Nanotubes Presentation

1. Carbon Nanotubes By Bryan Sequeira Bertug Kaleli Murshed Alam Farooq Akbar Zac Lochner

2. What are Carbon Nanotubes ?Carbon nanotubes are fullerene-relatedstructures which consist of

graphenecylinders closed at either end with capscontaining pentagonal rings

3. Caps* Typical high resolution TEM image of a nanotube cap

4. DiscoveryThey were discovered in 1991 by the Japanese electron microscopist Sumio Iijima who was

studying the material deposited on the cathode during the arc-evaporation synthesis of fullerenes. He

found that the central core of the cathodic deposit contained a variety of closed graphitic structures

including nanoparticles and nanotubes, of a type which had neverpreviously been observed

5. Carbon Nanotubes:• This is a nanoscopic structure made of carbon atoms in the shape of a hollow

cylinder. The cylinders are typically closed at their ends by semi-fullerene-like structures. There are

three types of carbon nanotubes: armchair, zig-zag and Chiral (helical) nanotubes. These differ in their

symmetry. Namely, the carbon nanotubes can be thought of as graphene planes rolled up in a cylinder

(the closing ends of carbon nanotubes cannot be obtained in this way). Depending on how the graphene

plane is cut before rolled up, the three types of carbon nanotubes are obtained. Within a particular type,

carbon nanotubes with many different radii can be found (depending on how large is the graphene area

that is folded onto a cylinder). These tubes can be extremely long (several hundreds of nanometers and

more). Some consider them as special cases of fullerenes. When produced in materials, carbon

nanotubes pack either in bundles (one next to another within a triangular lattice) - single-walled carbon

nanotubes, or one of smaller radius inside others of larger radii - multi-walled carbon nanotubes. Carbon

nanotubes have already found several technological applications, including their application in high-

field emission displays. Carbon nanotubes were discovered by Sumio Ijima in 1991.

6. The way tofind out howthe carbonatoms arearranged in amolecule canbe done byjoining

thevectorcoordinatesof the atoms.By this way itcan beidentifiedwhether if thecarbonatoms arearranged

in azig-zag, armchair or in ahelicalshape.

7. Nanotubes are formed by rolling up a graphene sheet into a cylinder and capping each endwith half of

a fullerene molecule.Shown here is a (5, 5) armchair nanotube (top), a (9, 0) zigzagnanotube (middle)

and a (10, 5)chiral nanotube. The diameter of the nanotubes depends on the values of n and m.

8. Process in ARC discharge• Carbon is vaporized between two carbon electrodes• Small diameter,

single-wall nanotubes can be synthesized using a Miller XTM 304 dc arc welder to maintain the optimal

settings between two horizontal electrodes in helium or argon atmospheres.• The voltage is controlled by

an automatic feedback loop that senses the voltage differences between the two electrodes and adjusts

them accordingly.

9. Laser VaporizationConsist of three parts:•Laser•Optical Delay: The optical delay is used todelay

mostly the 1064nm when in use withanother line• Reactor

10. Arc discharge method Chemical vapor Laser ablation deposition (vaporization)Connect two graphite

rods to a Place substrate in oven, heat Blast graphite with intense power supply, place them to 600 C,

and slowly add a laser pulses; use the laser millimeters apart, and throw carbon-bearing gas such as

pulses rather than electricity to switch. At 100 amps, carbon methane. As gas decomposes generate

carbon gas from vaporizes in a hot plasma. it frees up carbon atoms, which the NTs form; try various

which recombine in the form of conditions until hit on one that NTs produces prodigious amounts of

SWNTs Can produce SWNT and Easiest to scale to industrial Primarily SWNTs, with a large MWNTs

with few structural production; long length diameter range that can be defects controlled by varying the

reaction temperature Tubes tend to be short with NTs are usually MWNTs and By far the most costly,

because random sizes and directions often riddled with defects requires expensive lasers

11. Uses of Carbon NanoTubes• Since discovering them more than a decade ago, scientists have been

exploring possible uses for carbon nanotubes, which exhibit electrical conductivity as high as copper,

thermal conductivity as high as diamond, and as much as 100 times the strength of steel at one-sixth the

weight. In order to capitalize on these properties, researchers and engineers need a set of tools -- in this

case, chemical processes like pyrolytic fluorination -- that will allow them to cut, sort, dissolve and

otherwise manipulate nanotubes.• Molecular and Nanotube Memories Nanotubes hold promise for non-

volatile memory; with a commercial prototype nanotube-based RAM predicted in 1-2 years, and terabit

capacity memories ultimately possible. Similar promises have been made of molecular memory from

several companies, with one projecting a low-cost memory based on molecule-sized cylinders by end

2004 that will have capacities appropriate for the flash memory market. These approaches offer non-

volatile memory and if the predicted capacities of up to 1Tb can be achieved at appropriate cost then

hard drives may no longer be necessary in PCs.

12. Laser applications heat up for carbon nanotubes• Carbon nanotubes---tiny cylinders made of carbon

atoms---conduct heat hundreds of times better than todays detector coating materials. Nanotubes are also

resistant to laser damage and, because of their texture and crystal properties, absorb light efficiently.

Nanoelectronics• Nanotubes are either conducting or semi-conducting depending upon their structure (or

their twist) so they could be very useful in electronic circuitry. Nanotube Ropes/Fibers: These have great

potential if the SWNTs can be made slightly longer they have the potential to become the next

generation of carbon fibers. Carbon nanotubes additionally can also be used to produce nanowires of

other chemicals, such as gold or zinc oxide. These nanowires in turn can be used to cast nanotubes of

other chemicals, such as gallium nitride. These can have very different properties from CNTs - for

example, gallium nitride nanotubes are hydrophilic, while CNTs are hydrophobic, giving them possible

uses in organic chemistry that CNTs could not be used for.• Display Technologies Nanomaterials will

help extend the range of ways in which we display information. Several groups are promising consumer

flat screens based on nanotubes by the end of 2003 or shortly after (Carbon nanotubes are excellent field

emitters). E-paper is another much heralded application and nanoparticles figure in several approaches

being investigated, some of which promise limited commercialization in the next year or two. Soft

lithography is another technology being applied in this area. •Carbon nanotube fibers under an electron

microscope

13. • Light Emitting Polymer Technology Light Emitting Polymer technology is leading to a new class

of flat panel displays. Researchers have discovered that Light Emitting Diodes (LEDs) could be made

from polymers as well as from traditional semiconductors. It was found that the polymer poly p-

phenylenevinylene (PPV) emitted yellow-green light when sandwiched between a pair of electrodes.

Initially this proved to be of little practical value as it produced an efficiency of less than 0.01%.

However, by changing the chemical composition of the polymer and the structure of the device, an

efficiency of 5% was achieved, bringing it well into the range of conventional LEDs. Some Amazing

facts and Applications• Carbon Nanotubes possess many unique and remarkable properties (chemical,

physical, and mechanical), which make them desirable for many applications. The slender proportions of

carbon nanotubes hide a staggering strength: it is estimated that they are 100 times stronger than steel at

only one sixth of the weight - almost certainly the strongest fibres that will ever be made out of anything

- strong enough even to build an elevator to space. In addition they conduct electricity better than copper

and transmit heat better than diamond.• Enhancements in miniaturization, speed and power

consumption, size reduction of information processing devices, memory storage devices and flat

displays for visualization are currently being developed• The most immediate application for nanotubes

is in making strong, lightweight materials. It will be possible to build a car that is lighter than its human

driver, yet strong enough to survive a collision with a tank• Aircraft built with stronger and lighter

materials will have longer life spans and will fly at higher temperatures, faster and more efficiently.

Nanotubes are being explored as receptacles - storage tanks - for hydrogen molecules to be used in the

fuel cell that could power automobiles of the future. Hydrogen does not produce pollution or greenhouse

emissions when burned and is considered to be the clean energy of the future.

14. Some applications of Carbon• Nanotubes include the following Micro-electronics / • Nanotube

actuator semiconductors Molecular Quantum wires Conducting Composites Hydrogen Storage

Controlled Drug Noble radioactive gas storage Delivery/release Solar storage Artificial muscles Waste

recycling Supercapacitors Electromagnetic shielding Batteries Dialysis Filters Field emission flat panel

Thermal protection displays Nanotube reinforced Field Effect transistors and composites Single electron

transistors Reinforcement of armour and Nano lithography other materials Nano electronics

Reinforcement of polymer Doping Avionics Nano balance Collision-protection materials Nano tweezers

Fly wheels" Data storage Magnetic nanotube Nanogear

15. Picture of Carbon NanoTubes

16. Future Uses of CNTs• Nano-Electronics – Nanotubes can be conducting or insulating depending on

their properties • Diameter, length, chirality/twist, and number of walls – Joining multiple nanotubes

together to make nanoscale diodes – Max Current Density: 10^13 A/cm^2

17. The Space Elevator• The Idea – To create a tether from earth to some object in a geosynchronous

orbit. Objects can then crawl up the tether into space. – Saves time and money• The Problem – 62,000-

miles (100,000-kilometers) – 20+ tons

18. The Space ElevatorPictures

fromhttp://www.space.com/businesstechnology/technology/space_elevator_020327-1.html

19. The Space Elevator• The Solution: Carbon Nanotubes – 10x the tensile strengh (30GPa) • 1 atm =

101.325kPA • 10-30% fracture strain• Further Obstacles – Production of Nanofibers • Record length

4cm – Investment Capital: $10 billion

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Applications of carbon nanotubes

by Nitin Patel on May 30, 2013

Applications of carbon nanotubes Presentation Transcript

1. APPLICATIONS OF CARBON NANOTUBESFOR DRUG DELIVERYSYSTEMSPRESENTED

BY :MURTAZA PUTLIWALAM.PHARM, SGSITS

2. INTRODUCTION Carbon nanotubes are cylindrical carbon molecules haveNovel properties.

They can be about 1/50,000th the thickness of a humanhair. Their unique surface area, stiffness,

strength andresilience have led to much excitement in the field ofpharmacy. High Thermal

conductivity. Excellent electron emission characterstics. Good candidates for a wide variety of

applications,including drug transporters, new therapeutics, deliverysystems and diagnostics.

3. STRUCTURE OF CARBON NANOTUBES Carbon nanotube (CNT ; also known as buckytubes) is

anallotrope of Carbon that is Graphite , in which Carbon atomhave sp2 hybridized state. Nanotubes are

cylindrical fullerenes. CNT, which have been constructed with length-to-diameterratio of up to

132,000,000:1. Diameters of the carbon nanotubes have ranging from 2 nm to55 nm. The lengths of

CNT are typically several microns. Configurationally it is twodimensional graphene (a singlesheet of

graphite ) sheet rolledup with continuous unbrokenhexagonal mesh into acylindrical tube.

4. GEOMETRY OF CARBON NANOTUBESARMCHAIR ARRANGEMENT ZIGZIG

ARRANGEMENTCHIRAL ARRANGEMENT

5. TYPES OF CARBON NANOTUBES1. SINGLE WALLED NANOTUBES : The diameter of

single-wallednanotubes (SWNTs) has approximatelyto 1 nanometer. SWNT are wrapping with layer

ofgraphite which one-atom-thick layercalled graphene into a seamlesscylinder. It requires catalyst for

their synthesis. Less accumulation in the body.

6. CONTD…2. MULTIPLE WALLED NANOTUBES : Multi-walled nano tubes (MWNT)consist of

multiple rolled layers(concentric tubes) of graphite. It has very complex structure It can be produced

without catalyst. Purity of product is high. More chances for accumulation in thebody.

7. Synthesis of Carbon NanotubeVarious Techniques have been developed to producenanotubes in

sizeable quantities, which includs :1. Arc discharge2. Laser ablation3. Chemical vapor deposition

(CVD).

8. Arc Discharge Method• It is the first macroscopicproduction of carbonnanotubes.• Its cost very high

and givesyield up to 30 – 90 %• During this process, the carboncontained in the negativeelectrode

sublimates becauseof the high dischargetemperatures.• At 100 amps, carbon vaporizesand forms hot

plasma.

9. Chemical Vapor Deposition (CVD) The catalytic vapor phase deposition of carbonwas first reported

in 1959 . Most economical method due to cheapest sourceof material i.e Fossil hydrocarbon and gives

yieldupto 20-100%•During CVD, a substrate is prepared with a layer ofmetal catalyst particles, most

commonly nickel,cobalt, iron, or a combination.•The diameters of the nanotubes that are to begrown are

related to the size of the metal particles.•Nanotubes grow at the sites of the metal catalyst;the carbon-

containing gas is broken apart at thesurface of the catalyst particle, and the carbon istransported to the

edges of the particle, where itforms the nanotubes.

10. Laser Ablation Method• In the laser ablation process, a pulsed laser vaporizes a graphite targetin a

high-temperature reactor .• A water-cooled surface may be included in the system to collect

thenanotubes.• The laser ablation method yieldsaround 70% and producesprimarily single-walled

carbonnanotubes with a controllablediameter determined by thereaction temperature.• it is more

expensive than eitherarc discharge or chemical vapordeposition.

11. FUNCTIONALIZATION OF CARBON NANOTUBES FORBIOLOGICAL APPLICATIONS:•

Raw carbon nanotubes have highly hydrophobicsurfaces, and are not soluble in aqueous solutions.• For

biomedical applications, surface chemistry orfunctionalization is required to solubilize CNTsimprove

biocompatibility and low toxicity.• Two type of Surface fuctionalization of carbonnanotubes

:CovalentNoncovalent• Surface fuctionalization of carbon nanotubes

12. Covalent fuctionalization• By attaching hydrophilic polymers such as poly ethylene glycol(PEG) to

oxidized CNTs, yielding CNT-polymer conjugatesstable in biological environments.• Covalently

PEGylated SWNTs synthesized by this strategy forboth In vitro and in vivo applications.Non Covalent

fuctionalization• NCF of CNTs can be carried out by coating CNTs with amphiphilicsurfactant

molecules or polymers.• NCF of SWNTs by PEGylated phospholipids (PL-PEG) high watersolubility of

nanotubes and versatile functionalities Phospholipidsare the major component of cell membranes, and

are safe to use inbiological systems.

13. APPLICATIONS OF CNTsA) Carbon Nanotube Membranes for TransdermalDrug DeliveryB)

CNT’S for cancer treatmentC) CNTs for Cardiac Autonomic RegulationD) CNTs for platelet

activationE) CNT for tissue regenerationF) Carbon Nanotubes in Drug Delivery: Future Trends

14. Carbon Nanotube Membranes forTransdermal Drug Delivery• Transdermal systems are attractive

methods of drug administrationspecifically when treating patients for drug addiction such as nicotine

forsmoking cessation.• Through the use of functionalized carbon nanotube (CNT) membranes,drug

delivery to the skin can be controlled by applying a small electricalbias to create a programmable drug

delivery system.• a transdermal patch system that can be tailored to an individual’s needswill increase

patient compliance as well as provide much more effi cienttherapy.

15. CNT’S for cancer treatment• CNT’s can be considered as antitumor agents and when incombination

with conventional drugs, can significantly enhance theirchemotherapeutic effect with the help of the

advanced drug deliverysystem.• It has been reported that Paclitaxel loaded PEG-CNT’s are promisingfor

cancer therapeutics.• There are three key features of this nanoscale drug delivery system(DDS):1. Use of

functionalized SWCNTs as a biocompatible platform forthe delivery of therapeutic drugs or

diagnostics.2. Conjugation of prodrug modules of an anticancer agent that isactivated to its cytotoxic

form inside the tumor cells uponinternalization and in situ drug release.3. Attachment of tumor-

recognition modules to the nanotubesurface (binding EGFR antibody)

16. Mechanism by which CNTs enter cells• Incorporation of the drug Either by :– Loading into hollow

CNT– Attaching at their outer surface Attachment of the anticancer drug to the outer surface of the

CNT canbe through either covalent or noncovalent bonding. CNT with a diameter of 80 nm can be

loaded up to 5 million drugmolecules.These are : Passive diffusion of CNTs through the lipid bilayers

of the cell membrane Attachment of CNTs to the external cell membrane, resulting in its absorption by

thecell using an energy-dependent process, such as Pinocytosis. Endocytosis : Engulfing of CNTs

directly by cell.

17. Summary of Anticancer drug delivery via carbon nanotubesCNTType ofcancer/disease In vivo/in

vitro Drug Method of loadingSWCNTs Ovarian cancer NA Gemcitabine Use of external forces to

particles in aselected directionSWCNTs Leukemia In vitro Daunorubicin Daunorubicin incubated in

phosphate-buffered saline at 37°C for 16 hours withSWCNTsSWCNTs Breast cancer In vitro and

inmicePaclitaxel Paclitaxel was modified by succinicanhydride, adding a carboxyl group atthe C-2-OH

position SWCNTs withbranched PEG-NH2MWCNTs Human gastriccarcinomaIn vitro and

inmiceHCPT(10-hydroxycamptothecin)HCPT is linked to MWCNTs usingdiaminotriethylene glycol

(hydrophilicspacer) biocleavable ester linkageSWCNTs Chorio-

,nasopharyngealepidermoidtesticularcarcinomaIn vitro Platinum (IV) The SWCNT-PL-PEG-NH2 was

initiallyformed. The SWCNT coated with PEGwas then reacted with the platinum inthe presence of

coupling agentsincluding EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimidehydrochloride)and

NHS

18. Summary of Anticancer drug delivery via carbon nanotubesCNTType ofcancer/disease In vivo/in

vitro Drug Method of loadingSWCNTs52 CervicalcancerIn vitro siRNA SWCNTs reacted with PL-

PEG. For theincorporation of disulfide bond, the amide groupof PEG was attached to a

heterobifunctionalcrosslinker (sulfo-LC-SPDP). The siRNA was thenattached to SWCNTs via a

disulfide bondSWCNTs43 Lymphoma In mice Doxorubicin SWCNTs were sonicated in a solution of

PL-PEGfollowed by centrifugation. Excess surfactant wasremoved by filtration and washing.

Doxorubicinloading onto pegylated SWCNTs was carried out bymixing.MWCNs51 Breast cancer In

vitro Methotrexate Amine-MWCNTs was generated through 1,3-dipolar cycloaddition reaction of

zomethineylides.Methotrexate was reacted with f-MWCNTsthrough coupling agents, ie, HATU and

DIEA

19. CNTs for Cardiac AutonomicRegulation• There are single-walled carbon nanotubes used in

thecardiac autonomic regulation.• Single-walled carbon nanotubes are portion ofphysicochemical

properties with fine component whichmay damage cardiovascular autonomic control thatproved after

the study in rats.• SWCNTs may alter the baroreflex function, then affectingthe autonomic

cardiovascular control regulation

20. CNTs for platelet activation• SWCNTs using alongwith platelet P-selectin when injected

intoanaesthetized mice, light dye induced thrombus formationwas found and the platelet found to be

activated.• Activate blood platelets by inducing extracellular Ca2+ influxthat could be inhibited by

calcium channel blockers.

21. CNT for tissue regeneration• CNTs are combined with polymers such as poly-l-lactide,Polylactide

and poly-D,Llactide- coglycolide copolymer whichhave been used as a scaffolds in tissue regeneration.•

It can be prepared by mixing solubilized collagen with solutionhaving carboxylated SWCNTs.• Living

smooth muscle cell were integrated at the collagenstage to produce cell-seeded collagen carbon

nanotubes.

22. Carbon Nanotubes in Drug Delivery:Recent Trends• f-CNTs have been demonstrated to deliver

proteins, nucleic acids, drugs,antibodies and other therapeutics.• Ammonium functionalized CNTs can

also be considered very promising vectors forgene-encoding nucleic acids.• CNT’s in Gene Therapy :

Gene therapy involves transport of the correct gene byviral or nonviral vectors to the affected area•

CNTs seem to represent a very good nonviral vector for gene therapy, because theycan cross the cell

membrane by an endocytosis process, and also, because of thefunctionalization of CNTs, the DNA can

be transferred without any degradation.• The siRNA delivered via MWCNTs achieved significant

inhibition of tumor growth.

23. Commercially available Carbon Nanotubes• Specification details for carbon nanotubes (SWCT &

MWCT)available from Aldrich Materials Science, Sigma-Aldrich Co. LLC.Aldrich Product No. TEM

Image Description755710 Single-walled isolated and bundled carbonNanotubes powder2 nm x several

µm (length, measured byTEM / SEM) Carbon purity : > 70 % (by TGA)Metal oxide impurity: < 30 %

(by TGA) Highspecific surface area (> 1000 m2/g )755133Thin multi-walled (avg. 7~9 walls)

carbonnanotubes powder 9.5 nm (diameter, byTEM) x 1.5 µm (length, by TEM)Carbon purity : > 95 %

(by TGA)Metal oxide impurity: < 5 % (by TGA)High level of purity.

24. Aldrich Product No. TEM Image Description755168 Double-walled isolated andbundled carbon

nanotubes powder3.5 nm (diameter, by HRTEM) x 1 -10 µm (length, by TEM / SEM)Carbon purity : >

90 % (by TGA)Metal oxide impurity: < 10 % (byTGA) Specific surfacearea: >500 m2/g (by BET)High

filed emission characteristicsTransparency755141 Short double-walled isolated andbundled carbon

nanotubes powder3.5 nm (diameter, by HRTEM) x 3µm (length, by TEM / SEM)Carbon purity : > 90 %

(by TGA)Metal oxide impurity: < 10 % (byTGA) Surface chemistrycharacteristics.755125 Short thin

multi-walled (avg. 7~9walls) carbon nanotubes powder9.5 nm (diameter, by TEM) x < 1 µm(length, by

TEM) Carbon purity : >95 % (by TGA) Metal oxideimpurity: < 5 % (by TGA) Surfacechemistry

characteristics Ease ofdispersability

25. Why only Carbon Nanotubes out oftremendous Nanocarriers?• CNTs act as promising drug carrier

due to their unique chemical, physical,and biological properties, nanoneedle shape, hollow monolithic

structure,and their ability to obtain the desired functional groups on their outerlayers.• In case of gene

therapy liposomes and microparticles, seem not to be asafer option because of their poor

pharmacokinetic profile of theadministered oligonucleotide and conjugated plasmid DNA.• They can be

functionalized to be more water-soluble and serum-stable,with low toxicity at the cellular level.•

Detection CNTs does not require any type of fluorescent labelling, such asquantum dots. It can be

detected directly by TEM or AFM due to theirelectron emission spectroscopy.• Destruction of cancer

cells for thermal ablation.• Another application of CNTs for drug delivery is intravenous injection.

26. Thank You