Volume 5, Issue 8, August 2014


Editorial

Advanced Materials World Congress, Sweden

Ashutosh Tiwari

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 421-421

Dear Reader,
We are pleased to announce next Advanced Materials World Congress (AMWC), 23-26 August, 2015, www.vbripress.com/amwc. It is a four-day international event organised by the International Association of Advanced Materials and sponsored by the VBRI Press, which usually meets every two-year. The upcoming world congress is going to host in the city of Nobel Prize, Stockholm, Sweden. The venue of congress will be on the floor of Baltic Sea from Stockholm-Mariehamn-Stockholm via the Viking Cinderella. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research results and activities in the field of fundamental and interdisciplinary research of materials science. The World Congress will provide opportunities for the delegates to exchange their face-to-face novel ideas and experiences with the international experts during the plenary and invited talks, oral presentations and poster sessions. We will also set up sessions with keynote forum, panel discussion and project negotiation. Important dates:
• Abstract submission start: 10 July 2014
• Deadline of abstract submission: 15 December 2014
• Confirmation of abstract acceptation: 25 February 2015
• Registration starts: 15 January 2015
• Early bird registration closed: 30 April 2015

 Nanofibrous Filtering Materials With Catalytic Activity

Ganna Ungur; Jakub Hruza

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 422-428
DOI: 10.5185/amlett.2014.amwc1025

This research describes the fabrication of nanofibrous materials for the air purification with high filtration efficiency and catalytic properties to clean the air from solid particles and emissions of automobile's transport. The polyurethane (PU) nanofibers were modified by particles of SnO2 and CrO2 in the ratio 95/5 to impart catalytic properties in the reaction with emission gases (CO, NOx).The modification process was provided by the introduction of metal’s oxide’s particles of different concentrations (1;2; 3; 4%) into the polymer solution. Reological properties and conductivity of the modified solutions were studied. The viscosity of solutions grew up gradually with increasing of SnO2/CrO2 concentrations. Fiber's samples were produced from modified solutions by the electorstatic fiber forming using Nanospider technology. The morphology of produced fibers was analysed by the Scanning Electron Microscopy (SEM). SEM pictures confirmed the smoothness of fibrous layer. The diameters of fibres were measured with the help of Lucie 32G computer software. The obtained results demonstrated increasing of average diameters of nanofibers for the concentration 1and 2% of catalysts in comparison with the pure PU samples. But fibers with 3 and 4% of SnO2/CrO2 particles showed the decreasing of average fiber diameters. The presence of catalyst on the nanofiber`s surface was proved by the method of Energy Dispersive Spectroscopy (EDS). The catalytic properties of produced nanolayers in the reaction with emission's gases were studied with the measurement setup consisting from the engine, a system of analyzers and UV lamp as a sourse of energy to activate the catalyst. All samples demonstrated good catalytic efficiency. The best result showed the sample of PU nanofibers with 3% of SnO2/CrO: the concentrations of CO and NOx reduced by 81% and 73% respectively. Produced samples are the promising materials for air-conditioning systems.

Modified Arcan Tests For Concrete With Multi-walled Carbon Nanotubes

Siddik Sener; Yasin Caglar; Cagatay M. Belgin; Kadir C. Sener

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 429-434
DOI: 10.5185/amlett.2014.amwc1032

An experimental study consisting 70 tests have been conducted to study the influence of addition of reinforcing fibers on concrete specimens. The experimental program included concrete specimens that were tested with modified Arcan test machine with different notch lengths. The reinforcing effect of highly dispersed multi-walled carbon nanotubes (MWCNTs) in concrete has been investigated. The results revealed that inclusion of CNTs in the design mix improve both the tensile fracture characteristics and compressive strength when not mixed with a surfactant compound. The improvement in the mechanical properties specimens with the addition of CNTs are observed more clearly with increasing curing age. The mixing process to achieve uniformly dispersed and properly mixed mortar however requires specialized equipment, such as ultrasonic mixers. The results also indicated some dependency on the size of the specimens, which is a well known phenomenon that is observed for brittle heterogenous materials such as concrete.

Amperometric Immuno-sensor For Detection Of Toxin Aflatoxin B1 Based On Polyaniline Probe Modified With Mc-IgGs-a-AFB1 Antibodies

Keisham Radhapyari; Raju Khan

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 435-440
DOI: 10.5185/amlett.2014.5562

An amperometric sensor for detection of toxin aflatoxin B1 from aspergillus flavus based on conducting polyaniline probe using monoclonal anti-aflatoxin B1 (Mc-IgGs-a-AFB1) antibodies after activation with 3% Bovine Serum Albumin (BSA) through electrochemical polymerization has been proposed. The electrode was fabricated by immobilizing Mc-IgGs-a-AFB1 antibodies molecules onto electrode surface and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and fourier transform infrared spectroscopic (FT-IR) etc. The proposed amperometric immune-sensor has demonstrated excellent electro-analytical properties relative to Aflatoxin B1 in a linear range from 0.20 to 1.30 AngmL -1 with a relatively low detection limit of 0.059 AngmL -1 . The present study will help in improving for quantitative determination of mycotoxins in food samples may provide significant improvements in quality control of food safety through a simple, rapid, and sensitive testing system for agricultural products monitoring.

Electronic Structure And NMR Study Of Selected Doped And Functionalized Graphene 

A. Nouri; M. Mirzaei; T. Tayebi; Z. Alipanah

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 441-446
DOI: 10.5185/amlett.2014.amwc.1024

In this work, density functional theory (DFT) calculations at the BLYP/6-31G* level was performed to investigate doping and functionalizing effect on the graphene in according geometric, NMR parameters and electronic properties. In the considered models, the energy gap is decreased in doped and functionalized models in respect to the pristine model but there are not significant changes between energy gap of the pristine model and functionalized models. Furthermore, results show the high and low sensitivity of the electronic properties of doped and functionalized models towards pristine model respectively. The results indicate that the formation energies of functionalized models are smaller than doped models ones. The NMR parameters follow the results of structural properties. It was found that for production of electronic devices doped models is better than functionalized models and nitrogen atom is a better choice for this purpose respect to the boron atom. All DFT calculations are performed by the Gaussian 98 package.

Structural, Dielectric And Magnetic Properties Of Nanocrystalline BaFe12O19 Hexaferrite Processed Via Sol-gel Technique

Virender P. Singh; Gagan Kumar; Pooja Dhiman; R. K. Kotnala; Jyoti Shah; Khalid M. Batoo; M. Singh

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 447-452
DOI: 10.5185/amlett.2014.554

In the present work BaFe12O19 nano-hexaferrite had been synthesized by sol-gel method and then characterized for its structural, electric, dielectric and magnetic properties. X-ray diffraction studies confirmed the hexagonal structure of the prepared nanohexaferrite with no secondary phase and the particle size was found to be of the order of 49 nm. Further, the morphology of the sample has been studied by using transmission electron microscopy (TEM). A high value of the DC resistivity (5.5 × 106 Ω cm), has been obtained at room temperature. The dielectric properties such as dielectric constant (ε′), dielectric loss tangent (tan δ) and ac electrical conductivity (σac) are investigated as a function of frequency. The dielectric constant and loss tangent are found to be decreasing with the increase in frequency while ac electrical conductivity is observed to be increasing with the increase in frequency. The dielectric properties have been explained on the basis of Maxwell-Wagner’s two-layer model and hopping of the charge. The magnetic properties such as initial permeability (µi) and relative loss factor (RLF) have been investigated as a function of frequency in the range 75 kHz to 30 MHz .Fairly constant value of initial permeability and low values of RLF of the order of 10-4 over a wide frequency range are the cardinal achievements of the present work. The room temperature M-H study shows that present nanohexaferrite has high value of coercivity (2151.3 Oe) and high saturation magnetization (32.5 emu/gm), which make present nanohexaferrite very suitable for magnetic applications. The M-T study shows that prepared nano-hexaferrite has high Tc (746 K).

 Synthesis Of Zeolite X-carbon From Coal Bottom Ash For Hydrogen Storage Material

Nurul Widiastuti; Mila Zhely Nurul Hidayah; Didik Praseytoko; Hamzah Fansuri

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 453-458
DOI: 10.5185/amlett.2014.amwc1019

Coal bottom ash is one of the solid wastes produced from coal combustion process in coal fired power station. The conversion of coal bottom ash into zeolite X-carbon was investigated in this research as an alternative method to reduce disposal cost or to minimize the environmental impact of the coal. Coal bottom ash was alkali fused using NaOH followed by hydrothermal at various time to produce zeolite X-carbon. The synthesized zeolite X-carbon was characterized using X-ray diffraction, scanning electron microscopy, and nitrogen adsorption. Hydrogen adsorption capacity was also determined. The crystalinity of the synthesized zeolite was found to change with hydrothermal time and the maximum value was obtained at hydrothermal temperature of 90 o C for hydrothermal time of 15 hours. The obtained zeolite X-carbon exhibits a high degree of crystalinity having BET surface area of 185.83 m2/gram and a hydrogen sorption capacity of 1,66% wt at 30 °C/ 20 psi using gravimetric method.

 Synthesis And Photoluminescence Property Of RE3+ Activated Na2CaP2O7 Phosphor

J. A. Wani; N. S. Dhoble; N. S. Kokode; S. J. Dhoble

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 459-464
DOI: 10.5185/amlett.2014.amwc.1211

As host materials, phosphate compounds offer great potential for lanthanides to display luminescence characteristics. In this work luminescence behaviour of Na2CaP < sub>2O7:RE 3+ are presented for the first time. Na2CaP < sub>2O7 novel phosphors activated with the trivalent rare earth ions ((RE = Ce, Eu, Tb, Sm) were synthesized by solid state diffusion method.  Phosphors were characterized for phase purity and luminescent properties. The emission and excitation spectra were followed to explore the luminescence attributes. The as prepared powders of Ce 3+ , Eu 3+ ,Tb 3+ and Sm 3+   doped Na2CaP < sub>2O7  emit near-uv, red, green and orange reddish light as result of f-d and f-f  transitions respectively. The study is novel as no such luminescence data are available for this compound. The results are promising in view of the requirement for pc-white LEDs for solid state lighting applications.

 Effect Of Ni/NiO Particles On Structure And Crack Propagation In Zirconia Based Composites

I. Danilenko; F. Glazunov; T. Konstantinova; I. Yashchyshyn; V. Burkhovetski; G. Volkova

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 465-471
DOI: 10.5185/amlett.2014.amwc1040II

The structure formation of yttria stabilized zirconia - nickel oxide composites sintered in air and argon atmosphere were studied. It was shown that the crack propagation in 3Y-TZP ceramics greatly inhibited by creation of composite structure by addition of NiO particles and sintering at 1500 o C in argon atmosphere. Prevention of formation of the monoclinic phase of zirconia was conditioned by sintering composite under argon. Increasing of K1C value was found as in sample shell as in sample core of composite, in comparison with matrix 3Y-TZP ceramics. The increasing of K1C value of obtained intergranular type of composite structure cannot be explained by crack deflection and crack bridging processes by Ni and NiO particles, respectively. The possible explanation of K1C value increasing is the intensification of phase transformation toughening of zirconia by formation of metastable tetragonal phase depleted by Y 3+ ions. The reversibly dissociation of NiO on Ni and oxygen in neutral atmosphere provided the formation of cubic phase and Y 3+ depleted tetragonal phase. Internal oxidation of Ni during cooling leads to formation metastable tetragonal phase in depleted Y 3+ zirconia grains. The formation of NiO particles during cooling lead to emergence of large compressive stresses, which also increased the metastability of tetragonal zirconia grains, depleted of Y 3+ ions.

Metal-tetraphenylporphyrin Functionalized Carbon Nanotube Composites As Sensor For Benzene, Toluene And Xylene Vapors

Swasti Saxena; A. L. Verma

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 472-478
DOI: 10.5185/amlett.2013.2429

A process for non-covalent functionalization of multi-walled carbon nanotubes with metal-tetraphenylporphyrins is reported in this paper. The TEM and SEM images and FTIR results show that the nano-sized clusters of aggregated metal-tetraphenyl porphyrin molecules get attached and anchor the surface of carbon nanotubes. We have utilized the prepared nano-composites to fabricate very fast and sensitive sensors for detection of benzene, toluene and xylene in vapor form. The sensors made from cobalt-, and copper-tetraphenylporphyrins functionalized multi-walled carbon nanotubes having resistivity in the kilo-ohms range show response and recovery times of few seconds. However, the response and recovery times and change in resistance are strongly dependent on the type of metal-porphyrin and the chemical vapors. With the help of principal component analysis and other statistical techniques, these sensors can be used in sensor arrays to identify the specific chemicals in vapor form. The nano-composite sensors are easy to fabricate, portable, low cost, reversible, stable and very fast for detection of benzene, toluene and xylene chemicals in the vapor form.

Structural And Dielectric Properties Of Nb And Fe Co-doped PZT Ceramic Prepared By A Semi-wet Route

Arvind Kumar; S. K. Mishra

Advanced Materials Letters, 2014, Volume 5, Issue 8, Pages 479-484
DOI: 10.5185/amlett.2014.564

In the present work, detailed investigation of dielectric, piezoelectric and ferroelectric properties of Nb and Fe co-doped PZT ceramic near the MPB composition has been carried out. Pb1-3x/2 Fex(Zr0.52Ti0.48)1-5y/4 NbyO3 (PFZTN) ceramics for x = 1- 6 mol% and y = 5.50 mol% have been prepared by a semi-wet route. X-ray diffraction studies confirm the formation of single phase perovskite structure. It is shown that Fe doping in PZNT improves the dielectric, ferroelectric and piezoelectric properties of ceramics. It has been found that at room temperature, dielectric constant and d33 start to increase up to the composition x = 0.05 and thereafter decrease. The maximum value of dielectric constant and d33 has been found for the composition x = 0.05. It has been shown that doping of Fe does not affect over the transition temperature uptown x = 0.04. The value of remnant polarization is of the order of 11.62 µC/cm 2 at x= 0.04. The investigated material seems to be promising candidate for multilayer capacitor applications.