Microbeam Small Angle X-ray Scattering (μSAXS) and Microbeam X-ray Diffraction (μXRD) of fibrous carbon materials

摘要

At the microfocus beamline (ID13) in the “European Synchrotron Radiation Facility” (Grenoble, France) there are available X-rayrnmicrobeams with sizes down to 2 μm. The availability of these microbeams X-ray together with the existence of a positionresolvedrnscattering set-up make this technique suitable for the study of fibrous materials. In the case of porous materials, SmallrnAngle X-ray Scattering (SAXS) experiments can be run. Considering the beam size, this technique is called (μSAXS). In previousrnworks [1,2], it has been shown that this experimental technique (μSAXS) is suitable to study single activated carbon fibres byrnSAXS, instead of using a bundle of fibers. On the other hand, in the case of crystalline materials, microbeam X-Ray Diffractionrn(μXRD) experiments can be done.rnIn the present work, the results corresponding to μSAXS and μXRD experiments on carbonaceous materials are presented.rnμSAXS technique is used for studying the evolution of the porosity in carbon fibers during physical activation with CO2. In doingrnthat, measurements in the center of the fiber, before and after contrast-matching conditions, for activated carbon fibers (ACFs)rnwith different burn-off degree have been done. The results show the suitability of the contrast-matching experiments to analyzernthe widening of the microporosity during the CO2 activation process. On the other hand, μXRD experiments have been done withrna zeolite supported on an activated carbon fibre [7]. The preliminary results corresponding to those experiments are presented.