Surface treatment: Plasma — the fourth state of matter

Aug. 26, 2015

Since we know what plasma can do in treating plastic surfaces, we ought to know what it is. Plasma is one of the four states of matter, the others being solid, liquid and gas. When sufficient energy is applied to solid matter, it becomes liquid. More energy turns liquid into a gas. Applying more energy to a gas causes it to ionize and enter the energy-rich plasma state. Plasma is like a cloud of protons, neutrons and electrons where all the electrons have detached from their respective molecules and atoms. The plasma can act as a whole rather than as a bunch of atoms. Scientists call that collective behavior, meaning the plasma can flow like a liquid or contain areas that are like clumps of atoms stuck together.

Though it wasn't discovered until 1928, plasma is anything but rare. In fact, it's the most abundant form of matter, making up as much as 99 percent of what can be seen in the universe. Most of it is in the intergalactic regions and the stars, including our sun. The glowing area in front of a spacecraft's heat shield during re-entry is plasma and so are lightning, sparks and the aurora borealis. Neon signs should be called plasma signs since that is what is glowing inside them. Plasma can be defined as an electrically neutral medium of unbound positive and negative particles.

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