electrical double layer

      region of molecular dimension at the boundary of two substances across which an electrical field exists. The substances must each contain electrically charged particles, such as electrons, ions, or molecules with a separation of electrical charges (polar molecules). In the electrical double layer, oppositely charged particles attract each other and tend to collect at the surface of each substance but remain separated from one another by the finite size of each particle or by neutral molecules that surround the charged particles. The electrostatic attraction between the two opposite and separated charges causes an electrical field to be established across the interface.

      The electrical field generated within an electrical double layer has a major influence on physical and chemical processes that occur at phase boundaries. For example, in electrochemical cells (electrolytic cell) (apparatus used to generate electric current from a chemical reaction or vice versa) where the fundamental process involves the transfer of electrons between a metallic electrode and a solution, small changes in the electrical field strength across the interface produce large changes in the rate of flow of electrons (current). Consideration of the electrical field strength across the interface is also important in industrial processes in which it is desired to transfer a substance across an electrode–solution boundary, such as the deposition of metal from solution or the dissolution of a metal electrode. The concept of an electrical double layer is essential to the understanding of a large group of electrical phenomena associated with the movement of a solid in a liquid medium—e.g., colloidal particles dispersed in solution—or the movement of a liquid along a fixed solid—e.g., flow of liquid through a capillary tube.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Electrical double layer — The electrical double layer is a structure that describes the variation of electric potential near a surface, and has a large bearing on the behaviour of colloids and other surfaces in contact with solutions and solid state fast ion conductors.… …   Wikipedia

  • Double layer (interfacial) — A double layer (DL, also called an electrical double layer, EDL) is a structure that appears on the surface of an object when it is placed into a liquid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The… …   Wikipedia

  • Double layer — may refer to: Double layer (plasma), a structure in a plasma and consists of two parallel layers with opposite electrical charge Double layer (interfacial), a structure that appears on the surface of an object when it is placed into a liquid… …   Wikipedia

  • Double layer (plasma) — This article is about the structure in plasma physics. For other uses, see Double layer. Saturnian aurora whose reddish colour is characteristic of ionized hydrogen plasma.[1] Powered by the Saturnian equivalent of (filamentary) Birkeland… …   Wikipedia

  • Electric double-layer capacitor — Maxwell Technologies MC and BC series supercapacitors (up to 3000 farad capacitance) An electric double layer capacitor (EDLC), also known as supercapacitor, supercondenser, electrochemical double layer capacitor, or ultracapacitor, is an… …   Wikipedia

  • Helicon Double Layer Thruster — The Helicon Double Layer Thruster is a prototype spacecraft propulsion engine. It was created by Australian scientist Dr. Christine Charles, based on a technology invented by Professor Rod Boswell, both of the Australian National University.The… …   Wikipedia

  • Double-sided tape — A leaf sticking to double sided tape looked at with a Scanning Electron Microscope Double sided tape is any pressure sensitive tape that is coated with adhesive on both sides. It is designed to stick two surfaces together, often in a way which is …   Wikipedia

  • Insulator (electrical) — Ceramic insulator at railways Conducting copper wire insulate …   Wikipedia

  • electrochemical reaction — ▪ chemistry Introduction       any process either caused or accompanied by the passage of an electric current and involving in most cases the transfer of electrons between two substances one a solid and the other a liquid.       Under ordinary… …   Universalium

  • Nanofluidic circuitry — is a nanotechnology aiming for control of fluids in nanometer scale. Due to the effect of an electrical double layer within the fluid channel, the behavior of nanofluid is observed to be significantly different compared with its microfluidic… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.