Abstract:The article investigates the effect of thermal modification of porous carbon material (PCM), obtained from plant feedstock, on its morphology and fractal structure by small-angle X-ray scattering (SAXS) method. The analysis of the scattering intensity curves serve the basis for calculating the parameters of the PCM porous structure: the Porod constant, the Porod invariant, average pore radius, specific surface area, and mass and surface fractal dimensions. It has been found out that the PCMs obtained have frac… Show more
“…The X-ray scattering is due to differences in the electronic density between the voids (pores) and the carbon aggregates in the matrix. The scattering intensity decay monotonously in the whole q-interval, indicating a random distribution of the scattering, similar to that observed in other amorphous carbons [68,69].…”
Section: Raman Spectroscopy and X-ray Diffraction Analysissupporting
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Bimodal mesoporous hard carbons from stabilized resorcinol-formaldehyde resin and silica template with enhanced adsorption capacity
“…The X-ray scattering is due to differences in the electronic density between the voids (pores) and the carbon aggregates in the matrix. The scattering intensity decay monotonously in the whole q-interval, indicating a random distribution of the scattering, similar to that observed in other amorphous carbons [68,69].…”
Section: Raman Spectroscopy and X-ray Diffraction Analysissupporting
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Bimodal mesoporous hard carbons from stabilized resorcinol-formaldehyde resin and silica template with enhanced adsorption capacity
“…Note that the G400 sample was with very low open porosity; therefore, the nitrogen adsorption isotherm was not recorded. However, this sample has certain closed porosity because the specific surface area estimated from the SAXS data corresponds to 185 m 2 /g (the procedure of SAXS investigation is described in detail in [51]).Fig. 6Nitrogen adsorption-desorption isotherms for chars (L400, S400) and AC
…”
Glucose, lactose, and saccharose were used as precursors to prepare chars at 400 °C then activated at 800 °C or 1000 °C in closed vessels with controlled amounts of oxygen penetrating through nanopores in the vessel walls. There are correlations between the porosity, amounts of residual O- and H-containing functionalities, and electroconductivity of amorphous carbons studied. The pore size distributions calculated using the nitrogen adsorption isotherms and TEM images show that all carbons are mainly nanoporous with certain contribution of narrow mesopores (at pore half-width x < 5 nm). Oxidizing activation by oxygen penetrating into the closed vessels with chars through nanopores can more strongly change the outer layers of char particles than the inner pores. Therefore, despite relatively great burn-off degree, the textural characteristics are relatively low for activated carbons.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1723-z) contains supplementary material, which is available to authorized users.
“…[12]. This is why, one of the fundamental tasks in theoretical descriptions linked to experimental determinations in this research area is to reveal the relationship between the structure of fractals and their corresponding diffraction spectrum or scattering intensity distribution vs. scattering wave vector.…”
Section: Introductionmentioning
confidence: 99%
“…One of the most reliable methods to determine the structural properties of both deterministic and random fractals [ 10 , 11 ] is employing wave diffraction in the context of small-angle scattering on nano- or micro-structured materials, using neutrons or electromagnetic waves (x-ray, light, etc.) [ 12 ]. This is why, one of the fundamental tasks in theoretical descriptions linked to experimental determinations in this research area is to reveal the relationship between the structure of fractals and their corresponding diffraction spectrum or scattering intensity distribution vs. scattering wave vector.…”
Small-angle scattering (of neutrons, x-ray, or light; SAS) is considered to describe the structural characteristics of deterministic nanoscale fat fractals. We show that in the case of a polydisperse fractal system, with equal probability for any orientation, one obtains the fractal dimensions and scaling factors at each structural level. This is in agreement with general results deduced in the context of small-angle scattering analysis of a system of randomly oriented, non-interacting, nano-/micro-fractals. We apply our results to a two-dimensional fat Cantor-like fractal, calculating analytic expressions for the scattering intensities and structure factors. We explain how the structural properties can be computed from experimental data and show their correlation to the variation of the scaling factor with the iteration number. The model can be used to interpret recorded experimental SAS data in the framework of fat fractals and can reveal structural properties of materials characterized by a regular law of changing of the fractal dimensions. It can describe successions of power-law decays, with arbitrary decreasing values of the scattering exponents, and interleaved by regions of constant intensity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
