Synthesis of Heterogeneous β-SiC Nano-Particles and Nano-Whisker from TEOS/SiO2 Bead/PMMA Ternary Xerogel
A modified sol-gel method is proposed for the preparation of silicon carbide nano-particles and nano-whisker. Tetraethoxysilane (TEOS), SiO2 bead, and PMMA as precursor of carbon source were used for preparing a ternary carbonaceous silicon xerogel, and morpholine is employed in the sol-gel process as a catalyst reagent. SiC nano-particles and nano-whisker were obtained from carbothermal reduction and vapor-solid (VS) reaction of the ternary xerogel at 1300°C for 9h in a dynamic argon atmosphere (flow rate; 600 cm3/min), and then purified by removing excess silica, residual carbon, and other impurities. The purified SiC sample was characterized by TG/DTA, XRD, SEM, and HRTEM. The nano-particles and the nano-whisker were synthesized by different growth mechanisms, with an initial nucleation via a VS reaction between SiO vapor and carbon precursor (PMMA) and a partially subsequent growth via a vapor-vapor (VV) reaction between SiO and CO, respectively.
Hyung Sun Kim, Sang-Yeop Park, Bo Young Hur and Soo Wohn Lee
J. W. Kim et al., "Synthesis of Heterogeneous β-SiC Nano-Particles and Nano-Whisker from TEOS/SiO2 Bead/PMMA Ternary Xerogel", Materials Science Forum, Vols. 486-487, pp. 522-525, 2005