Inverse gas chromatography of chromia. Part I. Zero surface coverage
Apstrakt
The surface properties of the solid obtained from colloidal chromia were investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II healed at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/bass constants for the solids wore calculated from the IGC measurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar but much greater in the case of solid I. All the sorbents had a basic character, with the K-D/K-A ratio decreasing in the order I GT II GT III. The retention and resolution in thr separation of a vapour mixture of C-5-C-8 n...-alkanes on the three substrates were different. A rapid separation was observed on solid II and an enhanced I retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface.
Ključne reči:
inverse gas chromatography / chromia / Adsorption / thermodynamicsIzvor:
Journal of the Serbian Chemical Society, 2001, 66, 4, 259-271Kolekcije
Institucija/grupa
VinčaTY - JOUR AU - Onjia, Antonije E. AU - Milonjić, Slobodan K. AU - Rajaković, Ljubinka V. PY - 2001 UR - https://vinar.vin.bg.ac.rs/handle/123456789/2434 AB - The surface properties of the solid obtained from colloidal chromia were investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II healed at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/bass constants for the solids wore calculated from the IGC measurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar but much greater in the case of solid I. All the sorbents had a basic character, with the K-D/K-A ratio decreasing in the order I GT II GT III. The retention and resolution in thr separation of a vapour mixture of C-5-C-8 n-alkanes on the three substrates were different. A rapid separation was observed on solid II and an enhanced I retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface. T2 - Journal of the Serbian Chemical Society T1 - Inverse gas chromatography of chromia. Part I. Zero surface coverage VL - 66 IS - 4 SP - 259 EP - 271 UR - https://hdl.handle.net/21.15107/rcub_vinar_2434 ER -
@article{ author = "Onjia, Antonije E. and Milonjić, Slobodan K. and Rajaković, Ljubinka V.", year = "2001", abstract = "The surface properties of the solid obtained from colloidal chromia were investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II healed at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/bass constants for the solids wore calculated from the IGC measurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar but much greater in the case of solid I. All the sorbents had a basic character, with the K-D/K-A ratio decreasing in the order I GT II GT III. The retention and resolution in thr separation of a vapour mixture of C-5-C-8 n-alkanes on the three substrates were different. A rapid separation was observed on solid II and an enhanced I retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface.", journal = "Journal of the Serbian Chemical Society", title = "Inverse gas chromatography of chromia. Part I. Zero surface coverage", volume = "66", number = "4", pages = "259-271", url = "https://hdl.handle.net/21.15107/rcub_vinar_2434" }
Onjia, A. E., Milonjić, S. K.,& Rajaković, L. V.. (2001). Inverse gas chromatography of chromia. Part I. Zero surface coverage. in Journal of the Serbian Chemical Society, 66(4), 259-271. https://hdl.handle.net/21.15107/rcub_vinar_2434
Onjia AE, Milonjić SK, Rajaković LV. Inverse gas chromatography of chromia. Part I. Zero surface coverage. in Journal of the Serbian Chemical Society. 2001;66(4):259-271. https://hdl.handle.net/21.15107/rcub_vinar_2434 .
Onjia, Antonije E., Milonjić, Slobodan K., Rajaković, Ljubinka V., "Inverse gas chromatography of chromia. Part I. Zero surface coverage" in Journal of the Serbian Chemical Society, 66, no. 4 (2001):259-271, https://hdl.handle.net/21.15107/rcub_vinar_2434 .