Triboelectric effect Guide, Meaning , Facts, Information and Description

The triboelectric effect is an electrical phenomenon where certain materials become electrically charged after coming into contact with another, different, material. The polarity and strength of the charges produced differ according to material and surface smoothness. Amber, for example, can acquire an electric charge by friction. This property, first recorded by Thales of Miletus, suggested the word "electricity", from the Greek word for amber, elektron. Other examples of materials that can acquire a charge when rubbed together include glass rubbed with silk, and hard rubber rubbed with fur.

Series

Materials are often listed in order of the charge built up when they are touched with another object. A material towards the bottom of the series, when touched to a material near the top of the series, will attain a more negative charge, and vice versa. The further away two materials are from each other on the series, the greater the charge transferred. Materials near to each other on the series may not exchange any charge, or may exchange the opposite of what is implied by the list. This depends more on other properties than the type of material. Lists vary somewhat as to the exact order of some materials, since the charge also varies for nearby materials.

Effect

Although the word comes from the Greek for "rubbing", tribos, the two materials only need to come into contact and then separate for electrons to be exchanged. After coming into contact, a chemical bond is formed between some parts of the two surfaces, called adhesion. When separated, some of the bonded atoms have a tendency to keep extra electrons, and some a tendency to give them away. This is what creates the net charge imbalance between the objects. The triboelectric effect is only related to friction because they both involve adhesion. However, the effect is greatly enhanced by rubbing the materials together, as they touch and separate many times.

Because the material is now electrically charged, either negatively or positively, contact with an uncharged object or one with a substantially different charge may cause a discharge of the built-up static electricity; a spark. A person simply walking across a carpet may build up a charge of many thousands of volts, enough to cause a spark a centimeter long or more (this type of discharge is usually harmless, as it passes very little current).

Utilization

The effect is of considerable industrial importance both in terms of safety and also potential damage to manufactured goods. The spark produced is fully capable of igniting inflammable vapours, for example, petrol or ether fumes. Means have to be found to discharge hospital trolleys which may carry such liquids. Even where only a small charge is produced, this can result in dust particles being attracted to the rubbed surface. In the case of textile manufacture this can lead to a permanent grimy mark where the cloth has been charged.

This effect is the principle behind the charge build-up in a triboelectric-type Van de Graaff generator.

See also

• Capacitor
• Electric charge
• Examples of electrical phenomena
• Electrical generator
• Electrophorus
• Static electricity

• "Triboelectrics". Clean Air Systems (PDF)

This is an Article on Triboelectric effect. Page Contains Information, Facts Details or Explanation Guide About Triboelectric effect

	Web www.E-paranoids.com