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Pulsed field gradient NMR diffusion measurement in nanoporous materials Adsorption (IF 1.949) Pub Date : 2021-01-09 Jörg Kärger, Marija Avramovska, Dieter Freude, Jürgen Haase, Seungtaik Hwang, Rustem Valiullin
Labeling in diffusion measurements by pulsed field gradient (PFG) NMR is based on the observation of the phase of nuclear spins acquired in a constant magnetic field with purposefully superimposed field gradients. This labeling does in no way affect microdynamics and provides information about the probability distribution of molecular displacements as a function of time. An introduction of the measuring
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MIL-160(Al) MOF’s potential in adsorptive water harvesting Adsorption (IF 1.949) Pub Date : 2021-01-04 M. P. Silva, A. M. Ribeiro, C. G. Silva, I. B. R. Nogueira, Kyung-Ho Cho, U.-Hwang Lee, J. L. Faria, J. L. Loureiro, Jon-San Chang, A. E. Rodrigues, A. Ferreira
The water crisis is one of the main global risks based on its societal impact, particularly the access to safe drinking water in regions with a dry (arid) or mainly dry (semi-arid) climate. Several techniques are being developed, namely the use of regenerative desiccant (e.g., MOFs) to water capture through adsorption processes. MIL-160(Al) belongs to the fumarate-based MOFs family, and it is one of
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Quantitative analysis of liquid-phase adsorption over chromium-containing metal–organic frameworks of MTN topology Adsorption (IF 1.949) Pub Date : 2021-01-04 Daria V. Brazhnik, Igor Y. Skobelev, Konstantin A. Kovalenko, Oxana A. Kholdeeva
Excess adsorption of cyclohexanone, cyclohexanol and tert-butanol over metal–organic frameworks Cr-MIL-100 and structurally close Cr-MIL-101 from n-hexane was measured at room temperature. Apparent adsorption equilibrium constants were calculated under the assumption of monolayer adsorption. Two types of adsorption centers turned out to be enough to build a model of experimental isotherms for cyclohexanone
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Modeling fluids confined in three-dimensionally ordered mesoporous carbons Adsorption (IF 1.949) Pub Date : 2021-01-02 Anish Desouza, Peter A. Monson
We present a coarse grained lattice gas model for the thermodynamics and dynamics of adsorption and desorption in three dimensionally ordered mesoporous carbons, originally developed as templates for the synthesis of zeolites with mesoporosity. We model these systems as an assembly of interconnected spherical pores in an fcc structure which are coarse grained on to a simple cubic lattice. The adsorption
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Extracting adsorbate information from manometric uptake measurements of hydrogen at high pressure and ambient temperature Adsorption (IF 1.949) Pub Date : 2021-01-02 L. Naheed, K. E. Lamb, E. MacA. Gray, C. J. Webb
To calculate a gas sorption isotherm from measurements made using the manometric (Sieverts) technique requires accurate knowledge of the sample cell void volume, the volume able to be occupied by the free gas. For many combinations of material and morphology, this volume changes as the sample expands or compresses, swells, undergoes chemical change or adsorbs gas. For gas adsorption measurements on
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Effect of intermittent purge on O 2 production with rapid pressure swing adsorption technology Adsorption (IF 1.949) Pub Date : 2020-11-24 Yingshu Liu, Quanli Zhang, Yongzheng Cao, Xiong Yang, Ziyi Li, Wenhai Liu, Jean Baptiste Habyarimana, Yongkang Cui, Haoyu Wang, Ralph T. Yang
The rapid pressure swing adsorption (RPSA) technology has been widely used for applications including portable oxygen generators due to high O2 productivities and low bed size factors (BSF, total amount of adsorbent per ton of O2 produced per day, kg/TPDO2). The improvement of RPSA process has been a key issue for efficient O2 production in terms of its generally lower O2 recovery as compared to other
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A review of common practices in gravimetric and volumetric adsorption kinetic experiments Adsorption (IF 1.949) Pub Date : 2020-11-20 Jin-Yu Wang, Enzo Mangano, Stefano Brandani, Douglas M. Ruthven
The availability of commercial gravimetric and volumetric systems for the measurement of adsorption equilibrium has seen also a growth of the use of these instruments to measure adsorption kinetics. A review of publications from the past 20 years has been used to assess common practice in 180 cases. There are worrying trends observed, such as lack of information on the actual conditions used in the
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Accurate blank corrections for zero length column experiments Adsorption (IF 1.949) Pub Date : 2020-11-18 Maarten Verbraeken, Alessio Centineo, Luigi Canobbio, Stefano Brandani
In this study we present a new methodology for correcting experimental Zero Length Column data, to account for contributions to the measured signal arising from extra-column volumes and the detector. The methodology considers the experimental setup as a series of mixing volumes with diffusive pockets whose contributions to the overall measured signal can be accurately described by simple model functions
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Application of microimaging to diffusion studies in nanoporous materials Adsorption (IF 1.949) Pub Date : 2020-11-18 Christian Chmelik, Roger Gläser, Jürgen Haase, Seungtaik Hwang, Jörg Kärger
Microimaging on the basis of, respectively, interference microscopy and IR microscopy permit the observation of the distribution of guest molecules in nanoporous solids and their variation with time. Thus attainable knowledge of both concentration gradients and diffusion fluxes provides direct access to the underlying diffusion phenomena. This includes, in particular, the measurement of transport diffusion
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Steam adsorption on molecular sieve 3A for sorption enhanced reaction processes Adsorption (IF 1.949) Pub Date : 2020-11-12 Jasper van Kampen, Jurriaan Boon, Martin van Sint Annaland
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Effects of operating temperature on the performance of small scale rapid cycle pressure swing adsorption air separation process Adsorption (IF 1.949) Pub Date : 2020-11-06 Xianqiang Zhu, Yingshu Liu, Ralph T. Yang
The effects of operating temperature on the performance of small scale oxygen concentrator were experimentally investigated using a rotary valve multi-column rapid cycle pressure swing adsorption (PSA) unit which produced a continuous stream of ≥ 90% O2 from compressed air. Simple cooling fans and air cylinder were used for controlling the temperature of compressed air. The change of column midpoint
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Investigations of mechanism of Ca 2+ adsorption on silica and alumina based on Ca-ISE monitoring, potentiometric titration, electrokinetic measurements and surface complexation modeling Adsorption (IF 1.949) Pub Date : 2020-11-05 Karolina Szymanek, Robert Charmas, Wojciech Piasecki
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Diffusion in nanopores: inspecting the grounds Adsorption (IF 1.949) Pub Date : 2020-10-27 Jörg Kärger, Douglas M. Ruthven, Rustem Valiullin
This paper provides a general overview of the phenomenon of guest diffusion in nanoporous materials. It introduces the different types of diffusion measurement that can be performed under both equilibrium and non-equilibrium conditions in either single- or multicomponent systems. In the technological application of nanoporous materials for mass separation and catalytic conversion diffusion often has
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The H + ions and static electric field effects on the adsorption and detection of cyanogen fluoride on the surface of boron nitride nanocage: a DFT, TD-DFT study Adsorption (IF 1.949) Pub Date : 2020-10-19 Rezvan Alvand, M. Rezaei-Sameti
By using the DFT and TD-DFT method, the potential of B12N12 nanocage to adsorb and detect of cyanogen fluoride (FCN) as a toxic gas molecule in the present of 1H+, 2H+, and 3H+ ions field and static electric field (SEF) were investigated at the WB97XD level of theory at the 6-31G (d, p) basis set. The structural and electrical parameters, adsorption energy, quantum descriptor, quantum theory of atom
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Influence of the main operating parameters on the DRPSA process design based on the equilibrium theory Adsorption (IF 1.949) Pub Date : 2020-10-12 Ester Rossi, Giuseppe Storti, Renato Rota
Among the adsorption-based separation processes for gaseous mixtures, those exploiting pressure variations, so-called Pressure Swing Adsorption (PSA) processes, are the most popular. In this work, we focus on the specific PSA configuration known as Dual Reflux-Pressure Swing Adsorption (DR-PSA) given its ability to achieve sharp separations. In the case of binary mixtures, an analytical approach based
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The zero length column technique to measure adsorption equilibrium and kinetics: lessons learnt from 30 years of experience Adsorption (IF 1.949) Pub Date : 2020-10-09 Stefano Brandani, Enzo Mangano
The zero length column technique has been developed over the past 30 years as a versatile experimental method to measure adsorption equilibrium and kinetics. In this review we discuss in detail the theory that forms the basis for the technique in order to understand how to design and operate efficiently a system. Experimental checks that should be performed to ensure the correct interpretation of the
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Effect of aluminum and sodium on the sorption of water and methanol in microporous MFI-type zeolites and mesoporous SBA-15 materials Adsorption (IF 1.949) Pub Date : 2020-10-06 Zheng Li, Carolin Rieg, Ann-Katrin Beurer, Michael Benz, Johannes Bender, Christof Schneck, Yvonne Traa, Michael Dyballa, Michael Hunger
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Dynamic column breakthrough experiments for measurement of adsorption equilibrium and kinetics Adsorption (IF 1.949) Pub Date : 2020-09-30 Nicholas Stiles Wilkins, Arvind Rajendran, Shamsuzzaman Farooq
This paper provides a set of comprehensive guidelines for the use of dynamic column breakthrough experiments to measure single and multi-component equilibria and kinetics. Recommendations are made for the design of the experimental rig, experimental procedures, and data processing methods to minimize errors and increase data reliability. Designing experiments to identify the transport mechanism, and
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Value added utilization of ferronickel slags as raw materials of 4A zeolite for CO 2 reduction Adsorption (IF 1.949) Pub Date : 2020-09-29 Shuwen Cheng, Tao Du, Yuan Long, Liying Liu, Gang Li
The scale of smelting ferronickel by RKEF (Rotary kiln—electric furnace) process is increasing these years, these untreated ferronickel slags will occupy a large area as accumulation and cause ecological damage. On the other hand, the CO2 emission and global warming are urgent problems to be solved as they have resulted in severe climate change. Carbon Capture and Storage (CCS) technology is considered
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Dynamics in nanoporous materials probed by 2 H solid state NMR: estimation of self-diffusion coefficients Adsorption (IF 1.949) Pub Date : 2020-09-27 Daniil I. Kolokolov, Dieter Freude, Alexander G. Stepanov
2H solid-state NMR represents a reliable method for probing the dynamics of the molecules in confined geometries, including microporous and mesoporous materials such as zeolites or metal–organic frameworks (MOFs). Dynamic characteristics derived from analyses of 2H NMR line shape and spin relaxation for adsorbed deuterated molecules can be related with translational motions along the porous framework
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Characterization of resorcinol–formaldehyde hydrogel as adsorbent for cesium ion Adsorption (IF 1.949) Pub Date : 2020-09-26 Shogo Taguchi, Tomoki Nakatani, Haruna Saeki, Mélaz Tayakout‑Fayolle, Kazuhiro Itoh, Takuji Yamamoto
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Quantitative imaging of gas adsorption equilibrium and dynamics by X-ray computed tomography Adsorption (IF 1.949) Pub Date : 2020-09-26 Ronny Pini, Lisa Joss, Sayed Alireza Hosseinzadeh Hejazi
We present the development and application of X-ray Computed Tomography (CT) for the determination of the adsorption properties of microporous adsorbents and the study of breakthrough experiments in a laboratory fixed-bed adsorption column. Using the model system \(\text {CO}_2/\text {helium}\) on activated carbon, equilibrium and dynamic adsorption/desorption measurements by X-ray CT are described
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Temperature and pressure dynamics in sorption cells Adsorption (IF 1.949) Pub Date : 2020-09-22 A. Davidesko, N. Tzabar
Sorption processes are incorporated in a wide range of applications. A heat and mass transfer model which calculates the temperature distribution and pressure in a sorption cell is desired for developing any sorption system. In this paper, we present a one-dimensional dynamic numerical model for closed sorption cell systems, which is based on adsorption isotherm measurements of the working pair. The
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Non-porous organic crystals and their interaction with guest molecules from the gas phase Adsorption (IF 1.949) Pub Date : 2020-09-18 Mirian Elizabeth Casco, Felix Krupp, Sven Grätz, Alexander Schwenger, Vassiliki Damakoudi, Clemens Richert, Wolfgang Frey, Lars Borchardt
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Sorption kinetics: measurement of surface resistance Adsorption (IF 1.949) Pub Date : 2020-09-18 Douglas M. Ruthven, Jörg Kärger, Stefano Brandani, Enzo Mangano
The problem of measuring sorption kinetics in microporous adsorbents and distinguishing experimentally between surface resistance and internal diffusion is discussed and reviewed with reference to several commonly used experimental techniques; direct uptake rate measurements, zero length column (ZLC), frequency response, PFG NMR and interference microscopy.
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Exact equivalence at cyclic steady state between isothermal diffusion and linear driving force models for linear adsorption systems Adsorption (IF 1.949) Pub Date : 2020-09-15 Stefano Brandani
To match the dynamics of a linear driving force model and the diffusion equation is of great practical importance in the design and optimization of adsorption separation processes. A frequency response analysis is applied to show that it is not possible to arrive at an equivalence based on a single parameter. Using this as the basis, a universal equivalence for the linear problem is constructed and
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Using classical methods to start quantum mechanical calculations for microporosity and mesoporosity Adsorption (IF 1.949) Pub Date : 2020-09-15 James Condon
One primary measurement of open porosity uses physical adsorption isotherm, amount adsorbed versus gas pressure. Classical treatments, including the BET, cannot fit the isotherm for its full range, therefore standard curves have been created from non-porous materials for comparison. This classical method yields three output parameters, two surface areas, pore and external, relative to the standard
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Diffusion coefficients in nanoporous solids derived from membrane permeation measurements Adsorption (IF 1.949) Pub Date : 2020-09-14 Juergen Caro
Based on the molecular understanding of the interplay of diffusion and adsorption, new membrane materials can be developed and the operational conditions of gas separation membranes can be optimized. Therefore, numerous diffusion and adsorption studies are conducted to optimize membrane materials. However, in an opposite way, transport or Fickian diffusion coefficients DT can be derived from membrane
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Effect of the surface hydration of clay minerals on the adsorption of cesium and strontium from dilute solutions Adsorption (IF 1.949) Pub Date : 2020-09-12 Yuriy Zabulonov, Vadym Kadoshnikov, Halyna Zadvernyuk, Tetyana Melnychenko, Valeriy Molochko
The use of clay minerals for the decontamination of liquid radioactive waste generated during the work of nuclear energy enterprises remains currently relevant. The effect of the surface hydration of a montmorillonite nanocrystal on the adsorption of cesium and strontium ions from dilute solutions was studied. As opposed to the generally accepted mechanism of the adsorption of cesium and strontium
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Self-assembly of the surfactant mixtures on graphene in the presence of electrolyte: a molecular simulation study Adsorption (IF 1.949) Pub Date : 2020-09-12 Mahdiye Poorsargol, Beheshteh Sohrabi, Maryam Dehestani
The insolubility of graphene nanosheets in aqueous media has been a limitation for the practical applications of this unique material. The non-covalent functionalization of graphene with mixed surfactants is an effective procedure for preparation of stable graphene dispersions. Physical adsorption of surfactants onto graphene surfaces is a significant stage in the dispersion of graphene nanosheets
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Kinetics of liquid phase batch adsorption experiments Adsorption (IF 1.949) Pub Date : 2020-09-11 Stefano Brandani
Batch adsorption experiments are carried out by adding a known amount of adsorbent to a liquid solution at a known initial concentration and following the evolution in time of the concentration of the adsorbate. This is a very common method to obtain equilibrium and kinetic information in liquid systems, but in most cases kinetic results are analysed on the basis of empirical models. Two phenomenological
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A reference high-pressure CH 4 adsorption isotherm for zeolite Y: results of an interlaboratory study Adsorption (IF 1.949) Pub Date : 2020-09-11 H. G. T. Nguyen, C. M. Sims, B. Toman, J. Horn, R. D. van Zee, M. Thommes, R. Ahmad, J. F. M. Denayer, G. V. Baron, E. Napolitano, M. Bielewski, E. Mangano, S. Brandani, D. P. Broom, M. J. Benham, A. Dailly, F. Dreisbach, S. Edubilli, S. Gumma, J. Möllmer, M. Lange, M. Tian, T. J. Mays, T. Shigeoka, S. Yamakita, M. Hakuman, Y. Nakada, K. Nakai, J. Hwang, R. Pini, H. Jiang, A. D. Ebner, M. A. Nicholson
This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess methane adsorption isotherms on NIST Reference Material RM 8850 (Zeolite Y), at 25 °C up to 7.5 MPa. Twenty laboratories participated in the study and contributed over one-hundred adsorption isotherms of methane
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Surface barriers and symmetry of adsorption and desorption processes Adsorption (IF 1.949) Pub Date : 2020-09-10 German Sastre, Jörg Kärger, Douglas M. Ruthven
Adsorption and desorption of hydrocarbons in a realistic model (2496 atoms) of ZSM-5 zeolite (MFI), including an external surface and a reservoir for molecules, have been studied using classical molecular dynamics, with special focus on surface barriers. Different degrees of surface blocking have been modeled according to experimental observations. Using previous molecular dynamics results, from the
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Monte Carlo simulations of simple gases adsorbed onto graphite and molecular models of activated carbon Adsorption (IF 1.949) Pub Date : 2020-09-03 M. E. Farías Hermosilla, A. G. Albesa
We had performed GCMC simulations to study the adsorption isotherms, the isosteric heats of argon, methane, nitrogen, carbon dioxide, methanol and water adsorption on molecular models of activated carbons at their boiling points in order to understand the contributions of the different functional groups of the adsorbent sites in the adsorption process. We had found that the values obtained from the
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Potentials and challenges of high-field PFG NMR diffusion studies with sorbates in nanoporous media Adsorption (IF 1.949) Pub Date : 2020-08-25 Amineh Baniani, Samuel J. Berens, Matthew P. Rivera, Ryan P. Lively, Sergey Vasenkov
High magnetic fields (up to 17.6 T) in combination with large magnetic field gradients (up to 25 T/m) were successfully utilized in pulsed field gradient (PFG) NMR studies of gas and liquid diffusion in nanoporous materials. In this mini-review, we present selected examples of such studies demonstrating the ability of high field PFG NMR to gain unique insights and differentiate between various types
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Biomethane production by adsorption technology: new cycle development, adsorbent selection and process optimization Adsorption (IF 1.949) Pub Date : 2020-08-17 Najib Chouikhi, Federico Brandani, Pluton Pullumbi, Patrick Perre, Francois Puel
Gas separation by adsorption processes such as pressure swing adsorption (PSA) presents an attractive alternative for upgrading biogas to biomethane. A new vacuum pressure swing adsorption (VPSA) cycle is proposed for a unit designed to purify pre-cleaned biogas (40% CO2 and 60% CH4) in industrial conditions (feed flow rate more than 500 Nm3/h and large-volume equipment). The process simulations performed
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Model-based optimization strategies for chromatographic processes: a review Adsorption (IF 1.949) Pub Date : 2020-08-17 Yoshiaki Kawajiri
Many decisions must be made when determining design and operation of a chromatographic process. Such decisions should optimize the performance, including product purity, recovery, productivity, and desorbent consumption. For this problem, model-based optimization has been shown to be a powerful approach, aided by recent developments in modeling of chromatographic processes. In this article, past studies
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Analysis of direct capture of $${\hbox {CO}}_{2}$$ CO 2 from ambient air via steam-assisted temperature–vacuum swing adsorption Adsorption (IF 1.949) Pub Date : 2020-08-11 Valentina Stampi-Bombelli, Mijndert van der Spek, Marco Mazzotti
In this work, direct air capture (DAC) via adsorption is studied through the design and analysis of two temperature–vacuum swing adsorption (TVSA) cycles. In the first part, a novel way of describing the adsorption of \({\hbox {CO}}_{2}\) in presence of water vapor is proposed for co-adsorption kinetic and thermodynamic data gathered from the literature. Secondly, two TVSA cycle designs are proposed:
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Theoretical study on the adsorption ability of (ZnO) 6 cluster for dimethylmercury removal and the influences of the supports and other ions in the adsorption process Adsorption (IF 1.949) Pub Date : 2020-08-10 Thi Thu Ha Nguyen, Minh Cam Le, Zhong-Tao Jiang, Ngoc Ha Nguyen
In this work a number of computational methods have been applied to study the adsorption of dimethylmercury (DMM) on the (ZnO)6 cluster and the influences of the supports (MgO, SBA-15) and external ions (Cl−, OH−) on the adsorption process: the energy and electronic properties were calculated using Geometry, Frequency, Noncovalent, eXtended Tight Binding method; global minimum was found by using the
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Interaction of propylthiouracil, an anti-thyroid drug with boron nitride nanotube: a DFT study Adsorption (IF 1.949) Pub Date : 2020-07-13 Behzad Hosseinzadeh, Alireza Salimi Beni, Razieh Eskandari, Marzieh Karami, Morteza Khorram
A theoretical study was performed on the adsorption of propylthiouracil (PTU) on the outer surface of boron nitride nanotube (BNNT). In this investigation, the BNNTs with (5,5), (6,6) and (7,7) chiralities were selected. The PTU molecule was located on the outer surface of BNNT in perpendicular and parallel modes. After the relaxation of whole system, the energy values and optimum distances in two
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Adsorption of cytarabine and gemcitabine anticancer drugs on the BNNT surface: DFT and GD3-DFT approaches Adsorption (IF 1.949) Pub Date : 2020-07-13 Hossein Roohi, Ahmad Facehi, Katereh Ghauri
In this work, at first, in order to find the most stable conformers of the two types of anticancer cytarabine (CYT) and gemcitabine (GEM) drugs, the potential energy curves for rotation around the C1′-N bond were explored at M06-2X/6–311 + + G(2d,2p) level of theory. Adsorption of the most stable conformers of CYT and GEM drugs on the BNNT surface was explored. Depending on the orientation of CYT and
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Small molecule substances as molecular probes of structure and texture of coal under sorption process and modelling Adsorption (IF 1.949) Pub Date : 2020-07-10 Marta Wójcik, Grzegorz S. Jodłowski
Multiple Sorption Model (MSM) is used to simulate sorption isotherms and the effect of the multiplicity of physicochemical parameters is reduced by introducing an invariant procedure using a few sorbates that are small molecules. This study presents the use of water, methanol, carbon dioxide and methane as test molecules to determine the structure and texture of coal and energy parameters. Parallel
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Remarks on adsorbent surface barrier to adsorbate mass transport Adsorption (IF 1.949) Pub Date : 2020-07-09 Shivaji Sircar
The existence of a skin resistance for adsorbate mass transport at the surface of a pelletized adsorbent particle or at the surface of adsorbent crystals within a particle has been proven by many macroscopic and microscopic experiments. An isothermal and isobaric column dynamic test method may be used to approximately estimate the relative magnitude of the skin resistance.
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Assessment of the potential use of zeolites synthesized from power plant fly ash to capture CO 2 under post-combustion scenario Adsorption (IF 1.949) Pub Date : 2020-06-30 Rafael Morales-Ospino, Yan Goltzman, A. Eurico B. Torres, Enrique Vilarrasa-García, Moises Bastos-Neto, Celio L. Cavalcante, Diana C. S. Azevedo, Carolina Resmini Melo Marques, Thiago Fernandes de Aquino, Vanessa Reich de Oliveira
Two types of zeolites (type X and type A) were synthesized from fly ash of two Brazilian coal based power plants via hydrothermal treatment after ash fusion with NaOH. The synthesized zeolites were characterized by means of XRF, XRD, SEM and gas adsorption (N2 and CO2 adsorption/desorption at − 196 and 0 °C, respectively). Pure CO2 and N2 adsorption equilibrium isotherms were performed at 50, 70 and
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Studied on the interaction between Ag-DNA nanocomposites and lipids monolayers Adsorption (IF 1.949) Pub Date : 2020-06-22 Hongjin Qu, Changchun Hao, Zhiqiong Yin, Hengyu Liu, Ziyi Zhang, Runguang Sun
The adsorption behavior of AgNPs-DNA nanocomposites on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphoserine (DMPS) lipid monolayers has been investigated by analyzing adsorption dynamic process, surface pressure-area isotherms (π-A), excess mean area (\({\Delta \mathrm{A}}_{\mathrm{e}\mathrm{x}\mathrm{c}}\)), excess Gibbs free energy (\(\Delta {\mathrm{
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Ionic liquid loaded polyether sulfone microspheres for CO 2 separation Adsorption (IF 1.949) Pub Date : 2020-06-09 D. Shanthana Lakshmi; Y. S. Sistla; A. Khanna; A. Figoli
Carbon dioxide permeation studies were conducted on polyether-sulfone (PES) microspheres fabricated using phase-inversion technique by loading various amine-functionalized imidazolium cation ILs with a common anion bis-trifluoromethylsulfonylamide ([TF2N]−) on PES-polymer matrix. The cations include: Aminopropyl-butyl-imidazolium [APBIM], Diethyl-aminoethyl-imidazolium [DEAEBIM], Diaminopropyl-butyl-imidazolium
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Chemical modification of the polymer of intrinsic microporosity PIM-1 for enhanced hydrogen storage Adsorption (IF 1.949) Pub Date : 2020-06-01 Mi Tian, Sébastien Rochat, Hamish Fawcett, Andrew D. Burrows, Christopher R. Bowen, Timothy J. Mays
A detailed investigation has been carried out of the pre-polymerisation modification of the polymer of intrinsic microporosity PIM-1 by the addition of two methyl (Me) groups to its spirobisindane unit to create a new chemically modified PIM-1 analogue, termed MePIM. Our work explores the effects of this modification on the porosity of PIM-1 and hence on its gas sorption properties. MePIM was successfully
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Experimental study of a rotary valve multi-bed rapid cycle pressure swing adsorption process based medical oxygen concentrator Adsorption (IF 1.949) Pub Date : 2020-05-19 Xianqiang Zhu, Xiaowei Wang
Rapid cycle pressure swing adsorption (RCPSA) characterized by short cycle time permits adsorbents to be used more frequently and increases process productivity. A rotary valve multi-bed RCPSA process is proposed to improve the performance of miniature oxygen concentrator. The RCPSA air separation system is highly integrated by four adsorbent beds and a rotary valve. The effects of process parameters
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Assessment of process configurations to combine enantioselective chromatography with enzymatic racemization Adsorption (IF 1.949) Pub Date : 2020-05-07 Isabel Harriehausen, Katarzyna Wrzosek, Heike Lorenz, Andreas Seidel-Morgenstern
Enantioselective chromatography is nowadays a reliable tool for single enantiomer production from a racemate. The recovery of the distomer by racemization and recycling is a promising method to tackle the 50% yield constraint and to increase the productivity. In this paper three process configurations are compared. The production of enantiopure mandelic acid and methionine enantiomers exploiting different
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Diffusion in nanopores: correlating experimental findings with “first-principles” predictions Adsorption (IF 1.949) Pub Date : 2020-05-06 Seungtaik Hwang, Jörg Kärger
Measurement of molecular diffusion in nanoporous host materials, which are typically inhomogeneous and anisotropic, often involves an intricate web of factors and relations to be taken into account since the associated diffusivities are a function of the diffusion path of the guest molecules during a given observation time. Depending on the observation time, therefore, the result of the experimental
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Impact of high adsorbent conductivity on adsorption of polar molecules: simulation of phenol adsorption on graphene sheets Adsorption (IF 1.949) Pub Date : 2020-05-02 Zineb El Oufir; Hamidréza Ramézani; Nathalie Mathieu; Suresh K. Bhatia; Sandrine Delpeux
The high conductivity of nanoprous carbons has a significant effect on adsorption of polar molecules; however, the mechanisms underlying this effect are not well-understood, and this effect is generally not considered in adsorption modeling. To investigate the impact of high host conductivity on the adsorption properties of vertical stacks of the graphene sheet, phenol vapor has been chosen as a simple
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Methoxy radical adsorption on gold nanoparticles: a comparison with methanethiol and methylamine radicals Adsorption (IF 1.949) Pub Date : 2020-04-30 Xavier Fenouillet; Magali Benoit; Nathalie Tarrat
The adsorption of a methoxy radical (\(\hbox {OCH}_3\)) on the low-energy flat gold surfaces Au(111), Au(100) and Au(110) and on surface defects (adatoms) was compared with those of methanethiol (\(\hbox {SCH}_3\)) and methylamine (\(\hbox {NHCH}_3\)) radicals. Using dispersion-corrected DFT, we showed that the adsorption energy of \(\hbox {OCH}_3\) on gold is significantly lower than that of \(\hbox
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A novel blended amine functionalized porous silica adsorbent for carbon dioxide capture Adsorption (IF 1.949) Pub Date : 2020-04-28 Peiyu Zhao; Guojie Zhang; Lanxia Hao
In order to accomplish efficient CO2 capture, poly(ethyleneimine) (PEI) and tetraethylenepentamine (TEPA), with commonly used and inexpensive, was codispersed into the as-prepared SBA-15 (SBA-15(p)) to prepared blended amine functionalized adsorbent. The influence of the mass ratio of PEI to TEPA on the adsorption property was investigated. The promoting effects of TEPA on CO2 capture property were
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Uncertainty analysis of adsorption measurements using commercial gravimetric sorption analyzers with simultaneous density measurement based on a magnetic-suspension balance Adsorption (IF 1.949) Pub Date : 2020-04-27 Xiaoxian Yang; Reiner Kleinrahm; Mark O. McLinden; Markus Richter
A commercial gravimetric sorption analyzer, which is based on a magnetic-suspension balance, was significantly improved to reduce the uncertainty in adsorption measurements. In a previous paper, we investigated the force-transmission error (FTE) of the instrument’s magnetic-suspension coupling, and we analysed the uncertainty of the density measurement. In the present paper, equations for the determination
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Effect of the curvature during the course of adsorption in elliptical pores: a study under the framework of the Broekhoff de Boer approximation Adsorption (IF 1.949) Pub Date : 2020-04-25 Erendira Aguilar-Huerta; Salomón Cordero-Sánchez; Fernando Rojas-González; Armando Domínguez-Ortiz; Juan Villegas-Cortez
This paper analyses the effect of an adsorbed layer of variable curvature during the course of adsorption. To this end the capillary condensation and evaporation verified in pores endowed with elliptical geometry is studied. An adsorption potential within the pore walls is defined and it is numerically derived in accordance with the curvature of the pores and the attraction between the adsorbate and
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Evaluation of surface energetics of zirconium-containing mesoporous silica using novel universal isotherm model Adsorption (IF 1.949) Pub Date : 2020-04-18 Jéssica de O. N. Ribeiro; Daniel D. Athayde; Daniela C. L. Vasconcelos; Wander L. Vasconcelos
A recently developed universal isotherm model was used in this work for the study of zirconium-added mesoporous silicas, focusing on the dehydration of low humidity gaseous streams. This modeling was chosen for its capability of calculating an energy distribution profile of the adsorption sites. This study was based on a systematic approach to evaluate three variables: the amount of zirconium substitution;
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Modelling binary non-linear chromatography using discrete equilibrium data Adsorption (IF 1.949) Pub Date : 2020-04-07 Arvind Rajendran, Rafael Teruo Maruyama, Héctor Octavio Rubiera Landa, Andreas Seidel-Morgenstern
Abstract The determination and description of adsorption equilibria is critical for the design of several separation processes. In some instances, the dependence of the solid phase loading on the fluid phase concentration is complex and it is difficult to find a suitable functional form to represent the adsorption equilibria. This difficulty can be overcome by the use of discrete equilibrium data,
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Nanoporous structures of metal oxides-loaded graphene nanocomposites and their energy storage performance Adsorption (IF 1.949) Pub Date : 2020-04-02 K. P. Annamalai, Tianlu Chen, Yousheng Tao
Abstract Efficient and stable supercapacitor electrodes must possess large surface area, excellent conductivity and electrochemical stability. In this regard, conductive carbon loaded metal oxide composites are of particular interest. Herein, Ru–Mn oxide loaded graphene was synthesized with different graphene oxide (GO) proportion using simple solution chemistry method. Morphological and compositional
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Simulation and energy consumption comparison of gas purification system based on elevated temperature pressure swing adsorption in ammonia synthetic system Adsorption (IF 1.949) Pub Date : 2020-03-28 Zhiming Liu, Peixuan Hao, Shuang Li, Xuancan Zhu, Yixiang Shi, Ningsheng Cai
Abstract Elevated temperature pressure swing adsorption (ET-PSA) is a novel process for hydrogen purification. By operating steam rinse and purge at conditions beyond the dew point will significantly improve the recovery rate of the product gas. Moreover, since cooling and reheating processes are not needed in ET-PSA, the sensible heat of the incoming gas could also be preserved. In this study, a seven-column
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Graphitic carbon nitride functionalized with four boron atoms for adsorption and separation of CO 2 /CH 4 : DFT calculations Adsorption (IF 1.949) Pub Date : 2020-04-11 Marisol Ibarra-Rodríguez; Mario Sánchez
The adsorption of CO2 and CH4 on graphitic carbon nitride (g-C3N4) functionalized with four boron atoms (g-C43N4B4) were investigated by using the density functional theory for adsorption and separation of the CO2/CH gas molecules. The calculated Eads values showed that the CO2 molecule, in comparison with the CH4 molecule, has favorable interaction with the boron cluster hosted in the sheet. The capacity
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