Chemists have dealt with naturally occurring nanoparticles all along. Think molecules or viruses. Toxicologists have dealt with nanoparticles that are the result of modern human life such as carbon particles in combustion engine exhaust. Without being aware of it, tire manufacturers used nanoparticles - carbon black - to improve the performance of tires as early as the 1920s. Medieval artists used gold nanoparticles to achieve the bright red color in church windows (gold particles in nanometer size are red, not golden).
Nanotechnologies and quantum mechanics
Leading categories "Nanotechnology"
President MAQ Roberto Denti
Virtual sample set of relaxed gold nanoparticles of different sizes and shapes. The subscripts refer to the number of atoms. Note examples where the same number of atoms may form more than one closed-shell shape (icosahedral and cuboctahedral Au 55 , octahedral and decahedral Au 146 , icosahedral and cuboctahedral Au 147 ). Source:
Quantum mechanics transcends and supplants classical mechanics at the atomic and subatomic levels. It provides the underlying framework for many subfields of physics, chemistry and materials science, including condensed matter physics, atomic physics, molecular physics, quantum chemistry, particle physics, and nuclear physics. It is the only way we can understand the structure of materials, from the semiconductors in our computers to the metal in our automobiles. It is also the scaffolding supporting much of nanoscience and nanotechnology. (Quantum Mechanics with Applications to Nanotechnology and Information Science - 1st Edition - A uthors: Yehuda Band Yshai Avishai - Imprint: Academic Press - Published Date: 27th November 2012)
The nanoworld is a land of dwarves: we are fascinated by the smallest functional structures making up matter, whose size is on the order of a nanometer – a billionth of a meter. The laws of the nanoworld are different from those governing our everyday experience. Quantum effects are important in most materials and give rise to different properties than we are familiar with on a macroscopic scale. Nanophysics forms the basis of many phenomena in medicine, life sciences and chemistry, and represents an important interface to these sciences.
The Laser standing for ‘light amplified by stimulated emission of radiation’ is the most well known application of the quantum theory. The stimulated emission of light due to light’s behaviour as a wave, allows lasers to occur. This process is when a photon transits an electron in its excited state to a lower level producing a new photon of the same energy. This process duplicates as more photons are produced forming what is known as a population inversion . For this transition to occur light must act as also a particle. Thus this allows emitted photons to have, “a definite time and phase relation to each other” which as a result enables coherence. It is this coherence that results in a concentrated beam of light that the laser is equipped with. Lasers have since been used in the design of CD and DVD players as well as missiles.
MAQ/April 2018/28