Absorption of water vapors and micropore structures of carbon adsorbents. 15. effect of the concentration of primary adsorption sites on the adsorption properties of active carbons

1988 ◽  
Vol 37 (7) ◽  
pp. 1299-1303
Author(s):  
R. Sh. Vartapetyan ◽  
A. M. Voloshchuk ◽  
M. M. Dubinin ◽  
T. A. Moskovskaya
Keyword(s):  
Adsorption Properties ◽  
Carbon Adsorbents ◽  
Active Carbons ◽  
Adsorption Sites ◽  
Water Vapors

Methods of Obtaining and Physicochemical Properties of Modified Carbonaceous Sorbents

2021 ◽  
Vol 1045 ◽  
pp. 117-126
Author(s):  
Olena Svietkina ◽  
Olga Netiaga ◽  
Hanna Tarasova ◽  
Ievgenii Ustymenko ◽  
Edgar Caseres Cabana
Keyword(s):  
Physicochemical Properties ◽  
Porous Structure ◽  
Radiation Resistance ◽  
Adsorption Process ◽  
Chemical Nature ◽  
Carbon Adsorbents ◽  
Electrophysical Properties ◽  
Active Carbons ◽  
Carbonaceous Sorbents ◽  
Peculiar Nature

The variety of practical problems solved in recent years with the help of sorption methods requires expanding the range of used adsorbents. Active carbons are very promising porous adsorbents. Due to a whole complex of valuable properties of a highly developed porous structure, a variety of the chemical nature of the surface, special electrophysical properties, as well as chemical, thermal and radiation resistance, various active carbons are widely used for the absorption of gaseous and dissolved substances. The peculiar nature of carbon adsorbents contributes to the fact that solutes on coal can be adsorbed by completely different; mechanisms, their sorption may be due to the different nature of the forces involved in the adsorption process. The purpose of the work is to obtain multipurpose sorbents; to study methods of modification of carbonaceous sorbents from ash waste, as well as their physicochemical properties

scholarly journals Oxidized BPL Carbons

1993 ◽  
Vol 10 (1-4) ◽  
pp. 75-84 ◽  
Author(s):  
S.S. Barton ◽  
M.J.B. Evans ◽  
J.A.F. Macdonald
Keyword(s):  
Nitric Acid ◽  
Surface Area ◽  
Water Adsorption ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Adsorption Sites ◽  
A Value ◽  
Nitrogen Desorption ◽  
Oxidized Carbon ◽  
Increasing Temperature

A series of oxidized carbons has been prepared by treatment of the carbon with concentrated nitric acid at various temperatures, and the surface and adsorption properties of the prepared carbons studied. Water adsorption was modelled using a recently derived equation capable of predicting a value for the primary adsorption sites on the surface of a microporous carbon while fitting the experimentally determined isotherm at high relative pressures. The concentration of primary sites was seen to increase with increasing temperature of oxidation. The very highly oxidized carbon samples were found to have a significantly lower BET surface area determined from nitrogen desorption at 77 K and higher apparent density measured from mercury displacement.

scholarly journals Statistical Thermodynamic Model of Gas Adsorption in a Metal-Organic Framework Harboring a Rotaxane Molecular Shuttle

2019 ◽  
Author(s):  
Jonathan Carney ◽  
David Roundy ◽  
Cory M. Simon
Keyword(s):  
Thermodynamic Model ◽  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Statistical Thermodynamic ◽  
Temperature Sensitive ◽  
Adsorption Sites ◽  
Metal Organic ◽  
Dynamic Components ◽  
Molecular Shuttle

Metal-organic frameworks (MOFs) are modular and adjustable nano-porous materials with applications in gas storage, separations, and sensing. Flexible/dynamic components that respond to adsorbed gas can give MOFs unique or enhanced adsorption properties. Here, we explore the adsorption properties that could be imparted to a MOF by a rotaxane molecular shuttle (RMS) in its pores. In an RMS-MOF, a macrocyclic wheel is mechanically interlocked with a strut. The wheel shuttles between stations on the strut that are also gas adsorption sites. We pose and analyze a simple statistical thermodynamic model of gas adsorption in an RMS-MOF that accounts for (i) wheel/gas competition for sites on the strut and (ii) the entropy endowed by the shuttling wheel. We determine how the amount of gas adsorbed, position of the wheel, and energy change upon adsorption depend on temperature, pressure, and the interactions of the gas/wheel with the stations. Our model reveals that, compared to an ordinary Langmuir material, the chemistry of the RMS-MOF can be tuned to render adsorption more or less temperature-sensitive and release more or less heat upon adsorption. The model also uncovers a non-monotonic relationship between temperature and the position of the wheel if gas out-competes the wheel for its preferable station.

scholarly journals Statistical Mechanical Model of Gas Adsorption in a Metal-Organic Framework Harboring a Rotaxane Molecular Shuttle

2020 ◽  
Author(s):  
Jonathan Carney ◽  
David Roundy ◽  
Cory M. Simon
Keyword(s):  
Mechanical Model ◽  
Gas Adsorption ◽  
Adsorption Properties ◽  
Temperature Sensitive ◽  
Adsorption Model ◽  
Adsorption Sites ◽  
Statistical Mechanical Model ◽  
Metal Organic ◽  
Statistical Mechanical ◽  
Molecular Shuttle

Metal-organic frameworks (MOFs) are modular and tunable nano-porous materials with applications in gas storage, separations, and sensing. Flexible/dynamic components that respond to adsorbed gas can give MOFs unique or enhanced adsorption properties. Here, we explore the adsorption properties that could be imparted to a MOF by a rotaxane molecular shuttle (RMS) in its pores. In the unit cell of an RMS-MOF, a macrocyclic wheel is mechanically interlocked with a strut of the MOF scaffold. The wheel shuttles between stations on the strut that are also gas adsorption sites. At a level of abstraction similar to the seminal Langmuir adsorption model, we pose and analyze a simple statistical mechanical model of gas adsorption in an RMS-MOF that accounts for (i) wheel/gas competition for sites on the strut and (ii) gas-induced changes in the configurational entropy of the shuttling wheel. We determine how the amount of gas adsorbed, position of the wheel, and differential energy of adsorption depend on temperature, pressure, and the interactions of the gas/wheel with the stations. Our model reveals that, compared to a rigid, Langmuir material, the chemistry of the RMS-MOF can be tuned to render gas adsorption more or less temperature-sensitive and to release more or less heat upon adsorption. The model also uncovers a non-monotonic relationship between the temperature and the position of the wheel if gas out-competes the wheel for its preferable station.

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