Issue 10


Editorial

Advanced Materials World Congress (AMWC) -2015, Sweden

Ashutosh Tiwari

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 549-549

VBRI Press AB is pleased to sponsor ‘Advanced Materials World Congress’ (AMWC) during 23-26 August, 2015, http://vbripress.com/amwc/ in Stockholm, Sweden. It is a four-day international event organised by the International Association of Advanced Materials (www.iaamonline.org), which regularly meet every two-year since 2010. This upcoming world congress is going to host in the city of Nobel Prize, Stockholm, Sweden. The venue of congress will be held on the Baltic Sea from Stockholm (Sweden) – Tallinn (Estonia) - Stockholm (Sweden) via Mariehamn and Helsinki, Finland by the Viking Line. 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.

Solvent Free Selective Isomerization Of  p-diethylbenzene To m-diethylbenzene Using Modified Hβ Zeolites

Mahesh S. Edake; Shriniwas D. Samant

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 550-556
DOI: 10.5185/amlett.2014.2586

Solvent free and selective isomerization of p-diethylbenzene (p-DEB) to m-diethylbenzene (m-DEB) was carried out using metal modified zeolite Hβ at high temperature. The metal modification of Hβ catalyst was carried out by using typical Lewis acidic cations Al 3+ , Fe 3+ , Ti 4+ , Sn 4+ and Sb 3+ . The catalysts were characterized by XRD, FE-SEM, HR-TEM, FT-IR, N2-desorption (BET), ICP-AES, NH3-TPD, pyridine-IR, and TGA techniques for structure, morphology, acidity and stability. Particle size of the crystallites was determined by HR-TEM and the size was in the range of 15 - 35 nm. At 250oC, Al-Hβ, Fe-Hβ and Ti-Hβ catalysts showed 69 - 75% conversion of p-DEB with 43 - 51% selectivity towards m-DEB. This process is a greener alternative to the classical AlCl3 process. Further, such an isomerization would make the styrene manufacture more economic.

Interesting Nanoshapes By “nano Artwork”

Sushilkumar A. Jadhav

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 557-561
DOI: 10.5185/amlett.2014.5570

Nanomaterials of interesting shapes such as nanostars, nanodiscs, nanorods and nanoflowers are frequently synthesized by chemists, experimental physicists and material scientists nowadays. Large number of the bottom-up or top-down synthetic techniques are invented and reported for the synthesis of these materials with interesting shapes. Such shapes found to already exist in nature. The great nature has done this nano artwork with its power and unbeatable architectural skills at molecular level. The ultimate aim of the synthesis techniques invented may not be to mimic nature or challenge it but instead to explore the use of these variously shaped nanomaterials in technological and biomedical applications. These materials found to be applicable in their use as drug delivery systems, catalysis, and energy and as biosensors. In the present note some of the recent examples of such materials are discussed with their images taken with high resolution microscopes.

Effective Antimicrobial Filter From Electrospun Polyacrylonitrile-silver Composite Nanofibers Membrane For Conductive Environments

Anisha Chaudhary; Ashish Gupta; Rakesh B. Mathur; Sanjay R. Dhakate

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 562-568
DOI: 10.5185/amlett.2014.572

Electrospun nanofibers based antimicrobial filter were examined for their capability to build conductive environment. An antimicrobial agent, silver nitrate (AgNO3), was added to the nanofibers membrane for its ability to prevent growth of microorganisms over the filter media. In this direction in the present investigation the different fractions of silver nanoparticles were in-situ synthesized in PAN solution and then polyacrylonitrile (PAN)-silver composite nanofibers membrane filter was prepared by electrospinning technique. The resultant solution and PAN-silver composite nanofibers was characterized by UV–visible spectroscopy, scanning electron microscope, atomic force microscope and X-ray diffraction. Antibacterial property of PAN silver composite nanofibers were investigated against gram positive Staphylococcus aureus and gram negative Escherichia coli microorganisms. The formation of clear zone suggests that composite nanofibers containing silver nanoparticles show strong antibacterial activity and it increases with increasing silver content in the composite nanofibers. The PAN-silver composite nanofibers sheet was also examined for filtration of microorganisms and dust particles. It was observed that PAN-silver composite nanofibers filter proven to be an excellent filter for creating microorganism and dust free hygienic environment. Thus electrospun PAN nanofibers filters containing an antibacterial agent can be a promising solution for effective microorganism filtration from indoor air in hospitals or other places which are more prone to bacterial infections.

Electrodeposition Of V2O5 Using Ammonium Metavanadate At Room Room Temperature

Dimitra Vernardou; Emmanouil Spanakis; Nikolaos Katsarakis; Emmanouil Koudoumas

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 569-572
DOI: 10.5185/amlett.2014.5577

Vanadium oxides were electrodeposited on fluorine doped tin dioxide glass substrates using an aqueous solution of ammonium metavanadate at room temperature for various growth periods keeping the current density constant. The deposition period was found to affect the structure and the morphology of the oxides indicating low crystalline quality and smooth surfaces respectively for periods < 2000 s. It has been found that crystalline vanadium pentoxide grown for 2000 s presented the highest amount of charge, being 0.43 0 C interchanged between the oxide and the electrolyte with a respective specific capacitance of 286 F g -1 having a satisfactory stability after 500 continuous scans. The significance of achieving crystalline low-cost vanadium pentoxide at room temperature with enhanced electrochemical properties for applications as electroactive material is highlighted.

Geometrical Shape Dependence Field Emission From Patterned Carbon Nanotube Array: A Simulation Based Study

Rajkumar Patra; Himani Sharma; Swati Singh; S. Ghosh; V. D. Vankar

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 573-577
DOI: 10.5185/amlett.2014.5578

Designing an efficient field emission source requires theoretical optimization of electron emitters’ geometrical distribution over the surface for its best performance in terms of current density. Seven and nineteen bundles of CNT arrays arranged in different models are analysed in detail using a computational theory in CST studio suite software based on the particle tracking mode. A three dimensional model has been employed to calculate FE properties with high accuracy. Simulations were carried out for a particular number of CNTs of constant height and radius located at fixed distances from each other and arranged in different geometrical patterns. Among all patterns, rectangular arrangement of CNTs is found to produce the maximum current. The edge effect and screening effect are incorporated in calculating total emission current and are found to diminish the contribution of inner rings 10% or less than that of maximum contribution. These findings can be employed as guideline to fabricate pattered CNT structures experimentally for industry applications. 

Microstructural Characterization Of Chitosan Films Used As Support For Ferulic Acid Release

Sandra Rivero; Maria A. Garcia; Adriana Pinotti

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 578-586
DOI: 10.5185/amlett.2014.5582

The influence of natural antioxidants incorporated to biodegradable materials has become a focus of attention in the current food packaging research and development. Chitosan is a functional natural polymer extensively used for tailoring systems or matrices for a different active compound delivery. This work was focused on studying the changes undergone by the chitosan matrix because of the addition of ferulic acid as an antioxidant. Thus, both microstructure and physical properties such as solubility, thermal stability, mechanical and barrier properties were monitored. The addition of ferulic acid caused a decrease in both the moisture content and water vapor permeability, an increase in resistance and a change at the structural level evidenced by TEM. Through FTIR spectra and their relationship with chitosan-based film properties, it was demonstrated that ferulic acid was effectively incorporated in the polymer matrix. The amount of the bioactive compound released from the chitosan matrix to a liquid medium was determined. The delivery profile suggested that the release of the antioxidant agent was controlled by two parallel mechanisms, one Fickian-type and the other associated to the high swelling of the matrix. The antioxidant and UV-barrier properties induced by the addition of ferulic acid turned the chitosan films into a potentially active material to be applied on high-fat foods.

Structural and Optical Properties of Sol-gel Processed ZnCdMgO Nanostructured Films as Transparent Conductor

Praveen Kumar; Amritpal Singh; Dinesh Pathak; Ludek Hromadko; Tomas Wagner

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 587-592
DOI: 10.5185/amlett.2014.6586

In the present work, we report the structural and optical properties of sol-gel synthesized Zn0.9(Cd1-xMgx)0.1O (0 ≤ x ≤ 1.0) nanostructured films investigated by using the X-ray diffraction, scanning electron microscopy, atomic force microscopy, electrical resistivity, optical absorption and photoluminescence spectroscopic techniques. The X-ray diffraction study has revealed the hexagonal wurtzite crystal structure having favorable c-axis orientation for the increase in Mg concentration. The stress-strain calculation reveals the compressive stresses in Cd rich films whereas Mg rich films experience the tensile stress. Reduction of grain size and surface roughness has been observed with the increase in Mg concentration with more spherical grains. The AFM and SEM micrographs reveal the smooth surface morphology of the synthesized films. The magnesium rich films show high transmission in the visible and NIR region but show decrease in it with the increase in Cd concentration. The band gap increases from 3.19 to 3.40 eV with increase in Mg content. The photoluminescence measurement reveals the decrease in the defects and increase in band gap with the increase in Mg content in the films. The electrical resistivity has been found to be increased from 0.3×10 2 to 169.4×10 2 Ω-cm with increase in Mg concentration. The present study reports that the compositions x=0.4 and x=0.6 have the optimized combination of optical transmittance and better electrical resistivity values in this system for their possible applications as transparent conductors. The present results provide important data for TCOs processing with an optimized content of metal dopants for better transparency and conductivity.

Investigation on The Effect of Micro-fillers on The Strength Reinforcement of Polypropylene

Hieu Giang Le; Shyh-Chour Huang; Van Son Nguyen; Thanh-Phong Dao

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 593-597
DOI: 10.5185/amlett.2014.6587

This paper describes on the effect the ratio of fillers (Na10MB3A and CaCO3) have on the tensile strength of polypropylene (PP). These fillers have been added to PP in various ratios and mixed evenly before injecting. Experimental specimens are then made by the injection process under the same conditions including mold temperature of 600C, filled pressure of 200MPa, and injecting speed 110cm3/s using injection process. It was discovered that the tensile strength of PP increases gradually when the ratio of fillers increases. The results revealed that the tensile strength reaches its maximum value with a certain ratio of fillers, and thereafter the strength decreases as the ratio of fillers is increased. This research also indicated that the tensile strength of PP can rise by approximately 13.5% with the addition of Na10MB3A at a ratio of 3%, and increase to 21.46% with the addition of a 4% ratio of CaCO3. They are expected that experimental samples are the usefully promising materials for automotive components. In the future work, this study will further carry out an investigation into glass filler -reinforced PP and determine the fatigue life limit of the fillers-reinforced PP material.

Microwave Assisted Synthesis Of Stable Biofunctionalized Silver Nanoparticles Using Apple Fruit (Malus Domestica) Extract

I.S. Vijayashree; S. Yallappa; P. Niranjana; J. Manjanna

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 598-603
DOI: 10.5185/amlett.2014.5680

A simple and eco-friendly biosynthesis of silver nanoparticles (AgNPs) is reported here using apple fruit extract as reducing and capping media under microwave irradiation. AgNPs were characterized by UV–visible spectroscopy, XRD, FT-IR and TEM. The kinetics of reduction of aqueous silver ions during reaction with the apple fruit extract were monitored with the help of UV-visible spectroscopy. The XRD pattern of AgNPs was found agreeing with the fcc structure of Ag metal. Further, where TEM analysis exhibited formation of spherical shaped nanoparticles in the range of 10–45nm; FTIR analysis was carried out to identify the functional groups which were responsible for reduction/capping of AgNPs and conclude that the characterized AgNPs carry the potential for adoption in various medical and industrial applications.

Tb3+ Doped Sr2(BO3)Cl  Green Emitting Phosphor For Solid State Lighting

Vishal R. Panse; N.S. Kokode; S.J. Dhoble

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 604-610
DOI: 10.5185/amlett.2014.amwc432

In this paper we present luminescence results on Tb 3+ doped Sr2(BO3)Cl green phosphor. The vibrational properties of Sr2(BO3)Cl phosphor was studied by Fourier transform infrared spectroscopy. Photoluminescence studies have been carried out to understand the mechanism of excitation and the corresponding emission in the as prepared phosphor. As the Tb 3+ ion is commonly used as an activator for the green emission, the excitation and emission spectra indicate that this phosphor can be effectively excited by 380 nm, to exhibit bright green emission centered at 546 nm corresponding to the f→f transition of Tb3 +ions.