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CONTENTS
Introduction
Advantages / Disadvantages of CNTs
Properties of CNTs
Structure of CNTs
Types of CNTs
Synthesis of CNTs
Functionalization of CNTs
Purification of CNTs
Applications of CNTs
Conclusion
References
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• Carbon nanotubes (CNTs) are allotropes of carbon, made of graphite
• Constructed in cylindrical tubes with nanometer in diameter and several millimeters in length with a high aspect
ratio (typically >1000)
• Can be open ended or capped
• CNTs possess high flexibility, low mass density
• Their impressive structural, mechanical, and electronic properties are due to their small size and mass, their strong
mechanical potency, and their high electrical and thermal conductivity.
• Successfully applied in pharmacy and medicine due to their high surface area
• Capable of adsorbing or conjugating with a wide variety of therapeutic and diagnostic agents (drugs, genes,
vaccines, antibodies, biosensors, etc.)
• Applications of CNTs have been extensively performed not only for drug and gene therapies but also for tissue
regeneration, biosensor diagnosis, enantiomer separation of chiral drugs, extraction and analysis of drugs and
pollutants
INTRODUCTION
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• Carbon nanotubes (CNTs) consist exclusively of carbon
atoms arranged in a series of condensed benzene rings
rolled up into a tubular structure.
• This novel artificial nanomaterial belongs to the family
of fullerenes, the third allotropic form of carbon along
with graphite and diamond which are both natural sp2
(planar)
• Have been constructed with Length-to-diameter ratio of
up to 132,000,000:1
• Diameter range : 2-55nm
• Length may be several µm to several mm
STRUCTURE of CNTs
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• They comprise of single sheet of graphite wrapped seamlessly into hollow
cylindrical tube having diameter between 0.4 to 2.5 nm and length 20 to
1000 nm
Single-walled coated nanotubes
(SWCNTs)
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0.3-4 nm
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• They are coaxial nanostructures that consist of two concentric graphene
cylindrical tubes.
• These DWCNTs resembles SWCNTs in their similar morphology and
properties.
Di-walled coated nanotubes
(DWCNTs)
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2-100 nm
1-3 nm
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• Oldest method used by Iijima in 1991
• Very costly method and yield upto 30-90%
• CNTs are formed by arc vaporization of highly pure graphite electrodes (anode and cathode), having 1mm distance, in a
reaction chamber comprising of inert gas, e.g. Helium (He), and argon (Ar)
• Applying high voltage current of 50 to 100 amps and pressure between 50-700 mbar, generates high temperature
discharge b/w two electrodes, carbon rods get evaporated and deposited on the cathode in the form of rod shaped tubes
Arc Discharge Method
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• CVD that seems to offer the best chance to obtain a controllable process for the selective production of nanotubes with
predefined properties
• First reported in 1959
• Cheaper and yield upto 20-100%
• CNTs synthesis is carried out in a quartz tube placed in a furnace
Chemical Vapour Deposition Method
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• First reported in 1995
• Cost effective and yield upto 70%
• Solid graphite target doped with metal (1% of Co and Ni) is irradiated by high-power laser
• Vaporization of pure graphite target inside a high temperature furnace at 1200⁰C temperature
• Throbbing or constant laser has been used to vaporize the graphite in an oven having Argon or Helium gas
• Water-cooled surface may be included in the system to collect the nanotubes
Laser Ablation Method
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• Raw CNTs have highly hydrophobic surfaces and are not soluble in aqueous solutions
• For Biomedical applications, surface chemistry or functionalization is require to solubilize CNTs improve biocompatibility
and low toxicity
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FUNCTIONALIZATION of CNTs
Covalent
Functionalization
• End and Defects
• Side Walls
Non-covalent
Functionalization
• Vander Waals
interactions
• Hydrophobic
interactions
• π-π stacking
Modification
With Biological
and Bioactive
Species
• Carbohydrates
• Proteins
• Nucleic acids
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APPLICATIONS of CNTs
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CNTs in Therapeutics CNTs in Diagnostics
Cancer Therapy
(Drug/ Immuno/ Hyperthermia)
Infection Therapy
Gene Therapy
Tissue generation
Neurodegenerative disorders
As Antioxidants
Biosensers vehicles for diagnosis
Enantioseparation of Chiral drugs
Extraction of drugs & biochemicals
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• In past few years carbon nanotubes emerged as a promising novel class of drug carrier for the delivery of
drugs in a site specific and target oriented manner due to their chemical, physical and biological properties
• Carbon nanotubes are finding a broad spectrum of advantages in today’s world of medical research
• Functionalization of CNT and further derivatization with biodegradable polymers render them compatible
with biological systems
• Attachment of an organic moiety to nanosized tubes has made possible their use in diagnostics for imaging
as well as for targeting purposes, especially in cancer therapy and infectious disease treatment
• Nanotube drug delivery holds future promise for high treatment efficacy combined with minimal side effects
for cancer therapy with low drug doses
• In addition, it is the most promising non-viral nanocarrier in human gene therapy and in nucleic acid,
peptide, vaccine and protein delivery
• As much work is under progress, it is expected that plenty of applications of CNTs will be explored in the
near future.
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CONCLUSION
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REFERENCES
1. Md. Harun-Or Rashid and Stephen F. Ralph, Carbon Nanotube Membranes: Synthesis, Properties, and
Future Filtration Applications, Nanomaterials 2017, 7, 99. (doi: 10.3390/nano7050099)
2. Vaibhav Rastogi, et al. , Carbon Nanotubes: An Emerging Drug Carrier for Targeting Cancer Cells, Hindawi
Publishing Corporation Journal of Drug Delivery Volume 2014, Article ID 670815, 23 pages. (doi:
http://dx.doi.org/10.1155/2014/670815)
3. Sharma et al. , Biomedical Applications of Carbon Nanotubes: A Critical Review, Current Drug Delivery,
Bentham Science Publishers, 2015, Vol. 12, No. 0 .
4. X. Zhao, R. Liu / Environment International 40 (2012) 244–256 (doi: 10.1016/j.envint.2011.12.003)
5. Sarwar Beg, et al. , Advancement in carbon nanotubes: basics, biomedical applications and toxicity, Journal
of Pharmacy and Pharmacology 2011; 63: 141–163. (doi: 10.1111/j.2042-7158.2010.01167.x)
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