.1014.pdf

13. 3. Description of
components
13

14. Graphene can be made in general by two
processes:
• Chemical exfoliation
• Micro mechanical cleavage
14

15. Chemical exfoliation
This is done by inserting various molecules
between the atomic planes of graphene.
15

16. Micro mechanical cleavage
Graphite crystal is split progressively into thin
layers by scrapping or rubbing them against
another surface
https://www.cambridge.org/core/journals/mrs-communications/article/
16

17. 4. Applications Of Graphene
Tissue
Engineering
To improve the mechanical properties
of biodegradable polymers
Electronics Graphene has high carrier mobility, and
low noise allowing to be used as in
transistor
Solar cells Graphene solar cells use graphene’s
unique combination of high electrical
conductivity and optical transparency.
Environment
contaminant
removal
It is non-toxic and biodegradable and
its surface is covered with epoxy,
hydroxyl and carboxyl groups/
17

18. "Graphene is a material that can be utilized in
numerous disciplines including, but not limited to:
bioengineering, composite materials, energy
technology and nanotechnology."
18

19. https://nearsay.com/c/408914/393942/3-innovative-uses-of--graphene-materials
19

20. Water Treatment
• Process that makes water more suitable for its
applications
• Involves the removal of solids, bacteria, algae, and
inorganic compounds
• New technologies are constantly discovered to lower
cost, and footprint of processes that make water as
portable water
Much research is focused on graphene for
different water treatment uses
20

21. 21

22. Carbon materials used in water treatment
• Activated carbon
• Charcoal
• Carbon nanotubes
• Graphene
https://sciencing.com/examples-carbon-molecules-role-everyday-life-
22

23. Graphene -the carbon based wonder material
Why graphene?
• Graphene shows higher absorption capacity
in comparison to activated carbon
• Graphene can remove heavy metal ions,
pesticides, natural dyes
• Graphene can be used in desalination to
convert sea water into drinkable form in
single step.
23

24. Graphene and water treatment
• Graphene is naturally hydrophobic.and repeals the
water
• When narrow pores are made in it, water permeation
occurs
• It allows water to pass and blocks substances and
contaminants
• Graphene can be used to make light weight,
environment friendly, energy efficient water filters and
desalinators.
24

25. Desalination
https://www.nature.com/articles/s41545-018-0004-z
25

26. Desalination
• It is the removal of salts and minerals from water
• Graphene oxides films can be used to effectively
converts salt water to drinkable water in a single step.
Bacterial removal
• Graphene oxide sheets are highly effective in killing
bacteria
Industrial water treatment
• Graphene sheets can produce heavy water from nuclear
and industrial wastes through effective filtration.
26Use of Graphene in Water Treatment

27. https://www.nature.com/articles/am201713
5
27

28. 5. Performance
Graphene as superior advantages compared to
different filtration processes
• It has more absorptive capacity than activated
carbon which is said to have the highest surface
area
• Efficiently removes heavy metal ions, dyes and
pesticides in compared to reverse osmosis
• As graphene is eco friendly, it doesn’t posses
side effects
28

29. Advantages of graphene
• Low cost water desalination by using graphene
desalination by graphene requires nearly 100
times less energy
• Graphene filters are 500 times thinner than the
best filters on the market and 1000 times
stronger
• Production of graphene is economically viable
10 micro meter in thickness
29

30. • Graphene technology are durable , size efficient
and highly efficient in filtration
• Besides use in water purification , graphene has
applicability in several other field as well
https://www.sciencedirect.com/science/article/pii/S0079642517300
713
30

31. 6. Limitations of Graphene technology
Graphene is a miracle material with wide
applications
It has numerous advantages, and many more yet to
be discovered.
31

32. 32
Disadvantages of Graphene
• Susceptibility to oxidative environment.
• Since the material is still in research stage
much more is yet to be revealed.
• Initially graphene is hydrophobic so artificial
pore have to be developed

33. https://iopscience.iop.org/article/10.1088/1755-1315/94/1/012060/pdf
If you want to learn and discover more about graphene
technology, check out the following links
Graphene is a blooming technology and still in research
phase
And it is viable to lot of new discoveries
https://repository.ntu.edu.sg/handle/10356/65205
https://www.dezeen.com/2018/03/04/graphene-water-filter-
produces-drinkable-water-in-just-one-step/
https://www.slideshare.net/FundacionAreces/rohit-karnifgraphene-
menmbranes-for-water-purification?qid=7dde4137-26f4-4192-a91f-
bcfe1baddd88&v=&b=&from_search=7
https://arxiv.org/ftp/arxiv/papers/1402/1402.
1014.pdf
33

35. • Guess what graphene can be made of?
• answer is soyabean oil
• Dirty to drinkable