title: EXAFS and DFT study of the cadmium and lead adsorption on modified silica nanoparticles.
abstract: Silica nanoparticles of 7 nm diameter were modified with (3-aminopropyl) triethoxysilane (APTES) and characterized by CP-MAS (13)C and (29)Si NMR, FTIR, zeta potential measurements, and thermogravimetry. The particles were shown to sorb successfully divalent lead and cadmium ions from aqueous solution. Lead complexation with these silica nanoparticles was clearly confirmed by EXAFS (Extended X-ray Absorption Fine Structure) with synchrotron light measurements. Predicted Pb-N and Pb-C distances obtained from quantum-chemical calculations are in very good agreement with the EXAFS determinations. The calculations also support the higher APTES affinity for Pb(2+) compared to Cd(2+).
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina; Centro de Investigaciones Ópticas (CIOp), CONICET La Plata-CIC, CC 3, 1897 Gonnet, La Plata, Argentina.
authors.forename: Valeria B
authors.initials: VB
authors.lastname: Arce
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: Romina M
authors.initials: RM
authors.lastname: Gargarello
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: Florencia
authors.initials: F
authors.lastname: Ortega
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: Virginia
authors.initials: V
authors.lastname: Romañano
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: Martín
authors.initials: M
authors.lastname: Mizrahi
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: José M
authors.initials: JM
authors.lastname: Ramallo-López
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Cobos
authors.affiliation: Chemistry Institute, University of Campinas, P.O. Box 6154, 13084-971 Campinas, São Paulo, Brazil.
authors.forename: Claudio
authors.initials: C
authors.lastname: Airoldi
authors.affiliation: Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (CCT La Plata-CONICET, Universidad Nacional de La Plata), Facultad de Ciencias Exactas, 50 y 115, 1900 La Plata, Argentina.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bernardelli
authors.affiliation: Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (CCT La Plata-CONICET, Universidad Nacional de La Plata), Facultad de Ciencias Exactas, 50 y 115, 1900 La Plata, Argentina.
authors.forename: Edgardo R
authors.initials: ER
authors.lastname: Donati
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina. Electronic address: dmartire@inifta.unlp.edu.ar.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Mártire
keywords: Cadmium; DFT; EXAFS; Lead; MEH-PPV; Silica nanoparticles