التفاصيل البيبلوغرافية
| العنوان: |
Interaction of catechol and gallic acid with titanium dioxide in aqueous suspensions. 1. Equilibrium studies |
| المؤلفون: |
Araujo, Paula Zulema, Morando, Pedro Juan, Blesa, Miguel Angel |
| بيانات النشر: |
American Chemical Society |
| المجموعة: |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
| مصطلحات موضوعية: |
Catechol, Gallic Acid, Titanium Dioxide, Equilibrium, https://purl.org/becyt/ford/1.4, https://purl.org/becyt/ford/1 |
| الوصف: |
The adsorption isotherms of catechol (1,2-dihydroxybenzene) and gallic acid (3,4,5-trihydroxybenzoic acid) onto titanium dioxide (Degussa P-25) were measured at various pH values and room temperature using attenuated total reflection Fourier transform infrared (FTIR-ATR) data, processed by singular value decomposition. The affinity is largely pH independent, although the deprotonatation of the carboxylic group in gallic acid might produce a slight increase in the affinity. Catechol was shown to form two complexes, with Langmuir stability constants log K of 4.66 (strong mode) and 3.65 (weak mode). Both complexes have the same spectral signature, and mononuclear and binuclear chelate structures are proposed for them. Gallic acid chemisorbs by complexation through two -OH groups and forms one complex only, log K= 4.70. The third -OH and the pendant carboxylate do not influence much the stability of the surface complex. Comparison with literature data demonstrates that the affinity of 4-chlorocatechol is also similar, whereas 2,3-dihidroxynaphthalene and 4-nitrocatechol form more stable complexes, probably because of the solvation contribution to the overall Gibbs adsorption energy. All quoted constants refer to the surface complexation equilibria written as follows: (≡Ti-OH) 2 + H2L = (≡Ti)2-L + 2H2O, i.e., as electroneutral processes. The FTIR-ATR spectra of the surface complexes are also discussed. © 2005 American Chemical Society. ; Fil: Araujo, Paula Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina ; Fil: Morando, Pedro Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Nacional de San Martín. Instituto Sabato; Argentina ; Fil: Blesa, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ... |
| نوع الوثيقة: |
article in journal/newspaper |
| وصف الملف: |
application/pdf |
| اللغة: |
English |
| تدمد: |
0743-7463 |
| Relation: |
http://hdl.handle.net/11336/55492; Araujo, Paula Zulema; Morando, Pedro Juan; Blesa, Miguel Angel; Interaction of catechol and gallic acid with titanium dioxide in aqueous suspensions. 1. Equilibrium studies; American Chemical Society; Langmuir; 21; 8; 4-2005; 3470-3474; CONICET Digital; CONICET |
| الاتاحة: |
http://hdl.handle.net/11336/55492 |
| Rights: |
info:eu-repo/semantics/openAccess ; https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
| رقم الانضمام: |
edsbas.C17FFD7 |
| قاعدة البيانات: |
BASE |