CONTROLLING THE DENSIFICATION BEHAVIOR OF NANO MICROSTRUCTURES TO MEET DIFFERENT APPLICATIONS By : Saied Darwish & M. A. E. Saleh King Saud University

CONTROLLING THE DENSIFICATION BEHAVIOR OF NANO CONTROLLING THE DENSIFICATION BEHAVIOR OF NANO MICROSTRUCTURES TO MEET DIFFERENT APPLICATIONSMICROSTRUCTURES TO MEET DIFFERENT APPLICATIONS

By :By :

Saied Darwish & M. A. E. SalehSaied Darwish & M. A. E. Saleh

King Saud UniversityKing Saud UniversityCollege of Engineering - Industrial Engineering DepartmentCollege of Engineering - Industrial Engineering Department

Riyadh – Saudi ArabiaRiyadh – Saudi Arabia

11-12/2/2008 Knowledge based industries & Nanotechnolgy conference

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. . Morphologies of nano-particlesMorphologies of nano-particles..

Remarkable properties of Nanoparticles.Remarkable properties of Nanoparticles.

Nanoparticles functionalisation.

Nanoparticles applications.

Sintering Nanoparticles.Nanoparticles production methodsNanoparticles production methods

Agenda :


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Definition of NanoparticlesDefinition of Nanoparticles

• Despite the fact that a unique definition does not exist for Despite the fact that a unique definition does not exist for Nanoparticles, they are usually referred to as particles with a size up Nanoparticles, they are usually referred to as particles with a size up to 100 nm.to 100 nm.

• Nanoparticles exhibit completely new or improved properties based Nanoparticles exhibit completely new or improved properties based on specific characteristics (size, distribution, morphology, phase, on specific characteristics (size, distribution, morphology, phase, etc.)etc.)

,, • Nanoparticles can be made of a wide range of materials, the most Nanoparticles can be made of a wide range of materials, the most

common being metal oxides, ceramics, metals, silicates and non-common being metal oxides, ceramics, metals, silicates and non-oxide ceramics , polymer materials or compound semiconductorsoxide ceramics , polymer materials or compound semiconductors


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Nano Particle

Size

Shape

Nanopowders are:Assemblage of Nanoparticles with various CHARACTERISTICS

Strength

Nano Powder

Size distribution

Shapedistribution

tap densityFrictionCohesionAnisotropy

Strengthdistribution


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Morphologies of nano-Morphologies of nano-particles:particles:

Nanoparticles present several different morphologies (flakes, spheres, dendritic shapes, etc.). While metal and metal oxide Nanoparticles in use are typically spherical, silicate Nanoparticles have flaky shapes with two of their dimensions in the range of 100-1000 nm.

They are generally designed and manufactured with physical properties tailored to meet the needs of the specific application they are going to beused for.


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Remarkable properties of NanoparticlesRemarkable properties of Nanoparticles

Nanoparticles exhibit completely new or improved properties based on specificcharacteristics (size, distribution, morphology, phase, etc.), if compared with larger

particles of the bulk material they are made of.


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Nanoparticles functionalisation

After Nanoparticles are produced and purified to a satisfactory level it can benecessary to functionalize them. This is an intermediate process that prepares themto be used for certain applications.

Nanoparticles can be functionalized in many different ways. Most commonly used functionalisation methods include :

•coating .•chemical modification of Nanoparticles.

Functionalisation is an extra step that will add cost to the total production chain butcan have such marked effects that in some cases it is necessary to use.


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Power/EnergyPower/Energy

• Dye-sensitized solar cells (e.g. using TiO2)• Hydrogen storage (e.g. using metal hydrides)• Improved anode and cathode materials for solid oxide fuel cells• Thermal control fluids (e.g. using Cu)• Environmental catalysts (e.g. ceria as diesel additive to improve combustion efficiency)• Automotive catalytic converters

Nanoparticles applicationsNanoparticles applications


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Healthcare / medicalHealthcare / medical

•Targeted drug delivery.•Alternative drug and vaccine delivery mechanisms (e.g. inhalation, oral in place of injection).•Bone growth promoters.•Cancer treatments.•Biocompatible coatings for implants.


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EngineeringEngineering

•Cutting tool bits (e.g. WC, TaC, TiC, Co).•Spark plugs (e.g. using nanoscale metal and ceramic powders).•Chemical sensors.•Molecular sieves.•Wear-resistant / abrasion-resistant coatings .•Nanoclay-reinforced polymer composites.


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Environmental

•Water treatment (photo-catalyst treatments, e.g. using TiO2)•Self-cleaning glass (e.g. using TiO2 based nanostructure coatings)•Anti-reflection

ElectronicsElectronicsNanoscale magnetic particles for high-density data storageEMI shielding using conducting and magnetic materialsElectronic circuits (e.g. using Cu, Al)Display technologies including field-emission devices (e.g. using conducting oxides)Ferro-fluids (e.g. using magnetic materials)Optoelectronics devices such as switches (e.g. using rare-earth-doped ceramics)Conductive coatings and fabrics (e.g. using rare-earth-doped ceramics)


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Nanoparticles production Nanoparticles production methodsmethods


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Bulk consolidation of nano Bulk consolidation of nano particlesparticles

• Closed die compaction

• Orthoptropic compaction

• Cold isostatic compaction

• Hot isostatic compaction


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COMPACTION: Closed die

Rearrangement Sliding Rotation Deformation Fracture

Densification Mechanisms:


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Biaxial compaction device

Fixed


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Orthotropic compaction device

Fixed

Fixed


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Isocratic pressingIsocratic pressing

Isostatic pressing: (a) ‘dry bag’ and (b) ‘wet bag’ method [After Bortzmeyer, 1995]


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Laser Ablation of Laser Ablation of Micro particlesMicro particles

In the LAM process, a high-energy laser pulse hits a micro particle (typically 2-20 mue dia.), initiating breakdown and shock- wave formation. As the shock passes through the micro particle, it converts a high percentage of the mass to Nanoparticles (<100 nm dia).


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Sintering Nanoparticles


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Conventional sintering usually requires holding the Conventional sintering usually requires holding the compacted ceramic bodies at the sintering compacted ceramic bodies at the sintering temperature for a period of time as long as a few temperature for a period of time as long as a few hours.hours.

The long time processing at high temperature could The long time processing at high temperature could result in substantial coarsening and grain growth.result in substantial coarsening and grain growth.

The microwave sintering technique could be a The microwave sintering technique could be a unique approach to achieving densification of nano-unique approach to achieving densification of nano-phase materials.phase materials.

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Microwave sinteringMicrowave sintering


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Conclusions

The present paper aims to accelerate the participation of the Arab world in manufacturing nano microstructures through directing densification process of commercial nano-particles to control characterization and application of nano microstructures, in order to suit different applications.

ReferencesReferences

1. ROADMAPS AT 2015 ON NANOTECHNOLOGY APPLICATION IN THE SECTORS OF:MATERIALS, HEALTH & MEDICAL SYSTEMS, ENERG,2005

2. A Industrial Materials of the Future Programby the Office of Industrial Technology of the US Department of Energy, 2005

3. S. Shima , M. A. E. Saleh and N. Hirata, “ Evolution of Structural anisotropy in Powders During Compaction.” Advanced Tech. Of Plasticity, Proceedings of the 3rd. Int. Conf. On Tech. Of Plasticity, Kyoto, July 1/6, Vol II (1990)., pp. 883-888.

4. S. Shima and M. A. E. Saleh, “ Development of Constitutive Equations for Granular Materials with induced anisotropy during compaction process”, Advances in micromechanics of granular materials, Proc. Of 2nd Us/Japan Seminar On Micromechanics Of granular materials.” Potsdam, NY, USA, Aug. 5-9, 1991. (1992) pp. 163-172.

5. S. Shima and M. A. E. Saleh, “ Compaction Induced Anisotropy in Internal Structure of Ceramic Powder.” J. of American Ceramic Soc. , Vol 76, No. 5, (1993) pp. 1303-1307.

6. S. Shima and M. A. E. Saleh, “ Development of Constitutive Equations for Ceramic Powders Describing Compaction-Induced anisotropy.”, Mech. Of Materials 16 (1993) pp. 73-81.

7. S. Shima and M. A. E. Saleh, “Effect of Particle Characteristics on Compaction Behavior of Powders-Experiment.”, Proc. Of 1993 powder Metall. World congress, Japan Soc. Of Powders and Powder Metallurgy.

8. M. A. E. Saleh,” Deformation Behavior Of Metal Powders At Advanced Compaction Stage.”Journal of Engineering Sciences, Assiut University , Vol., 32 , No., 2, July 2004.

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CONTROLLING THE DENSIFICATION BEHAVIOR OF NANO MICROSTRUCTURES TO MEET DIFFERENT APPLICATIONS By : Saied Darwish & M. A. E. Saleh King Saud University