scholarly journals Effects of Graphene Layer Size on the Adsorption of Fluids on Graphitized Thermal Carbon Black. A Computer Simulation Study

2006 ◽  
Vol 24 (3) ◽  
pp. 193-204 ◽  
Author(s):  
P. Luangkiattikhun ◽  
A. Wongkoblap ◽  
D.D. Do
Keyword(s):  
Adsorption Isotherm ◽  
Carbon Black ◽  
Crystallite Size ◽  
Surface Area ◽  
Graphene Layer ◽  
Graphite Surface ◽  
Surface Model ◽  
Damping Factor ◽  
Graphitized Thermal Carbon Black ◽  
Gcmc Simulation

The adsorption of Lennard-Jones fluids (argon and nitrogen) onto a graphitized thermal carbon black surface was studied with a Grand Canonical Monte Carlo Simulation (GCMC). The surface was assumed to be finite in length and composed of three graphene layers. When the GCMC simulation was used to describe adsorption on a graphite surface, an over-prediction of the isotherm was consistently observed in the pressure regions where the first and second layers are formed. To remove this over-prediction, surface mediation was accounted for to reduce the fluid–fluid interaction. Do and co-workers have introduced the so-called surface-mediation damping factor to correct the over-prediction for the case of a graphite surface of infinite extent, and this approach has yielded a good description of the adsorption isotherm. In this paper, the effects of the finite size of the graphene layer on the adsorption isotherm and how these would affect the extent of the surface mediation were studied. It was found that this finite-surface model provides a better description of the experimental data for graphitized thermal carbon black of high surface area (i.e. small crystallite size) while the infinite-surface model describes data for carbon black of very low surface area (i.e. large crystallite size).

scholarly journals Adsorption of Quadrupolar, Diatomic Nitrogen onto Graphitized Thermal Carbon Black and in Slit-Shaped Carbon Pores. Effects of Surface Mediation

2005 ◽  
Vol 23 (4) ◽  
pp. 267-288 ◽  
Author(s):  
D.D. Do ◽  
H.D. Do
Keyword(s):  
Carbon Black ◽  
Potential Energy ◽  
Effective Interaction ◽  
Filling Pressure ◽  
Intermolecular Potential ◽  
Graphitized Thermal Carbon Black ◽  
Pore Filling ◽  
Gcmc Simulation ◽  
Wide Range ◽  
Simulation Results

In this paper, we study the effect of solid surface mediation on the intermolecular potential energy of nitrogen, and its impact on the adsorption of nitrogen on a graphitized carbon black surface and in carbon slit-shaped pores. This effect arises from the lower effective interaction potential energy between two particles close to the surface compared to the potential energy of the same two particles when they are far away from the surface. A simple equation is proposed to calculate the reduction factor and this is used in the Grand Canonical Monte Carlo (GCMC) simulation of nitrogen adsorption on graphitized thermal carbon black. With this modification, the GCMC simulation results agree extremely well with the experimental data over a wide range of pressure; the simulation results with the original potential energy (i.e. no surface mediation) give rise to a shoulder in the neighbourhood of monolayer coverage and a significant over-prediction of the second and higher layer coverages. The influence of this surface mediation on the dependence of the pore-filling pressure on the pore width is also studied. It is shown that such surface mediation has a significant effect on the pore-filling pressure. This implies that the use of the local isotherms obtained from the potential model without surface mediation could give rise to a serious error in the determination of the pore-size distribution.

Synthesis of yttria-stabilized zirconia nanoparticles by decomposition of metal nitrates coated on carbon powder

1996 ◽  
Vol 11 (9) ◽  
pp. 2318-2324 ◽  
Author(s):  
Shusheng Jiang ◽  
Gregory C. Stangle ◽  
Vasantha R. W. Amarakoon ◽  
Walter A. Schulze
Keyword(s):  
Carbon Black ◽  
Crystallite Size ◽  
Surface Area ◽  
Yttria Stabilized Zirconia ◽  
Synthesis Process ◽  
Carbon Powder ◽  
Stabilized Zirconia ◽  
Black Powder ◽  
Carbon Black Powder ◽  
Metal Nitrates

Weakly agglomerated nanoparticles of yttria-stabilized zirconia (YSZ) were synthesized by a novel process which involved the decomposition of metal nitrates that had been coated on ultrafine carbon black powder, after which the carbon black was gasified. The use of ultrafine, high-surface-area carbon black powder apparently allowed the nanocrystalline oxide particles to form and remain separate from each other, after which the carbon black was gasified at a somewhat higher temperature. As a result, the degree of agglomeration was shown to be relatively low. The average crystallite size and the specific surface area of the as-synthesized YSZ nanoparticles were 5−6 nm and 130 m2/g, respectively, for powder synthesized at 650 °C. The as-synthesized YSZ nanoparticles had a light brown color and were translucent, which differs distinctly from conventional YSZ particles which are typically white and opaque. The mechanism of the synthesis process was investigated, and indicated that the gasification temperature had a direct effect on the crystallite size of the as-synthesized YSZ nanoparticles. High-density and ultrafine-grained YSZ ceramic articles were prepared by fast-firing, using a dwell temperature of 1250 °C and a dwell time of two minutes or less.

Application of Raman Spectroscopy to the Study of Adsorption Effects at Liquid-Solid Interfaces

1982 ◽  
Vol 36 (4) ◽  
pp. 471-473 ◽  
Author(s):  
Klaus Witke
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Tetrachloride ◽  
Adsorption Isotherm ◽  
Minimal Surface ◽  
Linear Relationship ◽  
Surface Area ◽  
Long Range ◽  
Raman Spectra ◽  
Sample Cell ◽  
Minimal Surface Area

A sample cell for investigating suspensions or emulsions by Raman spectroscopy in the optically favorable 90° scattering arrangement is described. The Raman spectra of pyridine in a suspension of Aerosil 200 in carbon tetrachloride are recorded. The adsorption isotherm of pyridine is determined from the intensities of the Raman lines at 1008 and 990 cm−1. Over a long range of coverage a linear relationship exists between reciprocal concentrations of chemisorbed and dissolved molecules. The minimal surface area that is occupied by a chemisorbed molecule is determined to be approximately 0.75 nm2.

An assessment of the Dead Sea level change using remotely sensed data

2021 ◽  
Author(s):  
Musab Mbideen ◽  
Balázs Székely
Keyword(s):  
Remote Sensing ◽  
Water Level ◽  
Surface Area ◽  
Dead Sea ◽  
Spectral Radiance ◽  
Water Volume ◽  
Surface Model ◽  
Atmospheric Effects ◽  
Level 1 ◽  
The Dead

<p>Remote Sensing (RS) and Geographic Information System (GIS) instruments have spread rapidly in recent years to manage natural resources and monitor environmental changes. Remote sensing has a vast range of applications; one of them is lakes monitoring. The Dead Sea (DS) is subjected to very strong evaporation processes, leading to a remarkable shrinkage of its water level. The DS is being dried out due to a negative balance in its hydrological cycle during the last five decades. This research aims to study the spatial changes in the DS throughout the previous 48 years. Change detection technique has been performed to detect this change over the research period (1972-2020). 73 Landsat imageries have been used from four digital sensors; Landsat 1-5 MSS C1 Level-1, Landsat 4-5 TM C1 Level-1, Land sat 7 ETM+ C1  Level-1, and Landsat 8 OLI-TIRS C1 Level. After following certain selection criteria , the number of studied images decreased. Furthermore, the Digital Surface Model of the Space Shuttle Radar Topography Mission and a bathymetric map of the Dead Sea were used. The collected satellite imageries were pre-processed and normalized using ENVI 5.3 software by converting the Digital Number (DN) to spectral radiance, the spectral radiance was converted to apparent reflectance, atmospheric effects were removed, and finally, the black gaps were removed. It was important to distinguish between the DS lake and the surrounding area in order to have accurate results, this was done by performing classification techniques. The digital terrain model of the DS was used in ArcGIS (3D) to reconstruct the elevation of the shore lines. This model generated equations to detect the water level, surface area, and water volume of the DS. The results were compared to the bathymetric data as well. The research shows that the DS water level declined 65 m (1.35 m/a) in the studied period. The surface area and the water volume declined by 363.56 km<sup>2 </sup>(7.57 km<sup>2</sup>/a) and 53.56 km<sup>3</sup> (1.11 km<sup>3</sup>/a), respectively. The research also concluded that due to the bathymetry of the DS, the direction of this shrinkage is from the south to the north. We hypothesize that anthropogenic effects have contributed in the shrinkage of the DS more than the climate. The use of the DS water by both Israel and Jordan for industrial purposes is the main factor impacting the DS, another factor is the diversion of the Jordan and Yarmouk rivers. Our results also allow to give a prediction for the near future of the DS: the water level is expected to reach –445 m in 2050, while the surface area and the water volume is expected to be 455 km<sup>2</sup> and 142 km<sup>3</sup>, respectively. </p>

Synthesis of ZrO2–Y6WO12 solid solution powders by a polymerized complex method

1998 ◽  
Vol 13 (4) ◽  
pp. 939-943 ◽  
Author(s):  
Junfeng Ma ◽  
Masahiro Yoshimura ◽  
Masato Kakihana ◽  
Masatomo Yashima
Keyword(s):  
Solid Solution ◽  
Crystallite Size ◽  
Surface Area ◽  
Solid Solutions ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Complex Method ◽  
Amorphous Precursor ◽  
Fine Powders ◽  
Polymerized Complex Method

A series of solid solutions (1 − x) ZrO2 · xY0.857 W0.143 O1.714 (1/7Y6WO12) of metastable cubic phase were synthesized at 800 °C through a polymerized complex method. Lattice parameter a0 of solid solutions varies linearly with Y0.857 W0.143 O1.714 content (x). Crystallization began to occur above 400 °C from amorphous precursor to yield at 800 °C fine powders of 6–10 nm and 19–40 m2/g for crystallite size and surface area, respectively.

PERMEABILITY STUDIES: III. SURFACE AREA MEASUREMENTS OF CARBON BLACKS

1948 ◽  
Vol 26a (2) ◽  
pp. 29-38 ◽  
Author(s):  
J. C. Arnell ◽  
G. O. Henneberry
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Carbon Black ◽  
Surface Area ◽  
Satisfactory Agreement ◽  
Nitrogen Adsorption ◽  
Average Particle ◽  
Carbon Blacks ◽  
Permeability Studies ◽  
Nitrogen Adsorption Isotherms

The modified Kozeny equation has been found to be satisfactory for the measurement of the specific surfaces of carbon blacks having average particle diameters ranging from 0.01 to 0.1 μ to within ±10%. Comparative data were obtained from electron microscope counting and from low temperature nitrogen adsorption isotherms. The three methods examined gave results that were in satisfactory agreement, except when the carbon black was porous, and then the adsorption value was extremely large.

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