Materials and Technology

Dyes
For thousands of years, dyes were obtained from natural sources, such as plants and animals. Today they are mostly produced synthetically and have replaced many natural dyes for commercial use. The molecules presented are used in the synthesis, production, manufacture, or application of dyes.

Electronic applications
Modern technology is based mainly in electricity. This list comprises materials used in electronic applications such as semiconductors, capacitors, circuits, electrolytes, and transistors.

Explosives and Propellants
Explosives are those molecules that decompose in a rapid chain reaction, often with the release of a large amount of energy. They are used in military applications, fireworks, and as propellants for projectiles and rockets. Some of the listed molecules are also used as propellants in rockets or aerosol sprays. A typical aerosol spray can contains gas under high pressure that will propel the liquid or solid contents when released.

Fuels
Fuel is a substance that is consumed through a redox reaction (loss and gain of electrons) to produce energy. Fossil fuels come from natural sources like coal, oil, and natural gas. Some examples are gasoline and diesel, which are liquid mixtures of molecules composed mostly of carbon and hydrogen (hydrocarbons).

Metallurgy
Metals such as aluminum, cobalt, copper, lead, magnesium, nickel, steel, super-alloys, titanium and zinc alloys, among others, are used everywhere from household utility items to aerospace and industrial applications. Metals have different properties that make them suitable to a wide range of uses (e.g., they conduct electricity and are malleable). This section lists molecules used in the manufacture, production, and refining of metals.

Polymers
Polymers includes plastics, nylon, Styrofoam, rubbers, PVC, and other materials that are made up of repeating units of smaller molecules. Since polymers themselves tend not to crystallize, the molecules listed here include monomers, catalysts, and reagents that are important in the synthesis of polymers.

Refrigeration
Refrigeration is the process by which heat is removed and transferred from one place to another. This technology advanced considerably during the 19th century, to the point where it is now possible to liquefy atmospheric gases. The molecules mentioned here are used as or in the manufacture of refrigerants employed in freezers, air conditioning, icemakers, heat pumps, and other applications. Some of these molecules have adverse environmental effects. For example, chlorofluorocarbons (CFC's) deplete of the ozone layer in the stratosphere.