Hexafluoroethane plasma polymerized

Figure 10. Carbon Is spectrum from hexafluoroethane plasma polymerized onto polystyrene.

Figure 11a. Carbon Is spectrum from hexafluoroethane plasma polymerized on wool fabric. (Reproduced, with permission, from Ref. 42. Copyright 1976, Dekker.)...

Figure 12a. Oxygen Is spectra obtained from hexafluoroethane plasma polymerized on polystyrene.

T/F plasma polymer was also selected to improve the adhesion of different spray paints to IVD Al-coated panels. As presented in Table 32.3, T/F plasma polymer [DC plasma-polymerized trimethylsilane (TMS) followed by hexafluoroethane (HFE)] gave rise to such a strong adhesion of E-coat that could not be stripped off after 24-h application of Turco solution. Since the formation of mechanical interlocking between primers and porous IVD surfaces could conceal the role of plasma treatment in enhancing adhesion, bare 7075-T6 aluminum alloy panels with smooth surfaces were first used as substrate to examine the effect of plasma treatment on the adhesion of spray paints. 

Tubular blood-contacting polymeric materials were modified by plasma polymerization and evaluated in animals (baboons) with respect to th r c iadty to induce acute and chronic arterial thrombosis. Nine plasma polymers based on tetrafluoro-ethylene, hexafluoroethane, hexafluwoethane/H, and methane, when deposited on silicone rubber, consumed platetets at rates ranging from l.l-5.6x 10 platelets/on day. Since these values are close to the lower detection limit for this test system, tl plasma polymers were considered relatively nonthrombogenk. Thus, artificial blood tube made of polyesters, having the inner side coated with plasma-pcrfymerized tetra-fluoroethylene, is now commercially available. 

The monomer chosen is hexafluoroethane, which cannot be polymerized by plasma-induced polymerization and which cannot be polymerized in a glow discharge imder ordinary conditions presumably because the ablation process associated with the glow discharge is excessive. Attempts have been made to supress the ablation process and to shift the balance between plasma state polymerization, which is assumed to be present, and ablation. However, it has been observed that polymer formation for hexafluoroethane does occur when polyethylene is used as substrate. On the other hand, no polymer formation can be observed either with ESCA or by surface energy analysis when glass is used as a substrate. 

This indicates that ablation is no loiter dominant, and polymer formation prevails. This phenomenon can be explained by postulating that Hg reacts with F atoms emanating from the fluorine containing compound in the glow discharge and forms the more stable HF, which reduces the ablation in a dramatic manner. Because hexafluoroethane does not form a polymer by plasma-induced polymerization, the overall effect can be explained by the balance between plasma state polymerization and ablation. 

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