Modification of inert surfaces via functional polymer layers prepared by plasmapolymerization

There are cases where substrates have to be modified that do not carry any functional group that can be used for the attachment of suitable molecules. Many polymeric materials such as polyolefins are examples for such substrates. One way to create reactive sites on these materials is a etching plasma treatment using gases such as argon, hydrogen, nitrogen or oxygen, sometimes followed by post-plasma processes. In many cases, however, the groups generated at the surface disappear in the bulk over time because of the thermodynamic drive to minimize the surface free energy of system.

For this and for other reasons we prefer a somewhat different approach and use low energy plasmas for the deposition of functional polymers on top of these substrates. Most often, allylamine is used as a monomer because it yields strongly chemically attached plasma polymerized films. The amino functionalities can then be used to immobilize further functional molecules such as initiators of photoreactive groups for a subsequent attachment of polymers.