An ATR-FTIR study of different phosphonic acids adsorbed onto boehmite.
An ATR-FTIR study of the vibrational spectra of N,N-bis(2-hydroxyethyl) aminomethylphosphonic acid (BHAMP), 1-hydroxyethane-1,1'-diphosphonic acid (HEDP) and nitrilotris(methylenephosphonic acid) (NTMP) adsorbed onto boehmite is presented. The study was performed in the pH range from 5 to 9, and bands assignments are given in the 1200-900 cm(-1) wavenumber range, where the bands associated with various P-O(H) vibrations can be found. The three phosphonic acids adsorb onto boehmite by forming inner-sphere surface complexes. ATR-FTIR data indicates the presence of both protonated and deprotonated mononuclear surface species. In all cases, the surface-bound ions undergo protonation reactions as pH is decreased. The results are in good agreement with previously proposed surface complexation models.
Zenobi
María C
MC
Departamento de Química, Universidad Nacional del Sur, Bahía Blanca, Buenos Aires, Argentina. mzenobi@criba.edu.ar
Luengo
Carina V
CV
Avena
Marcelo J
MJ
Rueda
Elsa H
EH
D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D063065:Organophosphonates / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared
D063065:Organophosphonates; D009943:Organophosphorus Compounds; D012996:Solutions; C041182:(nitrilotris(methylene))triphosphonic acid; D000536:Aluminum Hydroxide; C069471:aluminum oxide hydroxide; D000537:Aluminum Oxide