Nanoporous anodic aluminum oxide (AAO) has been used in many different fields of science and technology, due to its great structural characteristics. Solar selective surface is an important application of this type porous material. This paper investigates the effect of nanoporous AAO properties, including; film thickness, pore area percentage and pore diameter, on absorption spectra in the range of solar radiation. The parameters were verified individually depending on anodization condition, and the absorption spectra were characterized using spectrophotometer analysis. The results showed that the absorptivity was increased with growth of the film thickness. Furthermore, increasing the pore diameter shifted the absorption spectra to the right range, and vice versa. The investigation revealed the presence of an optimum pore area percentage around 14% in which the absorptivity was at its maximum value.
Aluminum anodizing: The study of the structure of the alumina layerSilio Moura
This work is focused on the study of the formation of an alumina (aluminum oxide) layer by double anodizing of aluminum. From this controlled oxidation method, a nanostructured porous layer with hexagonal cells was obtained. Ordered porous structures with 40-52 nm pore diameter were obtained by applying oxalic acid and a voltage-controlled procedure. The morphology of the surface and cross-section of the samples was analyzed by electron microscopy (Scanning and transmission). Finally, using this porous alumina as a template, Ni nanowires were obtained by electrochemical growth of the metal into the pores.
Sebastiani - Nano-mechanical and microstructural characterization of MS-PVD N...thinfilmsworkshop
http://www.surfacetreatments.it/thinfilms
Nano-mechanical and microstructural characterization of MS-PVD Nb thin films (Marco Sebastiani - 30')
Speaker: Marco Sebastiani - Roma 3 University | Duration: 30 min.
Abstract
E. Bemporad1, M. Sebastiani1, F. Carassiti1
1Mechanical and Industrial Engineering Department, University of Rome ‘Roma Tre’, Via della Vasca Navale 79-00146 Rome, Italy
The main objective of the present study was to identify the influence of the applied bias voltage on the microstructural and mechanical properties of magnetron sputtering physical vapour deposition (MS-PVD) niobium thin films for use in superconducting resonant cavities for particle accelerators.
The microstructure and mechanical properties evolution as a function of the applied bias voltage and nature of the substrate (copper or quartz) were investigated by means of micro-hardness and nanoindentation testing, FIB/SEM, AFM and TEM techniques.
The superconducting properties (critical temperature Tc and residual resistivity) were determined by a calibrated four-contact probe and a cryogenic apparatus and then correlated to the mechanical properties.
Significant difference in terms of microstructure, surface roughness and mechanical properties were observed for biased coatings grown on different substrates. The observed differences are likely connected to the low conductivity of quartz that induces a re-sputtering effect and a consequent modification of the superconducting performances.
SIMONA CAVALU_Surface Modification of Alumina/ Zirconia Ceramics Upon Differe...Simona Cavalu
The aim of this study was to prepare and to characterize the structure of Al2O3–3YSZ composites with 5% TiO2 addition
as well as the surface modification upon treatments with SnF2 and NaBF4, respectively. SEM micrographs showed the
controlled densification of the composites as an effect of 3YSZ and TiO2 addition to alumina matrix. By FTIR and XRD,
the characteristics of Al-O and Zr-O vibrations, respectively, the diffractions lines related to a-corundum and zirconia in
tetragonal phase were discussed. Qualitative and quantitative results obtained by XPS and ATR FTIR demonstrated that the
proposed materials are more sensitive to SnF2 than to NaBF4 treatment.
Aluminum anodizing: The study of the structure of the alumina layerSilio Moura
This work is focused on the study of the formation of an alumina (aluminum oxide) layer by double anodizing of aluminum. From this controlled oxidation method, a nanostructured porous layer with hexagonal cells was obtained. Ordered porous structures with 40-52 nm pore diameter were obtained by applying oxalic acid and a voltage-controlled procedure. The morphology of the surface and cross-section of the samples was analyzed by electron microscopy (Scanning and transmission). Finally, using this porous alumina as a template, Ni nanowires were obtained by electrochemical growth of the metal into the pores.
Sebastiani - Nano-mechanical and microstructural characterization of MS-PVD N...thinfilmsworkshop
http://www.surfacetreatments.it/thinfilms
Nano-mechanical and microstructural characterization of MS-PVD Nb thin films (Marco Sebastiani - 30')
Speaker: Marco Sebastiani - Roma 3 University | Duration: 30 min.
Abstract
E. Bemporad1, M. Sebastiani1, F. Carassiti1
1Mechanical and Industrial Engineering Department, University of Rome ‘Roma Tre’, Via della Vasca Navale 79-00146 Rome, Italy
The main objective of the present study was to identify the influence of the applied bias voltage on the microstructural and mechanical properties of magnetron sputtering physical vapour deposition (MS-PVD) niobium thin films for use in superconducting resonant cavities for particle accelerators.
The microstructure and mechanical properties evolution as a function of the applied bias voltage and nature of the substrate (copper or quartz) were investigated by means of micro-hardness and nanoindentation testing, FIB/SEM, AFM and TEM techniques.
The superconducting properties (critical temperature Tc and residual resistivity) were determined by a calibrated four-contact probe and a cryogenic apparatus and then correlated to the mechanical properties.
Significant difference in terms of microstructure, surface roughness and mechanical properties were observed for biased coatings grown on different substrates. The observed differences are likely connected to the low conductivity of quartz that induces a re-sputtering effect and a consequent modification of the superconducting performances.
SIMONA CAVALU_Surface Modification of Alumina/ Zirconia Ceramics Upon Differe...Simona Cavalu
The aim of this study was to prepare and to characterize the structure of Al2O3–3YSZ composites with 5% TiO2 addition
as well as the surface modification upon treatments with SnF2 and NaBF4, respectively. SEM micrographs showed the
controlled densification of the composites as an effect of 3YSZ and TiO2 addition to alumina matrix. By FTIR and XRD,
the characteristics of Al-O and Zr-O vibrations, respectively, the diffractions lines related to a-corundum and zirconia in
tetragonal phase were discussed. Qualitative and quantitative results obtained by XPS and ATR FTIR demonstrated that the
proposed materials are more sensitive to SnF2 than to NaBF4 treatment.
Surface Morphological and Electrical Properties of Sputtered Tio2 Thin FilmsIOSR Journals
Titanium dioxide films were formed on quartz and crystalline p-Si (100) substrates by DC reactive magnetron sputtering method. Pure titanium target was sputtered at a constant oxygen partial pressure of 5x10-2 Pa, and at different sputtering powers in the range 80 – 200 W. The as-deposited films were annealed in air for 1 hour at 1023 K. The deposited films were characterized by studying the surface morphology by atomic force microscopy (AFM), electrical and dielectric properties from current-voltage and capacitance-voltage measurements. Atomic force micrographs of the films showed that the Rrms and Ra increased with the increase of sputter power from 80 to 200 W. The leakage current density was increased by increasing the sputtering power.
TALAT Lecture 5102: Reactivity of the Aluminium Surface in Aqueous SolutionsCORE-Materials
This lecture provides better understanding of the electrochemistry of aluminium; it gives an introduction to the other lectures. Some knowledge in aluminium metallurgy, simple chemistry (thermodynamics and kinetics), electricity and general electrochemistry is assumed.
Electrochemical Supercapacitive Performance of Sprayed Co3O4 ElectrodesIJERA Editor
Nanocrystalline cobalt oxide (Co3O4) thin film electrodes were fabricated by spray pyrolysis method on conducting fluorine doped tin oxide (FTO) substrates using ammonia complexed with cobalt chloride (CoCl2. 6H2O) solution. The structural and morphological properties of Co3O4electrodes were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The surface morphology study showed the film formation of porous surface with clusters. The electrochemical supercapacitive properties ofCo3O4 electrodes were evaluated using cyclic voltammetry and galvanostatic charge-discharge method. The Co3O4electrodes showed maximum specific capacitance of 168 F/g in 1 M aqueous KOH electrolyte at the scan rate of 20 mV/s. The maximum specific energy and specific power of the cell are 2.2Wh/kg and 0.23 kW/kg, respectively.
Process flow of spray pyrolysis techniqueIOSR Journals
The chemical spray pyrolysis technique (SPT) has been, throughout last 3 decades, one amongst the most important techniques to deposit a large type of materials in thin film kind. The prime requisite for getting sensible quality thin film is that the optimization of propaedeutic conditions viz. substrate temperature, spray rate, concentration of solution etc. However, in recent years a stress has been given to a range of atomization techniques like supersonic nebulisation, improved spray reaction, corona spray transformation, electricity spray transformation and microchip primarily based spray transformation. This is often the foremost crucial parameter because it permits management over the scale of the droplets and their distribution over the preheated substrates. An intensive review of thin film materials ready throughout the last ten years is given to demonstrate the flexibility of the chemical SPT. the assorted conditions to get thin films of metal compound, metallic mineral oxides, binary, ternary and quaternary chalcogenides and superconducting oxides are given. The consequences of precursor, dopants, substrate temperature, post tempering treatments, answer concentration etc., on the physico-chemical properties of those films are given likewise. It’s discovered that the properties of thin films rely significantly on the propaedeutic conditions. The properties of the thin film will be simply tailored by adjusting or optimizing these conditions that successively are appropriate for a specific application.
Study of some Mechanical Properties of Galvanized 4140 SteelsIJAEMSJORNAL
The effect of three different galvanizing processes on the microstructure and tensile behavior and hardness of galvanized AISI 4140 steels was investigated. The thicknesses of the galvanized layers were measured as 34 μm, 90 μm and 140 μm for the electro galvanized, zinc-rich coated and hot dip galvanized AISI 4140 steels, respectively. No significant increase in tensile strength was observed with the galvanizing process. It was even observed that there was a decrease in tensile strength compared to the samples that were not galvanized. It is concluded that galvanizing processes is not effective in improving the tensile performance of AISI 4140 steels.
Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
SRF is a surface phenomenon where only ~10 penetration depths are needed (l=40 nm for niobium), thus it has been recognized for some time now that it would be economically convenient to use thin film coated cavities. But problems arise with defects within 1 or 2 l of the surface or on the surface, and insufficient attention has been paid to this topic, including trapping of impurities like oxygen in defects as well as surface roughness enabling magnetic field pinning sites. Earlier attempts at CERN applied standard sputter PVD methods, but the grain size for the CERN Nb/Cu films was 100 nm, which is 10,000 times smaller than for conventional SRF cavities with the ensuing problems that appear at grain boundaries. Thus, these prior attempts showed higher surface resistance and worst Q-slope than bulk. I will review more modern approaches using higher energetic PVD methods for thin film deposition which offer promise to achieve thin films with improved superconducting performance.
Metallic scaffolds for bone tissue engineering (Titanium/Nickel-Titanium/Tantalum/Cobalt chromium and stainless steel ).
We will discuss metallic scaffolds requirements,disadvantages,types and the pros and cons of each type.
Assessment of mechanical,physical,chemical and biological properties of dental alloys .
This presentation discusses the assessment of the properties of different alloys used in dentistry such as gold,NiTi and base metal alloys .
Detecting of NH3, CO2 polluted gases by using ZnO- In2O3 thin filmsijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The presentation takes into account widely used surface finishing processes including electroplating, anodizing, alodining, cadmium plating, zinc plating, phosphating, passivation
Surface Morphological and Electrical Properties of Sputtered Tio2 Thin FilmsIOSR Journals
Titanium dioxide films were formed on quartz and crystalline p-Si (100) substrates by DC reactive magnetron sputtering method. Pure titanium target was sputtered at a constant oxygen partial pressure of 5x10-2 Pa, and at different sputtering powers in the range 80 – 200 W. The as-deposited films were annealed in air for 1 hour at 1023 K. The deposited films were characterized by studying the surface morphology by atomic force microscopy (AFM), electrical and dielectric properties from current-voltage and capacitance-voltage measurements. Atomic force micrographs of the films showed that the Rrms and Ra increased with the increase of sputter power from 80 to 200 W. The leakage current density was increased by increasing the sputtering power.
TALAT Lecture 5102: Reactivity of the Aluminium Surface in Aqueous SolutionsCORE-Materials
This lecture provides better understanding of the electrochemistry of aluminium; it gives an introduction to the other lectures. Some knowledge in aluminium metallurgy, simple chemistry (thermodynamics and kinetics), electricity and general electrochemistry is assumed.
Electrochemical Supercapacitive Performance of Sprayed Co3O4 ElectrodesIJERA Editor
Nanocrystalline cobalt oxide (Co3O4) thin film electrodes were fabricated by spray pyrolysis method on conducting fluorine doped tin oxide (FTO) substrates using ammonia complexed with cobalt chloride (CoCl2. 6H2O) solution. The structural and morphological properties of Co3O4electrodes were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The surface morphology study showed the film formation of porous surface with clusters. The electrochemical supercapacitive properties ofCo3O4 electrodes were evaluated using cyclic voltammetry and galvanostatic charge-discharge method. The Co3O4electrodes showed maximum specific capacitance of 168 F/g in 1 M aqueous KOH electrolyte at the scan rate of 20 mV/s. The maximum specific energy and specific power of the cell are 2.2Wh/kg and 0.23 kW/kg, respectively.
Process flow of spray pyrolysis techniqueIOSR Journals
The chemical spray pyrolysis technique (SPT) has been, throughout last 3 decades, one amongst the most important techniques to deposit a large type of materials in thin film kind. The prime requisite for getting sensible quality thin film is that the optimization of propaedeutic conditions viz. substrate temperature, spray rate, concentration of solution etc. However, in recent years a stress has been given to a range of atomization techniques like supersonic nebulisation, improved spray reaction, corona spray transformation, electricity spray transformation and microchip primarily based spray transformation. This is often the foremost crucial parameter because it permits management over the scale of the droplets and their distribution over the preheated substrates. An intensive review of thin film materials ready throughout the last ten years is given to demonstrate the flexibility of the chemical SPT. the assorted conditions to get thin films of metal compound, metallic mineral oxides, binary, ternary and quaternary chalcogenides and superconducting oxides are given. The consequences of precursor, dopants, substrate temperature, post tempering treatments, answer concentration etc., on the physico-chemical properties of those films are given likewise. It’s discovered that the properties of thin films rely significantly on the propaedeutic conditions. The properties of the thin film will be simply tailored by adjusting or optimizing these conditions that successively are appropriate for a specific application.
Study of some Mechanical Properties of Galvanized 4140 SteelsIJAEMSJORNAL
The effect of three different galvanizing processes on the microstructure and tensile behavior and hardness of galvanized AISI 4140 steels was investigated. The thicknesses of the galvanized layers were measured as 34 μm, 90 μm and 140 μm for the electro galvanized, zinc-rich coated and hot dip galvanized AISI 4140 steels, respectively. No significant increase in tensile strength was observed with the galvanizing process. It was even observed that there was a decrease in tensile strength compared to the samples that were not galvanized. It is concluded that galvanizing processes is not effective in improving the tensile performance of AISI 4140 steels.
Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
SRF is a surface phenomenon where only ~10 penetration depths are needed (l=40 nm for niobium), thus it has been recognized for some time now that it would be economically convenient to use thin film coated cavities. But problems arise with defects within 1 or 2 l of the surface or on the surface, and insufficient attention has been paid to this topic, including trapping of impurities like oxygen in defects as well as surface roughness enabling magnetic field pinning sites. Earlier attempts at CERN applied standard sputter PVD methods, but the grain size for the CERN Nb/Cu films was 100 nm, which is 10,000 times smaller than for conventional SRF cavities with the ensuing problems that appear at grain boundaries. Thus, these prior attempts showed higher surface resistance and worst Q-slope than bulk. I will review more modern approaches using higher energetic PVD methods for thin film deposition which offer promise to achieve thin films with improved superconducting performance.
Metallic scaffolds for bone tissue engineering (Titanium/Nickel-Titanium/Tantalum/Cobalt chromium and stainless steel ).
We will discuss metallic scaffolds requirements,disadvantages,types and the pros and cons of each type.
Assessment of mechanical,physical,chemical and biological properties of dental alloys .
This presentation discusses the assessment of the properties of different alloys used in dentistry such as gold,NiTi and base metal alloys .
Detecting of NH3, CO2 polluted gases by using ZnO- In2O3 thin filmsijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The presentation takes into account widely used surface finishing processes including electroplating, anodizing, alodining, cadmium plating, zinc plating, phosphating, passivation
Production, Manufacturing and Extraction of Silver, Gold, Copper, Magnesium,...Ajjay Kumar Gupta
Electroplating involves passing an electric current through a solution called an electrolyte. This is done by dipping two terminals called electrodes into the electrolyte and connecting them into a circuit with a battery or other power supply. The electrodes and electrolyte are made from carefully chosen elements or compounds. When the electricity flows through the circuit they make, the electrolyte splits up and some of the metal atoms it contains are deposited in a thin layer on top of one of the electrodes—it becomes electroplated. All kinds of metals can be plated in this way, including gold, silver, tin, zinc, copper, cadmium, chromium, nickel, platinum, and lead.
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Application of Zinc Refining Process, Book of Non-Ferrous Metal, Book on Non-Ferrous and Precious Metals with Electroplating Chemicals, Chemical Extraction of Precious Metals, Chemicals are used for the preparation of precious metal plating, Chromium Chemistry, Chromium occurrence, principles of extraction, Chromium uses, Copper extraction and purification, Copper extraction techniques, Copper refining process, Electrolysis of Magnesium Chloride, Electrolysis Production of Magnesium, Electrolytic processes for the extraction of nickel, Electroplating Chemicals & Non Ferrous Metals, Electroplating Chemicals, Essential Guide to Investing in Precious Metals, Extracting Lead Materials from Ore, Extracting precious metals from electronics, Extraction of Copper, Extraction of Lead, Extraction of nickel from its ore, Extraction of nickel from sulphide ore, Extraction of Nonferrous Metals book, Extraction of nonferrous metals, Extraction of Platinum Group Metals, Extraction of precious metals, Extraction of zinc by electrolysis, Extraction of Zinc, Gold Extraction in India, How electroplating works, How is lead processed?, How is nickel extracted?, How lead is made - material, used, processing, product, industry, How Nickel is produced, How to remove precious metals, How to start Non-ferrous Businesses, How to start Precious Metals Businesses, How to start your own Precious Metals Business, Indian Non-Ferrous Metals Industry, Lead Essential Chemical Industry, Lead processing, Lead smelting, producing and classification, Lead uses, Magnesium electrolysis process, Magnesium Essential Chemical Industry, Magnesium Production in India, Method used to extract nickel, Nickel electroplating, Nickel processing, Nickel smelting process, Nickel uses, Nickel, non ferrous extractive metallurgy book, non ferrous metal Business Line, non ferrous metal business, non ferrous metals, Non-ferrous and Precious Metals Businesses, Non-Ferrous and Precious Metals Mining Projects, Nonferrous Metal Processing Business Unit, Non-Ferrous Metal Scrap Business, Non-ferrous metals Aluminium, Non-Ferrous Metals and their Uses,
40 cfr 261.4(b)(6) The RCRA Exclusion From Hazardous Waste for Trivalent Chro...Daniels Training Services
The Trivalent Chromium Wastes Exclusion from Regulation as a Hazardous Waste
40 CFR 261.4(b)(6) excludes Trivalent Chromium Waste, a solid waste, from regulation as a hazardous waste if the requirements of the regulations are met. This presentation briefly summarizes the requirements of this RCRA exclusion from regulation.
Those in the leather tanning industry, leather product manufacturing industry, shoe manufacturing industry, and titanium dioxide manufacturing industry should be aware of this RCRA exclusion and its possible impact on their operations.
10 major industrial applications of sulfuric acidrita martin
sulfuric acid commonly known as king of chemicals and also as oil of vitriol find its applications across many industries like lubricants, drugs, rayon, metal processing, batteries, chemical manufacturing and more
A SHORT REVIEW ON ALUMINIUM ANODIZING: AN ECO-FRIENDLY METAL FINISHING PROCESSJournal For Research
Protection of aluminium alloys is most commonly done by forming anodic films. Anodic films can also be formed on metals like titanium, zinc, magnesium, niobium, and tantalum. Aluminium alloy parts are anodized to greatly increase the thickness of the natural oxide layer for corrosion resistance. A thin aluminium oxide film, that seals the aluminium from further oxidation when it is exposed to air. The anodizing process increases the thickness of the oxidized surface. Anodizing is accomplished by immersing the aluminium into an acid electrolyte bath and passing an electric current through the medium. In an anodizing cell, the aluminium work piece is made the anode by connecting it to the positive terminal of a dc power supply and the cathode is connected to the negative terminal of the dc source. Sealing is needed to seal the pores in oxide layer to prevent further corrosion. Oxide layer on the anodized aluminium has a highly ordered, porous structure that allows for secondary processes such as dyeing, printing and sealing. Nanowires and nanotubes can be made by using the pores in the oxide layer as templates.
A presentation giving the basic principles of corrosion. Electrochemical nature of corrosion, anodic and cathodic reactions, electrode potentials, mixed potential theory and kinetics of corrosion, thermodynamics of corrosion and Pourbaix diagrams, and passivization behavior of metals are outlined.
Protection des métaux contre la corrosionCHTAOU Karim
Cette présentation présentent tout d’abord les principaux types de la corrosion et il présente une description détaillée des trois grandes méthodes, préventives et curatives, utilisées en anticorrosion.
Influence of Thickness on Electrical and Structural Properties of Zinc Oxide ...paperpublications3
Abstract: Zinc Oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 1500C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 〖34.31^0-34.35〗^0with hkl (002). Other parameters calculated include the stress ( ) and the grain size (D).
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Optical and surface properties of al doped ga2 o3 by elemental stack methodeSAT Journals
Abstract Al doped Ga2O3 thin film was prepared by stacking of Al thin film on Ga2O3 thin film using thermal evaporator. The doping process was carried out by post annealing process at three different temperatures. The absorbance spectra revealed the Al doping process and showed low absorbance at high annealing temperature. Scanning Electron Microscope images were the evidence of surface effect due to Al diffuses at high annealing temperature (> 400°C). Energy Dispersive Spectra showed the changes in the elemental composition of Al doped Ga2O3 thin film for various annealing temperature and revealed Al diffusion by observed low Al content at the surface of the doped Ga2O3 thin film. Keywords: Ga2O3, Al doping, Optical properties, Surface analysis
Un doped and doped with Al ZnS thin Films have been fabricated by vacuum evaporation
technique under the vacuum of 10-5 Torr on glass substrate at room temperature and with different
ratio of Al concentration of thickness (0.8µm). The optical properties were revealed by UV-Visible
transmittance spectra and the band gap energy was determined. Transmission spectra indicate a high
transmission coefficient (¨95%). The results showed that films have direct optical transition, and the
values of energy gap were found to decrease with doping concentrations. Also the optical constants
such as absorption coefficient, refractive index, extinction coefficient and dielectric constant have
been calculated. The effect of doping concentration on the electrical properties has been studied
To ensure good adhesion between a 200 nm thick silicon dioxide layer and a 4.5 μm thick hardcoat polymeric coating, a better understanding of mechanisms of adhesion at this interface is needed. To reach this purpose, focus is placed on two axes: characterizing mechanical properties of materials composing the system and in parallel, finding an applicable and effective method to quantify adhesion. Small dimension of SiO2 thin film makes it challenging to accurately characterize it. Hence the use of both nano-indentation and AFM to attempt assessment of SiO2 thin film elastic modulus Ef; taking into account limitations and uncertainty associated with each technique. Elastic modulus of SiO2 thin film determined by nano-indentation is roughly 50 GPa on a wafer substrate and 15 GPa on a lens substrate. As for AFM, modulus measured is approximately 56 GPa on a wafer substrate and 22 GPa on a lens substrate. This highlights significant influence of substrate for both techniques. Impact on mechanical properties between SiO2 thin films under different intrinsic stresses was also investigated. Results suggest that higher density of SiO2 thin film leads to higher elastic modulus.
To quantify adhesion, micro-tensile and micro-compression tests were performed. Micro-tensile experiments give ultimate shear strengths of hardcoat-substrate interface ranging from 9 to 14 MPa. Values of energy release rates of SiO2 / Hardcoat, range from 0.1 J/m² to 0.5 J/m², depending on moduli values found on wafer or lens substrate.
Detecting of NH3, CO2 polluted gases by using ZnO- In2O3 thin filmsijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This research was conducted by using the electrochemical anodizing technique in oxalate solution. This research focused on the effects of coating parameters on the fabrication of hard nano-CuO coating with hydrophobic properties, studying the effect of coating grain size on the coating characteristics and heat transfer performance.
Characterization of Aluminum Doped Nanostructured ZnO/p-Si Heterojunctionstheijes
In this study we investigated electrical and optical properties of heterojunctions made of aluminum doped Zinc oxide (ZnO) nanorods and 4% Boron doped p-type silicon (p-Si). ZnOnanorods were grown by a chemical bath deposition (CBD) techniqueon a seed layer of ZnOsputtered on p-Si. Aluminum doping was achieved by incorporating 0-20% of aluminum nitrate in the chemical bath precursor solution. Room temperature photoluminescence showed a systematic decrease in the defect peak at 560 nm with increasing doping. Band gap was measured using UV-VIS spectroscopy shows that the band gap increased from 3.31 eV to 3.58 eV as the doping is varied from 0-20%. This increase in band gap could be due to the Burstein-Moss effect previously observed in heavily doped semiconductors. In addition, we also performed current-voltage (I-V), capacitancevoltage(C-V) measurements on Aluminum doped ZnO/p-Si nanorods samples under both dark and illumination conditions. I-V characteristics showed a good rectifying behavior under dark and illumination conditions. The saturation current, diode ideality factor, carrier concentrations, built in potential, and barrier height were calculated from I-V and C-V measurements for each sample. We will discuss the implications of the variations in band gap, I-V, and C-V measurements with variation in aluminum doping
Investigation of the Effects of Fullerene addition and Plasma Exposure on Opt...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Structural Stability of Nano-Crystalline Aluminum-Glass CompositesIOSRJAP
Effects of particle size of the material in nanometer on solid state, structural properties AluminumGlass based samples are reported in this study. The particle size of 25µm was used for both Aluminum and Glass powders respectively. The samples were prepared in powdered form of various Al-Glass proportions. The weight of Aluminum ranges between 20 – 60 percent in the composites. Results showed from X-ray diffraction analyses that Aluminum addition and the determined particle size greatly influence the structural stability of the samples. It was revealed that samples were structurally stable in the range of Aluminum composition and the observed size of crystals, measured Width at Middle of Maximum Height and structural parameters were found in nanometers. The Al-Glass materials were noted to crystallize with FCC and BCC lattice structures.
Similar to Effect of Nanoporous Anodic Aluminum Oxide (AAO) Characteristics On Solar Absorptivity2 (20)
Mixed Convection of Variable Properties Al2O3-EG-Water Nanofluid in a Two-Dim...A Behzadmehr
In this paper, mixed convection of Al2O3-EG-Water nanofluid in a square lid-driven enclosure is investigated numerically. The focus of this study is on the effects of variable thermophysical properties of the nanofluid on the heat transfer characteristics. The top moving and the bottom stationary horizontal walls are insulated, while the vertical walls are kept at different constant temperatures. The study is carried out for Richardson numbers of 0.01–1000, the solid volume fractions of 0–0.05 and the Grashof number of 104. The transport equations are solved numerically with a finite volume approach using the SIMPLER algorithm. The results show that the Nusselt number is mainly affected by the viscosity, density and conductivity variations. For low Richardson numbers, although viscosity increases by increasing the nanoparticles volume fraction, due to high intensity convection of enhanced conductivity nanofluid, the average Nusselt number increases for both constant and variable cases. However, for high Richardson numbers, as the volume fraction of nanoparticles increases heat transfer enhancement occurs for the constant properties cases but deterioration in heat transfer occurs for the variable properties cases. The distinction is due to underestimation of viscosity of the nanofluid by the constant viscosity model in the constant properties cases and states important effects of temperature dependency of thermophysical properties, in particular the viscosity distribution in the domain.
Using Lattice Boltzmann Method to Investigate the Effects of Porous Media on ...A Behzadmehr
A numerical investigation of forced convection in a channel with hot solid block inside a square porous block mounted on a bottom wall was carried out. The lattice Boltzmann method was applied for numerical simulations. The fluid flow in the porous media was simulated by Brinkman-Forchheimer model. The effects of parameters such as porosity and thermal conductivity ratio over flow pattern and thermal field were investigated. In this paper the effects of mentioned parameters were discussed in detail. The result show with increasing the thermal conductivity ratio and porosity the fluid temperature will reduce.
Moving Lids Direction Effects on MHD Mixed Convection in a Two-Sided Lid-Driv...A Behzadmehr
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Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
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• Compatible with MAFI CCR system.
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Student information management system project report ii.pdfKamal Acharya
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Top 10 Oil and Gas Projects in Saudi Arabia 2024.pdf
Effect of Nanoporous Anodic Aluminum Oxide (AAO) Characteristics On Solar Absorptivity2
1. Trans. Phenom. Nano Micro Scales, 1(2):110-116, Summer – Autumn 2013
DOI: 10.7508/tpnms.2013.02.004
110
ORIGINAL RESEARCH PAPER .
Effect of Nanoporous Anodic Aluminum Oxide (AAO) Characteristics
On Solar Absorptivity
Hamid Moghadam1
, Abdolreza Samimi*1
, Amin Behzadmehr2
1-Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
2- Department of Mechanical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Abstract
Nanoporous anodic aluminum oxide (AAO) has been used in many different fields of science and technology,
due to its great structural characteristics. Solar selective surface is an important application of this type porous
material. This paper investigates the effect of nanoporous AAO properties, including; film thickness, pore area
percentage and pore diameter, on absorption spectra in the range of solar radiation. The parameters were verified
individually depending on anodization condition, and the absorption spectra were characterized using
spectrophotometer analysis. The results showed that the absorptivity was increased with growth of the film
thickness. Furthermore, increasing the pore diameter shifted the absorption spectra to the right range, and vice
versa. The investigation revealed the presence of an optimum pore area percentage around 14% in which the
absorptivity was at its maximum value.
Keywords: Film thickness, Nanoporous Anodic Aluminum Oxide (AAO); Pore diameter; Pore area percentage, Solar
absorptivity.
1. Introduction
Nanoporous anodic aluminum oxide (AAO) has
been produced for more than a century by anodizing
of aluminum [1]. It contains close-packed array of
columnar hexagonal cells with a central pore normal
to the substrate [2]. Fig. 1 shows a schematic
presentation of AAO. It is well known that AAO
films, which is produced by two-step anodization
process, comprise a high structural regularity [3]. The
produced nanoporous film would attain
characteristics, such as; high aspect ratio, high pore
__________
*
Corresponding author:
Email Address: a.samimi@eng.usb.ac.ir
density, uniform pore size, and uniform nanopores
dispersion [4]. The pore diameter (10–500 nm), inter-
pore spacing (20–1000 nm), pore ordering, film
thickness (50–200 μm), and other structural features
of AAOs would be controlled by manipulating the
anodizing operational parameters. The latter
parameters are included of composition and pH of
electrolyte, anodizing potential, anodizing time,
temperature and etching methods [1, 5]. High pore
density, thermal stability, and cost effectiveness are
the other advantages of AAO films as compared to
other porous materials [6]. Because of these
properties, in recent decades, AAO films have been
extensively used as a template for fabricating of
nanotubes, nanowires, nanorods, nanorings,
nanocones, nanomembranes, and nanoparticles [7].
2. A. Samimi et al./ TPNMS 1 (2013) 110-116
111
AAO film has attracted considerable attention in
diverse applications in the fields of molecular
separation, catalysis, energy storage, drug delivery,
integrated circuits, chemical sensing, medicine,
military, biomedical, optoelectronics, and magnetic
recording [6, 8-10]. The current AAO studies focus
on the types of pore structure, high-speed film growth,
controlling the pore diameter and its uniformity,
interpore distance and thickness, as well as new
applications of AAO films [1].
Fig. 1. a) 3D schematic presentation of nanoporous AAO
film.
The application of nanoporous AAO for production of
solar selective surfaces goes back to about 1980.
However, in recent years, it has drawn the attentions
more due to increasing the solar energy usage. Recent
investigations deal mostly with deposition of different
metals (e.g. Ag, Ni, Cu, etc.) on the thin AAO film
with the aim of improvement of optical properties [11-
14]. Nevertheless, there are few studies centered on
the optical properties of bare AAO film in the
literature [15-18]. Moreover, high-purity aluminum
(more than 99.9%) has been used in most of these
researches. An important disadvantage of high-purity
aluminum is its relatively high price, and its limited
size. On the other hand, aluminum alloys with a lower
purity are cheap and easily available [5].
The main aim of this paper is to investigate the effect
of nanoporous AAO properties (i.e. film thickness,
pore area percentage and pore diameter) on solar
absorptivity. In the study, these parameters are
changed individually by manipulating the anodization
condition, and then the absorption spectra are
characterized using spectrophotometer analysis. The
paper focuses on relatively thicker nanoporous AAO
films, produced by two-step anodizing of
commercially aluminum alloy 1050.
2. Experimental
The AAO films were fabricated using the two-step
anodization of 1050 aluminum alloy sheets (1mm
thickness). The aluminum sheet was initially cut into
1cm×5cm pieces and degreased in acetone, without
further thermal treatment or chemical polishing. The
first anodization step was then carried out on the
aluminum specimen, suspended in the electrolyte as
anode, under constant current density of 5mA/cm2
for
10 h. Another aluminum specimen was used as
cathode. Oxalic acid and sulfuric acid solutions
(0.4M concentration) were used as electrolyte, and
the electrolyte temperature was controlled at 5, 15,
and 35˚C using cold water circulation bath. Since the
anodization was an exothermic process, the
temperature distribution over specimen was kept
constant by vigorous stirring the electrolyte bath.
The formed AAO film was chemically removed by
immersing the specimen in 0.4M phosphoric acid
solution at 50˚C for 1 h. The second anodization step
was subsequently conducted at various times under
the same condition mentioned before for the first
step, to produce the final AAO film with a regular
nanopore array. Some final samples were immersed
in 0.2M phosphoric acid at 40˚C and appropriate
etching time to widen the pores. Finally, the
specimens were rinsed several times with deionized
water and then dried in air. The schematic diagram of
experimental setup is shown in Fig. 2.
Pore diameter and percentage of pore area were
determined by analyzing the SEM images of samples
using FE-SEM (MIRAII TESCAN) and Motic Image
Advanced 3.2 software. At first, each image was
calibrated in the software with its scale bar. Then,
diameter of at least 200 pores was measured with ruler
of the software. The obtained pore diameter for each
sample was the average of these measurements. Pore
area percentage was determined automatically by the
software, according to the color difference between
the pores and AAO surface. Spectral reflection of
each samples determined using spectrophotometer
(Varian-Cary500) in the range of solar radiation (200-
Cell size
Barrier layer
thickness
Pore diameter
3. A.Samimi et al./ TPNMS 1 (2013) 110-116
112
3000 nm). Solar absorptivity of the samples were
calculated using the following equation [19].
Fig. 2. Schematic illustration of experimental setup
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where R(λ), and I(λ) are the reflection intensity and
solar radiation intensity at the wavelength λ,
respectively.
3. Results and discussion
Table 1 summarizes the anodization conditions and
properties of produced nanoporous AAO films
including pore diameter, percentage of pore area and
solar absorptivity. The first three test runs in this table
deal with the effect of film thickness on solar
absorptivity. Test runs 3, 4, and 5, consider the
relation between pore area percentage and solar
absorptivity. The last three test runs, study the effect
of pore diameter on the solar absorptivity, where
sulfuric acid was considered as their electrolyte. Two
different acids were selected in this study as pores’
diameter of AAO film obtained in sulfuric acid were
smaller as compared those produced in oxalic acid
[20].
3-1. Effect of film thickness on solar
absorptivity
The second step anodization time varied only the
AAO film thickness. Therefore, the effect of
anodization time (in fact film thickness) on solar
absorptivity of AAO films, produced at various
durations (test runs; 1, 2, and 3), was investigated.
Left hand of Fig. 3 illustrates these results as the
absorptivity of the nanoporous AAO films versus the
wave length of radiated light on the surface of
mentioned samples. According to the table 1, AAO
film on sample 1 is thinner than sample 2. Sample 3
has thickest film among these three samples. Digital
image of these samples presented in the right hand of
Fig. 3.
As it is seen in the Fig. 3, absorption spectra of
sample 1 (with thinnest AAO film) placed under two
other curves. In addition, the upper curve belongs to
the sample 3 (with thickest AAO film). Therefore, it is
conclude that, increasing the film thickness by the
increasing of anodizing time, leads to enhancement of
absorption over the solar spectra range. Similar result
was obtained in the study of Santos et al. for thinner
AAO films [18]. However, absorption growth is more
vigorous for shorter wavelength, especially for
λ<1200nm in this study. Therefore, it is generally
concluded that the solar absorptivity increases by
thickening of the film. Indeed, more penetrated beams
are trapped by thicker AAO film due to its deeper
medium. This concept can be used in the volumetric
solar receiver, in which the porous film absorbs the
solar concentrated radiation in the depth of their
structure, and transferring the heat to the working
fluid. Decreasing the heat loss by temperature
reduction on the irradiated side of the volumetric solar
receiver is an important feature [21], where it looks
the thick nanoporous AAO films can play this role
properly.
3-2. Effect of pore area percentage on solar
absorptivity
Pore area percentage depends straightly on the pore
density (number of pores in a certain area). It has
been reported that pore density increases by rising the
anodization temperature [17]. Therefore, the effect of
anodization temperature on the pore area percentage
and consequently on the absorptivity of AAO film
was studied. The test runs 3, 4, and 5 in Table 1
V
A
Al
old water input
Cold water output
Magnet stirrer
2 cm
4. A. Samimi et al./ TPNMS 1 (2013) 110-116
113
Table1. Anodization conditions and properties of produced nanoporous AAO films
Test
run
2nd
step
time
(h)
Electrolyte Anodization
temperature
(˚C)
Etching
time
(min)
Pore
diameter
(nm)
Pore
area %
Solar
absorptivity
1 2 Oxalic acid 35 - 27.07 ± 2.98 23.04 0.3249
2 4 Oxalic acid 35 - 27.46 ± 3.11 23.25 0.4376
3 6 Oxalic acid 35 - 27.83 ± 3.03 23.41 0.5529
4 6 Oxalic acid 15 - 27.15 ± 3.70 14.62 0.6192
5 6 Oxalic acid 5 - 27.62 ± 3.43 8.13 0.5827
6 6 Sulfuric acid 35 - 14.78 ± 1.58 4.25 0.4213
7 6 Sulfuric acid 15 10 17.39 ± 1.60 4.04 0.4110
8 6 Sulfuric acid 5 20 23.54 ± 1.27 4.11 0.3932
Fig. 3. Effect of nanoporous AAO film thickness on absorption spectra.
present this effect in which a reduction in pore area
percent is observed from 23.41% to 8.13% when
the temperature is reduced from 35˚C to 5 ˚C.
Digital images of samples 3, 4, and 5 presented in
the right hand of Fig. 4. Central part of Fig. 4
shows the SEM images of these samples.
Absorptivity of the nanoporous AAO films
produced on samples 3, 4, and 5 versus the wave
length is presented in the left hand of Fig. 4. Fig. 4
shows that decreasing the pore area percentage
from 23.41% to 14.62% (correspond to the
temperature reduction from 35˚C to 15˚C) leads to
an increase of the absorption intensity in the most
wavelengths. In this case, the, absorptivity
increases from 0.553 to 0.619 . This observation is
confirmed by the results presented by Shih et al.
study [17]. In fact, high reflection characteristic of
Al substrate has a great influence on the reflection
spectra of the AAO film [15]. Considerable portion
of penetrated beams could reach to the Al substrate
for the AAO film with large void fraction. These
beams are reflected toward the film surface, and a
portion of them refracted to the outside of the film.
The refracted beams to the outside of AAO are
reduced by the pore area percentage reduction,
leading to increasing of absorptivity. Nevertheless,
absorption spectra of test run 5 reveals that, further
decreasing of pore area percentage may have
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 500 1000 1500 2000 2500 3000
α(λ)
Wavelength (nm)
test run 1 (α = 0.3249)
test run 2 (α = 0.4376)
Test run 3 (α = 0.5529)
5. A. Samimi et al./ TPNMS 1 (2013) 110-116
114
Test
run 3
Test
run 4
Test
run 5
Fig. 4. Effect of pore area percentage on absorption spectra
opposite effect. Further decreasing of the pore area
percentage from 14.62 to 8.13 reduces the
penetrated beams or absorptivity from 0.619 to
0.583. In fact, in this case, most portions of incident
beams on the AAO surface are reflected from it.
3-3.Effect of pore diameter on solar
absorptivity
Pores diameter could be increased by etching of
the produced AAO in phosphoric acid solution.
The surface widening of pores occurs effectively at
longer etching time, leading to an increase in
pores’ diameter. Nevertheless, as the diameter of
pores increases, the percentage of pore area also
increases simultaneously. This fact has been
neglected by the researches which have
investigated the effect of pore diameter on the
optical properties of AAO film, such as the work
of Huang et al. [4]. Therefore, etching should be
carried out on the AAO film with lower pore
density. This strategy causes that the pore area
percentage remains constant after the etching step.
In fact, more etching time needs less pore density
or pore area percent. Pore density could be
decreased by decreasing of the anodization
temperature. Anodization condition defined for test
runs 6, 7, and 8 obviously indicates this strategy. It
is clear from Table 1 that with the mentioned
strategy the pore diameter is increased
considerably from 14.78 to 23.54 nm, with
decreasing the temperature from 35 to 5 0
C and
increasing the etching time from 0 to 20 min. Right
hand of Fig. 5 shows digital images of samples 6,
7, and 8. SEM images of these samples presented
in the central part of this Fig. Absorptivity of the
samples 6, 7, and 8 versus the wave length is
presented in the left hand of Fig. 5. As it seen, peak
of absorption spectra shifts to the right with
increasing of pore diameter. This result implies the
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 500 1000 1500 2000 2500 3000
Wavelength (nm)
Test run 3 ( α = 0.553 )
Test run 4 ( α = 0.619 )
Test run 5 ( α = 0.583 )
6. A. Samimi et al./ TPNMS 1 (2013) 110-116
115
Test
run 6
Test
run 7
Test
run 8
Fig. 5. Effect of pore diameter on absorption spectra
straight dependence between the peak of absorption
spectra and the pore diameter. Furthermore,
increasing the pore diameter leads to a slight
reduction in the absorption spectra from 0.4213 to
0.3932. This reduction is more apparent for shorter
wavelengths, since they penetrate more to AAO
film.
4. Conclusion
AAO films with various structural features were
produced on 1050 Aluminum alloy by a two-step
anodization at different conditions. The main
objectives of the paper were to investigate the
effects of film thickness, percentage of pore area,
and pore diameter on solar absorptivity. These
properties were investigated individually to avoid
their interactions. The film thickness and pore area
percentage were changed by variation of the
anodization time and electrolyte temperature,
respectively. The pore diameter was altered by
varying etching time and electrolyte temperature.
The results showed that, increasing of the film
thickness shifted the absorption spectra to the
higher value, leading to growth of solar
absorptivity. Furthermore, an optimum pore area
percentage could be characterized (14.6% in this
study) in which the absorptivity had a maximum
value. At last, it was found that the peak of
absorption spectra depended on the pore diameter.
In this case, decreasing of the pore diameter shifted
the absorption spectra curve to the left, and vice
versa.
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0
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