Apr 4 2013
Updated on 15th December by Stephen Edgar
Orange Deer Studio / Shutterstock
Nanoparticles are being used more and more often in research and in industry, due to their enhanced properties compared to bulk materials. Nanoparticles are fabricated from ultrafine particles less than 100 nm in diameter. This is a somewhat arbitrary value but was chosen because in this size range the first signs of “surface effects” and other unusual properties found in nanoparticles appear. The effects are directly related to their small size, as when materials are produced from nanoparticles, a substantial number of atoms are exposed on the surface. It has been shown that the performance and behavior of materials are altered significantly when constructed from a nanoscale. Improved hardness and strength, electrical and thermal conductivity some examples of enhancements that occur when composited from nanoparticles
This article discusses the properties and applications of aluminum oxide nanoparticles. Aluminum is a Block P, Period 3 element, while oxygen is a Block P, Period 2 element.
The morphology of aluminum oxide nanoparticles is spherical, and they appear as a white powder. Aluminum oxide nanoparticles (both liquid and solid forms) are graded as highly flammable and an irritant that can cause serious eye and respiratory irritation
Chemical Properties
The chemical properties of aluminum oxide nanoparticles are outlined in the following table.
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Chemical Data
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Chemical symbol
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Al2O3
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CAS No.
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1344-28-1
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Group
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Aluminum 13
Oxygen 16
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Electronic configuration
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Aluminum [Ne] 3s23p1
Oxygen [He] 2s2 2p4
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Chemical Composition
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Element
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Content (%)
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Aluminum
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52.92
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Oxygen
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47.04
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Physical Properties
The physical properties of aluminum oxide nanoparticles are given in the following table.
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Properties
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Metric
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Imperial
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Density
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3.9 g/cm3
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0.140 lb/in3
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Molar mass
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101.96 g/mol
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Thermal Properties
The thermal properties of aluminum oxide nanoparticles are provided in the table below.
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Properties
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Metric
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Imperial
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Melting point
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2040°C
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3704°F
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Boiling point
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2977°C
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5391°F
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Manufacturing Process
Aluminum oxide nanoparticles can be synthesized by many techniques including ball milling, sol-gel, pyrolysis, sputtering, hydrothermal, and laser ablation. The laser ablation is a commonly used technique to produce nanoparticles, since it can be synthesized in gas, vacuum or liquid. The technique offers several advantages such as rapid and high purity process compared with other methods. Additionally, nanoparticles prepared by the laser ablation of materials in liquid are collected easier, than those in a gas atmosphere. Recently chemists at the Max-Planck-Institut für Kohlenforschung in Mülheim an der Ruhr found a way to produce corundum (also known as alpha-alumina), a very stable variant of alumina, in the form of nanoparticles using the simple mechanical method in a ball mill.
Applications
The key applications of aluminum oxide nanoparticles are listed below:
• In integrated circuit baseboards
• Transparent ceramics, high-pressure sodium lamps, and EP-ROM window
• In YAG laser crystals
• As cosmetic fillers
• Single crystal, ruby, sapphire, sapphire, and yttrium aluminum garnets
• High-strength aluminum oxide ceramic and C substrates
• Packaging materials, cutting tools, high purity crucible, winding axle, and furnace tubes
• Polishing materials, glass products, metal products, semiconductor materials
• Plastic, tape, and grinding belts
• Paint, rubber, plastic wear-resistant reinforcement, and advanced waterproof materials
• Catalyst, catalyst carrier, analytical reagents
• Aerospace aircraft wing leading edges
• Vapor deposition materials, special glass, fluorescent materials, composite materials and resins
In cases where aluminum oxide nanoparticles are used in the liquid form such as an aqueous dispersion, the key applications are as follows:
• Plastics, rubber, ceramics, refractory products
• To improve ceramics density, smoothness, fracture toughness, creep resistance, thermal fatigue resistance, and polymer products wear resistance
• Ideal material of far-infrared emission
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