Polymerization and competitive ablation

These two early findings lead to the concept of competitive ablation and polymerization (CAP) which emphasizes the importance of a balance between polymer formation and ablation [3]. The first finding demonstrated the control of ablation due to extremely reactive fluorine-related species (atomic fluorine, F , etc.) by chemical reactions, and the second demonstrated the role of discharge conditions that control the production of highly ablative species. 

Figure 10.1 Schematic diagram of the Competitive Ablation and Polymerization (CAP) principle (1) dissociation (ablation) of monomer to form reactive species, (2) deposition of plasma polymer and ablation of solid including plasma polymer deposition, (3) deposition to and ablation from nonsubstrate surfaces, and (4) removal of stable molecules from the system.

Competitive Ablation and Polymerization (CAP) Mechanisms of Glow Discharge Polymerization... 

CAP (COMPETITIVE ABLATION AND POLYMERIZATION) SCHEME OF GLOW DISCHARGE POLYMERIZATION... 

Fig. 8. CAP (Competitive Ablation and Polymerization) (Scheme of glow dndiarge polymerization by H. Yasuda)...

Figure 5. Competitive ablation and polymerization (CAP) and plasma induced polymerization (PIP) mechanisms.

Both ions and radicals are suggested as significant precursors in the production of pyrolytic carbon from methane. There are, of course, several pathways leading to polymerization and an overall scheme described as a Competitive Ablation Polymerization (CAP) has been set out. ... 

The general scheme of plasma polymerization in the glow regions of a competitive process of polymerization and ablation implies that the rate of deposition will be an optimum for a given set of operational parameters in a reactor of a given type. That this is indeed the case is readily apparent if deposition rate is monitored as a function of power at a given pressure and typical data for the polymer from fluorobenzene are displayed in Figure... 

Because polymer formation and ablation are competitive and opposing processes, polymer-forming plasma has the least ablative effect however, ablation in such plasmas cannot be completely ruled out. Sputtering of metals used as the internal electrodes for plasma polymerization has been recognized as a contamination of plasma polymers. Under certain conditions, the sputtering of the electrode materials becomes significant and plays an important role in the engineering of interface as described in Chapter 9. 

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