Mesoporous silica MCM-41 with rod-shaped morphology: Synthesis and characterization

A new synthesis route has been established to prepare highly pure mesoporous silica material (Si-MCM-41) with rod-like morphology. To improve the stability and to bring about the long range ordering in the mesoporous material, a series of tetra-alkylammonium salts has been employed in the new procedure in addition to the surfactant, cetyl-trimethylammonium bromide. The mesoporous silica materials have been characterized by small-angle X-ray diffraction (SAX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 sorption and solid state 29Si NMR measurements. The XRD study revealed that an excellent long range structural ordering of mesoporous material can be achieved using tetra-butylammonium bromide as a promoter. SEM study showed that rod-shaped single crystal like particles were formed in hydrothermal synthesis. TEM study revealed the presence of hexagonal voids on the face of the rod-shaped particles while nitrogen sorption study establishes the mesoporosity of the material. A high degree of cross-linking of –Si–O–Si– networks in the mesoporous silica has been evidenced in 29Si NMR study.

Highly pure mesoporous silica material, Si-MCM-41@TBA with single crystal-like rod shaped morphology has been prepared by following hydrothermal process using a promoter tetra-butyl-ammonium bromide salt. The mesoporous material shows a higher degree of hydrothermal stability and a better long-range structural ordering with thicker pore walls. Transmission electron micrographs revealed the presence of hexagonal voids on the face of the rod-shaped particles while nitrogen sorption study establishes the mesoporosity of the material.Figure optionsDownload as PowerPoint slideHighlights
► Highly pure mesoporous silica material.
► Rod-shaped particles.
► High degree of cross-linking of –Si–O–Si– networks.