Faculty: Dr. Bruce Locke
Plasma, often considered the 4th state of matter, can be defined as a system of highly ionized species which are on average electrically neutral. Plasma systems are extensively used in industry and in commercial products, and are quite common in nature. Some examples include reactors for ozone production for use in water treatment and pollution control, plasma displays in televisions, and lightning. Plasmas are typically made when a large electric field is formed in a gas leading to ionization and subsequent electrical breakdown.
A plasma contains free electrons and positive and negative ions. These highly energetic electrons and ions can be used for a number of purposes, with particular interest here in initiating desirable chemical reactions in gases, liquids, and on the surfaces of solids. For example, gas phase electrical discharges can be used to either reduce or oxidize (depending upon the chemical environment) hazardous and toxic gases such as nitrogen oxides, sulfur dioxide, and many volatile organic compounds. Gas phase electrical discharges have also been used commercially for the production of ozone for many years. Liquid phase discharges have recently been used to oxidize small aromatic organic species, destroy microorganisms, and for use as tools in surgery. Surface discharges are commercially used for the plasma coating of polymers.