Plasma Pretreatment of PTFE Surfaces

A few variants for producing well-adhering Al-PTFE systems were tested (a) deposition of plasma polymers bearing a single type of functional group as adhesion promoters on virgin PTFE (b) H2 plasma pretreatment of PTEE followed by deposition of an adhesion-promoting plasma polymer layer and (c) H2 plasma pretreatment of PTFE alone. 

Process (a) did not give any Al-PTEE bond strength because of the poor adhesion of the plasma polymers to the PTEE surface. Process (b) provided adequate 

The introduction of oxygen is most likely due to post-plasma reactions of plasma-produced C-radical sites at the PTFE surface by reaction with molecular oxygen when the samples were transferred from the plasma reactor to the XPS spectrometer with transient contact with air [73, 80]. This post-plasma reaction is unavoidable, but in this case it may help to promote the adhesion between the deposited plasma polymer layer and the pretreated PTFE. 

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