Introduction to Nanoscience

Nanoscience Definition

• Nanoscience is the study of material behavior at the nanoscale.
• The prefix "nano" comes from the Greek word "Nanos", meaning "dwarf", and represents one billionth of a meter (0.000000001 m = 1 nm).

Scale of Nanometers

• To put the size of nanometers into perspective, a human hair is approximately 75,000 nm.
• A 1 nm size nanomaterial can have around 50 atoms, while a 20 nm size nanomaterial can accommodate around 10,000 atoms.

Interdisciplinary Science

• Nanoscience is an emerging, interdisciplinary science that involves physics, biology, chemistry, materials science, engineering, computer science, and more.

History of Nanotechnology

• Richard Feynman was the first to propose the idea of novel properties of materials at the nanometer length scale in his 1959 talk "There's Plenty of Room at the Bottom".
• The term "nanotechnology" was coined in 1974 by Norio Taniguchi at the University of Tokyo.

Definition of Nanotechnology

• Nanotechnology is the creation of useful/functional materials, devices, and systems through control and manipulation of matter on the nanometer length scale (1-100 nm).
• It involves the exploitation of novel phenomena and properties that arise due to the nanometer length scale.

Properties of Nanomaterials

• Nanomaterials are materials with at least one dimension in the nanometric regime (1-100 nm) and at least one size-dependent property.
• Properties that can change at the nanoscale include physical, chemical, biological, magnetic, optical, electrical, and mechanical properties.

Examples of Nanomaterials

• Natural nanomaterials: DNA, viruses.
• Artificial nanomaterials: carbon nanotubes, fullerenes, inorganic nanowires, metal quantum dots.

Reasons for Property Changes

• The properties of materials in the nanoscale change mainly due to two reasons:
  • Quantum size effect.
  • Increase in surface to volume ratio.