Argon sources

Clamp the flask above the hotplate stirrer. Flush the flask with argon by piercing the septum with a needle from the argon source and a second needle for venting. Allow the gas to flow through the flask for a minute. Reduce the gas pressure and attach the venting needle to a gas bubbler. 

Dry, 250 mL, two-necked flask equipped with a Argon source magnetic stir bar, rubber septum, and argon... 

Two-necked, round-bottom flask (20 mL) with a magnetic stirrer bar, septum cap (8 mm), and three-way stopcock, connected to a vacuum/ nitrogen (or argon) source... 

Two-necked, round-bottomed flask (30 mL) fitted with a reflux condenser, and a magnetic stirring bar—a three-way stopcock is fitted to the top of the condenser and connected to a vacuum/ argon source another top is sealed with a rubber septum... 

Vacuum/inert gas source (argon source is an argon balloon)... 

Connect both the dropping funnel and 4-necked flask to the argon source by means of a V-shaped PVC tubing adaptor. 

A Schlenk apparatus, illustrated in Fig. 3 and similar to that employed by Collman et al., is used for the reaction sequence. Vacuum and argon sources are provided by a double manifold, to which the stopcocks of the apparatus are attached. Prepurified nitrogen can be used in place of argon. 

Interferences for AES can be classified into two main categories, spectral and matrix interferences. Spectral interference can occur as a result of an interfering emission line from either another element or the argon source gas, impurities within or entrained into the source, e.g. molecular species such as N2. Such interferences can be eliminated or reduced either by increasing the resolution of the spectrometer or by selecting an alternative spectral emission line. 

FIGURE 3-7 Room-temperature tensile strength of SiC fibers after lOhour thermal exposure in argon. Source Takeda, 1997. 

FIGURE 3-8 Tensile strength of SiC fibers after aging for 10 hours at 1,550°C (2,822°F) in argon. Source Lipowitz et al., 1997. 

Replace the argon source with an oil bubbler fitted to the top of the condenser. Pierce the septum with the needle and bubble carbon monoxide through the solution for 1 h whilst slowly warming the oil bath to 85 C. Ensure the gas is vented into the top of the fume hood via the oil bubbler. 

Clamp the two-necked flask (containing the stirrer bar) fitted with the condenser, in the oil bath above the stirrer hot plate. Fit the argon source to... 

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