含氢硅油对高比表面积碳化硅孔结构的影响

Influences of Polymethylhydrosiloxane on the Pore Structure of Silicon Carbide

以糠醇为碳源,正硅酸乙酯为硅源,含氢硅油(PMHS)为结构助剂制备碳化硅前驱体,通过溶胶-凝胶法和碳热还原法制备出高比表面积多孔碳化硅,采用XRD、FTIR、SEM、HRTEM和BET对所制备的样品进行表征。结果表明,所得碳化硅具有高的比表面积130m2/g;含氢硅油的特殊结构有利于形成多孔碳化硅,且对碳化硅样品的比表面积、孔容起着至关重要的影响。

In the sol-gel method, furfuryl alcohol and tetraethoxysilane were used respectively as carbon, silicon precursors, polymethylhydrosiloxane（PMHS） was employed as pore-adjusting agent for preparing a carbonaceous silica xerogel. SiC was obtained by the carbothermal reduction of the carbonaceous silica xerogel. XRD, FTIR, SEM, HRTEM and BET were used to characterize the SiC samples. The results show that the SiC product is found to have high specific surface area of 130m^2/g. PMHS has important effects on the surface area, pore volume of the SiC product. It is therefore suggested that PMHS plays the role of structure-directing agent that enhances the production of mesoporous pores in the SiC product.