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dc.contributor.authorArmatas, G. S.en
dc.contributor.authorPetrakis, D. E.en
dc.contributor.authorPomonis, P. J.en
dc.date.accessioned2015-11-24T16:57:59Z-
dc.date.available2015-11-24T16:57:59Z-
dc.identifier.issn0021-9673-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/10642-
dc.rightsDefault Licence-
dc.subjecteffective diffusivityen
dc.subjecttortuosity factorsen
dc.subjecthenry constantsen
dc.subjectporous solidsen
dc.subjectfunctionalized silicaen
dc.subjectgas chromatographyen
dc.subjectzeolite crystal diffusivityen
dc.subjectgas-chromatographyen
dc.subjectcoefficientsen
dc.subjectcatalysten
dc.titleEstimation of diffusion parameters in functionalized silicas with modulated porosity - Part I: Chromatographic studiesen
heal.typejournalArticle-
heal.type.enJournal articleen
heal.type.elΆρθρο Περιοδικούel
heal.identifier.primaryDOI 10.1016/j.chroma.2005.03.046-
heal.identifier.secondary<Go to ISI>://000229192500008-
heal.identifier.secondaryhttp://ac.els-cdn.com/S0021967305005820/1-s2.0-S0021967305005820-main.pdf?_tid=a56dcfd897b8737292906106b38566db&acdnat=1333035463_ff05200e1bf8b357520a0e5c443909c0-
heal.languageen-
heal.accesscampus-
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείαςel
heal.publicationDate2005-
heal.abstractThe diffusion parameters of binary gas mixture He (tracer gas)-N-2 (carrier gas) in hybrid organic-inorganic SiO2-X Porous solids which have suffered gradual functionalization with functional groups X of increasing length (X = theta, equivalent to Si-H, equivalent to Si-CH2OH, equivalent to Si-(CH2)(3)OH, equivalent to Si-(CH2)(11)CH3) are reported. The effective diffusivities D-eff, the Henry law constants K as well as the tortuosity factors tau for the examined solids were estimated by a typical pulse gas chromatographic method. Analysis of the experimental results was carried out by the well-known method of linearization of moments. The moments s analysis provides a powerful means for extracting diffusion parameters from the experimental response curves The proposed methodology is simple compared to other similar studies and provides rapidly reliable data. The results of this work indicate that the effective diffusivity D-eff in porous networks drops markedly as the initial porosity of the parent SiO2 sample is blocked by the functionalization of the pore surfaces with functional groups of increasing size, equivalent to Si-H, equivalent to Si-CH2OH, equivalent to Si-(CH2)(3)OH and equivalent to Si-(CH2)(11)CH3. The low values of the Henry law constants K found indicate that the adsorption of He on the porous surfaces for all the solids is weak. Also, the tortuosity factor tau is proportionally correlated to the pore blocking effects and the percolation phenomena of gases flowing into the porous network. (c) 2005 Elsevier B.V. All rights reserved.en
heal.publisherElsevieren
heal.journalNameJournal of Chromatography Aen
heal.journalTypepeer reviewed-
heal.fullTextAvailabilityTRUE-
Appears in Collections:Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά). ΧΗΜ

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