Modification of polymeric surfaces with plasmas

The modification to a polymeric material that occurs by exposure to a plasma is largely determined by the following: (1) the process gas(es), (2) the exposure time to the plasma, (3) the energy and power densities, and to a lesser degree (4) the original composition of the surface. Types of modifications span from relatively simple surface morphological roughening or smoothing changes to complex grafting of radically different functional groups or molecular moieties to totally enveloping coatings that completely alter the surface properties of the bulk material. Free-radical chemistry appears to be the dominant mechanistic pathway for achieving most surface modifications. In spite of the high complexity of the ensuing chemistry in a typical plasma, it is possible to tailor the process to perform specific targeted changes to polymeric surfaces.