What is Nanotechnology?
Dealing with various structures of matter having dimensions of the order of a billionth of a meter is called nanotechnology. After the famous lecture, “There is plenty of room at the bottom” by Richard Feynman it all started on December 29, 1959.
Types of Nanoparticles
According to the chemical and physical properties, morphology, size nanoparticles can be classified into different types.
1. Carbon-Based Nanoparticles
Carbon nanotubes (CNTs) and fullerenes are the two main materials included in carbon-based nanoparticles. Graphene sheets rolled into a tube are called CNTs. These are 100 times stronger than steel and therefore used for the structural reinforcement.
CNTs are of two types that is single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). These tubes are thermally conductive along the length and non-conductive across the tube.
2. Ceramic Nanoparticles
These are inorganic solids that are made up of carbides, carbonates, oxides and phosphates. These nanoparticles have chemical inertness and high heat resistance. Drug delivery, imaging, photocatalysis and photodegradation of dyes are some of its applications.
They perform as a good drug delivery agent by controlling some of their characteristics like porosity, size, surface area, surface to volume ratio, etc.
3. Lipid-Based Nanoparticles
These particles have a diameter ranging from 10 to 100nm and are spherical in shape. A solid core made of lipid and a matrix containing soluble lipophilic molecules is present in it. Emulsifiers and surfactants are used to stabilize the external core of the nanoparticles. In biomedical field these particles have an application as a drug carrier and delivery and RNA release in cancer therapy.
4. Metal Nanoparticles
Metal precursors are used to prepare metal nanoparticles. Chemical, electrochemical, or photochemical methods can be used to synthesize them. In chemical methods, reducing the metal-ion precursors in solution by chemical reducing agents produces metal nanoparticles. These have the ability to absorb small molecules and have high surface energy.
5. Polymeric Nanoparticles
These organic based nanoparticles have structures shaped like nanocapsular or nanospheres depending upon the method of preparation. A nanocapsular particle has core -shell morphology while a nanosphere particle has a matrix-like structure. The active compounds are confined and surrounded by a polymer shell in the former while in the latter the active compounds and the polymer are uniformly dispersed.