Low energy surfaces are made wettable by plasma activation
Plasma Cleaning with oxygen is a dry, solvent free technology used to precision clean substrates at the molecular level. Precision cleaning is a requirement for a broad spectrum of industries with applications ranging from semiconductor wafer cleaning in micro-electronics to bio-burden decontamination of medical devices. Achieving and maintaining surface cleanliness at the molecular level during manufacturing demands careful attention and exhaustive procedures.
Oxygen plasma cleaning removes surface contamination at the molecular level following machining, tooling and wet chemical processing steps. Plasma precision cleaning is a conformal process, not only for substrates of complex geometries but also on textured surfaces with “rough” topographies.
Since plasma cleaning is a dry, gaseous process there are none of the liabilities associated with wet chemistry, such as chemical storage and waste disposal, evolving restrictions on the use of dangerous solvents, solvent absorption into product, etc. Indeed, it this reason that plasma cleaning has earned itself the status “The green alternative to solvent cleaning”
Plasma Activation and Functionalization
Plasma Activation or Plasma Functionalization is a method used to modify or improve adhesion properties of surfaces prior to coating, painting, bonding, etc. Commonly, the surface in question is a polymer material and an ionized oxygen plasma can be used. Other gasses are often used depending on the material type and the required lifetime of the treatment.
Activation of the surface occurs through the following processes:
Removal of weak boundary layers. Plasma strips away surface layers with the lowest molecular weight, at the same time it oxidizes the uppermost atomic layer of the polymer.
Cross-linking of surface molecules. Oxygen radicals assist in breaking up bonds and promote the 3 dimensional cross bonding of molecules
Generation of polar groups. Oxidation of the polymer is responsible for the increase in polar groups which is directly related to the adhesion properties of the surface.