聚碳硅烷先驱体法制备连续SiC自由膜研究

Studies on fabrication of continuous freestanding SiC films from polycarbosilane precursor

以聚碳硅烷（PCS）为先驱体，通过自行设计的喷膜板熔融纺出连续PCS自由薄膜，并对其进行氧化交联与高温裂解烧结可制得连续SiC自由薄膜。用扫描电镜分析薄膜表面和横断面的形貌，通过红外光谱（FTIR）分析氧化交联后薄膜的结构，通过拉曼光谱（Raman spectroscopy）、X射线衍射（XRD）与场发射高分辨透射电子显微镜（HRTEM）对薄膜进行微观分析。结果表明，熔融纺膜与聚碳硅烷先驱体法相结合可制得均匀、致密的连续β-SiC自由薄膜，其厚度可通过调节喷膜板的喷膜口尺寸大小和纺膜速度进行控制，薄膜的厚度大约在10～30μm。

Under the technique of the melt spinning of precursor, the uniform and dense continuous freestanding SiC films were successfully fabricated. A special spinneret was designed and manufactured for melt spinning. Polycarbosilane （PCS） was melt spun, cured and pyrolysis treated in the inert gas at high temperature, the initial amorphous PCS green films transformed to polycrystalline β-SIC. The continuous freestanding SiC films were studied for the first time. The microscopic surface and cross-section of resulting freestanding SiC films were investigated by SEM （scanning electron microscope）, and their composition and microstructure were characterized by Raman spectrometer, FTIR （fourier transform infrared spectrometer）, HRTEM （high resolution transmission electron microscope） and XRD （X-ray diffractometer）. The results showed that continuous freestanding SiC films contained amorphous SiOxCy, β-SIC nano-crystals and free carbon. And they could be obtained at thickness from 10-30μm through adjusting the spout size of spinneret and spinning speed.