Adela Egelja

Preparation of Porous Silica Ceramics Using the Wood Template

Porous silica (SiO2) ceramic with a wood-like structure was prepared by wet impregnation tetraethyl orthosilicate (TEOS) into biological template that was derived from linden wood (tilia amurensis). After repeated pressure impregnation the subsequent annealing in air atmosphere at 800°C resulted in burn out of the template and consolidation of the oxide layers. The products exhibit structures corresponding to negative replication of biological templates. X-ray diffraction (XRD), scanning electron microscopy (SEM), infra red (IR), and Brunauer Emmett Teller (BET) measurements were employed to characterize the phases and crystal structure of biomorphic ceramics. It was found that the bio-organic structure was converted into oxide ceramics (SiO2). At low temperature (800°C), pore radius varied between 2 and 10 nm indicating that the samples were mostly mesoporous. Samples treated at higher temperature (1300°C) lost the mesoporous character; however, they were still porous having the microstructural features of the biological perform.