Theory of the propagation of finite concentration bands in gas chromatography. A numerical solution of the ideal problem

1985 ◽  
Vol 89 (10) ◽  
pp. 2076-2082 ◽  
Author(s):  
Pierre Rouchon ◽  
Marc Schoenauer ◽  
Patrick Valentin ◽  
Claire Vidal-Madjar ◽  
Georges Guiochon
2010 ◽  
Vol 387 (1-2) ◽  
pp. 79-86 ◽  
Author(s):  
Raimundo Ho ◽  
Steven J. Hinder ◽  
John F. Watts ◽  
Sarah E. Dilworth ◽  
Daryl R. Williams ◽  
...  

1992 ◽  
Vol 65 (5) ◽  
pp. 890-907 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff

Abstract Carbon blacks ranging from N110 to N990 were characterized by means of inverse gas chromatography at finite concentration. The isotherms, net heat, and spreading pressures for benzene and cyclohexane adsorption suggest a general trend of increasing surface activity with increases in specific surface area. This is in good agreement with surface-energy measurements reported previously. The energy-distribution function of adsorption shows that while the concentrations of low-energy sites are comparable for most of the carbon blacks, differences exist with regard to high-energy sites. These suggest that small-particle-size blacks possess a greater number of high-energy centers. The graphitization of carbon blacks results in a considerable reduction in their adsorption capacity and narrows the energy distribution of their surfaces. One can therefore conclude that high-energy sites play an important role in the determination of the surface energies and reinforcing ability of carbon blacks.


1995 ◽  
Vol 73 (11) ◽  
pp. 1855-1861 ◽  
Author(s):  
G. Julius Vancso ◽  
Zhanjie Tan

The spatial distribution of toluene and THF in the polyester poly(diethylene glycol-co-succinic acid) and its Mg2+-containing "telechelic" derivative was described by Kirkwood–Buff–Zimm (KBZ) cluster integrals. The values of KBZ integrals as a function of the volume fraction of solvent in the polymer–solvent systems were obtained from finite concentration inverse gas chromatography measurements utilizing the elution-on-a-plateau technique. The results show that toluene has a higher self-affinity to form clusters in the pure polyester than THF, which is more homogeneously distributed in the polymer. Data for preferential solvation indicate that a segregation of parts of the polymer chains is present in the toluene–polyester system. When metal ions are introduced, the self-affinity of the solvent molecules to gather increases, whereas solvent clusters of toluene form in the free volume, and the gathering of the THF is likely to take place close to the metal ions. Based on the electron donacity values of the various donor groups present in the metal-ion-containing polymer it was assumed that THF in the Mg2+-containing polyester will be bound to the central metal ion while the apolar toluene will participate in the solvation of the apolar parts of the polymer and will be "repelled" from the ion-containing regions. The concentration of these ionic centres, which act as effective cross-links in the coordination polymer, was determined from measurements of thermodynamic activity. A comparison of the experimental and estimated effective cross-link density values indicates a nearly atomic dispersion of Mg2+ in the metal-ion-containing polyesters. Keywords: inverse gas chromatography, cluster integrals, solvent partition in polymers, metal-ion-containing polyesters, Flory–Huggins interaction parameter.


1980 ◽  
Vol 202 (1) ◽  
pp. 21-28 ◽  
Author(s):  
S.A. Volkov ◽  
Yu.A. Sultanovich ◽  
K.I. Sakodynskii

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