Macromolecular plasma-chemistry: an emerging field of polymer science

It is now well established that exposing inorganic and organic polymeric substrates to cold-plasma species represents an unusually convenient and versatile surface-modification and coating technology. The uniqueness of non-equilibrium plasma processes is related to the fact that they permit the conversion of a wide range of organic materials and organic compounds containing main group elements, including organometallic derivatives, into charged and neutral molecular-fragments and atomic species. These fragments can then promote surface-functionalization reactions or generate macromolecular thin layers as a result of recombination of nascent species on the surfaces that confine the plasma. In earlier work the control of the composition of polymeric films generated via plasma treatment was focused predominately on synthesis of unique, highly cross-linked polymers produced under relatively high power conditions. However, interest recently increased in providing less cross-linked, more highly functionalized films. Modem non-equilibrium plasma technologies are 'par excellence' surface modification processes which result in surface material layers that retain the inherent advantages of the substrates while providing more exact film chemistry control, and as a result they have potential appeal in many applications. Most of the prior research related to discharge-mediated surface-modification reactions involved low-pressure cold-plasma environments. However, in recent last years, atmospheric pressure non-equilibrium plasma installations have been designed, developed and tested with great success. This review on Macromolecular Plasma Chemistry illustrates the continuing interest in achieving controlled surface modification under plasma conditions, and the potential of plasma-chemistry for advancing future technologies. (C) 2004 Elsevier Ltd. All rights reserved.