Electrochemically fabricated zero-valent iron, iron-nickel, and iron-palladium nanowires for environmental remediation applications

2007 ◽  
Vol 55 (1-2) ◽  
pp. 149-156 ◽  
Author(s):  
B.-Y. Yoo ◽  
S.C. Hernandez ◽  
B. Koo ◽  
Y. Rheem ◽  
N.V. Myung
Keyword(s):  
Pore Structure ◽  
Environmental Remediation ◽  
Pore Diameter ◽  
Zero Valent Iron ◽  
Nickel Iron ◽  
Palladium Nanowires ◽  
Iron Nickel ◽  
High Purity Aluminium ◽  
Iron Iron ◽  
Iron Palladium

Monodisperse crystalline zero-valent iron, iron-nickel, iron-palladium nanowires were synthesised using template-directed electrodeposition methods. Prior to nanowire fabrication, alumina nanotemplates with controlled pore structure (e.g. pore diameter and porosity) were fabricated by anodising high purity aluminium foil in sulphuric acid. After fabrication of alumina nanotemplates, iron, iron-nickel and iron-palladium nanowires were electrodeposited within the pore structure. The dimensions of nanowires including diameter and length were precisely controlled by pore diameter of anodised alumina and deposition rate and time. The composition, crystal structure and orientation were controlled by adjusting electrodeposition parameters including applied current density and solution compositions.

scholarly journals Структура и магнитные свойства нанопроволок из маталлов группы железа, полученных методом матричного синтеза

2018 ◽  
Vol 60 (11) ◽  
pp. 2075
Author(s):  
Д.Л. Загорский ◽  
К.В. Фролов ◽  
С.А. Бедин ◽  
И.В. Перунов ◽  
М.А. Чуев ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Pore Diameter ◽  
Growth Stress ◽  
X Ray Diffraction ◽  
Matrix Synthesis ◽  
Track Membranes ◽  
Iron Nickel ◽  
Iron Iron ◽  
Loop Shape ◽  
Iron Nickel Alloys

Abstract —Samples of arrays of nanowires are produced from iron, iron–cobalt and iron–nickel alloys via matrix synthesis based on polymer track membranes with pore diameters ranging from 30 to 300 nm. The influence of stress and pore diameter on the galvanic process and structure of nanowires is studied. The arrays of nanowires are examined by microscopy and X-ray diffraction. The magnetic properties are inspected via magnetometry and Mössbauer spectroscopy. The angular dependences of hysteresis loop shape are obtained and comprehensively discussed. As shown, decreasing the growth stress and/or increasing the pore diameter make the Mössbauer spectra of nanowires similar to those of bulk materials. Furthermore, the higher the growth stress is, the larger is the coercive force of nanowires. For the studied species of nanomaterials, the ability to control the magnetic properties during the synthesis is shown, as well.

scholarly journals Carbothermal Synthesis of Ni/Fe Bimetallic Nanoparticles Embedded into Graphitized Carbon for Efficient Removal of Chlorophenol

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1417
Author(s):  
Min Zhuang ◽  
Wen Shi ◽  
Hui Wang ◽  
Liqiang Cui ◽  
Guixiang Quan ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Surface Passivation ◽  
Bimetallic Nanoparticles ◽  
Zero Valent Iron ◽  
Molar Ratio ◽  
Particle Sizes ◽  
Iron Corrosion ◽  
Graphitized Carbon ◽  
Nanoscale Zero Valent Iron ◽  
Iron Nickel

The reactivity of nanoscale zero-valent iron is limited by surface passivation and particle agglomeration. Here, Ni/Fe bimetallic nanoparticles embedded into graphitized carbon (NiFe@GC) were prepared from Ni/Fe bimetallic complex through a carbothermal reduction treatment. The Ni/Fe nanoparticles were uniformly distributed in the GC matrix with controllable particle sizes, and NiFe@GC exhibited a larger specific surface area than unsupported nanoscale zero-valent iron/nickel (FeNi NPs). The XRD results revealed that Ni/Fe bimetallic nanoparticles embedded into graphitized carbon were protected from oxidization. The NiFe@GC performed excellently in 2,4,6-trichlorophenol (TCP) removal from an aqueous solution. The removal efficiency of TCP for NiFe@GC-50 was more than twice that of FeNi nanoparticles, and the removal efficiency of TCP increased from 78.5% to 94.1% when the Ni/Fe molar ratio increased from 0 to 50%. The removal efficiency of TCP by NiFe@GC-50 can maintain 76.8% after 10 days of aging, much higher than that of FeNi NPs (29.6%). The higher performance of NiFe@GC should be ascribed to the significant synergistic effect of the combination of NiFe bimetallic nanoparticles and GC. In the presence of Ni, atomic H* generated by zero-valent iron corrosion can accelerate TCP removal. The GC coated on the surface of Ni/Fe bimetallic nanoparticles can protect them from oxidation and deactivation.

The characterization and preparation of porous low dielectric films using various cyclodextrins as template materials

2003 ◽  
Vol 766 ◽  
Author(s):  
Jin-Heong Yim ◽  
Jung-Bae Kim ◽  
Hyun-Dam Jeong ◽  
Yi-Yeoul Lyu ◽  
Sang Kook Mah ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Dielectric Constant ◽  
Pore Structure ◽  
Pore Diameter ◽  
Dielectric Films ◽  
Low Dielectric Constant ◽  
Cyclodextrin Derivatives ◽  
Low Dielectric ◽  
Low K

AbstractPorous low dielectric films containing nano pores (∼20Å) with low dielectric constant (<2.2), have been prepared by using various kinds of cyclodextrin derivatives as porogenic materials. The pore structure such as pore size and interconnectivity can be controlled by changing functional groups of the cyclodextrin derivatives. We found that mechanical properties of porous low-k thin film prepared with mCSSQ (modified cyclic silsesquioxane) precursor and cyclodextrin derivatives were correlated with the pore interconnection length. The longer the interconnection length of nanopores in the thin film, the worse the mechanical properties of the thin film (such as hardness and modulus) even though the pore diameter of the films were microporous (∼2nm).

scholarly journals New Perspectives on Iron-Based Nanostructures

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1128
Author(s):  
Seyedeh-Masoumeh Taghizadeh ◽  
Aydin Berenjian ◽  
Marziyeh Zare ◽  
Alireza Ebrahiminezhad
Keyword(s):  
Pure Iron ◽  
Human Life ◽  
Zero Valent Iron ◽  
Iron Hydroxides ◽  
Human Beings ◽  
Iron Iron ◽  
Iron Based ◽  
Forms Of Iron ◽  
Structure Properties

Among all minerals, iron is one of the elements identified early by human beings to take advantage of and be used. The role of iron in human life is so great that it made an era in the ages of humanity. Pure iron has a shiny grayish-silver color, but after combining with oxygen and water it can make a colorful set of materials with divergent properties. This diversity sometimes appears ambiguous but provides variety of applications. In fact, iron can come in different forms: zero-valent iron (pure iron), iron oxides, iron hydroxides, and iron oxide hydroxides. By taking these divergent materials into the nano realm, new properties are exhibited, providing us with even more applications. This review deals with iron as a magic element in the nano realm and provides comprehensive data about its structure, properties, synthesis techniques, and applications of various forms of iron-based nanostructures in the science, medicine, and technology sectors.

scholarly journals A magnetic study of the iron-nickel-aluminium system

1939 ◽  
Vol 171 (947) ◽  
pp. 525-540 ◽  
Keyword(s):  
Magnetic Properties ◽  
X Ray ◽  
Nickel Iron ◽  
Fundamental Properties ◽  
Saturation Intensity ◽  
Structure Changes ◽  
Iron Nickel ◽  
The Subject ◽  
High Fields ◽  
Ferromagnetic Magnetization

The iron-nickel-aluminium ternary system has been brought into prominence in recent years on account of its application in the permanent magnet industry. A study of some magnetic properties of this system has been made by Köster (1932-3), but his work is largely concerned with features other than those dealt with by the writer. An exhaustive X-ray examination of these alloys has been carried out by Bradley and Taylor (1938), and the information obtained has been used to throw light on the permanent magnetism in this system (Bradley and Taylor 1937 a, b, c ). Through the collaboration of Dr Bradley the writer has been able to make magnetic investigations on the same specimens as were used in the X-ray analysis, and the present account deals with a survey of the variation of the saturation intensity of these alloys with temperature. Owing to the complexity of the magnetic properties of alloys in this system, it is essential that the more fundamental properties should be the subject of the first investigation. The properties of ferromagnetic materials in low magnetizing fields depend to a considerable extent upon heat treatment, whilst on the other hand the saturation intensity in high fields shows less variation, and is in some degree a measure of the number of elementary magnets, presumably electron spins, contributing to the ferromagnetic magnetization of the particular alloy. Furthermore, the variation of the saturation intensity with temperature should give indications of any structure changes which may occur. A new method for the rapid measurement of saturation intensities for a few milligrams of substance over a range of temperature has been evolved (Sucksmith 1939) and the method there described has been used in the investigation on the nickel-iron-aluminium system.

Nano/Micro Pore Structure and Fractal Characteristics of Baliancheng Coalfield in Hunchun Basin

2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Coal Reservoir

The pore structure characteristic is an important index to measure and evaluate the storage capacity and fracturing coal reservoir. The coal of Baliancheng coalfield in Hunchun Basin was selected for experiments including low temperature nitrogen adsorption method, Argon Ion milling Scanning Electron Microscopy (Ar-SEM), Nuclear Magnetic Resonance (NMR), X-ray diffraction method, quantitative mineral clay analysis method. The pore structure of coal was quantitatively characterized by means of fractal theory. Meanwhile, the influences of pores fractal dimension were discussed with experiment data. The results show that the organic pores in Baliancheng coalfield are mainly plant tissue pores, interparticle pores and gas pores, and the mineral pores are corrosion pores and clay mineral pores. There are mainly slit pore and wedge-shaped pore in curve I of Low temperature nitrogen adsorption. There are ink pores in curve II with characteristics of a large specific surface area and average pore diameter. The two peaks of NMR T2 spectrum indicate that the adsorption pores are relatively developed and their connectivity is poor. The three peaks show the seepage pores and cracks well developed, which are beneficial to improve the porosity and permeability of coal reservoir. When the pore diameter is 2–100 nm, the fractal dimensions D1 and D2 obtained by nitrogen adsorption experiment. there are positive correlations between water content and specific surface area and surface fractal dimension D1, The fractal dimension D2 was positively and negatively correlated with ash content and average pore diameters respectively. The fractal dimensions DN1 and DN2 were obtained by using the NMR in the range of 0.1 μm˜10 μm. DN1 are positively correlated with specific surface area of adsorption pores. DN2 are positively correlated volume of seepage pores. The fractal dimension DM and dissolution hole fractal dimension Dc were calculated by SEM image method, respectively controlled by clay mineral and feldspar content. There is a remarkable positive correlation between D1 and DN1 and Langmuir volume of coal, so fractal dimension can effectively quantify the adsorption capacity of coal.

Pore Structure Analysis on Hardened Paste of CaO-Al2O3-P2O5 Cement

2013 ◽  
Vol 591 ◽  
pp. 44-49 ◽  
Author(s):  
Xiao Dong Wang ◽  
Zhu Ding ◽  
Bi Qin Dong ◽  
Ming Zhang
Keyword(s):  
Pore Structure ◽  
Pore Diameter ◽  
Mercury Intrusion Porosimetry ◽  
Fractal Theory ◽  
Diameter Distribution ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Hydraulic Cement ◽  
Pore Area ◽  
Curing Age

CaO-Al2O3-P2O5cementitious material (PAC) is a type of new developed hydraulic cement, which has excellent cementitious performance and mechanical property. In cement based materials, the pore structure of hardened cement paste has a significant effect on their performance, such like strength, permeability and durability. In the current paper, pore structure parameters of hardened PAC paste samples in five different curing stages were measured respectively by MIP (Mercury Intrusion Porosimetry). The pore fractal features (pore volume, pore area, porosity) were investigated with fractal theory. Results showed that the porosity of hardened PAC paste does not exactly decline with elongation of curing age and increase of compression strength. The PAC pastes pore structures have typical fractal nature which changes with curing age and pore diameter distribution. The fractal feather of hardened PAC paste can be effectively understood by using porosity fractal dimension.

Preparation of Macroporous Hydroxyapatite/Chitosan-Alginate Composite Scaffolds for Bone Implants

2007 ◽  
Vol 342-343 ◽  
pp. 217-220 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Hyang Mi Lee ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
Seog Young Yoon
Keyword(s):  
Pore Structure ◽  
Pore Diameter ◽  
Precipitation Method ◽  
Bone Implants ◽  
Composite Scaffolds ◽  
Uniform Microstructure ◽  
Alginate Content ◽  
Co Precipitation

Porous HAp/chitosan-alginate composite scaffolds were successfully synthesized by insitu co-precipitation method. During the preparation of HAp/chitosan-alginate composite scaffolds, the interaction between chitosan-alginate molecules would be reduced with increasing HAp content, with the resulting that the chitosan-alginate molecules were homogeneously dispersed in the composite scaffolds. The chitosan-alginate content was found to be almost consistent as initially added during the preparation. These results imply that chitosan-alginate was almost perfectly incorporated into the composites. It was found that the pore structure of the composite scaffolds with low HAp content was similar to chitosan-alginate scaffolds, and the morphology of uniform microstructure was unaffected by the presence of HAp. However, the pore diameter decreased with increasing the HAp content up to HAp content of 30 wt%, eventually the pore structure was collapsed and the composites scaffolds appeared to be agglomerated at higher HAp content.

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