Fractal analysis methods to characterize porous solids using nitrogen adsorption data

2000 ◽  
Vol 77 (9) ◽  
pp. 653-658
Author(s):  
B Sahouli ◽  
S Blacher ◽  
F Brouers ◽  
L Chahed
Keyword(s):  
Adsorption Isotherms ◽  
Fractal Analysis ◽  
Nitrogen Adsorption ◽  
Porous Solids ◽  
Complex Materials ◽  
Fractal Approach ◽  
Adsorption Data ◽  
Commercial Carbon ◽  
Recent Developments ◽  
Nitrogen Adsorption Data

The use of the fractal concept to characterize the morphological nature of complex materials, such as porous solids, is considered. The most popular approaches, which are based on analysis of the shape of the adsorption isotherms of a substance vapor (in this case nitrogen at 77 K), are outlined and applied to characterizing a series of commercial carbon blacks. The most recent developments in this domain are given. The results obtained show that some methods, although derived using different arguments, are equivalent in some conditions, and the concept of a standard isotherm can be used in the fractal approach PACS Nos.: 61.43 H Fractals -68.45 -v

scholarly journals Textural properties of synthetic clay-ferrihydrite associations

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 395-407 ◽  
Author(s):  
R. Celis ◽  
J. Cornejo ◽  
M. C. Hermosin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mercury Porosimetry ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Fractal Approach ◽  
Adsorption Data ◽  
Synthetic Clay ◽  
Nitrogen Adsorption Data

AbstractKaolinite-ferrihydrite and montmorillonite-ferrihydrite associations were prepared following a procedure based on the Russell method for the synthesis of ferrihydrite and the texture of the clay-ferrihydrite complexes was studied using different techniques. The textural properties of kaolinite were little affected by the Fe association, showing only a slight increase in the specific surface area measured by nitrogen adsorption and a decrease in the largest pores (>10 µm), as measured by mercury porosimetry. In contrast, the nitrogen specific surface area of the montmorillonite complexes was much higher than that of the clay without Fe and the pore structure depended on the amounts of Fe in the complexes. Application of the fractal approach to nitrogen adsorption data indicated that the surface roughness (microporosity) was greater for the complexes prepared from diluted Fe(III) solutions, in agreement with the information obtained from classical interpretation of the adsorption isotherms (shape of the isotherms and t-plots).

Fractal Analysis of Commercial and Pyrolytic Carbon Blacks Using Nitrogen Adsorption Data

1995 ◽  
Vol 68 (2) ◽  
pp. 330-341 ◽  
Author(s):  
H. Darmstadt ◽  
C. Roy ◽  
S. Kaliaguine ◽  
B. Sahouli ◽  
S. Blacher ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Nitrogen Adsorption ◽  
Pyrolytic Carbon ◽  
Sorption Data ◽  
Carbon Blacks ◽  
Vacuum Pyrolysis ◽  
Adsorption Data ◽  
Commercial Carbon ◽  
Different Temperatures ◽  
Nitrogen Adsorption Data

Abstract The surface fractal dimension of commercial rubber-grade carbon blacks and of pyrolytic carbon blacks (CBp) was determined using nitrogen sorption data. The CBp were produced by vacuum pyrolysis of used tires at different temperatures and pressures. Commercial carbon blacks and CBp obtained at low pyrolysis pressures have a similar fractal dimension of the surface (Ds) or roughness. CBp produced at higher pyrolysis pressures have a smaller fractal dimension than commercial grades, suggesting a smoother surface. Complementary SIMS and ESCA investigations showed that the decreasing fractal dimension with increasing pyrolysis pressure is due to the formation of carbonaceous deposits on the CBp from the pyrolyzed organic material.

scholarly journals New approach in the application of lignin for the synthesis of hybrid materials

2017 ◽  
Vol 89 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Beata Podkościelna ◽  
Marta Goliszek ◽  
Olena Sevastyanova
Keyword(s):  
Suspension Polymerization ◽  
Nitrogen Adsorption ◽  
Experimental Protocol ◽  
New Approach ◽  
Surface Areas ◽  
Adsorption Data ◽  
Novel Method ◽  
Derivatives Of ◽  
Polymerization Method ◽  
Nitrogen Adsorption Data

AbstractIn this study, a novel method for the synthesis of hybrid, porous microspheres, including divinylbenzene (DVB), triethoxyvinylsilane (TEVS) and methacrylated lignin (L-Met), is presented. The methacrylic derivatives of kraft lignin were obtained by reaction with methacryloyl chloride according to a new experimental protocol. The course of the modification of lignin was confirmed by attenuated total reflectance (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy. The emulsion-suspension polymerization method was employed to obtain copolymers of DVD, TEVS and L-Met in spherical forms. The porous structures and morphologies of the obtained lignin-containing functionalized microspheres were investigated by low-temperature nitrogen adsorption data and scanning electron microscopy (SEM). The microspheres are demonstrated to be mesoporous materials with specific surface areas in the range of 430–520 m2/g. The effects of the lignin component on the porous structure, shape, swelling and thermal properties of the microspheres were evaluated.

Stability of cobalt-based Fischer–Tropsch catalyst supported on oxidized carbon nanotubes

2020 ◽  
Vol 13 (04) ◽  
pp. 2050021 ◽  
Author(s):  
Sergei Chernyak ◽  
Alexander Burtsev ◽  
Alexander Egorov ◽  
Konstantin Maslakov ◽  
Serguei Savilov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Nitrogen Adsorption ◽  
Structural Transformations ◽  
Fischer Tropsch ◽  
Cobalt Particle ◽  
Adsorption Data ◽  
Oxidized Carbon ◽  
Oxidized Carbon Nanotubes ◽  
The Stability ◽  
Nitrogen Adsorption Data

The stability of 20[Formula: see text]wt.% Co/CNT catalyst was tested in the Fischer–Tropsch synthesis and the structural transformations both in the catalyst and support were analyzed. The catalyst showed high conversion and stable selectivity during three weeks of the test, which was attributed to the optimal and stable cobalt particle size of [Formula: see text]13–14[Formula: see text]nm promoted by the support pre-oxidation. XPS, Raman, and nitrogen adsorption data revealed that the carefully chosen catalyst annealing and reduction conditions ensured the preservation of the support structure.

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