화학공학소재연구정보센터
Materials Science Forum, Vol.486-487, 522-525, 2005
Synthesis of heterogeneous beta-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 degrees C for 9h in a dynamic argon atmosphere (flow rate; 600 cm(3)/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 (W) reaction between SiO and CO, respectively.