Optimized vacuum/pressure sol impregnation processing of wood for the synthesis of silica/biocarbon composite

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.