Hard templating synthesis of nanoporous silicon carbide SiC with different structure and morphology

Abstract

Silicon Carbide (SiC), one of the most promising ceramic materials, exhibits a combination of properties which makes it exciting for a number of applications both in industry and for experiments in academia. Several types of Si-based ceramics materials have been prepared using an organic-to-inorganic conversion process. We demonstrate here a one step synthesis of highly crystalline mesoporous silicon carbide materials with high specific surface areas and tunable pore diameter. Thermogravimetric analysis (TGA), nitrogen sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and infrared (IR) spectroscopy were used to characterize SiC products. Mesoporosity of the SiC showed a decrease with increasing PCS content. The rough surface and high order of the nanowire arrays observed in SiC material result from the strong interconnections of the products. The ordered structures of mesoporous SiC were exact inverse replicas of their respective silica templates, as characterized by low angle X-ray diffraction (XRD), transmission electron microscope (TEM) images, and the adsorption desorption isotherm of nitrogen. The elemental analysis and thermogravimetric analysis indicates the formation of silicon oxycarbide on the surface of SiC samples. The amount of free carbon deposited was examined by using thermogravimetric measurements in air. All the SiC samples were characterized by XRD, SEM, TEM, thermogravimetric analysis and nitrogen physisorption studies, which showed that the SiC samples were well crystalline and had a surface area up to 115.8 m2/g. The high temperature properties are dependent on the atomic arrangement and the quantity of amorphous SiC and glassy carbon in the fibers. Possible applications for these fibers are as refractory materials, and as reinforcement fibers for plastics, metals, and ceramics. The results of the investigations have been published in international journals and presented in International conferences. newline newline newline