Editorial
Editors .
Abstract
Dear Readers,International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased to announce the 25th Assembly of Advanced Materials Congress - Advanced Functional Materials Congress (AFMC, www.advancedmaterialsseries.com/afmc19/), to be held during 24 – 27 March 2019 ...
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Dear Readers,International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased to announce the 25th Assembly of Advanced Materials Congress - Advanced Functional Materials Congress (AFMC, www.advancedmaterialsseries.com/afmc19/), to be held during 24 – 27 March 2019 in Stockholm (Sweden) and Helsinki (Finland) while cruising on the Baltic Sea. Advanced Materials Congress (AMC) provides an international platform for the academia and industries to discuss the recent trends in new age innovations and technology on the interdisciplinary field of advanced materials science and technology.
Review Article
Neha Agrawal; Manu Aggarwal; Debmalya Roy; Kingsuk Mukhopadhyay; Arup R. Bhattacharya
Abstract
This review article focuses on the micro-fibrillar fiber origin, its importance and its traditional methods of preparation. Further the different factors which effect the properties of microfiber are being summarized over here. The effect of viscosity ratio, compatibilzer role as constituents are highlighted ...
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This review article focuses on the micro-fibrillar fiber origin, its importance and its traditional methods of preparation. Further the different factors which effect the properties of microfiber are being summarized over here. The effect of viscosity ratio, compatibilzer role as constituents are highlighted in the view to point out there importance in microfiber formation. Also the two most common and easily controllable processing factors: draw ratio and drawing temperature are studied over here which governs the structure, crystallinity and conductivity of the fiber. The review covers the CNTs based microfibers being researched so far describing the factors effecting the properties of the fiber and hence correlating the traditional method of fiber formation with incorporation of modern concept of nanotechnology to form high performance micro-fibrillar fiber. Copyright © 2018 VBRI Press.
Research Article
Sourav Das
Abstract
The impact toughness of closed-cell aluminum foam with various densities was investigated using Charpy impact. The impact load history revealed an elastic region followed by a rapid load drop region. The peak load and impact toughness of aluminum foam increase exponentially with density. The power exponents ...
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The impact toughness of closed-cell aluminum foam with various densities was investigated using Charpy impact. The impact load history revealed an elastic region followed by a rapid load drop region. The peak load and impact toughness of aluminum foam increase exponentially with density. The power exponents for the impact toughness test are greater than that of the compressive test. Fracture analysis indicated a mixed-rupture mode of quasi-cleavage and small shallow dimples. It can be attributed to the complex state of stress of notched specimens and elevated impact velocity under impact loading. Copyright © 2018 VBRI Press.
Research Article
Wenbo Wang; Fangfang Wang; Yuru Kang; Li Zong; Qin Wang; Aiqin Wang
Abstract
In this paper, we developed a simple mechanical/chemical process to efficiently disperse palygorskite (PAL) crystal bundles into individual nanorods. The “cavity effect” of high-pressure homogenization process generated many “Miniature bombs” in the interior gap of crystal bundles, ...
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In this paper, we developed a simple mechanical/chemical process to efficiently disperse palygorskite (PAL) crystal bundles into individual nanorods. The “cavity effect” of high-pressure homogenization process generated many “Miniature bombs” in the interior gap of crystal bundles, which may mildly “blast” and effectively burst through the hugged PAL rod crystals without losing their original aspect ratio. Sodium metaaluminate (SM) was simultaneously introduced in the high-pressure homogenization process to promote the dispersion of crystal bundles and restrain the re-aggregation of dispersed nanorods. The dispersion degree and surface charge of PAL nanorods were greatly improved, and the colloidal viscosity of aqueous suspension of highly dispersed PAL rods greatly enhanced by 148% in contrast to raw PAL aggregates. Also, the colloidal stability and rheological properties of PAL were clearly improved after dispersion. As a whole, this process can produce PAL nanorods in an industrial scale, which opens a new avenue to extend the application of PAL in many industrial areas such as fine chemicals, functional carriers and nanocomposites. Copyright © 2018 VBRI Press.
Research Article
Gyung Soo Jeon
Abstract
The effect of humidity aging time of adhesion samples made up of brass-plated steel cord and rubber compound on the adhesion interphase was studied by the depth profiling of Auger electron spectroscopy and FE-SEM. It was shown that humidity aging time of adhesion samples played major role of formation, ...
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The effect of humidity aging time of adhesion samples made up of brass-plated steel cord and rubber compound on the adhesion interphase was studied by the depth profiling of Auger electron spectroscopy and FE-SEM. It was shown that humidity aging time of adhesion samples played major role of formation, growth and deterioration of copper sulfide and zinc oxide at the adhesion interphase with increased humidity aging time of adhesion samples. The adhesion interphase of adhesion sample after cure appeared the spherical shape whereas that after humidity aging treatment appeared the needle-like shape from FE-SEM analyses. The adhesion stability of adhesion samples against humidity aging treatment may be related to the suppression of the excessive growth of copper sulfide and the inhibition of dezincification during humidity aging time. Copyright © 2018 VBRI Press.
Research Article
Ramakanta Naik; C. Sripan; R. Ganesan
Abstract
In this manuscript, the As40Se60 and As50Se50 samples of 800nm thickness were deposited onto glass substrate by thermal evaporation technique. The as-deposited films were characterized using X-ray diffraction (XRD) and FTIR Spectrophotometer. The prepared samples are amorphous type. The transmission ...
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In this manuscript, the As40Se60 and As50Se50 samples of 800nm thickness were deposited onto glass substrate by thermal evaporation technique. The as-deposited films were characterized using X-ray diffraction (XRD) and FTIR Spectrophotometer. The prepared samples are amorphous type. The transmission is found to be decreased for As50Se50 film. The indirect optical transition mechanism for the photon absorption happens inside the studied film. The optical band gap is decreased with change in As and Se content. The density of state model and increase in disorder is responsible for the reduction of optical band gap in the studied films. The addition of more % As creates localised states in the gap which results the tailing of the band edges. The Urbach energy which gives the degree of disorder changes that indicates the more disorderness of As50Se50 than As40Se60 film. The XPS As3d, Se3d core level spectra variation infers the optical changes in the film and such type of film can be used for optical materials and optoelectronics.
Research Article
P. Neelima; S. R. Murthy
Abstract
Microwave-hydrothermal (M-H) method had been employed to synthesize a series of Dy3+doped Mn-Zn ferrite Mn0.6Zn0.4Fe2–xDyxO4 (x=0, 0.01, 0.03, 0.05, 0.07, 0.09) nanopowders at 160°C/30 min. The prepared samples have been characterized by Fourier Transform Infrared Spectrometer. The grain size ...
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Microwave-hydrothermal (M-H) method had been employed to synthesize a series of Dy3+doped Mn-Zn ferrite Mn0.6Zn0.4Fe2–xDyxO4 (x=0, 0.01, 0.03, 0.05, 0.07, 0.09) nanopowders at 160°C/30 min. The prepared samples have been characterized by Fourier Transform Infrared Spectrometer. The grain size of sintered ferrites are in the range of 60-70 nm. Decrease in saturation magnetization and increase in coercivity were observed with an increase of Dy3+ concentration in Mn-Zn ferrites. The complex permeability and complex permittivity of the prepared samples were measured in the frequency range of 2–18 GHz using a using a vector network analyzer. It is observed that small variation of Dy3+ substitution in spinel ferrite tailored microwave absorbing parameters dramatically. The reflection loss (RL) increased with the Dy3+ content upto x ≤ 0.03. The sample with x=0.03 of thickness 2.3 mm showed minimum reflection loss of -20.5 dB with a bandwidth of 3.8 GHz. Thus the present materials exhibit good microwave absorption properties and hence can act as EMI suppressors. Copyright © 2018 VBRI Press.
Research Article
Kalawati Saini; Florence Jojeph; Smriti S. Bhatia
Abstract
The copper (II) extended metal organic frameworks with oxalic acid ( ox = oxalate ) [Na 2 ( Cu ( ox) 2 ].H2O and[ (NH4)2 ({ Cu ( ox)2(H2O)2}{ Cu( ox)2 }] .H2O have been synthesized using electrochemical route at room temperature and applied potential at 12.5 V. Herein copper rod ...
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The copper (II) extended metal organic frameworks with oxalic acid ( ox = oxalate ) [Na 2 ( Cu ( ox) 2 ].H2O and[ (NH4)2 ({ Cu ( ox)2(H2O)2}{ Cu( ox)2 }] .H2O have been synthesized using electrochemical route at room temperature and applied potential at 12.5 V. Herein copper rod has taken as a working electrode and platinum wire as a reference electrode. The single crystal X-ray diffraction (SXRD) and other supportive techniques like as PXRD, TGA/DTA, FT-IR have been used for structural characterizations. Metal organic frameworks (MOFs) are crystalline in nature where the ligands and metal ions are assembled infinitely resulting in one, two or three-dimensional networks having direct metal-ligand coordination. The growth of the solids has been explained corresponding to the mechanistic approach proposed by Ramanan and Whittingham. The crystal packing has been influenced by the supporting electrolyte. The electrolytic method is a simple process, low energy consumption, high yield, easy control and no environmental pollution. Copyright © 2018 VBRI Press
Research Article
Arul Murugesan; Robert M Gengan
Abstract
A simple and efficient procedure for the preparation of boron nitride bound N-propyl triethylenetetramine sulfonic acid (BN-BPTETSA) by the reaction of boron nitride bound N-propyl triethylenetetramine (3-TETANP BN) with chlorosulfonic acid in chloroform is described. The boron nitride (BN) ...
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A simple and efficient procedure for the preparation of boron nitride bound N-propyl triethylenetetramine sulfonic acid (BN-BPTETSA) by the reaction of boron nitride bound N-propyl triethylenetetramine (3-TETANP BN) with chlorosulfonic acid in chloroform is described. The boron nitride (BN) nanomaterial was prepared by first activating BN with nitric acid under reflux for 24h. Thereafter trimethoxy -3-mercaptopropylchloride was added, refluxed for 24 h then an excess of triethylenetetramine was added in anhydrous xylene and the system was refluxed. After filtration and washing of the filter cake with xylene, chlorosulfonic acid was added drop-wise at 0 °C over a period of 3 h. Further filtration yielded a solid cake which was washed with ethanol and air died. The morphological properties of catalyst was characterized by FT-IR, XRD, TEM, SEM, BET and Raman spectroscopy techniques. The preparation of the catalyst is safe and demonstrates high catalytic activity for the synthesis of piperazinyl quinolinyl carbaldehyde derivatives. Furthermore, a small amount of catalyst was used, demonstrated good reusability and may have potential for industrial applications in the future. Copyright © 2018 VBRI Press.
Research Article
Aboo Bakar Khan; Mohini Sharma; Syed Gulraze Anjum; Mohd Jawaid Siddiqui
Abstract
In this work, we have performed the influence of back barrier layer thickness variation on AlGaN/GaN Metal Oxide Semiconductor High Electron Mobility Transistor (MOS-HEMT) device with 0.5 µm Schottky gate length. The AlGaN back barrier layer presented increases the conduction band with respect ...
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In this work, we have performed the influence of back barrier layer thickness variation on AlGaN/GaN Metal Oxide Semiconductor High Electron Mobility Transistor (MOS-HEMT) device with 0.5 µm Schottky gate length. The AlGaN back barrier layer presented increases the conduction band with respect to GaN channel layer so that more no of electron confinement into the GaN channel layer and improve the high-frequency performance. The effect of the back-barrier layer thickness is performed by using 2-D TCAD Atlas Silvaco numerical simulation tool by taking Hydrodynamic mobility model. Due to a large amount of two-dimensional electron gas (2-DEG) density at the AlGaN/GaN heterointerface of the MOS-HEMT device higher drain current density is obtained. The 2-D simulation is carried out with a variation of back barrier layer thickness for various device parameter such as transfer characteristics (Id-Vg), drain current with a drain voltage (Id-Vd), transconductance (gm), drain induced barrier lowering (DIBL), conduction band energy and electron concentration into the channel. In this simulation, we have also performed the RF performance like a gate to source capacitance (Cgs) and current gain cut-off frequency of AlGaN/GaN MOS-HEMT device. The results obtained by variation of AlGaN back barrier layer thickness can be a better solution in future analog and RF device application. Copyright © 2018 VBRI Press.