Volume 3, Issue 5, November 2012


Editorial

Editorial

Ashutosh Tiwari

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 355-355

We are pleased to publish the 3 volume, 5th issue, 2012 of Advanced Materials Letters, a quarterly international journal that is intended to provide top-quality peer-reviewed articles in the fascinating field of materials science particularly in the area of structure, synthesis and processing, characterization, advanced-state properties, and applications of materials. The journal publishes review articles, research articles, notes and short communications. The peer-review and proof-ready editing is expected to be completed with-in 3 months and the online version will be published immediately. Advanced Materials Letters is fully committed to publish articles with no page charges and all the published articles are indexed and are available for download for free.

Synthesis And Organic Functionalization Approaches For Magnetite (Fe3O4) Nanoparticles

Sushilkumar A. Jadhav; Roberta Bongiovanni

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 356-361
DOI: 10.5185/amlett.2012.7381

Several new techniques are invented in recent years to attach organic, bio-organic functionalities to the nanostructures such as the nanoparticles. This approach of adding surface reactivity to the particles enables to tune the properties and reactivity of the resulting hybrid monolayer protected nanoparticles. Magnetic iron oxide nanoparticles of various sizes are reported which bears different organic or polymeric groups. In the present note we have revised the important methods of synthesis of magnetite (Fe3O4) nanoparticles and highlighted the most common strategies for the functionalization of these nanoparticles with organic compounds from very recent literature. This short note will help the students and researchers to screen and choose methods for the synthesis and functionalization of magnetite nanoparticles.

Tensile Properties Of Strontium Metal 

Andrew E. Frerichs; Alan M. Russell

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 362-364
DOI: 10.5185/amlett.2012.6360

The yield strength, ultimate tensile strength, elastic modulus, and strain rate sensitivity of pure Sr metal in the as-extruded condition were determined by tensile testing and compared with the properties of other alkaline metals. Two strain rates were used for testing. At a strain rate of 6.5×10 -4 s -1 , Sr has a 0.2% offset yield strength of 71.6 MPa, an ultimate tensile strength of 88.1 MPa, and 10.4% elongation at fracture. At a strain rate of 6.3×10 -3 s -1 , Sr has a 0.2% offset yield strength of 81.9 MPa, and ultimate tensile strength of 101.5 MPa, and 5.0% elongation at fracture. The strain rate sensitivity was determined to be 0.059.

Fabrication Of Ultra-sensitive Optical Fiber Based Humidity Sensor Using TiO2 thin Film

S. K. Shukla; G. C. Dubey;Ashutish Tiwari; Anand Bharadvaja; G. K. Parashar; A. P. Mishra

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 365-370
DOI: 10.5185/amlett.2012.5350

Thin films of titanium dioxide in anatase form have been prepared using isobutyl titanate as precursor. The resulting TiO2 was coated on an U-shaped pyrex glass rod to sense the humidity of a controlled humid environment using optical fiber approach. The humidity sensing characteristics and the sensing mechanism have been investigated by measuring the output power of the sensor at different humidity. The developed humidity sensor was responded in the humidity ranging from 10 to 95% of relative humidity and exhibited the sensitivity of 0.78, response time 36s and recovery time 73s.

Magnetoelectric Coupling In Multiferroic Ba(Fe0.01Ti0.99)O3 nanowires

Jaspreet Kaur; Jasneet Kaur; Jyoti Shah; R.K. Kotnala; Vinay Gupta; Kuldeep Chand Verma

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 371-375
DOI: 10.5185/amlett.2012.5352

In the present work, structural, microstructural and magnetoelectric (ME) coupling of multiferroic Ba(Fe0.01Ti0.99)O3 (BFT1) nanowires have been studied. BFT1 nanowires were prepared by a hydrothermal method with reaction temperature 180 o C for 48 hours. The X-ray diffraction shows that BFT1 is polycrystalline with cubic phase. The calculated value of distortion ratio (c/a) is ~ 1. No impurity or extra phase is observed. The micrographs by transmission electron microscopy reveal nanowires like structure of BFT1with diameter lie in the range of ~ 40 - 50 nm and length greater than 1.5 μm. The ME coefficient measurement shows that the ME coupling under the effect of both ac and dc bias. It shows strong dependence on ac and dc bias applied field. The value of linear coefficient (α) called ME coefficient is calculated as ~ 16 mV/Oecm at a fixed frequency of 850 Hz. This ME coefficient α corresponds to induction of polarization by a magnetic field or of magnetization by an electric field. The observed optimum dc bias field at which the maximum magneto-electric coupling occurs is ~ 750 Oe. The magnetization hysteresis shows strong ferromagnetism.

Rapid Green Synthesis Of Silver And Gold Nanoparticles Using Peels Of Punica Granatum 

Naheed Ahmad; Seema Sharma;Radheshyam Rai

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 376-380
DOI: 10.5185/amlett.2012.5357

We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel extract as the reducing agent. Peel extract of Pomegranate was challenged with silver nitrate (AgNO3) and chloroauric acid (HAuCl4) solution for the production of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple for the formation of highly stable silver and gold nanoparticles at room temperature by using the biowaste of the fruit. The morphology and crystalline phase of the NPs were determined from UV-Vis spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) spectra. TEM studies showed that the average particle size of silver nanoparticles were 5 ±1.5 nm whereas the gold nanoparticles were found to be 10 ±1.5 nm. An effort has been also been made to understand the possible involved mechanism for the biosynthesis of the NPs. Presumably biosynthetic products or reduced cofactors play an important role in the reduction of respective salts to nanoparticles.

Polyamide 66/nanoclay Composites: Synthesis, Thermal And Flammability Properties

Sudesh Rathi;J. B. Dahiya

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 381-387
DOI: 10.5185/amlett.2012.5354

PA66/nanoclay nanocomposites with flame retardant (dimelamine phosphate) and other supportive additives (ammonium pentaborate, zinc borate and potassium nitrate) were prepared by melt blending method using single screw extruder. The prepared nanocomposites were characterized by XRD and FTIR techniques. The thermal properties were analysed using thermogravimetry and differential scanning calorimetry. A significant reduction in flame spread rate in UL-94 horizontal test was observed on inclusion of ammonium pentaborate to PA66/nanoclay/dimelamine phosphate composite.

Fabrication Of Polyaniline Nanofibers By Chronopotentiometery

Yasir Ali; R G Sonkawade;A S Dhaliwal; Vijay Kumar

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 388-392
DOI: 10.5185/amlett.2012.6358

We have electrochemically synthesized polyaniline nano fibers with optimized process parameters (viz. concentration of monomer and dopant, applied current density, deposition time, etc.) on ITO coated glass substrate. The nano fibers of polyaniline were subjected to UV Visible, SEM and Raman spectroscopy. UV Vis spectra show two prominent peaks at 317 and 418 nm, which confirm the presence of different forms of polyaniline. Raman spectra confirm the formation of polyaniline. SEM image of synthesized nano fibers showed a flower like structure with an isotropic growth rate.

Conductive Polyaniline-tin Oxide Nanocomposites For Ammonia Sensor

S. B. Kondawar; S. P. Agrawal; S. H. Nimkar; H. J. Sharma; P. T. Patil

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 393-398
DOI: 10.5185/amlett.2012.6361

Tin oxide (SnO2) nanoparticles have been synthesized by simple route of sol-gel method. Polyaniline-tin oxide (PANI/SnO2) nanocomposite (sample A) was prepared by an in-situ polymerization of aniline in the presence of as-synthesized SnO2 nanoparticles. Similarly, tin oxide-intercalated polyaniline nanocomposite (sample B) was prepared using tin chloride (SnCl4.5H2O) as precursor during polymerization of aniline. Morphology and structure of both the nanocomposites have been studied using XRD pattern, FTIR spectra and SEM images which reveals that SnO2 was uniformly mixed within the PANI matrix. In this paper we report the comparison of polyaniline-tin oxide (PANI/SnO2) nanocomposites sample A and B for the response to ammonia. A laboratory set up for sensing ammonia has been built up using four probe resistivity unit and the response of the prepared PANI/SnO2 nanocomposites to ammonia vapour for different concentration (5, 10, and 15%) was tested. PANI/SnO2 nanocomposites were found to be good materials for NH3 detection even at room temperature as compared to that of pure SnO2. By comparing the response of sample A and B to the ammonia vapour, the sample A was found to be more sensitive than sample B due to highly porosity and surface activity of sample A. The results were reproducible and checked by repeating observations. Synthesis route for the preparation of PANI/SnO2 nanocomposites is an important factor while selecting the materials for ammonia sensing.

Induced Size Effects Of Gd3+ ions Doping On Structural And Magnetic Properties Of Ni-Zn Ferrite Nanoparticles

Balwinder Kaur; Avanish Kumar Srivastava;Rajendra Prasad Pant; Manju Arora; Ajay Shankar

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 399-405
DOI: 10.5185/amlett.2011.7288

Gd 3+ ions substituted in Ni0.5Zn0.5GdxFe2-xO4 (where x = 0.1, 0.2, 0.3) ferrite nanoparticles in the size range from 15 to 25 nm were prepared by chemical method. The effect of Gd 3+ ions in spinel structure in correlation to structural and magnetic properties have been studied in detail using XRD, HRTEM and EPR techniques. The spin resonance confirms the ferromagnetic behaviour of these nanoparticles and higher order of dipolar-dipolar interaction. On increasing Gd 3+ ions concentrations, the super exchange interaction i.e. increase in movement of electron among Gd 3+ - O - Fe 3+ in the core group and the spin biasing in the glass layer has been interpreted. The decrease in ‘g’ value and increase in relaxation time is well correlated with the change of particle size on different concentrations of Gd 3+ ions in Ni-Zn ferrite.

Ionic Conductivity And Electrochemical Cell Studies Of New Mg2+ ion Conducting PVA/PEG Based Polymer Blend Electrolytes 

Anji Reddy Polu; Ranveer Kumar;K Vijaya Kumar

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 406-409
DOI: 10.5185/amlett.2012.6375

Solid Polymer blend electrolytes based on Polyvinyl alcohol (PVA) and Polyethylene glycol (PEG) complex with Mg(CH3COO)2 at different weight percent ratios were prepared using solution cast technique. Conductivity in the temperature range 303-373 K and transference number measurements have been employed to investigate the charge transport in this solid polymer electrolyte system. The highest conductivity is found to be 3.23 x 10 -5 S/cm at 373K for sample with 30 weight percent of Mg(CH3COO)2 in PVA/PEG blend matrix. Transport number data shows that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this electrolyte, an electrochemical cell with configuration Mg /(PVA+PEG+Mg(CH3COO)2)/ (I2+C+electrolyte) was fabricated and its discharge characteristics profile has been studied.

The Influence Of Substrate Temperature On The Structure, Morphology, And Optical Properties Of ZrO2 thin Films Prepared By E-beam Evaporation

K. J. Patel; M. S. Desai; C. J. Panchal

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 410-414
DOI: 10.5185/amlett.2012.5364

Zirconium dioxide thin films were prepared by e-beam evaporation method to study the effect of substrate temperature on the structural, surface morphology, compositional, and optical properties. X-ray diffraction measurement shows that the films grown at 400 ℃ substrate temperature have monoclinic crystal structure. The root mean square surface roughness of the film increases with increase in the substrate temperature. The optical transmittance spectra indicate an average 80% transmittance in the visible region of light. The optical energy band gap of ZrO2 thin film decreases from 5.68 to 5.63 eV as the substrate temperature increases from room temperature to 400 ℃, respectively.

Induced Size Effect On NixCo1-xFe2O4 (0.1 ≤ X ≤ 0.9)

Ajay Shankar; Sandeep Kumar; Sanjeeve Thakur; Rajni Porwal; R. P. Pant

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 415-420
DOI: 10.5185/amlett.2012.6370

Nanocrystalline NixCo1-xFe2O4 were synthesized and studied for their structural and magnetic properties. The effect of doping ion concentration on lattice parameter, crystallite size and the lattice strain pertaining to the ionic radii has been investigated. Electron microscopy supports the parameters and gives morphological view of the system. The magnetic measurement reveals the information on the effect of stoichiometry variation in existing superparamagnetism. Further, the spin dynamics and their role on dipolar interactions, extent of superexchange and spin-spin relaxation among nanoparticles have been investigated. Also, an attempt has been made to understand the UV irradiation effect on photosensitive Co 2+ ion on Ni ferrite by in-situ electron spin resonance measurements.

Fabrication Of Electro-chemical Humidity Sensor Based On Zinc Oxide/polyaniline Nanocomposite

S. K. Shukla; Aparna Shekhar;Ashutosh Tiwari; Anand Bharadavaja

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 421-425
DOI: 10.5185/amlett.2012.5349

The present work reports the synthesis of nano size zinc oxide encapsulated polyanaline by wet-chemical method at ambient condition. The prepared composite was characterized by XRD, SEM, TGA and UV-Vis spectroscopy. The results revealed the formation of the crystalline homogenous ZnO centered composite with electrical conductance in the range of 10 -2 scm -1 and thermal stability up to 280 0 C. Further, electrical resistance of a ZnO/PANi film of ~200 nm thickness was monitored against humidity to use as humidity sensitive element. The observed sensing parameters were response time, 32 sec; and recovery time, 45 sec; sensor has exhibited better sensing characteristics than pure PANi and other reported humidity sensors.

Spectroscopic And Morphological Evaluation Of Gamma Radiation Irradiated Polypyrrole Based Nanocomposites

M. Roy; J. Bajpai;A. K. Bajpai; R. G. Mahloniya

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 426-432
DOI: 10.5185/amlett.2012.6373

Novel electrically conducting nanocomposite materials comprising of poly (pyrrole) (PPy) nanoparticles dispersed homogeneously in a poly (vinyl alcohol)-g-poly (2-acrylamido-2-methyl-1-propanesulphonic acid-co-acrylonitrile) matrix were prepared by in situ polymerization of pyrrole. Radiation shielding potential of so designed polypyrrole based nanocomposites was studied by exposure of polymer materials to gamma radiation under varying experimental conditions and structural and morphological changes in irradiated materials were examined by FTIR and SEM techniques.

In Situ Impedance Spectroscopy Study Of The Electrochemical Corrosion Of Orthopedic Ti-6Al–7Nb In Simulated Body Fluid

N. A. Al-Mobarak

Advanced Materials Letters, 2012, Volume 3, Issue 5, Pages 433-440
DOI: 10.5185/amlett.2012.9425

The corrosion resistance of titanium alloy, Ti–6Al–7Nb, was investigated through electrochemical impedance spectroscopy (EIS), open circuit potential (OCP) measurements and scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. The tests were done in Hank's solution at 37 o C for immersion periods expanded to 169 h. A high corrosion resistance was obtained for Ti–6Al–7Nb alloy in hank's solution due to the stable passive film formed on its surface. The EIS results indicated the presence of a single passive layer immediately after immersion. However, after 24 h of immersion in hank's solution, the EIS exhibited the presence of a bi-layered surface corresponding to an inner layer and an outer layer. Further, the film formed on the alloy after 169 h was confirmed by SEM and EDX analysis as calcium and phosphate may be due to apatite formation.