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Application of Statistical Rate Theory of Interfacial Transport to Study Solid Surface Heterogeneity from Controlled-rate Thermal Desorption (1999)

Villiéras, F. ; Michot, L. J. ; Gérard, G. ; [weitere]

Springer

Journal of thermal analysis and calorimetry 55 (1999), S. 511-530

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ISSN: 1572-8943

Schlagwort(e): apatite ; CRTD spectra ; surface heterogeneity ; thermal desorption

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie

Notizen: Abstract Controlled-rate thermodesorption (CRTD) spectra are obtained by adjusting the heating rate in such a way that the rate of desorption can be constant. A quantitative analysis of the obtained spectra is presented, based on application of the statistical rate theory of interfacial transport (SRTIT) to describe both adsorption and desorption kinetics. The SRTIT approach relates the rates of adsorption and desorption to the chemical potentials of the adsorbate in the gaseous and in the adsorbed phases. This quantitative analysis of the CRTD spectra yields the condensation approximation for the actual adsorption energy distribution. For the purpose of illustration, an analysis is made of water desorption from a synthetic apatite mineral under CRTD and classical TPD conditions. The influence of the adsorption and desorption rates is also discussed.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1010197903581

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Digitale Medien

Analysis of polymer films by diffuse reflectance FTIR spectroscopy: Characterization of terminal carboxyl functionalities (1992)

de Donato, P. ; Cases, J. M. ; Humbert, B. ; [weitere]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 30 (1992), S. 1305-1310

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ISSN: 0887-6266

Schlagwort(e): infrared spectra of PET film from diffuse reflectance ; poly(ethylene terephthalate), polymerization rate study by diffuse reflectance FTIR of ; carboxyl terminal functionalities in polymerizing PET films from FTIR study ; Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: Fourier transform infrared (FTIR) spectroscopy in the diffuse reflectance mode was used to study polyethylene terephthalate (PET) films. The polymer film (12 μm, molecular weight M1 = 18,000) was placed on a finely powdered KBr matrix, used as a reference. Infrared spectra exhibited a new band at 1684 cm-1, not usually reported in the literature. This band is assigned to the C—O stretching vibration of a terminal acidic function in the presence of internal hydrogen bonds. In the carbonyl region, artifacts created by specular reflection are also discussed. The assignment of the band at 1684 cm-1 is confirmed by transmission measurements on the overtone of carbonyl group (3335 cm-1), using polymer films with thicknesses greater than 200 μm and by comparison with polymer of different molecular weight. These acidic functions can be used to monitor the rate of polymerization. It is therefore possible to obtain information on the polymerization rate of PET films, using diffuse reflectance and transmission analysis, directly on the solid. © 1992 John Wiley & Sons, Inc.

Zusätzliches Material: 7 Ill.