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 60 mm×18 mm×5 mm (axial) was selected as the raw material, samples were dried at 105°C for 24 h. 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°C 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.