Fluorocarbon plasma treatment

Pretreatment of PBS films in an oxygen plasma allows the creation of a chemically altered surface during subsequent fluorocarbon plasma treatment which provides enhanced etching resistance. 

The etch resistance of poly (butene-1 sulfone) in fluorocarbon-based plasmas can be enhanced by prior treatment of the surface in an oxygen plasma. This pretreatment inhibits or retards the depolymerization reaction that characterizes normal etching in fluorocarbon plasmas, thereby permitting formation of a surface-modified layer which exhibits a substantially reduced etch rate. Pretreating PBS in an oxygen plasma enables it to be used subsequently in selective reactive-ion etch processes involving fluorocarbon plasmas to delineate submicron, anisotropically etched patterns. 

A study of the pretreatment application and the surface prior to deposition indicates that the aluminum alloy panels have a marked sensitivity to the buildup of a fluorocarbon background in the plasma reactor. This study also showed that the application of the O2 plasma treatment modified the alloy surface, changing it... 

Fluorine contamination has been reported in various environments and applications in the past. It has shown up in plasma processing [10-18], as crosscontamination from storage in contaminated containers or with contaminated samples [14,18], and modification of aluminum deposited on fluoropolymer substrates and other polymers having fluorine-based plasma treatments has also been observed [19-21]. Fluorocarbon lubricants have also been noted to modify the oxide structures on aluminum alloys [22,23], and the degradation of AI2O3 catalytic supports has been associated with fluoride conversion during reactions with fluorocarbons [24]. Alloy oxide modification has also been well noted in the presence of fluorine compounds not of the fluorocarbon family [25]. 

The films deposited in various substrates after plasma treatment in the presence of perfluorinated olefins were subject to partial removal with extraction. Generally, after extraction, the fluorine to carbon ratio, determined through XPS analysis, decreased to 0.2 1 to 0.3 1 regardless of the applied power and residence time used during the fonnation of the film. In all cases a moderate but consistent amount of oxygen was detected in the fluorocarbon film. The oxygen to carbon ratio 0.12 1 to O.l t before extraction and 0.08 1 to 0.1 1 after extraction. 

Several smdies have been conducted on the use of plasma for water-repellent deat-ment of fabrics (Ceria and Hauser, 2010 Leroux et al., 2008 Di Mundo et al., 2009). Most of these studies have used fluorocarbon-based chemistry however, none of them attempted a dual treatment with antimicrobials. One study combined a water-repellent finish with a flame-retardant finish (Tsafack and Levalois-Griitzmacher, 2007). Moreover, a review paper entitled Non-thermal Plasma Treatment of Textiles provides a comprehensive review of how nonthermal plasma was used effectively to impart different properties to textiles such as hydrophihc, hydrophobic, and oleopho-bic properties (Morent, et al., 2008). 

Pre-treatment of fluorocarbon polymers D M BREWIS Problems of these materials, chemical and plasma treatment... 

Perz and coworkers [17] earlier published Si 2p and C Is specUa of untreated and various plasma-treated samples of PMTFPS gum and elastomer. PMTFPS is affected by RF plasma treatment in much the same way as PDMS. Significant improvements in wettability are possible but the treatments are temporary and hydrophobic recovery is mostly complete within 24 hours. A related topic to preformed fluoropolymers is the introduction of fluorocarbon gases into the plasma to create fluorinated surface layers. In the specific example of the use of a CF4 plasma to treat PDMS surfaces [30], a fluorine content as high as 47% can be achieved. Unlike, for example, an oxygen plasma that produces a brittle surface, the CF4 treatment is not brittle. However, contrary to expectations, the CF4 treatment resulted in a decreased water contact angle, from 119° to 101° at 100 W, 300 s. This was attributed to possible side effects such as surface oxidation, chemical heterogeneity, and surface reorganization. 

Switchable Hydrophilic/Hydrophohic Fluorocarbon Layer Obtained on Porous Alumina using C-C4FS Plasma Treatment... 

Stability attributed to the presence of long and thin nanohairs on the fibers (Shin et al., 2012). In another example, inherent microstructure of cellulose paper was enhanced by plasma-assisted nanostructuring to create a surface that once coated with a thin fluorocarbon film was superhydrophobic (Balu et al., 2008).The nanotopography was varied with plasma treatment, yielding a surface in either the Wenzel or Cassie—Baxter states. 

It is known from conventional (wet-chemical) fluorocarbon finishes that thermal post-treatments can enhance the effect of the finish. In view of the problems encountered with respect to effecting durability, similar post-treatments of the plasma... 

Recent experiments by the authors studied the water repellence of PET fabrics (technical fabrics), photochemically treated in the presence of, e.g., 1,5-hexadiene, 1,7-octadiene, diallylphthalate (DAP) and l//,l//,2//,2H-perfluorodecyl acrylate (PFDA). Exemplary experimental data are summarized in Fig. 13 showing drop penetration times in excess of 1 hour (measurements were stopped after this time) and DuPont grading of up to 8. The relevant values for the untreated fabrics were drop penetration time approx. 20 s and a DuPont grading 0. Based on the well-known effect of heat treatments on long-chain fluoro compounds (cf. Sections 4 and 5.1), the samples treated with PFDA were also characterized following a further heat treatment. As was found in the case of wet-chemical finishes and plasma-deposited fluorocarbon thin layers, the water repellence of the samples could be further enhanced by heat treatment in this case also. 

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