Organically Modified Saponites: SAXS Study of Swelling and Application in Caffeine Removal

Author(s)

Marcal, Liziane ^[1] ; de Faria, Emerson H. ^[1] ; Nassar, Eduardo J. ^[1] ; Trujillano, Raquel ^[2] ; Martin, Nuria ^[2] ; Vicente, Miguel A. ^[2] ; Rives, Vicente ^[2] ; Gil, Antonio ^[3] ; Korili, Sophia A. ^[3] ; Ciuffi, Katia J. ^[1]

Affiliation

^[1] Univ Franca, BR-14404600 Franca, SP - Brazil

^[2] Univ Salamanca, Dept Quim Inorgan, GIR QUESCAT, E-37008 Salamanca - Spain

^[3] Univ Publ Navarra, Dept Quim Aplicada, Pamplona 31006 - Spain

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 7, n. 20, p. 10853-10862, MAY 27 2015.
• Web of Science Citations: 20

Abstract

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. (AU)

• FAPESP's process: 13/50216-0 - New clay-based materials with advanced technological and environmental applications
• Grantee: Katia Jorge Ciuffi Pires
• Support Opportunities: Regular Research Grants