Volume 6, Issue 2, February 2015


Advanced Materials World Congress, Sweden  

Ashutosh Tiwari

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 86-86
DOI: 10.5185/amlett.2015.2001

VBRI Press AB is pleased to organise ‘Advanced Materials World Congress’ (AMWC) during 23-26 August, 2015, www.vbripress.com/amwc in Stockholm, Sweden. It is a four-day international event of the International Association of Advanced Materials (www.iaamonline.org), which regularly meets 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.

Keys And Regulators Of Nanoscale Theranostics 

Amineh Ghaderi; Yugal Agrawal;Ashutosh Tiwari; Eduardo Antunez de Mayolo; Hirak Kumar Patra; Mohsen Golabi; Onur Parlak; Rickard Gunnarsson; Raul Campos; Revuri Vishnu; Sami Elhag; Selvakumar Subramanain; Wetra Yandi; Yuan Liu

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 87-98
DOI: 10.5185/amlett.2015.1045

Nanoscale theragnosis is the biomedical aspect of nanomaterials for simultaneous diagnosis and therapy. The last decade was completely devoted by the scientist to combine the advancement in nanotechnology molecular biotechnology for the development of future nanomedicine. The approach started with the development of target-specific delivery of the cargo imaging molecule or drugs for biomedical applications. The cutting edge advantages of the nanoscale materials (e.g., large surface to volume ratio, size-shape dependent physicochemical properties and multi-functionality etc.) proved themselves as the most potential preferences to design optimal therapy for the personalized medicine. The present tutorial review will highlight the recent advances in the development on the regulation of such theragnosis system and their biomedical perspectives to act as a future nanomedicine.

Formation Of Nanowires From Pentacene Derivatives By Single-particle Triggered Linear Polymerization

Yuki Takeshita; Tsuneaki Sakurai; Atsushi Asano; Katsuyoshi Takano; Masaaki Omichi; Masaki Sugimoto; Shu Seki

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 99-103
DOI: 10.5185/amlett.2015.5720

The present paper highlights the development of organic nanowires from small-molecular organic compounds through intra-track chemical reactions by using ion beams.  Thin films of pentacene derivatives, 6,13-bis(triethylsilylethynyl)pentacene (TES-Pn) and 6,13-bis((triisopropylsilyl)ethynyl)pentacene (TIPS-Pn), were subjected to high-energy particle irradiation at a fluence of 10 8 –10 10 cm –2 and thereafter developed by organic solvents. This method, referred as Single-particle Triggered Linear Polymerization (STLiP), afforded the isolation of wire-shaped nanomaterials on a substrate that were visualized by atomic force microscopy and scanning electron microscopy.  These derivatives exhibited high enough propagation and cross-linking reaction efficiencies (G) as GTES-Pn of > 7 and GTIPS-Pn of  > 5 (100 eV) –1 , whose values are significantly larger than those observed for previously studied simple cross-linking reactions observed in other polymeric materials, being apparently in the G-value range of chain reactions.  On the other hand, the pristine pentacene and derivative without (trialkylsilyl)ethynyl moiety did not give any nanowires. Considering these observations, highly efficient intra-track propagation/polymerization/cross-linking reactions would take place due to the introduction of (trialkylsilyl)ethynyl groups, resulting in the formation of one-dimensional nanostructures based on small molecules. The STLiP technique serves as a versatile and easy nanofabrication tool for small molecular materials and the resultant nanowires with high functional density are potentially usable as optical, electronic, and sensor materials.

Solvent Free, Efficient, Industrially Viable, Fast Dispersion Process Based Amine Modified MWCNT Reinforced Epoxy Composites Of Superior Mechanical Properties

Bhanu Pratap Singh; Veena Choudhary; Satish Teotia; Tejendra Kumar Gupta; Vidya Nand Singh; Sanjay Rangnath Dhakate; Rakesh Behari Mathur

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 104-113
DOI: 10.5185/amlett.2015.5612

Dispersion of multiwalled carbon nanotubes (MWCNTs) into epoxy resin is a challenging task for the process to be viable on industrial scale. Herein, amine functionalized MWCNTs (Am-MWCNTs) were reinforced into epoxy resin using industrially viable, fast, efficient, solvent free, high speed homogenizer dispersion technique. Am-MWCNTs ranging from 0.1 to 0.75% by w/w were loaded in epoxy and the effects of loading of Am-MWCNTs on mechanical properties of epoxy composites are investigated. The flexural strength of Am-MWCNTs based epoxy composites reached up to 163 MPa for 0.5 wt% MWCNTs loaded sample compared to 95 MPa for pure cured epoxy sample; an overall improvement of 72% in the flexural strength. In addition to this, the flexural modulus value reached to 3795 MPa for 0.75 wt% Am-MWCNTs loaded sample from 2250 MPa for pure epoxy sample, an improvement of 69%. The enhancement in the mechanical properties was correlated with the dynamic scanning calorimeter results, TEM and SEM images of fractured surface. The substantial improvement in the mechanical properties of the epoxy resin at such low CNT loading can open a venue for the preparation of structurally strong structures for aerospace, defence, automobile and sports industries.

Studies On The Chemical Resistance And Mechanical Properties Of Natural Polyalthia Cerasoides Woven Fabric/glass Hybridized Epoxy Composites  

J. Jayaramudu; S.C. Agwuncha; S.S. Ray; E. R. Sadiku; A. Varada Rajulu

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 114-119
DOI: 10.5185/amlett.2015.5680

In the present work, natural Polyalthiacerasoide woven fabrics were extracted from the bark of the tree and using these woven fabrics/glass fibre as reinforcements and epoxy as matrix the hybrid composites were prepared by the hand lay-up technique, at room temperature. The effect of alkali treatment of Polyalthiacerasoide fabrics on the chemical structure and morphology was examined using Fourier transforms infrared spectroscopic (FT-IR) and scanning electron microscopic techniques respectively. FT-IR analyses indicated the lowering of hemi-cellulose and lignin contents by alkali treatment of the woven fabric. The scanning electron micrographs indicated the removal of hemicelluloses layer on the surface of the fabric by alkali treatment. The effect of alkali treatment of the natural fabric on the mechanical properties, chemical resistance, and interfacial bonding of the hybrid composites was examined.The mechanical properties of the woven fabric/glass fiber hybrid composites with surface modified natural fabric were found to be higher than those with untreated fabric. The fractographs indicated a better interfacial bonding between the woven fabric/glass fibres and the matrix, particularly when the alkali-treated natural fabrics were used in the hybrid composites. Furthermore, these hybrid composites showed resistance to acids, alkalis and various solvents and also possessed lower water absorption.The natural fabric/glass fibre hybrid composites have the properties which advise their relevance for application in the building and construction industries.

80 MeV Carbon Ion Irradiation Effects On Advanced 200 GHz Silicon-germanium Heterojunction Bipolar Transitors

N.H. Vinayakprasanna; K.C. Praveen; N. Pushpa; Ambuj Tripathi; John D Cressler; A.P. Gnana Prakash

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 120-126
DOI: 10.5185/amlett.2015.5708

The total dose effects of 80 MeV carbon ions and 60 Co gamma radiation in the dose range from 1 Mrad to 100 Mrad on advanced 200 GHz Silicon-Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The stopping and range of ions in matter (SRIM) simulation study was conducted to understand the energy loss of 80 MeV carbon ions in SiGe HBT structure.  Pre- and post-radiation DC figure of merits such as Gummel characteristics, excess base current, ideality factor, DC current gain, damage constant, neutral base recombination, avalanche multiplication of carriers and output characteristics were used to quantify the radiation tolerance of the devices. The excess base current, current gain and damage constant for 80 MeV carbon irradiated SiGe HBTs show more degradation when compared to 60 Co gamma irradiation. The ideality factor for 80 MeV carbon ions irradiated SiGe HBTs is also more when compared to 60 Co gamma irradiated SiGe HBTs. The SiGe HBTs shows minimal degradation in current gain at collector current levels (~ 1 mA) where the circuits are biased even after 100 Mrad of total dose. Therefore SiGe HBTs are became the reliable candidate for deep space exploration programs and high energy physics experiments (HEP) like large hadron colliders (LHCs).

Pomosynthesis And Biological Activity Of Silver Nanoparticles Using Passiflora Tripartita Fruit Extracts

Brajesh Kumar; Kumari Smita; Luis Cumbal; Alexis Debut; Javier Camacho; Elisabeth Hernández-Gallegos; María de Guadalupe Chávez-López; Marcelo Grijalva; Yolanda Angulo; Gustavo Rosero

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 127-132
DOI: 10.5185/amlett.2015.5697

Silver nanoparticles (AgNPs) have been synthesized via the green pomosynthetic procedure, using Passiflora tripartita var. mollissima fruit pigments as both the reducing and stabilizing agents. UV–Vis Spectroscopy, Dynamic Light Scattering, Transmission Electron Microscopy with Selected Area Electron Diffraction and Powder X-Ray Diffraction are used to completely characterize the AgNPs. The prepared AgNPs are found to be mostly spherical shapes with an average diameter of 49.7 ± 24.6 nm at room temperature. XRD analysis revealed the face-centered cubic geometry of AgNPs whereas Infrared spectrum and cyclic voltammetry measurements hypothesize the possible biomolecules (flavonoid C & O-glycosides) responsible for stabilization of the AgNPs. Synthesized AgNPs shows significant antioxidant efficacy (67%, 0.15 mM) against 1, 1-diphenyl-2- picrylhydrazyl. The AgNPs (0.01 – 20 μΜ) did not affect cell proliferation of the human cancer cell lines A -549 and HeLa, from lung and cervix, respectively. The use of environmentally benign, cost-effective and renewable materials like P. tripartita extract offers numerous benefits of eco-friendliness and compatibility for potential future pharmaceutical and biomedical applications.

Synthesis Of Novel Al-doped SnO2 Nanobelts With Enhanced Ammonia Sensing Characteristics

Sudip K. Sinha

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 133-138
DOI: 10.5185/amlett.2015.5651

Pure and Al-doped single-crystalline 1-D SnO2 based nanostructures were synthesized via a catalyst free simple chemical vapour transport and condensation process in Ar/O2 atmosphere. The crystalline structure, morphology and defect states of pure and Al-doped SnO2 nanostructures have been investigated in detail. Incorporation of Al in the interstitial voids of tetragonal SnO2 lattice is proved by investigating through various analytical techniques. Al doping in SnO2 significantly increases its defect concentration as demonstrated by photoluminescence spectra. The PL spectra for pure and Al-loaded SnO2 samples shows a less intense excitonic peak at ~384 nm in the UV region apart from the broad and intense yellow emission peak centred at around ~596 nm and a shallow peak at ~672 nm, respectively. For the development of stable and economically viable sensor modules for ammonia vapour detection, sensitivity at three different concentration of NH3 vapours (25ppm, 50 ppm and 100 ppm) were investigated by varying the operating temperature (250–400 °C). The minimum sensitivity for Al-doped SnO2 nanobelts was found to be 0.47 (at 25 ppm and 250 °C) and the maximum as 1.85 (at 100 ppm and 350 °C), which is 2-3 times higher than that for pure SnO2 nanowire assembles. Our results are found to be reproducible after cross examination by repeated observations. The response time (35–110 s), and recovery time (50–120 s) of our Al-doped SnO2 nanostructured sensors, for different concentrations of NH3 vapours, are equivalent or less if compared to those of available metal-oxide sensors in market.

Structural Analysis By Rietveld Method And Its Correlation With Optical Propertis Of Nanocrystalline Zinc Oxide

Vikash Kumar; Swati Kumari; Pawan Kumar; Manoranjan Kar; Lawrence Kumar

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 139-147
DOI: 10.5185/amlett.2015.5632

The correlation between structural and optical properties of nanocrystalline ZnO synthesized by the citrate precursor method has been investigated. The Rietveld refinement of X-ray diffraction pattern confirms the P63mc space group and formation of single phase hexagonal wurtzite structure with presence of tensile strain at the lattice site. The presence of Raman active optical phonon mode at 436 cm -1 which is a significant character of ZnO with hexagonal wurtzite structure supports the XRD result. FE-SEM result shows that the size of the particle is about 20 nm with nearly spherical shapes. The optical band gap energy at room temperature has been calculated as 3.28 eV using the Tauc plot technique. The UV-Vis sub-gap absorption curve supports the presence of strain inside the crystal. The photoluminescence spectrum indicates the dominancy of the defect related deep level or trap state emissions over the near band edge UV emissions using an excitation wavelength of 320 nm.

Fabrication Of SnO2 Three Dimentional Complex Microcrystal Chains By Carbothermal Reduction Method

Neha Bhardwaj; Satyabrata Mohapatra

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 148-152
DOI: 10.5185/amlett.2015.5681

Three dimensional (3D) complex microcrystal chains of SnO2 have been fabricated by simple carbothermal reduction based vapour deposition method. The structural and optical properties of the as-synthesized materials were well characterized by field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), Raman spectroscopy and photoluminescence spectroscopy. FESEM studies revealed the formation of 3D complex chains of microcrystals of SnO2 of varying shape and size. The SnO2 microcrystals have been found to be inter-connected through oriented attachment, leading to the formation of 3D complex chains of microcrystals. XRD studies showed the presence of SnO2 and Sn in the synthesized material. Photoluminescence studies on SnO2 microcrystal chains revealed peaks at 361, 407, 438 and 465 nm. A tentative mechanism of formation of the 3D complex chains of SnO2 microcrystals is proposed. These SnO2 microcrystal chains have potential applications as building blocks in novel functional devices.

The Optical Characterization Of Polyvinyl Alcohol: Cobalt Nitrate Solid Polymer Electrolyte Films

Omed Gh. Abdullah; Dlear R. Saber; Sherzad A. Taha

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 153-157
DOI: 10.5185/amlett.2015.5687

Optical properties of solid polymer electrolyte films based on polyvinyl alcohol (PVA) with different concentration of cobalt nitrate Co(NO3)2 (3-12) wt% have been studied. The parameters such as refractive index, extinction coefficient, and optical energy gap were investigated by using the absorbance measurement from UV-visible spectrophotometer in the spectral range (190-790) nm. This study reveals that the optical properties of PVA are affected by salt concentration, where the absorption increases and absorption edge decreases as Co(NO3)2  concentration increases. The refractive index, and extinction coefficient values were found to increase with increasing Co(NO3)2  percentage. The optical energy gaps have been investigated and showed a clear dependence on the Co(NO3)2  concentration. The interpreted absorption mechanism is both direct- and indirect- electron transition, and it was found to be decreasing with increasing Co(NO3)2  concentration. The single oscillator model has been used to analyses the dispersion behavior of the refractive index, and the dispersion parameters are calculated.

Effect Of Synthesis Time On Structural, Optical And Electrical Properties Of CuO Nanoparticles Synthesized By reflux Condensation Method

N. Bouazizi; R. Bargougui; A. Oueslati; R. Benslama

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 158-164
DOI: 10.5185/amlett.2015.5656

CuO nanopowder oxide was synthesized by reflux condensation method without any surfactants or templates, using copper nitrate in deionized water and aqueous ammonia solution. The structural, optical and electrical properties of the sample were investigated using X-ray diffraction (XRD), FT-IR, UV–visible spectroscopy and impedance spectroscopy measurements. The X-ray diffraction patterns revealed that CuO nanoparticles (NPs) was formed in pure monoclinic phase and good crystalline quality, whose NPs sizes were of the order 25 nm which an average size can be tailored by the synthesis time. FT-IR spectra of CuO NPs used to detect the possible adsorbed species on the CuO materials. In addition, the peaks at 529 and 604 cm-1 correspond to the characteristic stretching vibrations of Cu-O bond in the monoclinic CuO. The optical absorption property has been determined by UV–visible Spectroscopy in the wavelength range of 200–800 nm which indicate the energy gap (Eg). As result, Eg increases with increasing the synthesis time from 2.72 to 1.87 eV. The complex measurement has been investigated at room temperature, and in the frequency range 40 Hz–100 kHz, showing that Nyquist plots (Z' versus Z'') are well fitted to an equivalent circuit model which consists of a parallel combination of a bulk resistance Rb and constant phase elements CPE. On the other hand, the capacitance and the conductance of CuO NPs have a proportional relationship to the charge transfer and the surface electrode-pallet. These properties make these materials very promising electrode.

Impedance Spectroscopy And Conductivity Studies Of CdCl2 Doped Polymer Electrolyte

Mayank Pandey; Girish M. Joshi; Kalim Deshmukh; Jamil Ahmad

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 165-171
DOI: 10.5185/amlett.2015.5639

Polyvinyl alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) based polymer electrolytes for different loading wt% of CdCl2 were prepared by solution casting. The structural complexation was confirmed and interlayer spacing (d) was evaluated by using X-ray diffraction (XRD) study. The chemical bonding between polymer and salt was identified by using Fourier transform infrared spectroscopy (FTIR) technique. The FTIR peak at 3402.43 cm -1 in addition of PVP in PVA/CdCl2 composite demonstrates the grafting between two polymers. The presence of ionic bright channels and variation in morphology for different loading wt% of CdCl2 was confirmed by scanning electron microscope (SEM) and was also verified by Atomic force microscopy (AFM) micrographs. The analysis of impedance spectroscopy represented by semicircular pattern is driven by conduction mechanism and correlated with electrical conductivity. The enhanced AC conductivity of polymer electrolyte is directly proportional to frequency (50Hz-1MHz). The maximum value of DC conductivity 1.65x10 -5 S/m evaluated from Arrhenius plots and attribute to high mobility of free charges at higher temperature. The evaluated results of structural, morphological and electrical properties of present composites make the present research good for electrochemical devices.

Zinc Oxide-urea Formaldehyde Nanocomposite Film As Low-cost Adsorbent For Removal Of Cu(II) From Aqueous Solution

Neeta Pandey; S.K. Shukla; N.B. Singh

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 172-178
DOI: 10.5185/amlett.2014.5604

Copper is widely used in different industries and found its significant loss during the manufacturing and processing. The lost Cu is discharged in the effluent, thus adsorption of heavy metals is an important technology for treatment of wastewater containing different types of selected heavy metals. In this study, nanosize (~95 nm) zinc oxide was prepared through KNO3-NaNO3 eutectic melt at 450 °C. The obtained ZnO was encapsulated in urea-formaldehyde (UF) resin during acid catalysed polymerization process. The characterization of ZnO and ZnO-UF were made by X- ray diffraction (XRD), Scanning electron microscope (SEM) and Infra red spectroscopic (FT-IR) techniques. The prepared ZnO encapsulated in urea-formaldehyde resin casted in the form of film (~0.5 mm thickness) was used to remove 80% Cu (II) content from aqueous solution in 15 minutes. Further, the adsorption process was investigated and data was explained with Langmuir adsorption isotherm model.

Impact Of Transition Metal Ion Doping On Electrical Properties Of Lithium Ferrite Nanomaterials Prepared By auto Combustion Method

Abdul Gaffoor; D. Ravinder; V. Nathanial

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 179-185
DOI: 10.5185/amlett.2015.5610

Nano crystalline cobalt substituted lithium ferrites having chemical formula [Li 0.5Fe0.5]1-x Cox Fe2O4 (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been prepared by the citrate gel auto combustion method at low temperature (180 o C). The prepared samples were sintered at 500 o C for 4 hours. Single phase of these samples were confirmed by x-ray powder diffraction technique and found that lattice parameter increases with increasing with the Cobalt substituted concentration, and the values of crystallite size, x-ray density, bulk density and porosity of the prepared samples were calculated from the XRD analysis. The dc electrical resistivities of the prepared Li-Co ferrites were studied by using the two probe method in the temperature range of 473-873 K (200-600 o C). A plot of log (?T) vs inverse of temperature yields a almost straight line which reveals the semiconducting behavior of prepared ferrite samples. The dielectric properties namely dielectric constant (ε'), dielectric loss tangent (tan δ) of these Li-Co nano crystalline ferrites have been studied using an LCR meter from the room temperature to 700 K at various selected frequencies up to 5 MHz. The dielectric constant (ε') of all prepared samples was increased with increasing in temperature. These results have been explained on the basis of Koop’s theory, concentration of Fe +2 and Fe +3 ions on the octahedral site and hoping frequency of charge carriers (electrons) between Fe +2 and Fe +3  ions.