New Materials Through Chemistry: Ceramics, Semiconductors, Polymers, and Composites

Flashcards covering the history, definitions, and applications of ceramics, semiconductors, polymers, and composite materials as described in the lecture notes.

Ceramics

Materials that are made from dried clay or claylike mixtures.

Jericho

A Middle Eastern city whose walls, built about 8000 B.C., consisted of ceramic bricks made from mud and straw baked in the Sun.

Traditional Ceramics Raw Materials

Easily obtainable materials including clay, silica (sand), and feldspar (crystalline rocks).

Firing

The heating process for ceramics, typically at temperatures between $1000^\circ\text{C}$ and $1700^\circ\text{C}$, which makes the structure dense and strong.

Dehydration

The loss of water during the firing process that causes ceramic particles to merge and the object to shrink.

Modern Ceramics Composition

Ceramics made from compounds of metallic and nonmetallic elements, such as carbon, nitrogen, or sulfur.

Chromium Dioxide

A nontraditional ceramic that conducts electricity as well as most metals.

Semiconductor

A class of materials that are poorer conductors of electricity than metals but better conductors than nonmetals, and whose electrical conductivities can be controlled.

Doping

The process of adding impurities, such as other elements, to a semiconductor to modify its conductivity.

n-type semiconductor

A semiconductor in which the added impurity causes the overall number of electrons to increase, creating free electrons.

p-type semiconductor

A semiconductor in which doping reduces the overall number of electrons, creating areas with fewer electrons called holes.

Integrated Circuit

Also known as a microchip, it is a small chip that contains many semiconducting devices.

Transistor

A device made using n-type and p-type semiconductors used to control the flow of electrons in electrical circuits; it replaced vacuum tubes in computers starting in 1953.

ENIAC

Short for Electronic Numerical Integrator and Computer, it was one of the first computers developed by the Army in 1946, featuring more than 18,000 vacuum tubes.

Computer Hardware

The major physical components of a computer, such as the keyboard, monitor, mouse, and central processing unit (CPU).

Processor

A special microchip inside the CPU that acts as a control center and is responsible for how all components work together.

Polymer

A class of substances composed of molecules arranged in large chains of simple, repeating units called monomers.

Monomer

The simple, repeating unit that serves as the building block of a polymer chain.

Synthetic

Materials that do not occur naturally but are manufactured in a laboratory or chemical plant.

Vulcanization (1839 Discovery)

A process found by Charles Goodyear where heating sulfur and natural rubber together prevented the rubber from becoming brittle in the cold or soft in the heat.

Hydrocarbons

Organic molecules made entirely of carbon and hydrogen, typically found in fossil fuels like oil, coal, and natural gas, used to make modern synthetic polymers.

Aramids

A family of nylons with special properties, including being five times stronger than steel, used for fireproof clothing and bulletproof vests.

Composite

A mixture of two or more materials, with one embedded or layered in another, designed to achieve specific properties like being lightweight but durable.

Fiberglass

A composite consisting of small fibers of glass embedded in a plastic, used to reinforce car and boat bodies.