Surface Cleaning of Polymers

• Plasma ablation mechanically removes contaminant layers through energetic electron and ion bombardment of the surface - see Ablation
• Plasma surface cleaning removes surface contaminants, unwanted surface finish from polymers and weak boundary layers which may be present in certain processed polymers

Surface Restructuring of Polymers

• The breaking of polymer surface bonds by plasma ablation using an inert gas leads to the creation of polymeric surface free radicals
• A surface free radical can rebond in its original polymeric structure, it can bond with an adjoining free radical on the same polymeric chain, or it can bond with a nearby free radical on a different polymeric chain - see Crosslinking
• Such polymer surface restructuring can improve surface hardness, as well as tribological and chemical resistance

Surface Alteration of Polymers

• The breaking of polymer surface bonds by plasma ablation leads to the creation of polymeric surface free radicals
• The bonding of these surface free radicals with atoms or chemical groups from the plasma leads to the replacement of surface polymer functional groups with new functional groups, based upon the chemistry of the plasma process gas - see Activation
• Typical polymer functional groups formed through plasma surface activation and grafting include: amine amino-carboxyl, carboxyl hydroxyl and fluorination carbonyl
• Such polymer surface alteration can modify the chemical properties of the surface while leaving the bulk properties unchanged

Surface Deposition of Polymers

• Plasma deposition involves the formation of a thin polymer coating on the substrate surface through polymerization of the process gas
• If a process gas comprised of more complex molecules, such as methane or carbon tetrafluoride, is employed, these may undergo fragmentation in the plasma, forming free radical monomers; these in turn bind to the surface and recombine into deposited polymeric layers
• These polymer thin-film coatings can dramatically alter the permeation and tribological properties of the surface - see Deposition