1. Carbon Nanotubes

2. Carbon Nanotubes were discovered by Mr. Sumio Ijima in the year 1991

3. Introduction As there name suggests, these are cylindrical in shape and their diameter is around 1 nm which is approximately 50,000 smaller compared to the diameter of a human hair. As there name suggests, these are cylindrical in shape and their diameter is around 1 nm which is approximately 50,000 smaller compared to the diameter of a human hair. These belong to the structural family of fullerenes. These belong to the structural family of fullerenes. These are made up of a single layered sheet of graphite known as graphene. Hence, they are allotropes of carbon. These are made up of a single layered sheet of graphite known as graphene. Hence, they are allotropes of carbon.

4. Types Of Carbon Nanotubes Single Walled Nanotubes ~ SWNT Single Walled Nanotubes ~ SWNT Multi Walled Nanotubes ~ MWNT Multi Walled Nanotubes ~ MWNT

5. SWNT These are made of a single sheet of graphene. These are made of a single sheet of graphene. They can be classified into three types depending on the orientation of the C – hexagons in the tube……Zig Zag Nanotubes, Armchair Nanotubes & Chiral Nanotubes. They can be classified into three types depending on the orientation of the C – hexagons in the tube……Zig Zag Nanotubes, Armchair Nanotubes & Chiral Nanotubes.

6. Zig Zag Nanotubes In these type of nanotubes the hexagons are so arranged that their apex is parallel to the axis of the tube. In these type of nanotubes the hexagons are so arranged that their apex is parallel to the axis of the tube. These are optically inactive. These are optically inactive.

7. Arm Chair Nanotubes In these type of nanotubes the hexagons are so arranged that their apex is perpendicular to the axis of the tube. In these type of nanotubes the hexagons are so arranged that their apex is perpendicular to the axis of the tube. These are optically inactive. These are optically inactive.

8. Chiral Nanotubes Arranging the hexagons in any other way other than that in the zig zag or arm chair models gives structures to nanotubes which are chiral i.e. they have mirror images and can’t be superimposed. Arranging the hexagons in any other way other than that in the zig zag or arm chair models gives structures to nanotubes which are chiral i.e. they have mirror images and can’t be superimposed. These are optically active. These are optically active.

9. SWNT ~ Compilation

10. MWNT These are prepared from either a single or many graphene sheets. These are prepared from either a single or many graphene sheets. There structures can be postulated by the two models ~ Russian Doll Model & The Parchment Model. There structures can be postulated by the two models ~ Russian Doll Model & The Parchment Model.

11. Russian Doll Model In this model graphene sheets are arranged in concentric cylinders. In this model graphene sheets are arranged in concentric cylinders.

12. The Parchment Model In this model a single graphene sheet is rolled over itself. It looks like a scroll. In this model a single graphene sheet is rolled over itself. It looks like a scroll.

13. Properties Of Carbon Nanotubes They possess the highest strength to weight ratio amongst all known materials. They possess the highest strength to weight ratio amongst all known materials. They are harder than steel but smaller than a single human hair. They are harder than steel but smaller than a single human hair. They are conductors of heat and electricity. They can be used to trap heat. They are conductors of heat and electricity. They can be used to trap heat. Their electrical conductivity can be manipulated to a higher scale of variance depending upon molecules that combine with the carbon atoms. Their electrical conductivity can be manipulated to a higher scale of variance depending upon molecules that combine with the carbon atoms.

14. Applications Of Carbon Nanotubes energy-storing electronic textiles energy-storing electronic textiles artificial muscles artificial muscles catalyst supports catalyst supports nearly impenetrable bullet-proof vests and body armor nearly impenetrable bullet-proof vests and body armor hydrogen, ammonia, humidity, and pollution sensors hydrogen, ammonia, humidity, and pollution sensors DNA biosensors, immunosensors, and health monitoring sensors DNA biosensors, immunosensors, and health monitoring sensors biological sensors, for applications such as: monitoring hydrogen levels in premature babies quality control in food production plants pollution monitoring in truck and auto engines biological sensors, for applications such as: monitoring hydrogen levels in premature babies quality control in food production plants pollution monitoring in truck and auto engines biomedical sensors (small enough to pass through cells, and not trigger immune response) biomedical sensors (small enough to pass through cells, and not trigger immune response)

15. Applications Of Carbon Nanotubes biological and chemical warfare agent sensors biological and chemical warfare agent sensors semiconductor devices semiconductor devices field-effect transistors (FET) field-effect transistors (FET) field emission displays (FED) for large-area TV's field emission displays (FED) for large-area TV's advanced generation high resolution flat panel displays advanced generation high resolution flat panel displays light emission devices light emission devices silicon etching silicon etching molecular electronics molecular electronics heat-conducting applications heat-conducting applications supercapacitors supercapacitors advanced reinforced composites advanced reinforced composites conductive adhesives, coatings, caulks, paints, and sealants conductive adhesives, coatings, caulks, paints, and sealants

16. Applications Of Carbon Nanotubes advanced atomic force microscopes advanced atomic force microscopes nano-motors and mechanisms nano-motors and mechanisms nanoscale tools, such as tweezers nanoscale tools, such as tweezers sports equipment (tennis racquets, yacht masts, fishing rods, etc.) sports equipment (tennis racquets, yacht masts, fishing rods, etc.) earthquake-resistant buildings or towers earthquake-resistant buildings or towers frictionless, low-wear bearings and other nanoscale components frictionless, low-wear bearings and other nanoscale components solid lubricant or as additives solid lubricant or as additives as heat sinks as heat sinks to develop lightweight spacecraft parts to develop lightweight spacecraft parts

17. Nanowires NW

18. Introduction A nanowire is a wire of dimensions of the order of a nanometer. A nanowire is a wire of dimensions of the order of a nanometer. At these scales, quantum mechanical effects are important — hence such wires are also known as "quantum wires". At these scales, quantum mechanical effects are important — hence such wires are also known as "quantum wires".

19. Types Of Nanowires Metallic ~ Ni, Pt,Au Metallic ~ Ni, Pt,Au Semi Conducting ~ InP, Si, GaN Semi Conducting ~ InP, Si, GaN Insulating ~ SiO2, TiO2 Insulating ~ SiO2, TiO2

20. Properties And Applications Of Nanowires Semi Conducting Nanowires can be used to make transistors which can be used as switches or as amplifiers. Semi Conducting Nanowires can be used to make transistors which can be used as switches or as amplifiers. NW are ballistic conductors as the electrons can flow continuously inside them which eliminates the evolution of heat and wastage of energy. NW are ballistic conductors as the electrons can flow continuously inside them which eliminates the evolution of heat and wastage of energy. They can be used as magnetic information storage mediums. They can be used as magnetic information storage mediums.

21. Properties And Applications Of Nanowires They are used in energy conversion devices. They are used in energy conversion devices. They can be used to construct logic gates. They can be used to construct logic gates. Nanowire arrays are used in Field Emission Devices. Nanowire arrays are used in Field Emission Devices. Their optical properties are intriguing which result in various applications. Their optical properties are intriguing which result in various applications. Alike carbon nanotubes their electrical resistance can be manipulated. Alike carbon nanotubes their electrical resistance can be manipulated.