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SYNTHESIS AND CHARACTERIZATION OF CNT-ALUMINA NANOCOMPOSITE BY RAJIV.S REG.NO-113012302031 M-TECH 1 ST YEAR REGULAR BA

SYNTHESIS AND CHARACTERIZATION OF CNT-ALUMINA NANOCOMPOSITE BY RAJIV.S REG.NO-113012302031 M-TECH 1 ST YEAR REGULAR BATCH-2013-15 PERIYAR MANIAMMAI UNIVERSITY. PLAN OF PRESENTATION ABSTRACT INTRODUCTION CARBON NANOTUBE(CNT) DEFECTS IN CNT TYPES OF ALUMINA PROPERTIES OF ALUMINA

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SYNTHESIS AND CHARACTERIZATION OF CNT-ALUMINA NANOCOMPOSITE BY RAJIV.S REG.NO-113012302031 M-TECH 1 ST YEAR REGULAR BA

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  1. SYNTHESIS AND CHARACTERIZATION OF CNT-ALUMINA NANOCOMPOSITE BY RAJIV.S REG.NO-113012302031 M-TECH 1ST YEAR REGULAR BATCH-2013-15 PERIYAR MANIAMMAI UNIVERSITY

  2. PLAN OF PRESENTATION ABSTRACT INTRODUCTION CARBON NANOTUBE(CNT) DEFECTS IN CNT TYPES OF ALUMINA PROPERTIES OF ALUMINA APPLICATION OF NANO ALUMINA EXPERIMENTAL METHOD CONCLUSION REFERENCES

  3. ABSTRACT Carbon nanotube (CNT) reinforced alumina matrix nanocomposite was successfully synthesized by two different processes and followed by sintering process. The first method was sol-gel process in which homogeneous distribution of CNTs within alumina matrix can be obtained by adding the CNTs in the alumina sol prepared by Yoldas’ method and followed by condensation into gel. The molecular level mixing process was adopted for synthesis of CNT-alumina nanocompositepowder.

  4. INTRODUCTION Many of our modern technologies require materials with unusual combinations of properties that can not be met by the conventional metal alloys, ceramics and polymeric materials. This is especially true for materials that are needed for aerospace, underwater and transportation applications. Material property combinations and ranges have been extended by the development of composite materials. A composite is considered to be any multiphase material that exibits a significant proportion of the properties of both constituent phases such that a better combination of properties is realized. Composites are produced when two materials are mixed to give a combination of properties that can not be attained in the original materials. According to this principle of combined action better property combinations are prepared by the combinations of two distinct materials. Composite materials may be selected to give unusual combinations of stiffness, strength, weight, high-temperature performance, corrosion resistance, hardness or conductivity.

  5. CARBON NANOTUBE Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material As individual molecules, nanotubes are 100 times stronger-than-steel and one-sixth its weight. Some carbon nanotubes can be extremely efficient conductors of electricity and heat; depending on their configuration, some act as semiconductors

  6. TYPES OF CNTs Single-walled CNT Multi-walled CNT Torus Nano bud Graphenatedcarbon nanotubes (g-CNTs) Nitrogen Doped Carbon Nanotubes Peapod Cup-stacked carbon nanotubes Extreme carbon nanotubes

  7. DEFECTS IN CNT As with any material, the existence of a crystallographic defect in CNTs affects its material properties. Defects can occur in the form of atomic vacancies. High levels of such defects can lower the tensile strength by up to 85%. Another form of carbon nanotube defect is the Stone Wales defect, which creates a pentagon and heptagon pair by rearrangement of the bonds. Because of the very small structure of CNTs, the tensile strength of the tube is dependent on its weakest segment in a similar manner to a chain, where the strength of the weakest link becomes the maximum strength of the chain. Crystallographic defects also affect the tube's electrical properties.

  8. ALUMINA (CORUNDUM) Corundum is the most common naturally-occurring crystalline form of aluminum oxide(alumina). Much less-common rubies and sapphires are gem-quality forms of corundum with their characteristic colours due to trace impurities in the corundum structure. Rubies are given their characteristic deep red color and their laser qualities by traces of the metallic element chromium. Sapphires come in different colors given by various other impurities, such as iron and titanium.

  9. TYPES OF ALUMINA Alpha (stable) Kappa (metastable) and Gamma (metastable).

  10. PROPERTIES OF ALUMINA Physical Properties Chemical Properties Alumina is an electrical insulator but has a relatively high thermal conductivity (40 W/mK). In its most commonly occurring crystalline form, called corundum or α-alumina, its hardness makes it suitable for use as an abrasive and as a component in cutting tools.

  11. Chemical Properties Molar mass:- 101.96gm Density:- 3.97g cm3, solid Melting point:- 2054 °C Boiling point:- 2980 °C Solubility:- insoluble in water Thermo chemistry : Standard enthalpy of formation ΔH298 :- -1675.7 kJ mol-1 Standard molar entropy:- 50.92 mol-1 K-1 Flash point:- non-flammable Phase:- solid,liquid,gas

  12. APPLICATION OF NANO ALUMINA 1.Biomedical Engineering 2. Abrasives 3. Coatings 4. Catalyst Support 5. Electronic Device 6. Structural Ceramics 7. Thermal Insulators 8. Sintering Aid for Ceramics

  13. EXPERIMENTAL METHOD SOL-GEL METHOD

  14. MOLECULAR LEVEL MIXING METHOD

  15. CONCLUSION Investigations had been carried out on the synthesis of the homogeneous CNT-Alumina nanocomposites by adding different percentage of CNTs into the pure alumina matrix. The homogeneous CNT-Alumina nanocomposite powder was successfully fabricated by Sol-gel process. Also the homogeneous CNT-Alumina nanocomposite with enhanced hardness was successfully synthesized by Molecular level mixing process and followed by Sintering. Various conclusions can be drawn from the different characterizations.

  16. REFERENCES 1. Bharat Bhushan(Ed.), Springer Handbook of Nanotechnology, Pages:1346-1347 2. G. D. Zhan & A. K. Mukherjee, Carbon nanotube reinforced alumina-based Ceramics with novel mechanical, electrical & thermal properties, Int. J. Appl. Ceram. Technol., 1[2] 161-71 (2004) 3. S. I. Cha, K. T. Kim,K. H. Lee, C. B. Mo, S. H. Hong, Strengthening and toughening of carbon nanotube reinforced alumina nanocomposite fabricated by molecular level mixing process, ScriptaMaterialia, Volume 53, Issue 7, October 2005, Pages:793-797 4. C. B. Mo, S. I. Chandran, K. T. Kim, K. H. Lee & S. H. Hong, Fabrication of carbon nanotube reinforced alumina matrix nanocomposite by Sol-gel process, Material Science & Engineering A, Volume 395, Issue 1-2, March 2005, Pages:124-128 5. Z. Xia, L. Riester, W. A. Curtin, H. Li, B. W. Sheldon, J. Liang, B. Chang, J. M. Xu, Direct observation of toughening mechanisms in carbon nanotube ceramix matrix composites, ActaMaterialia, Volume 52, Issue 4, February 2004, Pages:931-944

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