Post-plasma-treatment

Post-plasma treatment reactions of free radicals and other plasma-generated active species and groups between themselves and with the enviromnent. 

Table 19.4 PEF experimental parameters and contact angles of water on alumina plates after CF4 according to the different post-plasma treatments...

The plasma polymerization ofphosphazene monomers was the subject of a 1982 U.S. Patent [40], wherein the phosphazene monomers studied were trimers and tetramers substituted with halides or organic nucleophiles. Experiments were conducted by direct exposure of crystalline trimer to the plasma, followed by extraction of the residues into warm tetrachloroethane. It was concluded that the resultant polymers were crosslinked and formed in low yield (-10%). Another experiment used an initial plasma polymerization followed by post-plasma treatment at 210 °C. On comparison with a control sample which was subjected only to the post-plasma treatment, some polymerization was observed, although the only residues formed were insoluble in toluene. 

The percentage of surface bromination could be adjusted between 0 and 45 Br per 100 C by variation of treatment time. Exposure to air causes a post-plasma addition of oxygen. 

Monomers Not Polymerizable by Plasma Initiation. When styrene and a-methy1styrene were subjected to plasma treatment, the monomers became yellowish and only trace amounts of insoluble films were formed. The discoloration was intensified and extensive formation of dark films were observed if carbon tetrachloride was added as the solvent. No post-polymerization was detectable for these monomers. Generally styrene and a-methylstyrene readily undergo thermal polymerization. However, no thermal polymerization was possible for these monomers after having been subjected to plasma treatment for one minute or less. It has been demonstrated from the emission spectra of glow discharge plasma of benzene (6) and its derivatives (7 ) that most of the reaction intermediates are phenyl or benzyl radicals which subsequently form a variety of compounds such as acetylene, methylacetylene, allene, fulvene, biphenyl, poly(p-phenylenes) and so forth. It is possible that styrene and a-methylstyrene also behave similarly, so that species from the monomer plasma are poor initiators for polymerization. 

C) Plasma-treatment variables In all of the above comparisons, the various mica samples had been exposed to plasmas under arbitrarily selected, constant conditions of monomer pressure, plasma duration and applied power. It is very probable (2, that these variables and possibly others, such as reactor geometry and post-treatment history, may influence strongly the magnitude of surface modification effects attained by the present route. For this reason the performance modifications of polymer composites will also depend on the exact selection of treatment variables. 

Brossa F, Cigada A, Chiesa R, Paracchini L, Consonni C (1994) Post-deposition treatment effects on hydroxylapatite vacuum plasma spray coatings. Biomaterials 5 855-857 Brown CD, Mealey BL, Nummikoski PV, Bifano SL, Waldrop TC (1998) Hydroxylapatite cement implant for regeneration of periodontal osseous defects in humans. J Periodontol 69 146-157 Brown PW, Fulmer M (1996) The effects of electrolytes on the rates of hydroxylapatite formation at 25 and 388°C. J Biomed Mater Res 31 395-400... 

Fihaggi MJ, Pilhar RM, Coombs NA (1993) Post-plasma-spraying heat treatment of the HA coating/Ti-6A1-4V implant system. J Biomed Mater Res 27 191-198 Finet B, Weber G, Cloots R (2000) Titanium release from dental implants an in-vivo study on sheep. Mater Lett 43 159-165... 

The FE-DBD plasma treatment (see section 12.6.1) is shown to initiate apoptosis in Melanoma cancer cell lines, that is a threshold at which plasma treatment does not cause immediate necrosis but initiates a cascade of biochemical processes leading to cell death many hours after the treatment (Fridman et al., 2007). Melanoma cells, treated by plasma at doses below those required for cell destruction, survive the plasma treatment but develop apoptosis many hours post treatment and die (disintegrate) by themselves gracefully. This could potentially be an intriguing approach for cancer treatment, especially if by manipulation of plasma parameters the treatment could be made selective to cancerous cells over healthy cells, as was demonstrated before for bacteria vs. healthy cells (Fridman et al., 2006). 

The post-grafting reaction provides a strong and irreversible adhesion between the grafted layer and the substrate, since a covalent bond is estabhshed. We grafted N-vinylpyrrolidone (NVP) monomer onto a polypropylene (PP) surface pretreated with cold N2 plasma (Scheme 12.1). After the plasma treatment, the modified surface was dipped in aqueous NVP solution for several periods of time (1-50 h) and at various temperatures (60-80°C). 

Brisset, J. L., Moussa, D., Doubla, A., Hnatiuc, E., Hnatiuc, B., Youbi, G. K., et al. (2008). Chemical reactivity of discharge and temporal post-discharge in plasma treatment of aqueous media examples of gliding discharge treated solutions. Iruiustrial Engineering Chemistry Research, 47, 5761-5781. 

Current research into reactive atmospheric plasma techniques for the nanocoating of textile substrates includes a new atmospheric CoatingStar [16] technology for the appHcation of microcapsules [17] in aerosol form. Atmospheric plasma treatments represent an alternative to the (post) treatment of textiles. A schematic representation of the reactive plasma system is illustrated in Figure 7.10. 

Figure 4.25 Fourier Transform Infra-red (FTIR) spectra show that the post-CMP plasma treatment eliminates the extra peaks attributed to alkyl chains (Reprinted with permission from Papa Rao et al., 2009).

Intermediate-Temperature Solid Oxide Fuel Cells, hu. J. Appl. Ceram. Technoi, 6(4), 513-524 (2009). C.H. Tsai, C. S. Flwang, C. L. Chang, J. F. Yu and S. H. Nien, Post-heat treatment pressure effect on performances of metal-supported solid oxide fuel cells fabricated by atmospheric plasma spraying, 197, 145-153 (2012). 

SchwingungsriKkorrosions-Verhaltens verschweiKter Proben durch das WIG-und Plasmanachbehandlungsverfahren (Influence of TIG- and plasma post-weld treatment on corrosion fatigue behaviour of welded specimens) (in German) Werkst. Korros. 35 (1984) 7, p. 321... 

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