Characterization of nanoporous β-SiC fiber complex prepared by electrospinning and carbothermal reduction

Abstract

The nanoporous b-silicon carbide (SiC) nano-sized fiber complex were made from precursors of various ratios with (SiO 2 ) as silicon source and polyacrylonitrile as carbon source by simple electrospinning method and economical carbothermal reduction. The prepared samples were characterized by SEM for surface shape, XRD for crystalline properties, TGA in air for oxygen resistance, and BET for porosity according to the precursor components (C/Si mol ratio). The samples with carbon ratio to silicon (C/Si) of five or more in the precursor showed the long fiber shape. Increasing the C/Si in the precursor solution tended to lead higher b-SiC crystalline and smaller crystallite size than low C/Si in the precursor solution because excess carbon could act as a dispersant and barrier to prevent neck growth or adhesion of SiC. The prepared samples have superior oxidation resistance as a whole. The increment of the C/Si leads to the increment of porosity. Also, it seems that the gaseous pore development of carbon during carbothermal reduction leads to mainly small pores (micro-or mesopores).

Effects of heat-treatment temperature on carbon-based composites with added illite

“…With a heat-treatment temperature of 1,000°C, an SiO 2 peak at 19.88°, characteristic of the illite, was observed without any SiC peak. At heat-treatment temperatures of 1,650 and 2,300°C, three peaks were observed, at 35.68, 60.06, and 71.80°, corresponding to the (1 1 1), (2 2 0), and (3 1 1) peaks of β-SiC, respectively; these peak positions are in good agreement with the findings of other studies [16][17][18]. β-SiC was formed as a product of the carbothermal reaction as a result of intimate contact between the SiO 2 in the illite and the phenol resin in the precursor or carbon fibers in the preform [13,15].…”

“…These peaks corresponded to α-SiC. According to a computer simulation by Pujar and Cawley [19], these peaks arise from stacking faults, which are crystallographic defects in the stacking sequence [17]. Another study reported that these peaks arise from the presence of the 2H polytype [20], which denser than those without illite (Fig.…”

Influence of Cobalt Precursor on Efficient Production of Commercial Fuels over FTS Co/SiC Catalyst

“…β-SiC support presented characteristic spectra of the two main SiC polytypes, namely α and β. Reflections at 2θ: 35.5˝[111] and 33.7˝[0001] are ascribed to hexagonal α-SiC, being the first one (C-SiC) caused by heaping defects generated during the formation of the material [36]. However, those at 2θ: 41.4˝[002], 59.9˝ [202] and 71.7˝ [113] are assigned to face-centered cubic, β-SiC [37,38]. As depicted in Figure 3, catalyst preparation procedures were confirmed to result in the formation of a pure cobalt oxide spinel phase, Co 3 O 4 , regardless of the type of precursor.…”

Hybrid Carbon Nano-Fibers with Improved Oxidation Resistance

“…For instance, carbon/silicon (C/Si) composite nanofibers can be prepared by a judicious combination of colloid electrospinning and subsequent thermal treatments. Lee et al [25] added SiO 2 nanoparticles in a PAN to fabricate SiC nano-fibres using electrospinning technique. After using many characterization tools, the SiO 2 /C ratio played a key role in controlling the fibers morphology, structure, and properties.…”