Small Angle X-ray Scattering Study of Oak Charcoals


  • Carl R. von Bastian
  • Paul W. Schmidt
  • Paul S. Szopa
  • E. Allen McGinnes, Jr.


Small angle X-ray scattering data have been used to characterize the microscopic and submicroscopic structure of oak charcoals produced at different temperatures. The specific surface has been calculated for each sample. The observed scattering is ascribed to voids in a carbon matrix. The scattering data suggest that these voids have average dimensions that fall into two groups: (1) a relatively large-scale structure that is similar to the structure of the original wood and that has dimensions of the order of microns, and (2) a much finer structure, with dimensions about 15Å. In samples prepared at low temperature, only the large-scale structure is detectable. When charcoals are prepared at temperatures above approximately 1000 F, additional voids are generated. As a result, the average dimensions of the large-scale voids are apparently reduced and a small-scale structure develops.


Emmett, P. H. 1948. Characteristics of charcoals and whetlerites. Chem. Rev. 43: 140-144.nGuinier, A., G. Fournet, K. L. Yudowitch, and C. B. Walker. 1955. Small angle scattering of X-rays. J. Wiley and Sons, Inc., New York.nKähkönen, H. 1971. Small angle X-ray diffraction study of density fluctuations in porous carbons. Suom. Kemistil. B44: 183-185.nKratky, O., and Z. Skala. 1958. Neues Verfahren zur Herstellung von blendenstreu-ungsfreien Röntgen-Kleinwinkelaufnahmen. V. Beschreibung eines Modells der U-Kamera. Z. Elektrochemie-Ber. Bunsenges. phys. Chemie 62: 73-77.nMcGinnes, E. A. Jr., S. A. Kandeel, and P. S. Szopa. 1971. Some structural changes observed in the transformation of wood into charcoal. Wood and Fiber 3(2): 77-83.nPatel, I. S., and P. W. Schmidt. 1972. Experimental verification of small-angle X-ray scattering collimation corrections. J. Appl. Crystallogr. 5: 40.nRuland, W. 1971. Small-angle scattering of two-phase systems: Determination and significance of systematic deviations from Porod's law. J. Appl. Crystallogr. 4: 70-73.nSchmidt, P. W. 1960. Small-angle X-ray scattering from proteins. J. Dairy Sci. XLV: 266-273.nSchmidt, P. W. 1965. Collimation corrections in small angle X-ray scattering. Acta Cryst. 19: 938-942.nSchmidt, P. W. 1971. Small angle X-ray scattering from suspensions of particles. Soil Sci. 112: 53-61.nTaylor, T. R., and P. W. Schmidt. 1969. A computer program for slit-length collimation corrections for small angle X-ray scattering data obtained with the Kratky camera. J. Appl. Crystallogr. 2: 143.nWeast, Robert C. (Editor). 1969. Handbook of chemistry and physics, 50th edition, p. B-99. Chemical Rubber Publ. Co., Cleveland, Ohio.n






Research Contributions