Nanomaterials
Definition
Nanomaterials are materials that have at least one dimension in the nanometer range (1–100 nanometers).
At this ultra-small scale, materials show unique physical, chemical, electrical, optical, and mechanical properties that are very different from their bulk (normal-sized) form.
Example: Gold in bulk looks yellow, but gold nanoparticles look red or purple because of size-dependent properties.
Types of Nanomaterials
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Based on Dimensions
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0D (Zero-Dimensional): Nanoparticles, quantum dots.
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1D (One-Dimensional): Nanowires, nanotubes.
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2D (Two-Dimensional): Graphene, nanofilms, nanosheets.
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3D (Three-Dimensional): Nanostructured bulk materials, nanocomposites.
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Based on Origin
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Natural Nanomaterials: Found in nature (volcanic ash, sea spray, viruses, DNA).
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Synthetic Nanomaterials: Man-made in labs (carbon nanotubes, graphene, quantum dots, nano-silver).
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Unique Properties of Nanomaterials
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Large Surface Area: More reactive than bulk material.
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Optical Properties: Change color at nanoscale (used in sensors, imaging).
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Mechanical Strength: Stronger and lighter (CNTs stronger than steel).
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Electrical Conductivity: Can act as conductors or semiconductors.
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Magnetic Properties: Nanoparticles can be superparamagnetic.
Applications of Nanomaterials
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Medicine:
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Drug delivery, imaging, cancer therapy, biosensors.
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Electronics:
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Nano-transistors, flexible displays, memory chips.
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Energy:
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Solar cells, fuel cells, supercapacitors, batteries.
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Environment:
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Water purification (nano-filters), pollution control.
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Everyday Products:
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Sunscreens (nano-titanium dioxide, nano-zinc oxide).
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Stain-resistant fabrics, scratch-proof glasses.
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Simple Analogy
Think of a nanomaterial as a normal material shrunk down to the nano-world.
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At this scale, atoms arrange differently, giving new colors, strength, and behaviors that are impossible at larger scales.