Plasma argon-oxygen

For the same treatment conditions the degree of cross-linking (estimated from the remaining gel fraction) is the same, for PE treated in situ, whatever the gas plasma (argon, oxygen or nitrogen) [110]. 

Compared with the ICP, other atomic spectrometric detectors are not widely coupled to HPLC. Several interfaces have been described for AAS detector. Methods include a rotating platinum spiral collection system (Ebdon et al., 1987) and a flow injection thermospray sample introduction system (Robinson and Choi, 1987). Post-column hydride generation is also popular with AAS detection as will be described later. Pedersen and Larsen (1997) used an anion-exchange column to separate selenomethionine, selenocysteine, selenite and selenate with both FAAS and ICP-MS. The detection limits for the FAAS system were lmg H1 compared with 1 fig l-1 for ICP-MS. HPLC-MIP systems have been described to an even lesser extent. These either use elaborate interfaces to overcome the problems of quenching the low-power plasma (Zhang and Carnahan, 1989) or use a modified argon/oxygen mixed gas plasma (Kollotzek et al., 1984). 

Exposing a polymer surface to various kinds of plasmas can modify polymer surfaces. Plasmas of argon, oxygen, hydrogen, and air are frequently used in plasma surface modification of polymers. Plasmas of non-polymer-forming gases are used in... 

Plasma etching (e.g., nitrogen, argon, oxygen, water vapor) Plasma (gas discharge) (RF, microwave, acoustic) Radiation grafting (electron beam and y-irradiation) Silanization... 

The last reaction is particularly convenient for the passivation of device surfaces because of the low temperature required. Low-temperature layers can also be formed by the vacuum evaporation of Si02 powder or by ion-plasma sputtering of Si in an argon-oxygen mixture. The anodic oxidation of silicon in an ethylene glycol solution of KNO3 and various chemical oxidation reactions of Si (e.g., in H2O2) can also be used. 

The brittleness, however, may be an advantage insofar as joints in woodwork may be broken by a sudden impact and the residues are more easily scraped off. Intractable adhesive residues may also be removed by argon-oxygen plasmas, which slowly oxidize all organic materials into volatile gases. 

Gases or mixtures of gases used for plasma treatment of polymers include nitrogen, argon, oxygen, nitrous oxide, helium, tetrafluoromethane, water, and ammonia. Each gas produces a unique surface treatment process. It should be noted that surface chemistry modification by plasma treatment can make polymer surfaces totally wettable or nonwettable. Nonwettable plasma treatments generally... 

Brener, I.B., Zander, A., Kim, S. Shkolnik, J., (1996), Direct determination of lead in gasoline using emulsification and argon and argon-oxygen inductively coupled plasma atomic emission spectrometry, /, Anal. Atom. Spectrom. 11,91-97. 

The inside process is somethnes called inside vapor phase oxidation (IVPO) or inside vapor deposition (IVD). However, it is perhaps most commonly referred to as modified chemical vapor deposition (MCVD). In one variation, perhaps not currently in commercial use, an argon/oxygen plasma is generated within the tube by microwave radiation to provide the thermal energy for the chemical reaction, instead of relying on heat from a burner outside the tube. 

Plasma treatment —Activated gas plasma, using oxygen, argon, or water vapor plasma, has given good bonds 3—4 times stronger than those obtained with the abrasion method. 

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