Organically Modified Saponites: SAXS Study of Swelling and Application in Caffeine Removal.
This study aimed to assess the capacity of saponite modified with n-hexadecyltrimethylammonium bromide (CTAB) and/or 3-aminopropyltriethoxysilane (APTS) to adsorb and remove caffeine from aqueous solutions. Powder X-ray diffraction (PXRD) revealed increased basal spacing in the modified saponites. Small-angle X-ray scattering (SAXS) confirmed the PXRD results; it also showed how the different clay layers were stacked and provided information on the swelling of natural saponite and of the saponites functionalized with CTAB and/or APTS. Thermal analyses, infrared spectroscopy, scanning electron microscopy, element chemical analysis, and textural analyses confirmed functionalization of the natural saponite. The maximum adsorption capacity at equilibrium was 80.54 mg/g, indicating that the saponite modified with 3-aminopropyltriethoxysilane constitutes an efficient and suitable caffeine adsorbent.
†Universidade de Franca, Avenida Dr. Armando Salles Oliveira, Parque Universitário, 201, 14404-600, Franca/SP, Brazil.
Liziane
L
Marçal
†Universidade de Franca, Avenida Dr. Armando Salles Oliveira, Parque Universitário, 201, 14404-600, Franca/SP, Brazil.
Emerson H
EH
de Faria
†Universidade de Franca, Avenida Dr. Armando Salles Oliveira, Parque Universitário, 201, 14404-600, Franca/SP, Brazil.
Eduardo J
EJ
Nassar
‡GIR-QUESCAT, Departamento de Química Inorgánica, Universidad de Salamanca, 37008 Salamanca, Spain.
Raquel
R
Trujillano
‡GIR-QUESCAT, Departamento de Química Inorgánica, Universidad de Salamanca, 37008 Salamanca, Spain.
Nuria
N
Martín
‡GIR-QUESCAT, Departamento de Química Inorgánica, Universidad de Salamanca, 37008 Salamanca, Spain.
Miguel A
MA
Vicente
‡GIR-QUESCAT, Departamento de Química Inorgánica, Universidad de Salamanca, 37008 Salamanca, Spain.
Vicente
V
Rives
£Departamento de Química Aplicada, Universidad Pública de Navarra, 31006 Pamplona, Spain.
Antonio
A
Gil
£Departamento de Química Aplicada, Universidad Pública de Navarra, 31006 Pamplona, Spain.
Sophia A
SA
Korili
†Universidade de Franca, Avenida Dr. Armando Salles Oliveira, Parque Universitário, 201, 14404-600, Franca/SP, Brazil.
Katia J
KJ
Ciuffi
D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D002110:Caffeine / Q000737:chemistry / Q000302:isolation & purification*; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009930:Organic Chemicals / Q000737:chemistry*; D010316:Particle Size; D053838:Scattering, Small Angle; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction / Q000379:methods*
D000538:Aluminum Silicates; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D002110:Caffeine; C099453:saponite
caffeine adsorption; emerging contaminants; organoclay; saponite; wastewater