Effect of acrylamide monomer concentration in low temperature magnesiothermic synthesis of mesoporous silicon carbide from MCM-48/PAAM nanocomposite precursor

Abstract

Mesoporous silicon carbide with high specific surface area was successfully synthesised from a MCM-48/polyacrylamide nanocomposite precursor in two temperature ranges of 650-700uC and 800-850uC by a magnesiothermic reduction process. The MCM-48/polyacrylamide precursor nanocomposite was prepared by in situ polymerisation. Heat treatment using low concentrations of acrylamide monomer in the temperature range of 650-700uC and using high concentration of acrylamide monomer was carried in two temperature ranges of 650-700uC and 800-850uC. The products were characterised by X-ray diffraction, TEM and N 2 adsorption-desorption. The results show that synthesised SiC in both temperature ranges of 650-700uC and 800-850uC is mesoporous and has specific surface of 194/60 and 167/84 m 2 g 21 respectively. The results also show that the value of carbon content and the concentration of acrylamide monomer (factor affecting the amount of contact surface of carbon and silica) impress the starting temperature of the reaction.

Fabrication of SiC and Si3N4Whiskers under Pressurized Ar and N2Atmosphere through High-Energy Ball Milling

“…The unwanted impurities were removed from the product powder by room‐temperature acid treatment in a mixture of 10 wt% HF and 2 M HCL for 5 h, filtration, washing with distilled water, and drying at room temperature (24 h). The mesoporous silica had similar Brunauer–Emmett–Teller data as previously reported (total pore volume, average pore diameter, and BET surface area of 0.7 cm 3 /g, 2.2 nm, and 1200 m 2 /g, respectively) . High‐energy ball milling was carried out in a planetary ball mill at 600 rpm using a ball‐to‐powder mass ratio of 55:1 (total powder mass = 2 g).…”

Low-Temperature Transformation of C/SiO2 Nanocomposites to β-SiC with High Surface Area

“…To this end, increasing attention has been paid to alternative magnesiothermic reduction. − For example, Shi et al developed a template approach for directly converting C/SiO 2 composites to hierarchical SiC nanomaterials via a magnesiothermic reaction at a relatively low temperature . They adopted Pluronic F127 block copolymer and polystyrene spheres as dual templates to prepare the precursor.…”