Nanotechnology is the science, engineering, and application of materials and devices at the nanoscale โ typically 1 to 100 nanometers (nm) in size. Core Concept At the nanoscale, materials exhibit…
Nanotechnology is the science, engineering, and application of materials and devices at the nanoscale โ typically 1 to 100 nanometers (nm) in size.
1 nanometer (nm) = 1 billionth of a meter (10โปโน m).
For comparison:
A human hair โ 80,000โ100,000 nm wide.
A DNA molecule โ 2 nm wide.
Core Concept
At the nanoscale, materials exhibit unique physical, chemical, optical, and biological properties not seen at the macroscopic scale. Nanotechnology exploits these properties to design new materials and systems.
The Nanoscale: Why Itโs Special
Unique Properties
Property
Nanoscale Behavior
Surface Area-to-Volume Ratio
Increases dramatically โ more reactive surfaces.
Quantum Effects
Electrons behave differently, altering color, conductivity, and magnetism.
Mechanical Strength
Nanostructured materials can be stronger and lighter.
Optical Properties
Gold nanoparticles appear red or purple instead of gold color.
Chemical Reactivity
Enhanced catalytic activity due to more active sites.
Branches of Nanotechnology
Type
Focus
Examples
Nanomaterials
Design and synthesis of nanoscale materials
Nanotubes, quantum dots, nanoparticles
Nanoelectronics
Electronics at nanoscale
Transistors, memory devices, quantum computers
Nanobiotechnology
Combination of nano + bio
Drug delivery, biosensors
Nanomedicine
Medical applications
Targeted therapy, diagnostics
Nanophotonics
Lightโmatter interactions at nanoscale
Optical chips, photonic crystals
Green Nanotechnology
Environmentally friendly nanotech
Water purification, solar cells
Types of Nanomaterials
1. Carbon-Based Nanomaterials
Fullerenes (Cโโ) โ Hollow carbon spheres.
Carbon Nanotubes (CNTs) โ Cylindrical tubes with exceptional strength and conductivity.
Graphene โ Single-atom-thick sheet of carbon; highly conductive and flexible.
2. Metal-Based Nanoparticles
Gold (Au), Silver (Ag), Iron (Fe), Titanium dioxide (TiOโ), etc.
Used in catalysis, medicine, and imaging.
3. Quantum Dots
Semiconductor nanocrystals that emit light of specific colors depending on size (used in displays and imaging).
4. Polymeric Nanomaterials
Nanoscale polymers for drug delivery or coatings.
5. Lipid-Based Nanoparticles
Used for mRNA vaccine delivery (e.g., Pfizer/BioNTech COVID-19 vaccine).
Methods of Nanomaterial Synthesis
A. Top-Down Approach
Breaking down bulk materials into nanosized structures.
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