Adsorption-desorption isotherms and x-ray diffraction of Ar condensed into a porous glass matrix

1999 ◽  
Vol 60 (18) ◽  
pp. 12657-12665 ◽  
Author(s):  
P. Huber ◽  
K. Knorr
Keyword(s):  
Porous Glass ◽  
Glass Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Desorption Isotherms ◽  
Adsorption Desorption

scholarly journals Effect of Both the Phase Composition and Modification Methods on Structural-Adsorption Parameters of Dispersed Silicas

2018 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Tatyana Rakitskaya ◽  
Tatyana Kiose ◽  
Kristina Golubchik ◽  
Viacheslav Baumer ◽  
Vitaliya Volkova
Keyword(s):  
Water Vapor ◽  
Water Vapor Adsorption ◽  
X Ray Diffraction ◽  
Adsorption Parameters ◽  
X Ray ◽  
Vapor Adsorption ◽  
Crystallite Sizes ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Modified Forms

Tripoli from two Ukrainian deposits was studied in its natural and modified forms. The investigation of natural and modified tripoli involves the identification of their phase compositions through X-ray diffraction and the analysis of their water vapor adsorption-desorption isotherms. The obtained results are evidence of changes in the structural-adsorption parameters of tripoli as a result of modification. Their treatment in boiling water or acid causes apparent alterations of contents of the main phases and sizes of their crystallites, whereas their calcination causes not only the dehydroxylation of surfaces and the agglomeration of phases, but even phase transformation in the case of carbonate tripoli. After analyzing water vapor adsorption-desorption isotherms of natural and modified tripolis, some correlations between their adsorption parameters, phase compositions, main phase contents and crystallite sizes have been found.

Biosorption of crystal violet dye using inactive biomass of the fungus Diaporthe schini

2019 ◽  
Vol 79 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Patrícia Grassi ◽  
Caroline Reis ◽  
Fernanda C. Drumm ◽  
Jordana Georgin ◽  
Denise Tonato ◽  
...  
Keyword(s):  
Crystal Violet ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
Biosorption Capacity ◽  
X Ray ◽  
Crystal Violet Dye ◽  
Endothermic Process ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Scanning Electron

Abstract An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m2 g−1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L−1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g−1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiency of 87% in the decolorization of a simulated dye house effluent.

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

Preparation and Characterization of Al-Pillared Rectorite

2010 ◽  
Vol 96 ◽  
pp. 129-133 ◽  
Author(s):  
Hong Yan Xu ◽  
Ai Hong Guo ◽  
Xing Tong Chen
Keyword(s):  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Narrow Pore Size Distribution ◽  
X Ray ◽  
Bet Specific Surface Area ◽  
Infra Red ◽  
Desorption Isotherms ◽  
Pore Properties ◽  
Adsorption Desorption

. Al-pillared rectorites (Al-REC) were synthesized from natural calcium rectorite through the exchange of inter-lamellar ions with hydroxyalumina polycations. Furthermore, the morphology, composite structure and pore properties of such composite materials were investigated by Powder X-ray Diffraction (XRD), Fourier Transformation Infra-red Spectra (FTIR) and Nitrogen Adsorption-Desorption Isotherms. The products retain their layered structure and their pore structures are a slit-shaped pore between plate-like particles. The resultant products possess BJH pore volume as large as 0.04cm3g-1, high BET specific surface area of over 100m2g-1, narrow pore size distribution in the mesopore region of 7-9nm after thermal treatment at 300 °C.

scholarly journals Al-Si@Al(OH)3 Nanosheets Composite for Enhanced Efficient Strategy to Synthesize Al-Si@Al2O3 Core-shell Structure

2021 ◽  
Author(s):  
Yuhui Lin ◽  
Panyu Chen ◽  
Ying Wang ◽  
Wei He ◽  
Chao Tang ◽  
...  
Keyword(s):  
Heat Storage ◽  
X Ray Diffraction ◽  
Storage Material ◽  
X Ray ◽  
Catalyst Carrier ◽  
Heat Storage Material ◽  
Desorption Isotherms ◽  
Si Content ◽  
Adsorption Desorption

Abstract Owing to the combined advantages of Al-Si alloy and Al2O3, Al-Si@Al2O3 is widely utilized as a heat storage material, catalyst carrier and what adsorption host. Hence, the preparation of Al-Si@Al2O3 and corresponding precursors is of utmost significance. Herein, Al-Si@Al(OH)3 precursor is investigated and Al(OH)3 nanosheets are in-situ formed on the surface of Al-xSi alloy (x = 10, 20 and 30) in the presence of water. The influence of Si content, diameter of Al-Si particles and heating parameters on morphology and thickness of Al(OH)3 nanosheets is systematically explored using X-ray diffraction, electron microscopy, Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherms. The growth mechanism of Al(OH)3 nanosheets is revealed and a pathway to obtain Al-Si@Al2O3 nanosheets with desired structure and thickness is demonstrated.

scholarly journals Synthesis of Medium-temperature Protonic Conductor CsHSO4-Al2O3

2013 ◽  
Vol 16 (4) ◽  
pp. 273-278
Author(s):  
L.B. Yang ◽  
W.S. Ning ◽  
X.D. Wang ◽  
W. Liu ◽  
H.Y. Shen ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Medium Temperature ◽  
X Ray ◽  
Rotating Speed ◽  
Structures And Properties ◽  
Protonic Conductors ◽  
Desorption Isotherms ◽  
Adsorption Desorption

In this study, different methods are used to synthesize novel medium-temperature protonic conductors from CsHSO4 and mesoporous Al2O3. X-ray diffraction, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry, and nitrogen adsorption-desorption isotherms are performed to investigate the structures and properties of CsHSO4-Al2O3 conductors. Results show that the proton conductivities of the prepared CsHSO4-Al2O3 conductors increase as temperature increases from 100 °C to 200 °C. The optimum method involves mixing the equimolar CsHSO4 and Al2O3 with 5 ml ethanol and subsequently ball milling at a rotating speed of 200 rpm for 2 h. The highest proton conductivity obtained in this study is 1.06×10-6 S·cm–1 at 200 °C.

scholarly journals Influence of the Presence of Different Alkali Cations and the Amount of Fe(CN)6 Vacancies on CO2 Adsorption on Copper Hexacyanoferrates

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3371 ◽  
Author(s):  
Svensson ◽  
Grins ◽  
Eklöf ◽  
Eriksson ◽  
Wardecki ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Prussian Blue ◽  
Co2 Adsorption ◽  
X Ray Diffraction ◽  
Alkali Cations ◽  
Prussian Blue Analogue ◽  
X Ray ◽  
Infra Red ◽  
Adsorption Desorption ◽  
Adsorption Capability

The CO2 adsorption on various Prussian blue analogue hexacyanoferrates was evaluated by thermogravimetric analysis. Compositions of prepared phases were verified by energy-dispersive X-ray spectroscopy, infra-red spectroscopy and powder X-ray diffraction. The influence of different alkali cations in the cubic Fm3m structures was investigated for nominal compositions A2/3Cu[Fe(CN)6]2/3 with A = vacant, Li, Na, K, Rb, Cs. The Rb and Cs compounds show the highest CO2 adsorption per unit cell, 3.3 molecules of CO2 at 20 C and 1 bar, while in terms of mmol/g the Na compound exhibits the highest adsorption capability, 3.8 mmol/g at 20 C and 1 bar. The fastest adsorption/desorption is exhibited by the A-cation free compound and the Li compound. The influence of the amount of Fe(CN)6 vacancies were assessed by determining the CO2 adsorption capabilities of Cu[Fe(CN)6]1/2 (Fm3m symmetry, nominally 50% vacancies), KCu[Fe(CN)6]3/4 (Fm3m symmetry, nominally 25% vacancies), and CsCu[Fe(CN)6] (I-4m2 symmetry, nominally 0% vacancies). Higher adsorption was, as expected, shown on compounds with higher vacancy concentrations.

scholarly journals Adsorption of malic acid at the hydroxyapatite/aqueous NaCl solution interface

2021 ◽  
Author(s):  
Władysław Janusz ◽  
Ewa Skwarek
Keyword(s):  
Zeta Potential ◽  
Malic Acid ◽  
Particle Sizes ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Radioisotope Method ◽  
X Ray ◽  
Solution Interface ◽  
Adsorption Desorption ◽  
Kinetics Of

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.

Behaviours of direct yellow 12 adsorption on mesoporous carbons with different pore geometries

2018 ◽  
Vol 2017 (1) ◽  
pp. 219-228
Author(s):  
Fengling Liu ◽  
Ziyan Guo ◽  
Hui Qiu ◽  
Xia Lu ◽  
Hua Fang ◽  
...  
Keyword(s):  
Mesoporous Carbons ◽  
X Ray Diffraction ◽  
Pore Characteristics ◽  
X Ray ◽  
Transmission Electron ◽  
Cylindrical Pores ◽  
Pseudo Second Order ◽  
Hexagonally Ordered ◽  
Adsorption Desorption ◽  
Interconnected Pore

Abstract Four kinds of mesoporous carbons, C1-h-w, C2-h-h, C3-s-w, and C4-s-h, with different pore geometries were prepared and characterised, and their adsorption behaviours with aqueous direct yellow 12 (DY-12) were investigated. The results of X-ray diffraction and transmission electron microscopy show that C1-h-w and C3-s-w have wormlike pore characteristics, whereas C2-h-h and C4-s-h have 2-D hexagonally arranged pores. According to the N2 adsorption/desorption results, the specific surface area of C1-h-w (1,378 m2/g) is the largest among the four carbons. The adsorption isotherms could be effectively fitted using the Langmuir model. The maximum adsorption amounts of C1-h-w, C2-h-h, C3-s-w and C4-s-h are 0.968 mmol/g, 0.726 mmol/g, 0.161 mmol/g and 0.156 mmol/g, respectively. The pseudo-second-order rate constants of C1-h-w (39.8 g/(mmol·min)) and C2-h-h (7.28 g/(mmol·min)) are substantially larger than those of C3-s-w (0.0046 g/(mmol·min)) and C4-s-h (0.014 g/(mmol·min)), indicating that an open and interconnected pore geometry is favourable for DY-12 adsorption. Furthermore, DY-12 diffusion in 2-D hexagonally ordered cylindrical pores is superior to that in wormlike pores due to the smoothness of the channels in the former. External mass transfer and intraparticle diffusion both play roles in the adsorption process.

scholarly journals Synthesis and Characterization of Nanoporous Monetite Which Can Be Applicable for Drug Carrier

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Esmael Salimi ◽  
Jafar Javadpour
Keyword(s):  
Surface Area ◽  
Cetyltrimethylammonium Bromide ◽  
Drug Carrier ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Plate Shape ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Wormhole-like mesostructured monetite was successfully synthesized using cetyltrimethylammonium bromide (C19H42BrN, CTAB), as a porosity agent. X-ray techniques and FTIR reveal that the crystalline grains consist of highly crystalline pure monetite phase. Monetite rods with diameter around 20–40 nm and length in the range of 50–200 nm were confirmed by FESEM and TEM. Based on N2adsorption-desorption isotherms investigation, surface area increased up to 31.5 m2/g due to the removal of surfactant after calcinations at 400°C. The results indicate that CTAB can not only affect monetite crystallization but also change particles morphology from plate shape to rod-like.

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