Pore structure characteristics and fractal structure evaluation of medium- and high-rank coal

The presence of gas content in medium- and high-rank coal poses a threat to safety production. Safe gas extraction is based on a correct understanding of the pore structure of coal. This work investigates the pore structure characteristics of medium- and high-rank coal and evaluates their fractal structure. The coal samples were collected from Huainan Coalfield and Qinshui Coalfield, and divided into four types, according to the difference in surface bright characteristics. Through adopting low-temperature liquid nitrogen adsorption and desorption, and applying Kelvin equation, we obtain the main pore structure types and main pore size distribution characteristics of various coal briquettes. Electron microscope scanning structure and scientific analysis were used for special adsorption and desorption curves and hysteresis to find the dynamic reason. According to the different adsorption mechanism and Frenkel–Halsey–Hill-based model, with P/ P0 = 0.4 as the dividing point of fractal dimension analysis, the pore structure of coal samples is classified into five grades. The fractal evaluation results are consistent with the results of curve analysis and pore size analysis.

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Gas adsorption: A valuable tool for the pore size analysis and pore structure elucidation of ordered mesoporous materials

Nanotechnology in Mesostructured Materials, Proceedings of the 3rd International Materials Symposium - Studies in Surface Science and Catalysis ◽

10.1016/s0167-2991(03)80377-4 ◽

2003 ◽

pp. 263-269 ◽

Cited By ~ 7

Author(s):

Mietek Jaroniec ◽

Michal Kruk

Keyword(s):

Pore Structure ◽

Pore Size ◽

Mesoporous Materials ◽

Structure Elucidation ◽

Gas Adsorption ◽

Size Analysis ◽

Ordered Mesoporous Materials ◽

Ordered Mesoporous ◽

Pore Size Analysis

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The Synthesis and Electrochemical Performance of Si Composite with Hollow Carbon Microtubes by the Carbonization of Milkweed from Nature as Anode Template for Lithium Ion Batteries

Energies ◽

10.3390/en13195124 ◽

2020 ◽

Vol 13 (19) ◽

pp. 5124

Author(s):

Eun Hyuk Chung ◽

Jong Pil Kim ◽

Hyun Gyu Kim ◽

Jae-Min Chung ◽

Sei-Jin Lee ◽

...

Keyword(s):

Electron Microscopy ◽

Electrical Conductivity ◽

Electrochemical Performance ◽

Pore Size ◽

Lithium Ion Batteries ◽

Polyvinylidene Fluoride ◽

Lithium Ion ◽

Size Analysis ◽

Pore Size Analysis ◽

Hollow Carbon

It has been reported that improving electrical conductivity and maintaining stable structure during discharge/charge process are challenge for Si to be used as an anode for lithium ion batteries (LIB). To address this problem, milkweed (MW) was carbonized to prepare hollow carbon microtubes (HCMT) derived from biomass as an anode template for LIB. In order to improve electrical conductivity, various materials such as chitosan (CTS), agarose, and polyvinylidene fluoride (PVDF) are used as carbon source (C1, C2, and C3) by carbonization. Carbon coated HCMT@Si composits, HCMT@Si@C1, HCMT@Si@C1@C2, and HCMT@Si@C1@C3, have been successfully synthesized. Changes in structure and crystallinity of HCMT@Si composites were characterized by using X-ray diffraction (XRD). Specific surface area for samples was calculated by using BET (Brunauer–Emmett–Teller). Also, pore size and particle size were obtained by particle and pore size analysis system. The surface morphology was evaluated using high resolution scanning electron microscopy (HR-SEM), Field Emission transmission electron microscopy (TEM). The thermal properties of HCMT@Si composites were analyzed by thermogravimetric analysis (TGA). Our research was performed to study the synthesis and electrochemical performance of Si composite with HCMT by the carbonization of natural micro hollow milkweed to form an inner space. After carbonization at 900 °C for 2 h in N2 flow, inner diameter of HCMT obtained was about 10 μm. The electrochemical tests indicate that HCMT@Si@C1@C3 exhibits discharge capacity of 932.18 mAh/g at 0.5 A/g after 100 cycles.

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A multilayer thickness relationship applicable to pore size analysis of silica gel

Journal of Applied Chemistry and Biotechnology ◽

10.1002/jctb.5020230103 ◽

2007 ◽

Vol 23 (1) ◽

pp. 19-27 ◽

Cited By ~ 5

Author(s):

Badie S. Girgis

Keyword(s):

Pore Size ◽

Silica Gel ◽

Size Analysis ◽

Pore Size Analysis

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Investigate on Pore Structure Characteristics of Reactive Powder Concrete after High Temperatures

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.174-177.1010 ◽

2012 ◽

Vol 174-177 ◽

pp. 1010-1014 ◽

Cited By ~ 1

Author(s):

Hong Bin Liu ◽

Yang Ju ◽

Kai Pei Tian ◽

Jin Hui Liu ◽

Li Wang ◽

...

Keyword(s):

Pore Structure ◽

Pore Size ◽

Pore Volume ◽

Average Pore Size ◽

Reactive Powder Concrete ◽

Characteristic Parameters ◽

Average Pore ◽

Structure Characteristics ◽

Temperature Levels ◽

Reactive Powder

The pore structure characteristics of reactive powder concrete (RPC) were investigated by means of the mercury injection method at seven temperature levels, namely, 20°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, respectively. The characteristic parameters such as porosity, pore volume, average pore size and threshold aperture varied with temperatures were analyzed. The results indicate that the porosity, pore volume, threshold aperture and other characteristic parameters of RPC increased with the temperature increasing.

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