中文摘要：

二氧化硅/生物质碳复合材料是溶胶-凝胶/碳热还原法制备生物质多孔碳化硅陶瓷的关键。以尺寸为60mm×18mm×5mm的松木为原材料,在105℃下干燥24h,在不同真空/加压条件下浸渍二氧化硅溶胶,经过干燥和循环浸渍在松木孔道中填充二氧化硅凝胶,将二氧化硅凝胶/松木复合材料在500℃氮气气氛下碳化2h,制备出二氧化硅/生物质碳复合材料。采用扫描电子显微镜（SEM）、傅立叶变换红外光谱（FT-IR）、X射线衍射（XRD）对二氧化硅/生物质碳复合材料的形貌和结构进行表征,详细研究了浸渍压力和循环次数对二氧化硅/生物质碳复合材料结构的影响。

英文摘要：

The optimized vacuum/pressure impregnation technique of silica/biocarbon composite is highly effective for the preparation of biomorphic porous SiC ceramics.Pine wood with shaped sample dimensions of 60mm×18mm×5mm（axial） was selected as the raw material,samples were dried at 105℃ for 24h.SiO2 sol was impregnated into pine wood under different vacuum/pressure conditions.SiO2 gel was introduced in pine after drying procedures and multiple impregnation.SiO2/pine composites were pyrolyzed at 500℃ under N2 atmosphere for 2 h to prepare SiO2/biocarbon composite.The morphology and structure of the samples were investigated by scanning electron microscope（SEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）.The effects of impregnation pressure and cycles on the microstructures of silica/biocarbon composite were systematacially investigated.