Gas flow-solution trap method

Fig. 9.4.5 Size histogram of In ultrafine particles produced by a gas flow-solution trap method in acetone. The gas pressure was 1.3 kPa pure He. The maximum height is at d = 3 nm. Ordinate represents the number of samples at a given size interval. No good was obtained for normal and lognormal probability plots. (From Ref. 4.)...

Gas Flow-Solution Trap Method. Figure 9.4.9 shows an apparatus for a gas flow-solution trap method. Two kinds of gases, helium and argon, were introduced He for the production of fine particles and Ar for the collection and transportation of particles to a trapping vessel. The procedure is the same as for the case of the... 

Fig. 9.4.9 Apparatus for the gas flow-solution trap method. Nanoparticles produced in the inert gas stream are trapped in a cooled liquid to form a colloid. (From Ref. 10.)...

Al. Figure 9.4.16 shows AI colloids produced by a gas flow-solution trap method. The color of the colloids was dark blue. The size of the majority of panicles was around 30 nm. Note that the particle shape is spherical. 

Pb. Figure 9.4.22 displays a photograph of Pb nanoparticles produced by a gas flow-solution trap method with ethanol as a dispersion medium. The diameter of many particles was less than 10 nm, and the color of the colloid was dark brown. 

Fig. 9.4.21 Electron micrograph of Sb nanoparticles produced by a gas flow-solution trap method. Note that many particles are coalesced with each other, forming a fractal-like network structure.

Copper Dissolution in Alcohol. Copper is believed to be stable to alcohol, at least in bulk, because copper still is used in distillation processes for the production of whisky. However, it was found that the color of copper sols prepared by the gas flow-solution trap method changed from the initial wine red to yellow within 30... 

Fig. 9.4.25 Optical absorption spectra of copper colloid prepared by the gas flow-solution trap method as a function of lime development. The numbers in the figure are the time after the preparation of Lhe sample. The spectrum of sodium eihoxidc in ethanol (authentic sample) is also shown in the same figure, marked by b. The insertion is the expansion of the region of the isosbestic point. The deviation from the isosbestic point at 10 h after the preparation of colloids is shown by a in the insert. (From Ref. 26.)...

We point out here that the colloid prepared by these methods is very clean, because the carrier gas used is usually high-purity grade at six-nine, the chamber is once evacuated to depress the extent of contaminating oxygen and moisture, and the liquids themselves are always purified by sublimation process except for the solution trap method. To transfer the colloidal suspension after preparation, a specially designed stock bottle with a Luer-lock syringe is normally used in order to enable the operations under Ar flow to avoid unexpected air contamination. Therefore, we can carry the suspension liquid away from the production chamber without exposure to air, which means that the surface of colloidal metal is very clean if it does not react with suspension liquids. 

Fig. 9.4.11 Apparatus for the gas flow-sputtering method. A sputtering gas (mixture of He and 40% H2) was supplied from nozzle A. Produced particles are flowed into the other port B and trapped by a solution trap apparatus cooled at approximately - 50°C. (From Ref. 16.)...

An alternative to desorption of the analytes trapped on an SPE carPidge with an organic solvent is thermal desorption (SPETD). In the first on-line SPETD setup, 100 to 500 pi of aqueous sample were injected into the packed liner of a PTV [75]. The water was evaporated at a high gas flow rate and a backflush setup inserted between the PTV and the analytical GC column ensured that no water entered the analytical column. Next, the analytes were desorbed and transferred to the analytical column by rapidly increasing the injector temperature. Tenax GR and TA were found to be suitable sorbents [76], that is, they combined sufficient retention power for analytes in the liquid phase (sorption), poor interaction with water (drying), and good thermal stability (desorption). The potential of the method was demonstrated by the analysis of 10 pg/L solutions of /7-alkanes and... 

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