Synthesis of MCM-41 nanomaterial from Algerian bentonite: influence of synthesis pH

Abstract

Mesoporous materials of the MCM-41 type were synthesized from Algerian bentonite as an aluminosilicate source without the addition of pure silica and aluminum reagents. The samples were synthesized under hydrothermal condition using cetyltrimithylammonium bromide (CTAB) as surfactant. The influence of initial synthesis pH on the material properties of as-synthesis MCM-41 samples was studied at different temperatures of crystallization. The samples were characterized using several techniques e.g. X-ray diffraction (XRD), N 2 adsorption-desorption and transmission electron microscope (TEM). The experimental results showed that bentonite can be used as an aluminosilicate source for the synthesis of Al-MCM-41. By decreasing the synthesis temperature of crystallization, it is necessary to decrease the synthesis pH value to form the best ordered hexagonal phase and eliminate the lamellar phase.

Impregnation of Fe³⁺ into MCM-41 Pores: Effect of Fe³⁺ Concentration on the Weight Percent of Fe-Frameworks and Fe-Non-Frameworks

“…In general, silica precursors such as tetraethyl orthosilicate (TEOS) [5][6][7] and sodium silicate [8][9][10][11] are used in the synthesis of MCM-41, which is relatively expensive. Iron ore tailing [12][13], siliceous sugar industry waste [14], silicon carbide sludge and granite sludge [15], bentonite [16] and rice husk ash [17][18][19] have all been investigated for use as a silica precursor in the manufacture of MCM-41 to minimize production costs. Rice husk ash (RH) is the most potent natural substance because it contains SiO 2 at concentrations of over 90% [20][21][22].…”