Preparation and morphology of porous SiO2 ceramics derived from fir flour templates

The p reparation of Si O2 ceramics wi th controllable porous structur e from fir flour t emplates via so l–gel processing was inve stigated. The specifi c size the fir flour, which was tr eated with 20 % NaOH solution, was infiltrat ed with a low viscous silica sol and subsequently calcined in air, which resulted in the formation of highly porous SiO 2 ceramics. X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field e mission scanning electron microscopy (FESEM) were employed to investigate the microstructure and phase formation during processing as well as of the SiO2 ceramics. N2 adsorption measurements w ere used to analy ze the pore size di stributions (PSD) o f the final ceramics. The results i ndicated that the surface topography was changed and the pr oportion of the a morphous material was in creased in N aOH-treated fir flou r. The final ox ide product s re tained ord ered structures of th e pores and showed unique pore sizes and distributions with hierarchy on the nanoscale derived from the fir flour.