Synthesis of bamboo‐like SiC whiskers from waste silica fume

Abstract

A process for the utilization of wasted silica fume is proposed in this work. Silicon carbide (SiC) whiskers several tens of micrometers in length and with a bamboo‐like morphology have been successfully synthesized by a carbothermal reduction process using purified silica fume as the silicon source. The morphology and structure of SiC whiskers were investigated by X‐ray diffraction, Raman spectroscopy, scanning electron microscopy, and high‐resolution transmission electron microscopy. Studies found that the as‐synthesized whiskers were grown as single‐crystalline β‐SiC along the (111) growth direction. The whiskers consisted of hexagonal stems randomly decorated with larger‐diameter knots along their whole length. On the basis of the characterization results, a vapor–solid process was discussed as a possible growth mechanism of the β‐SiC whiskers.

A SiC whisker reinforced high-temperature resistant phosphate adhesive for bonding carbon/carbon composites

“…Moreover, the as-synthesized SiCw had variable diameters, as seen from Fig. 1A, which were also beneficial to the toughening properties of whisker-reinforced adhesives [33]. Fig.…”

“…Instead, the whisker growth was likely through vapor-solid (VS) nucleation mechanism which was supported by the observed phenomenon that a large number of slender SiC whiskers distributed in the pore [42]. Thus, it was also assumed that the whiskers were formed through CO(g) and SiO(g) reaction via the VS growth mechanism [33]. The whole processes were described in the following reactions [43,44] (1) and (2).…”

Molten salt assisted synthesis of 3C–SiC nanowire and its photoluminescence properties

“…Secondly, the microstructure development of SiC is probably affected by the Si and C atoms migration at high temperature [38], and the growth of SiC NWs is controlled by a stacking process along (111) the plane under the non-equilibrium thermal condition, which may lead to the formation of defects (e.g. stacking faults [39,40]). The liquid phase of molten salts used in this work may provide a more favorable condition for the diffusion or mobility of Si and C atoms at elevated temperatures, resulting in a significant decrease of the SF density in the as-prepared SiC NWs with an increase of molten salts from 1:1 to 7:1.…”

Defect-Rich Nickel Nanoparticles Supported on SiC Derived from Silica Fume with Enhanced Catalytic Performance for CO Methanation

“…However, handling the problems of silica fume properly is not easy or smooth during the production. There is a large quantity of silica fume deserted in industrial disposal, which not only brings about resource wastage, but also results in serious pollution from the dust and powder [1,2].…”