Low-temperature Magnesiothermic Synthesis of Mesoporous Silicon Carbide from an MCM-48/Polyacrylamide Nanocomposite Precursor
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2013年第3期
论文作者：Zahra Saeedifar Amir Abbas Nourbakhsh Roozbeh Javad Kalbasi Ebrahim Karamian
文章页码：255 - 260
摘 要：<正>Mesoporous silicon carbide with high specific surface area was successfully synthesized from an MCM-48/ polyacrylamide nanocomposite precursor in the temperature range of 550—600℃（below the melting point of Mg） by means of a magnesiothermic reduction process.The MCM-48/polyacrylamide precursor nanocomposite was prepared by in-situ polymerization of acrylamide monomer in the presence of mesoporous MCM-48 synthesized by sol-gel method.The physicochemical properties and microstructures of the nanocomposite precursor and the low-temperature SiC product were characterized by X-ray diffraction（XRD）, differential scanning calorimetry-thermo gravimetric analysis（DSC-TGA）,transmission electron microscopy （TEM） and N2 adsorption—desorption.TEM micrographs and Brunauer—Emmett—Teller（BET） gas adsorption studies showed that the SiC powder was nanocrystalline and had a specific surface area of 330 m2/g and a mesoporosity in the range of 2—10 nm.The presence of an exothermic peak in the DSC trace corresponds to the self-combustion process of the SiC magnesiothermic synthesis.The results also show that the carbon in excess to that required to produce SiC plays a role in the reduction of the SiO2.The mechanism of magnesiothermic synthesis of mesoporous SiC is discussed.
Zahra Saeedifar1，Amir Abbas Nourbakhsh2，Roozbeh Javad Kalbasi2，Ebrahim Karamian1
1. Department of Materials Engineering,Najafabad Branch,Islamic Azad University,P.O.Box 517,Isfahan,Iran2. Department of Materials Engineering,Shahreza Branch,Islamic Azad University,Isfahan,Iran
摘 要：<正>Mesoporous silicon carbide with high specific surface area was successfully synthesized from an MCM-48/ polyacrylamide nanocomposite precursor in the temperature range of 550—600℃（below the melting point of Mg） by means of a magnesiothermic reduction process.The MCM-48/polyacrylamide precursor nanocomposite was prepared by in-situ polymerization of acrylamide monomer in the presence of mesoporous MCM-48 synthesized by sol-gel method.The physicochemical properties and microstructures of the nanocomposite precursor and the low-temperature SiC product were characterized by X-ray diffraction（XRD）, differential scanning calorimetry-thermo gravimetric analysis（DSC-TGA）,transmission electron microscopy （TEM） and N2 adsorption—desorption.TEM micrographs and Brunauer—Emmett—Teller（BET） gas adsorption studies showed that the SiC powder was nanocrystalline and had a specific surface area of 330 m2/g and a mesoporosity in the range of 2—10 nm.The presence of an exothermic peak in the DSC trace corresponds to the self-combustion process of the SiC magnesiothermic synthesis.The results also show that the carbon in excess to that required to produce SiC plays a role in the reduction of the SiO2.The mechanism of magnesiothermic synthesis of mesoporous SiC is discussed.
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