Boron nitride (BN) powders were synthesized by pyrolysis at various temperatures to investigate the hydrolysis mechanism of borazine-derived BN pyrolysized below 1200 ℃. The BN was hydrolysized near room tem-perature at 65% or 90% relative humidity (RH) over 45 days. The long-term hydrolysis mechanism and structure evolution were investigated by a measurement of mass growth and by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) analyses. The sam-ples pyrolysized below 1200 ℃ were very sensitive to moisture, and their mass growth was closely related to the pyrolysis temperature. At 25 ℃ and 65% RH, the sample pyrolysized at 400 ℃ exhibited almost 100 wt% mass growth within 8 days, while the sample pyrolysized at 1200 ℃ exhibited about 20 wt% mass growth. The XRD analysis suggested a hydrolysis mechanism that corresponded to the interlayer spacing in the BN, which was consistent with the results reported. should be directly due to the residual N-H bonds On the other hand, the instability of borazine-derived BN in the compound, as suggested by FT-IR analysis.
参考文献
| [1] | S. Seghi;B. Fabio;J. Economy .Carbon/carbon-boron nitride composites with improved wear resistance compared to carbon/carbon[J].Carbon: An International Journal Sponsored by the American Carbon Society,2004(15):3043-3048. |
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