A Supramolecular Strategy for Self-Mobile Adsorption Sites in Affinity Membrane

2014 ◽  
Vol 35 (18) ◽  
pp. 1587-1591 ◽  
Author(s):  
Ligang Lin ◽  
Meimei Dong ◽  
Chunyu Liu ◽  
Chenjie Wei ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Adsorption Sites ◽  
Affinity Membrane ◽  
Mobile Adsorption

scholarly journals A Non-Analytical Solution of the Description of Single Gas Adsorption on a Microporous Adsorbent

1997 ◽  
Vol 15 (2) ◽  
pp. 99-108 ◽  
Author(s):  
J.K. Garbacz ◽  
M. Dabrowski
Keyword(s):  
Analytical Solution ◽  
Gas Adsorption ◽  
Distribution Functions ◽  
Microporous Adsorbent ◽  
Adsorption Model ◽  
Adsorption Sites ◽  
Type Zeolite ◽  
Mobile Adsorption ◽  
Microporous Solids

Two distribution functions for the energy of localization dividing two neighbouring adsorption sites were suggested for the model of partially mobile adsorption on energetically heterogeneous microporous solids. The experimental isotherms of ethane adsorption on NaX-type zeolite derivatives cationized by Li+, K+, Rb+, Ca2+, Sr2+ ions as well as isotherms of ethane, ethene and n-pentane adsorption on NaX-type zeolite were described by the relationships of the proposed adsorption model.

scholarly journals Stochastic Properties of the Solution Vector of Parameters for the Model of the Partially Mobile Adsorption of a Single Gas on an Energetically Heterogeneous Microporous Adsorbent

1997 ◽  
Vol 15 (10) ◽  
pp. 753-775 ◽  
Author(s):  
J.K. Garbacz ◽  
M. Dabrowski ◽  
E. Kopkowska
Keyword(s):  
Measurement Error ◽  
Adsorption Isotherms ◽  
Gas Adsorption ◽  
Mass Measurement ◽  
Distribution Functions ◽  
Solution Vector ◽  
Adsorption Sites ◽  
Mass Measurement Error ◽  
Mobile Adsorption ◽  
Parameter Values

For the previously formulated model of single gas adsorption on energetically heterogeneous microporous solids, two adsorption isotherms were generated — one for each distribution function of the localization energy dividing two neighbouring adsorption sites. Using numeric methods, a mass measurement error was ascribed to each point generated for both adsorption isotherms and an analysis of the influence of the normal distribution of this error on the type of distribution of the optimized parameter values was undertaken. The hypothesis regarding the agreement of the distributions of the parameter values for both energy distribution functions was verified. The work described was carried out for three arbitrary assumed values of the variation coefficients of the adsorbate mass measurement error.

Tuning Transition Metal Carbides Activity by Surface Metal Alloying: Case Study on CO2 Capture and Activation

2018 ◽  
Author(s):  
Marti Lopez ◽  
Luke Broderick ◽  
John J Carey ◽  
Francesc Vines ◽  
Michael Nolan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Co2 Capture ◽  
Density Functional ◽  
Deep Understanding ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Adsorption Sites ◽  
Surface Metal ◽  
A Minor

<div>CO2 is one of the main actors in the greenhouse effect and its removal from the atmosphere is becoming an urgent need. Thus, CO2 capture and storage (CCS) and CO2 capture and usage (CCU) technologies are intensively investigated as technologies to decrease the concentration</div><div>of atmospheric CO2. Both CCS and CCU require appropriate materials to adsorb/release and adsorb/activate CO2, respectively. Recently, it has been theoretically and experimentally shown that transition metal carbides (TMC) are able to capture, store, and activate CO2. To further improve the adsorption capacity of these materials, a deep understanding of the atomic level processes involved is essential. In the present work, we theoretically investigate the possible effects of surface metal doping of these TMCs by taking TiC as a textbook case and Cr, Hf, Mo, Nb, Ta, V, W, and Zr as dopants. Using periodic slab models with large</div><div>supercells and state-of-the-art density functional theory based calculations we show that CO2 adsorption is enhanced by doping with metals down a group but worsened along the d series. Adsorption sites, dispersion and coverage appear to play a minor, secondary constant effect. The dopant-induced adsorption enhancement is highly biased by the charge rearrangement at the surface. In all cases, CO2 activation is found but doping can shift the desorption temperature by up to 135 K.</div>

Adsorption on heterogeneous surfaces: Numerical analysis of models for the Dubinin-Radushkevich equation

1981 ◽  
Vol 46 (8) ◽  
pp. 1709-1721 ◽  
Author(s):  
Miloš Smutek ◽  
Arnošt Zukal
Keyword(s):  
Integral Equation ◽  
Numerical Analysis ◽  
Numerical Method ◽  
Adsorption Behaviour ◽  
Heterogeneous Surfaces ◽  
Strong Energy ◽  
Adsorption On Heterogeneous Surfaces ◽  
Heterogeneity Parameter ◽  
Adsorption Energies ◽  
Mobile Adsorption

A numerical method, based on the integral equation of the adsorption on energy heterogeneous surfaces, is suggested for the evaluation of overall isotherm. It is shown that for the distribution of adsorption energies given by Eq. (1.11) and different models of the adsorption behaviour, the overall isotherms obey approximately the Dubinin-Radushkevich equation. The strong energy heterogeneity smears effectively the differences between the localized and mobile adsorption and leads to the same character of the overall isotherm with only a slightly changed heterogeneity parameter.

Adsorption and advanced oxidation of diverse pharmaceuticals and personal care products (PPCPs) from water using highly efficient rGO–nZVI nanohybrids

2020 ◽  
Vol 6 (8) ◽  
pp. 2223-2238 ◽  
Author(s):  
Arvid Masud ◽  
Nita G. Chavez Soria ◽  
Diana S. Aga ◽  
Nirupam Aich
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Personal Care Products ◽  
Advanced Oxidation ◽  
Zero Valent Iron ◽  
Redox Activity ◽  
Personal Care ◽  
Adsorption Sites ◽  
Reduced Graphene ◽  
Nanoscale Zero Valent Iron

Reduced graphene oxide-nanoscale zero valent iron (rGO–nZVI) nanohybrid, with tunable adsorption sites of rGO and unique catalytic redox activity of nZVI, perform enhanced removal of diverse PPCPs from water.

scholarly journals Molecular simulation of gases competitive adsorption in lignite and analysis of original CO desorption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jing Zhang ◽  
Jiren Wang ◽  
Chunhua Zhang ◽  
Zongxiang Li ◽  
Jinchao Zhu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Molecular Simulation ◽  
Competitive Adsorption ◽  
Air Leakage ◽  
Adsorption Characteristics ◽  
Adsorption Sites ◽  
Simulation Based ◽  
Lignite Coal ◽  
Model C ◽  
Grand Canonical

AbstractTo study the adsorption characteristics of CO, CO2, N2, O2, and their binary-components in lignite coal, reveal the influence of CO2 or N2 injection and air leakage on the desorption of CO in goafs, a lignite model (C206H206N2O44) was established, and the supercell structure was optimized under temperatures of 288.15–318.15 K for molecular simulation. Based on molecular dynamics, the Grand Canonical Monte Carlo method was used to simulate the adsorption characteristics and the Langmuir equation was used to fit the adsorption isotherms of gases. The results show that for single-components, the order of adsorption capacity is CO2 > CO > O2 > N2. For binary-components, the competitive adsorption capacities of CO2 and CO are approximate. In the low-pressure zone, the competitive adsorption capacity of CO2 is stronger than that of CO, and the CO is stronger than N2 or O2. From the simulation, it can be seen that CO2, N2 or O2 will occupy adsorption sites, causing CO desorption. Therefore, to prevent the desorption of the original CO in the goaf, it is not suitable to use CO2 or N2 injection for fire prevention, and the air leakage at the working faces need to be controlled.

scholarly journals Adsorption process and mechanism of heavy metal ions by different components of cells, using yeast (Pichia pastoris) and Cu2+ as biosorption models

RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17080-17091
Author(s):  
Xinggang Chen ◽  
Zhuang Tian ◽  
Haina Cheng ◽  
Gang Xu ◽  
Hongbo Zhou
Keyword(s):  
Heavy Metal ◽  
Pichia Pastoris ◽  
Metal Ions ◽  
Cell Walls ◽  
Heavy Metal Ions ◽  
Adsorption Process ◽  
Yeast Pichia Pastoris ◽  
Adsorption Sites

The Cu2+ first bound to the outer mannan and finally entered the cytoplasm. During the whole adsorption process, the number of adsorption sites in the outer and middle cell walls was the largest, and then gradually decreased.

Proton magnetic relaxation of water sorbed by methaemoglobin crystals

1973 ◽  
Vol 331 (1587) ◽  
pp. 457-468 ◽  
Keyword(s):  
Relaxation Rate ◽  
Relaxation Times ◽  
Transverse Relaxation Rate ◽  
Ferric Ions ◽  
Transverse Relaxation ◽  
Water Binding ◽  
Adsorption Sites ◽  
Protein Molecules ◽  
Proton Magnetic Relaxation ◽  
Limiting Value

P. m. r. relaxation times ( T 1 and T 2 ) have been measured as a function of regain and temperature for water sorbed by lyophilized methaemoglobin. The purpose of the work was to gain information regarding the nature and extent of water binding by the protein molecules. The T 1 results are interpreted in terms of an exchange between the sixth ligand position of the Fe (III) and other adsorption sites on the protein. At high temperatures the relaxation rate at a given regain reaches a limiting value which allows the fraction of ferric ions hydrated to be calculated. Above 16% regain all the Fe (III) is hydrated. At 21 and 35% regains a maximum appears in the relaxation rate at about -46 °C indicating a contribution from a more mobile phase which produces a T 1 minimum at that temperature. The T 2 data are consistent with a model in which the main contribution to the transverse relaxation rate comes from a tightly bound fraction of the water with ω 0 Ƭ c ≫1. The temperature dependence of T 2 exhibits three different regions: ( a ) a low temperature region where lg T 2 ∝ T -1 ; ( b ) an intermediate region with a steeper increase of T 2 with temperature; and ( c ) a high temperature where T 2 levels off.

scholarly journals Kerogen nanoscale structure and CO2 adsorption in shale micropores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Gonciaruk ◽  
Matthew R. Hall ◽  
Michael W. Fay ◽  
Christopher D. J. Parmenter ◽  
Christopher H. Vane ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Focused Ion Beam ◽  
Gas Adsorption ◽  
Ion Beam ◽  
Molecular Size ◽  
Gas Sorption ◽  
Nanoscale Structures ◽  
Adsorption Sites ◽  
Nanoscale Structure

AbstractGas storage and recovery processes in shales critically depend on nano-scale porosity and chemical composition, but information about the nanoscale pore geometry and connectivity of kerogen, insoluble organic shale matter, is largely unavailable. Using adsorption microcalorimetry, we show that once strong adsorption sites within nanoscale network are taken, gas adsorption even at very low pressure is governed by pore width rather than chemical composition. A combination of focused ion beam with scanning electron microscopy and transmission electron microscopy reveal the nanoscale structure of kerogen includes not only the ubiquitous amorphous phase but also highly graphitized sheets, fiber- and onion-like structures creating nanoscale voids accessible for gas sorption. Nanoscale structures bridge the current gap between molecular size and macropore scale in existing models for kerogen, thus allowing accurate prediction of gas sorption, storage and diffusion properties in shales.

scholarly journals A theoretical and experimental study of the adsorptive removal of hexavalent chromium ions using graphene oxide as an adsorbent

2020 ◽  
Vol 18 (1) ◽  
pp. 936-942
Author(s):  
Ardhmeri Alija ◽  
Drinisa Gashi ◽  
Rilinda Plakaj ◽  
Admir Omaj ◽  
Veprim Thaçi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hexavalent Chromium ◽  
Adsorption Energy ◽  
Density Functional ◽  
Noncovalent Interactions ◽  
Theoretical Calculations ◽  
Chemical Oxidation ◽  
Chromium Ions ◽  
Adsorption Sites ◽  
Vis Spectroscopy

AbstractThis study is focused on the adsorption of hexavalent chromium ions Cr(vi) using graphene oxide (GO). The GO was prepared by chemical oxidation (Hummers method) of graphite particles. The synthesized GO adsorbent was characterized by Fourier transform infrared spectroscopy and UV-Vis spectroscopy. It was used for the adsorption of Cr(vi) ions. The theoretical calculations based on density functional theory and Monte Carlo calculations were used to explore the preferable adsorption site, interaction type, and adsorption energy of GO toward the Cr(vi) ions. Moreover, the most stable adsorption sites were used to calculate and plot noncovalent interactions. The obtained results are important as they give molecular insights regarding the nature of the interaction between GO surface and the adsorbent Cr(vi) ions. The found adsorption energy of −143.80 kcal/mol is indicative of the high adsorptive tendency of this material. The adsorption capacity value of GO toward these ions is q = 240.361 mg/g.

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