Modification of Zeolites Y and ZSM-5 adsorption of nanoparticles of transition metals from back-micellar solutions for separation of gas mixtures

On the basis of granular synthetic zeolites NaY, HY, and ZSM-5, adsorbents containing nanoparticles of silver, cobalt, molybdenum, and tungsten were obtained. The samples have a lower surface polarity in comparison with the initial zeolites, which is reflected in the selectivity of a number of samples with respect to argon. This is due to the fact that the argon molecule interacts with zeolites only through nonspecific forces. Modification was performed by interacting with reverse-micellar solutions of nanoparticles. The actual sizes of metal particles and their distribution over the surface of the modified samples of zeolites have been determined by the method of transmission electron microscopy. The samples’ equilibrium adsorption capacities for oxygen and argon (25°С and atmospheric pressure) and the separation coefficient of the argon–oxygen mixture as the ratio of Henry’s coefficients have been determined. It has been demonstrated that samples of the NaY zeolite modified with silver nanoparticles have the separation coefficient value of the argon–oxygen gas mixture equal to 1.6.

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Oxygen Precipitation Along Individual Ion Tracks During High Dose O+ Implantation into Silicon

MRS Proceedings ◽

10.1557/proc-93-143 ◽

1987 ◽

Vol 93 ◽

Cited By ~ 7

Author(s):

Witold P. Maszara

Keyword(s):

Silicon Layer ◽

High Dose ◽

Regular Array ◽

Ion Tracks ◽

Oxygen Precipitation ◽

Transmission Electron ◽

Oxygen Gas ◽

Kinetics Of ◽

Secondary Ion ◽

Lattice Matched

ABSTRACTSilicon wafers with and without protective1Ahermil oxide were implanted with oxygen at 150keV with doses 1.6 – 2.0×1018 cm−2. Transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS) were used to study the top silicon layer remaining above the implanted buried oxide. regular array of spheroidal voids filled with oxygen gas was observed only in the samples that were not protected by the oxide. The voids were aligned into individual columns whose crystallographic orientation with respect to the host silicon lattice matched the direction of the implantation. The origin and the kinetics of their formation are discussed.

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Origins of the Viscosity Peak in Wormlike Micellar Solutions. 1. Mixed Catanionic Surfactants. A Cryo-Transmission Electron Microscopy Study

Langmuir ◽

10.1021/la901189k ◽

2009 ◽

Vol 25 (18) ◽

pp. 10483-10489 ◽

Cited By ~ 103

Author(s):

Lior Ziserman ◽

Ludmila Abezgauz ◽

Ory Ramon ◽

Srinivasa R. Raghavan ◽

Dganit Danino

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Microscopy Study ◽

Electron Microscopy Study ◽

Micellar Solutions ◽

Transmission Electron Microscopy Study ◽

Catanionic Surfactants ◽

Transmission Electron

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A Comparative Analysis of In Vitro Toxicity of Synthetic Zeolites on IMR-90 Human Lung Fibroblast Cells

Molecules ◽

10.3390/molecules26113194 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3194

Author(s):

Seung-Hye Yu ◽

Manjesh Kumar ◽

Il-Won Kim ◽

Jeffrey D. Rimer ◽

Tae-Jung Kim

Keyword(s):

Human Lung ◽

Lung Fibroblast ◽

In Vitro Toxicity ◽

Pcr Analysis ◽

Human Lung Fibroblast ◽

Transmission Electron ◽

Synthetic Zeolites ◽

Potential Impact ◽

Intracellular Changes

Broad industrial application of zeolites increases the opportunity of inhalation. However, the potential impact of different type and composition of zeolite on the cytotoxicity is still unknown. Four types of synthetic zeolites with have been prepared for assessing the effect on lung fibroblast: two zeolite L (LTL-R and LTL-D, ZSM-5 (MFI-S), and faujasite (FAU-S). The cytotoxicity of zeolites on human lung fibroblast (IMR-90) was assessed using WST1 cell proliferation assay, mitochondrial function, membrane leakage of lactate dehydrogenase, reduced glutathione levels, and mitochondrial membrane potential were assessed under control. Intracellular changes were examined using transmission electron microscopy (TEM). Toxicity related gene expression were evaluated by PCR array. The result showed a significantly higher toxicity in IMR-90 cells with FAU-S than LTL-R, LTL-D and MFI-S exposure. TEM showed FAU-S, spheroidal zeolite with a low Si/Al ratio, was readily internalized forming numerous phagosomes in IMR-90 cells, while the largest and disc-shaped zeolites showed the lowest toxicity and were located in submembranous phagosomes in IMR-90 cells. Differential expression of TNF related genes was detected using PCR arrays and confirmed using qRT-PCR analysis of selected genes. Collectively, the exposure of different zeolites shows different toxicity on IMR-90 cells.

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Equilibrium, Kinetic and Thermodynamic Studies on Adsorptive Removal of H2S from Natural Gas by Amine Functionalisation of MCM-41

Progress in Reaction Kinetics and Mechanism ◽

10.3184/146867817x14806858831983 ◽

2017 ◽

Vol 42 (3) ◽

pp. 221-234 ◽

Cited By ~ 1

Author(s):

Jiao Jing Zhang ◽

Wen Yi Wang ◽

Guo Jian Wang ◽

Cheng Kai ◽

Hua Song ◽

...

Keyword(s):

Electron Microscopy ◽

Adsorption Isotherm ◽

Natural Gas ◽

Physical Adsorption ◽

Oxygen Mixture ◽

Impregnation Method ◽

X Ray Diffraction ◽

Transmission Electron ◽

Kinetic And Thermodynamic Studies ◽

Mcm 41

A model natural gas consisting of hydrogen sulfide, nitrogen and oxygen mixture was used to simulate materials to test the performance of an amine-modified MCM-41 adsorbent prepared by the impregnation method. The adsorbent was characterised by X-ray diffraction analysis, Brunauer–Emmett–Teller analysis, Fourier-transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The results showed that more molecules are able to penetrate the pores following modification, resulting in rapid structural collapse, thus lowering the diffraction intensity. Although the capacity of amine-modified MCM-41 decreased the physical adsorption, chemisorption increased significantly. (3-Aminopropyl)trimethoxysilane/MCM-41 was found to exhibit a good performance for H2S desulfurisation. At 45 °C the breakthrough time was 186 min, the saturated sulfur capacity was 134.38 mg g−1 and the degree of desulfurisation was 54.19%. The adsorption isotherm and kinetics were investigated and the relevant parameters were obtained. The results showed that the adsorption isotherm could be well fitted by the Langmuir model and the maximum adsorption capacities increased with increase of temperature. The adsorption kinetics could be represented by the Bangham model, which suggested that chemical reaction seemed significant in the rate-controlling adsorption step. The adsorption process was spontaneous and exothermic.

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Silver Nanoparticles/Montmorillonite Composites Prepared Using Nitrating Reagent at Water and Glycerol

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.088 ◽

2008 ◽

Vol 8 (6) ◽

pp. 3050-3058 ◽

Cited By ~ 11

Author(s):

Marta Valášková ◽

Gražyna Simha Martynková ◽

Jana Lešková ◽

Pavla Čapková ◽

Volker Klemm ◽

...

Keyword(s):

Silver Nanoparticles ◽

Silver Nitrate ◽

Interlayer Space ◽

Exchangeable Cations ◽

Metallic Silver ◽

Transmission Electron ◽

Modeled Structure ◽

Silicate Layers ◽

20 Nm ◽

Nanoparticles Of Silver

Three procedures (P) were applied to prepare silver nanoparticles on natural Ca-montmorillonite (MT). The intercalation of the montmorillonite with silver nitrate in aqueous solution (P1), the intercalation of the montmorillonite with silver nitrate in glycerol (P2) and the successive combination of both P1 and P2methods resulted to P3 method. X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier Transform Infrared (FTIR) spectroscopy and the molecular modeling were employed to characterize silver nanoparticles and montmorillonite nanocomposite. The P1 produced MT-1 composite with 2.3 wt% Ag and the partially collapsed layered structure. Nanoparticles of silver larger than 20 nm with a lot of planar defects were randomly distributed on the MT-1 surface; nanoparticles smaller than 20 nm were oriented to the montmorillonite substrate. The MT-2 composite from P2 contained only 1 wt% of Ag. The molecular simulation model of MT-2 showed the interlayer space with the exchangeable cations and metallic silver atoms arrangement within the glycerol bilayer. The P3 produced composite MT-3 that contained 2.4 wt% Ag. The nanoparticles > 20 nm size had a well-defined geometry, very small nanoparticles were amorphous. The modeled structure showed the exchangeable cations, Ag+ and Ag0 located close to the silicate layers and monolayer of glycerol molecules in the interlayer space.

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Diffusion and Cryo Transmission Electron Microscopy Studies of Bicontinuous "Micellar" Solutions

Langmuir ◽

10.1021/la00024a056 ◽

1994 ◽

Vol 10 (12) ◽

pp. 4731-4734 ◽

Cited By ~ 20

Author(s):

I. Harwigsson ◽

O. Soederman ◽

O. Regev

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Micellar Solutions ◽

Transmission Electron

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Rheology, Cryogenic Transmission Electron Spectroscopy, and Small-Angle Neutron Scattering of Highly Viscoelastic Wormlike Micellar Solutions

Langmuir ◽

10.1021/la0304114 ◽

2004 ◽

Vol 20 (1) ◽

pp. 277-277

Author(s):

Vania Croce ◽

Terence Cosgrove ◽

Geoff Maitland ◽

Trevor Hughes ◽

Göran Karlsson

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Electron Spectroscopy ◽

Small Angle Neutron Scattering ◽

Micellar Solutions ◽

Transmission Electron

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Heteroepitaxy: The Missing Link Between Surface Chemistry and Dry Corrosion

MRS Proceedings ◽

10.1557/proc-619-63 ◽

2000 ◽

Vol 619 ◽

Author(s):

Judith C. Yang ◽

Mridula Dixit Bharadwaj ◽

Lori Tropia

Keyword(s):

Electron Microscopy ◽

Water Vapor ◽

High Vacuum ◽

Ultra High Vacuum ◽

Solid State Reactions ◽

Transmission Electron ◽

Oxygen Gas ◽

Cu Oxidation

ABSTRACTWe have investigated the initial stages of Cu (001) oxidation in dry and moist oxidizing conditions using in situ ultra-high vacuum (UIHV) transmission electron microscopy (TEM). To investigate the role of moisture in the solid state reactions in Cu oxidation, we have examined the oxidation of Cu (001) with water vapor. Our observation indicate that water vapor causes reduction of Cu2O and retards the oxidation rate if both oxygen gas and water vapor are used simultaneously which contradicts the thermochemical data. We are also modeling the nucleation to coalescence of the oxide scale using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation and have noted a qualitative agreement.

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A Rapid Supercritical Extraction Process for the Production of Silica Aerogels

MRS Proceedings ◽

10.1557/proc-431-297 ◽

1996 ◽

Vol 431 ◽

Cited By ~ 36

Author(s):

J. F. Poco ◽

P. R. Coronado ◽

R. W. Pekala ◽

L. W. Hrubesh

Keyword(s):

Lawrence Livermore National Laboratory ◽

National Laboratory ◽

Lower Surface ◽

Extraction Process ◽

Silica Aerogels ◽

Supercritical Extraction ◽

Surface Areas ◽

Transmission Electron ◽

Near Net Shape ◽

Rapid Supercritical Extraction

AbstractSilica aerogels are a special class of porous materials in which both the pore size and interconnected particle size have nanometer dimensions. This structure imparts unique optical, thermal, acoustic, and electrical properties to these materials. Transmission electron microscopy and small angle x-ray scattering show that this nanostructure is sensitive to variations in processing conditions that influence crosslinking chemistry and growth processes prior to gelation. Recently, Lawrence Livermore National Laboratory (LLNL) has demonstrated that a Rapid Supercritical Extraction (RSCE) process can be used to prepare near-net shape silica aerogels in hours rather than days. Preliminary data from RSCE silica aerogels show that they have improved mechanical properties and slightly lower surface areas than their conventionally dried counterparts, while not compromising their optical and thermal performance.

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