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Typus
Verschleierung
Bearbeiter
Hindemith
Gesichtet
Yes.png
Untersuchte Arbeit:
Seite: 74, Zeilen: 1 ff. (entire page)
Quelle: Gupta 1997
Seite(n): 215, 216, Zeilen: 215: last paragraph; 216: 1 ff.
5.6.3. Gel permeation chromatography (GPC)

Gel permeation chromatography (GPC) is quite useful for routine estimate of molecular weight, owing to its convenience and the possibility of simultaneous evaluation of various averages of molecular weight, thus providing information about the molecular weight distribution. The GPC technique is based on the separation of solute molecules according to their size by passing the polymer solution through a column packed with microporous gel particles. A known small volume of polymer solution is injected into an already stabilized current of the solvent through the column, and then the out flowing liquid from the column is analyzed for the concentration of the solute as a function of time. Separations of molecules occur by their preferential penetration into the pores of the gel filled in the column, depending on their sizes. Small molecules penetrate more easily than the larger one, while the very large ones may either partially penetrate or not penetrate at all. Thus, during the passage of the solution through the column the largest molecules will take the shortest time while the smallest one will take the longest time to elute from the column. The eluting liquid passing through the detector is measured for its solute concentration through its refractive index or optical density. The detector signal, which is proportional to the solute concentration, thus gives a trace as a function of time or elution volume, as shown in Figure 5.6 for a polydisperse polymer sample.

Mrs 074a diss.png

Figure 5.6 Typical GPC curve for a polydisperse polymer sample.

(e) Gel permeation chromatography

Gel permeation chromatography (GPC) is quite useful for routine estimate of molecular weight, owing to its convenience and the possibility of simultaneous evaluation of various averages of molecular weight, thus providing information about the molecular weight distribution.

[page 216]

Mrs 074a source.png

Fig. 10.9 Typical GPC curve for a polydisperse polymer sample.

The GPC technique is based on the separation of solute molecules according to their sizes by passing the polymer solution through a column packed with microporous gel particles. A known small volume of polymer solution is injected into an already stabilized current of the solvent through the column, and then the out-flowing liquid from the column is analysed for the concentration of the solute as a function of time. Separation of molecules occurs by their preferential penetration into the pores of the gel filled in the column, depending on their sizes. Small molecules penetrate more easily than the larger ones, while the very large ones may either partially penetrate or not penetrate at all. Thus, during the passage of the solution through the column the largest molecules will take the shortest time while the smallest ones will take the longest time to elute from the column. The eluting liquid passing through a detector is measured for its solute concentration through its refractive index or optical density. The detector signal, which is proportional to the solute concentration, thus gives a trace as a function of time or elution volume, as shown in Fig. 10.9 for a polydisperse polymer sample.

Anmerkungen

The source is not mentioned. The two figures are similar, but not identical.

Sichter
(Hindemith), SleepyHollow02

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