Surface functionalization of mesoporous silica MCM-41 with 3-aminopropyltrimethoxysilane for dye removal: kinetic, equilibrium, and thermodynamic studies

Abstract

2015): Surface functionalization of mesoporous silica MCM-41 with 3-aminopropyltrimethoxysilane for dye removal: kinetic, equilibrium, and thermodynamic studies, Desalination and Water Treatment, A B S T R A C TMesoporous silica MCM-41 was synthesized and functionalized with a silane coupling agent (3-aminopropyltrimethoxysilane, APTMS) for the removal of Acid Blue 25 (AB25, anionic dye) and Methylene Blue (MB, cationic dye) from aqueous solutions as adsorbents. The synthesized (MCM-41) and functionalized (f-MCM-41) materials were characterized using field emission scanning electron microscopy, energy-dispersive X-ray spectrometry, transmission electron microscopy, particle size analysis, nitrogen gas adsorption-desorption analysis, X-ray diffraction spectrometry, and Fourier transform infrared spectrometry. The results indicate that the surface modification of MCM-41 with APTMS was successfully carried out. Batch experiments were performed to examine AB25 and MB removal by MCM-41 and f-MCM-41 under various experimental conditions. The results show that f-MCM-41 was a good adsorbent for anionic AB25, but not for cationic MB. This could be attributed to the presence of amine groups on the surfaces of f-MCM-41 from the APTMS modification. Conversely, MCM-41 was good for MB removal, but not for AB25 removal. AB25 removal in f-MCM-41 was sensitive to solution pH, with decreasing adsorption capacity as pH increased from 4.1 to 9.4. MB removal in MCM-41 was sensitive to solution pH in the opposite manner, with increasing adsorption capacity as pH increased from 4.1 to 10.3. Thermodynamic analysis showed that the adsorption of AB25 to f-MCM-41 and of MB to MCM-41 decreased with increasing temperature from 15 to 45˚C, indicating the exothermic nature of the sorption process. This study demonstrated that surface functionalization with silane coupling agents can help to make MCM-41 useful for the removal of various types of dyes.

Synthesis of Nano-Zinc Oxide Loaded on Mesoporous Silica by Coordination Effect and Its Photocatalytic Degradation Property of Methyl Orange

“…Figure 3 shows the low angle X-ray diffraction (LXRD) patterns of MCM-41, Sal-MCM-3, Sal-MCM-9, ZnO-MCM-3, and ZnO-MCM-9. Three characteristic peaks are shown in MCM-41, which could be ascribed to the (100), (110), and (200) crystal faces, indicating that the particles had a regular hexagonal pore structure [ 42 ]. The modification of salicylaldimine made the intensity of the low-angle XRD peaks decrease, especially in the (110) and (200) crystal face.…”

Highly efficient triazolone/metal ion/polydopamine/MCM-41 sustained release system with pH sensitivity for pesticide delivery

“…Three characteristic peaks of MCM-41 ascribed to the (100), (110) and (200) crystal face representing the regular hexagonal pore structure [32] still existed in the XRD patterns of PDA–MCM-41, indicating that the regular hexagonal pore structure remained after PDA encapsulation. The strength of the XRD peaks of the (100), (110) and (200) crystal face decreased after encapsulated by PDA, which convinced us that PDA was introduced to the system and decreased its degree of orderliness [33].…”

Synthesis and Characterization of Chlorpyrifos/Copper(II) Schiff Base Mesoporous Silica with pH Sensitivity for Pesticide Sustained Release

“…Figure shows the X-ray diffraction (XRD) patterns of MCM-41, Cu–MCM-41, SA–MCM-41, and CH–Cu–MCM-41. There are three characteristic peaks shown in MCM-41, which could be ascribed to (100), (110), and (200) crystal faces, which indicated that the particles had a regular hexagonal pore structure . As modified by salicylaldehyde, the strength of the XRD peaks decreased, especially in (110) and (200) crystal faces, which proved that APTES was introduced to the system and decreased its degree of orderliness .…”