Preparation and characterization of SiC hollow microspheres

摘要

We present the method of chemical vapor deposition-pyrolysis for the fabrication of SiC hollow microspheres. Microspheres with a diameter of approximately 480-550 mu m and wall thickness of 5-15 mu m are thus successfully prepared. The composition, especially the C/Si atomic ratio, and surface morphologies of the SiC microspheres can be flexibly adjusted by controlling the coating and heating parameters. The SiC microspheres mainly contain C-Si bonds with C/Si atomic ratios of approximately 1-3. The precursor microspheres are found to exhibit a large volume shrinkage (39-55%) during the pyrolysis process, while pyrolysis has a negligible impact on the yield of the SiC microspheres (>95%). The spherical degrees are greater than 98% with small dispersions. The wall thickness uniformities can be optimized as high as 95%. The density of SiC microspheres can be increased by prolonging the holding time at 450 degrees C, while the corresponding RMS roughness can be decreased. (C) 2017 Elsevier B.V. All rights reserved.