Carbonization of Wood-Silica Composites and Formation of Silicon Carbide in the Cell Wall

Authors

  • Takeshi Furuno
  • Masashi Fujisawa

Keywords:

Carbonization, wood-silica composite, silicon carbide, cristobalite, X-ray diffraction, EPMA

Abstract

Wood-mineral composites (WMCs) impregnated with silica (SiO2) were carbonized at high temperature to form silicon carbide (SiC) directly using carbon from the wood with the impregnated silica. Carbonized composites were investigated using X-ray diffraction and EPMA (electron probe X-ray microanalysis). Water-saturated sapwood specimens of sugi, Japanese cedar (Cryptomeria japonica), were diffuse-penetrated with a colloidal silica solution or a water glass solution followed by drying to fix silica gel for preparing wood-SiO2 composites. The composites were burned at 600°C, 1000°C, and 1300°C for 30-120 minutes in a furnace in nitrogen gas. X-ray diffraction showed that the peak of SiO2 was recognized at 20 = 22°, and the peak became greater with an increase in burning temperature. The peak at 1300°C became very sharp, revealing the change of crystalline structure of SiO2 (cristobalite). In addition, the occurrence of the peak around 20 = 35° at 1300°C appeared, which confirmed the formation of silicon carbide (β-SiC) in the carbonized composites. EPMA observation showed the distribution of silicon in the cell walls that were carbonized at 1300°C. In conclusion, we showed that SiC was produced in the cell walls and the crystalline structure-changed SiO2 (cristobalite) existed in the cell lumina.

References

Abe, I. 1996. Production and application of charcoal absorbent. Wood Industry51 (7):294-300.nBorg, I. Y., and D. K. Smith. 1969. Calculated X-ray powder patterns for silicate minerales. The Geological Society of America, Inc., Boulder, CO. Pp. 747-749.nByrne, C. E., and D. C. Nagle. 1997. Carbonization of wood for advanced materials applications. Carbon35 (2):259-266.nFuruno, T., and Y. Imamura. 1998. Combinations of wood and silicate Part 6. Biological resistances of wood-mineral composites using water glass-boron compound system. Sci. Technol.32 (3): 161-170.nFuruno, T., T. Uehara, and S. Jodai. 1993. Combinations of wood and silicate III. Some properties of wood-mineral composites using the water glass-boron compound system. Mokuzai Gakkaishi39 (5):561-570.nFuruno, T., R. Tadokoro, and T. Uehara. 1995. Glueability and fire resistance of wood-mineral composites using the water glass-boron compound system. J. Soc. Mat. Sci., Japan44 (498):292-296.nFuruno, T., S. Aono, and T. Uehara. 1996. Mechanical properties of wood-mineral composites using the water glass-boron compound system. J. Soc. Mat. Sci., Japan45 (6):687-693.nFuruno, T., T. Kuriu, S. Matsuoka, T. Inoue, and T. Uehara. 1997. Wood-mineral composites using colloidal silica solution system and their properties. J. Soc. Mat. Sci., Japan46 (4):401-407.nFuruno, T., Y. Imamura, O. Asada, and S. Katoh. 1999. Some properties of wood-mineral composites using the colloidal silica solution system—Termite resistance, photo stability, hardness, and abrasion resistance. J. Soc. Mat. Sci., Japan48 (3):245-250.nFuruno, T., T. Goto, and S. Katoh. 2001. EPMA observation of wood-mineral composites using silicate-boron compound system and estimation of fire resistance by oxygen index method. J. Mat. Sci., Japan50 (4):383-390.nGreil, P. 2001. Biomorphous ceramics from lignocellulosics. J. Europ. Ceram. Soc.21:105-118.nGreil, P., T. Lifka, and A. Kaindl. 1998a. Biomorphic cellular silicon carbide ceramics from wood: I. Processing and microstructure. J. Europ. Ceram. Soc.18:1961-1973.nGreil, P., T. Lifka, and A. Kaindl. 1998b. Biomorphic cellular silicon carbide ceramics from wood: II. Mechanical properties. J. Europ. Ceram. Soc.18:1975-1983.nIshihara, S. 1997. Harmless conversion and removal of Nox by waste wood charcoal. Eco Industry2 (2): 15-20.nKitamura, T., and H. Katayama. 2001. The effect of carbonizing conditions on the specific area of charcoal from sugi (Cryptomeria japonica) wood. Mokuzai Gakkaishi 47 (2): 164-170.nKitamura, T., S. Matsumoto, and H. Katayama. 1999. The effect of carbonizing conditions on the properties of charcoal absorbent from Cryptomeria. Mokuzai Gakkaishi45 (2):171-177.nKitamura, T., G. Taguchi, and H. Katayama. 2002. The effects of carbonizing conditions on the specific area of charcoal from sugi (Cryptomeria japonica) wood II. Effects of carbonizing temperature and carbon dioxide concentration in carbonizing atmospheres. Mokuzai Gakkaishi48 (4):272-279.nMartínez-Fernández, J., F. M. Valera-Feria, and M. Singh. 2000. High temperature compressive mechanical behavior of biomorphic silicon carbide ceramics. Scripta Mater.43 (9):813-818.nOta, T., M. Takahashi, T. Hibi, M. Ozawa, S. Suzuki, and Y. Hikichi. 1995a. Biomimetic process for producing SiC "wood." J. Am. Ceram.78 (12):3409-3411.nOta, T., Y. Hikichi, and T. Hibi. 1995b. SiC ceramic mimicking fossil wood. Annual Report of the Ceramics Research Laboratory. Nagoya Institute of Technology5:33-39.nOta, T., H. Ichiyama, Y. Hikichi, and H. Akahane. 1997. Production of ceramic wood by mimicking fossil wood. Annual Report of the Ceramics Research Laboratory, Nagoya Institute of Technology7:21-24.nOta, T., Y. Hikichi, H. Kawakami, and H. Akahane. 1998. Preparation of SiC ceramic woods by mimicking fossil woods—No. 3. Annual Report of the Ceramics Research Laboratory, Nagoya Institute of Technology8:39-47.nYatagai, M. 1997. Charcoal—Characterization and utilization. Wood Industry52 (10):472-477.n

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2007-06-05

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