Zeolite surface

Tubular zeolite BEA membrane was prepared by a hydrothermal secondary growth method in the absence of an organic structure directing agent (OSDA). Membrane formation process was carefully observed by using FE-SEM, XRD, and N2 adsorption, and the role of seed crystals on the support surface was discussed.

6p vironald 15-12-2022 9 3   Download

The fluorination reaction is strongly influenced by the nature of the intrapore cation. Intrapore Brønsted acids facilitate fluorination of the framework by in situ ion-exchange, releasing the acidic ions to the zeolite surface.

11p vironald 15-12-2022 4 2   Download

Two main types of morphological features resulting in surface roughness were observed on alumina discs used as supports for zeolite membranes. These features can be described as hills and pits and it was shown that defects as cracks formed in the zeolite film at these locations of the support.

5p vironald 15-12-2022 7 2   Download

The adsorption of simple gases begins with the formation of a monolayer on the pristine surface, not always followed by the formation of a second or more monolayers. Subsequently, cluster formation or cavity filling occurs, depending on the properties of the surface.

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The adsorption and mass transport of CO2 and CH4 in CHA zeolite were studied experimentally. First, large and well-defined CHA crystals with varying Si/Al ratios and morphologies ideal for adsorption studies were prepared. Then, adsorption isotherms were measured, and adsorption parameters were estimated from the data.

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(BQ) Ebook part 2 presents the following content: Chapter 9: Understanding Transport in MFI-Type Zeolites on a Molecular Basis; Chapter 10: Modeling Layered-Mineral Organic Interactions; Chapter 11: Status of Technology and Perspectives for Portable Applications of Direct Methanol Fuel Cells; Chapter 12: Semiconductor Block Copolymers for Photovoltaic Applications; Chapter 13: Switching-on: The Copper Age; Chapter 14: Understanding Single-Molecule Magnets on Surface; Chapter 15: Sculpting Nanometric Patterns: The Top-down.

177p runordie7 30-08-2022 5 2   Download

The present study addresses the removal of cadmium ions (Cd(II)) from aqueous solutions at a pH of 7.5 using zeolite-A activated by exposure to oxygen plasma. The activation process was performed over a wide range of plasma powers (10, 20, 30, and 40 W) and exposure times (30 to 360 s). Oxygen plasma cannot chemically modify zeolite to a considerable extent, but it can clean the surface, open blocked pores, and induce the formation of additional OH groups via exposure to humidity in ambient air. Therefore, Cd+2 ion removal is increased by approximately 10% with the plasma treatments.

13p tudichquannguyet 29-11-2021 8 1   Download

In this work, metal nanoparticles were successfully synthesized through the reduction of metal salts using reducing agents such as: ethylene glycol (EG) and sodium borohydride (NaBH4). These metal nanoparticles were impregnated into the supports M-X (M = Ni, Pd; X = Bent, C, Zeolite, and Al2O3) in high yield. The physio-chemical properties of these catalysts were characterized by various techniques such as UV-Vis spectroscopy, powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and the specific surface area of M-X was evaluated by N2 adsorption isotherm analysis at 77 K.

6p cothumenhmong11 06-05-2021 6 2   Download

ZSM-5 zeolite material (Si/Al ratio = 25) was synthesized with silica source of TEOS and TPAOH template. The zeolite is modified into proton form (HZSM-5) with 343 m2 /g of BET surface area, 324 m2 /g of micropore area, 0.1491 cm3 /g of micropore volume and 5.77 nm of BJH adsorption average pore width. Zinc oxide and iron oxide are dispersed onto HZSM-5 catalyst surface with different contents by wet impregnation method. The results of HZSM-5, Zn/HZSM5, Fe/HZSM-5 catalyst materials still retain the micropore structure of ZSM-5 zeolite.

8p cothumenhmong11 06-05-2021 21 1   Download

In this study, zeolite-activated carbon composite (Z/AC) was synthesized by hydrothermal reaction using kaolin as a source of silica and alumina. The synthesized materials were characterized by Brunner-Emmet-Teller (BET) surface area to calculate surface area, X-ray diffraction (XRD) to study the crystal structure of materials, Infrared spectroscopy (IR) to indicate the presence of functional groups on the surface and scanning electron microscopy (SEM) to determine the morphology of the composites.

10p cothumenhmong9 04-01-2021 36 2   Download

Acinetobacter baumannii is an emerging human pathogen causing great concern in hospitals. There are numerous studies regarding the virulence factors that contribute to the pathogenesis of A. baumannii clinical isolates, whereas data regarding environmental isolates are missing. The virulence factors (biofilm formation at the air-liquid/solid-liquid interfaces and surface motility) of A. baumannii isolated from natural environment were determined.

13p kethamoi6 29-06-2020 24 2   Download

India is a developing nation practicing intensive agriculture for fulfilling the needs of more than eighteen million peoples, for which huge and imbalance amount of fertilizer has been used. Consequently, soil quality deteriorates and inevitable loss of soil microbial diversity. In recent years zeolites a natural aluminosilicate was studied extensively as soil amendment as it increases the soil-nutrient surface area and extend the magnitude of nutrient use efficiency in farming systems.

13p kequaidan4 05-05-2020 13 1   Download

Nano fertilizers are the important tools in agriculture to improve crop growth, yield and quality parameters with increase nutrient use efficiency, reduce wastage of fertilizers and cost of cultivation. Nano-fertilizers are very effective for precise nutrient management in precision agriculture with matching the crop growth stage for nutrient and may provide nutrient throughout the crop growth period. Nano-fertilizers increase crop growth up to optimum concentrations further increase in concentration may inhibit the crop growth due to the toxicity of nutrient.

11p kethamoi4 16-04-2020 18 1   Download

The present work involves development of stable antimicrobial materials containing silver- and zinc-ion–exchanged zeolites. Faujasite X and Linde type A zeolites were synthesized, and following ion exchange with Ag+ and Zn++ ions they were found to exhibit antimicrobial effects against bacteria (E. coli, P. aeruginosa, and S. aureus), yeast (C. albicans and C.glabrata), and fungi (A. niger and P. expansum).

8p sony2711 01-02-2019 15 1   Download

The basic properties of zeolites were studied by using quantum-chemical calculations. The obtained results have demonstrated that the basicity of zeolites in the forms of alkali cations (Li, Na or K) is increased with increasing cation radius. While the Si/Al ratio in the framework increases, the basicity of zeolites decreases. The application of adsorption method using acidic gases (CO2) for determining basicity may be suitable for solid bases without exhanged ion, but not for zeolites.

6p uocvong04 24-09-2015 62 3   Download

Investigations of kinetics of p-xylene deep oxidation on CuO/ -Al2O3 and CuO/ZSM-5 have been carried out. Specific surface area and pore size of catalyst samples as well as metallic state characteristics and catalytic properties of copper have been established. Catalyst CuO/ZSM-5 has been found to be more active than the first one, but it expressed lower stability because of less stable active form of Cu2+ on zeolite surface.

6p uocvong03 24-09-2015 32 5   Download

It was the first time that zeolite NaY with the SiO2/Al2O3 ratio of 3.8 was synthesized from phlogopite taken in Yen Bai of Vietnam in the presence of organic complex, NaOH and liquid glass. Synthesized samples were characterized by X-ray diffraction (XRD), Infrared lattice vibration (IR), scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and Surface area by BET technique. The obtained results showed that the synthesized samples were well crystallized.

4p uocvong01 24-09-2015 71 3   Download

Two FCC catalysts with a 60
m average size, prepared with different crystallite sizes (0.4 and 0.9
m), are studied in terms of total acidity, energy of ammonia desorption, specific surface area, relative amount of Brönsted and Lewis acid sites, crystallite and particle size, and micropore size distribution.

17p tuananhhumg 04-11-2013 59 5   Download