Volume 6, Issue 3, March 2015

 Advanced Materials World Congress, Sweden  

Ashutosh Tiwari

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 186-186
DOI: 10.5185/amlett.2015.3001

VBRI Press AB is pleased to organize ‘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.

In Vivo Genotoxic Assessment Of Silver Nanoparticles In Liver Cells Of Swiss Albino Mice Using Comet Assay

Kumud Kant Awasthi; Rajbala Verma; Anjali Awasthi; Kamlendra Awasthi; Inderpal Soni; P. J. John

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 187-193
DOI: 10.5185/amlett.2015.5640

Silver nanoparticles (Ag NPs) has resulted their incorporation into consumer products due to their extensive application in health, electronic, and household products. In particular, the oral toxicity of Ag NPs is of particular concern to ensure public health. For the present study, a genotoxic and cytotoxic approach was employed to elucidate the activity of 5 nm size and spherical shaped Ag NPs in liver cells of Swiss albino mice by using alkaline comet assay. Statistically significant DNA damage raise the concern about the safety associated with the applications of the Ag NPs. The result showed that Ag NPs induced a significant concentration dependent increase in the frequency of tailed nuclei (DNA damage), tail moment, %DNA in the tail, and tail length in the liver cells. Additionally significant histopathological alterations were also observed. The results of present study suggest that exposure to silver nanoparticles has the potential to cause genetic damage.

Peroxidase Assisted Biosynthesis Of Silver And Gold Nanoparticles: Characterization And Computational Study

Abhijeet Mishra; Poonam Singh; Meryam Sardar

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 194-200
DOI: 10.5185/amlett.2015.5658

In this paper, we described a simple and single step procedure for the synthesis of horseradish peroxidise enzyme (HRP) capped silver and gold nanoparticles. HRP, a heme-containing enzyme utilises hydrogen peroxide to oxidise a wide variety of organic and inorganic compounds. The biosynthesized nanoparticles were characterized by means of UV-VIS spectroscopy, Dynamic light scattering (DLS), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). FTIR study confirms the presence of peroxidase enzyme on the nanoparticles. Computational studies reveal that exposed amino acids (viz serine, threonine, arginine and glycine) play key role in reduction and as well as stabilization of nanoparticles. The HRP assisted silver and gold nanoparticles retained its biological activity in the nanoparticles. The study indicates that Peroxidase which is found in almost all the plants can be used for the large scale synthesis of nanoparticles. Moreover additional attraction is the retention of the enzymatic activity on the nanoparticles. In a single step reaction enzyme is catalysing and in doing so it gets immobilized on it. The integration of biomolecules to nanoparticles is a tedious method mainly due to the surface of nanoparticles. Functionalization of noble metal nanoparticles with biomolecules (e.g., protein and DNA) is in demand because such systems possess numerous applications in catalysis, delivery, therapy, and imaging, sensing and controlling the structure of biomolecules. Computational study highlighted the amino acids which are interacting with the metal ions, thus synthetic peptides can also be designed to synthesize the metal nanoparticles.

Photoluminescence And Photoconductivity Of Ni Doped Titania Nanoparticles

Anand Kumar Tripathi; Mohan Chandra Mathpal; Promod Kumar; Vivek Agrahari; Manish Kumar Singh; Sheo Kumar Mishra; M. M. Ahmad; Arvind Agarwal

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 201-208
DOI: 10.5185/amlett.2015.5663

The Ni doped titania nanostructures were synthesized by sol-gel method followed by calcination at 400°C for one hour. The optical band gap for these nanostructures indicates the red shift. The doped TiO2 nanostructures are spherical in shape. The pure TiO2 exhibits all the possible emission bands while Ni-doped TiO2 nanoparticles show blue-green emission bands. The results suggest that Ni2+ replace some Ti 4+ in TiO2 lattice with tensile strain while TiO2 remained in the form of anatase phase, reduces its band gap energy. The synthesized TiO2 exhibits enhanced photoconducting properties. The work suggest that the titania based materials can have potential applications in photovoltaics, optoelectronic devices and photoconductors in replacement of expansive materials by controlling the compositions and morphology of the nanostructures.

Development And Validation Of Biosensing Method For Acetaminophen Drug Monitoring

Jagriti Narang; Nitesh Malhotra; Nidhi Chauhan; Sandeep Singh; Gajendra Singh; C.S. Pundir

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 209-216
DOI: 10.5185/amlett.2015.5675

A polyphenol oxidase (PPO) was immobilized by employing magnetic nanoparticles-zinc oxide/zinc hexacyanoferrate (Fe3O4NP-ZnO/ZnHCF) hybrid film electrodeposited on the surface of Pt electrode. The surface functionalization of Fe3O4NP-ZnO/ZnHCF hybrid film was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS) before and after immobilization of PPO. The biosensor exhibited optimum response within 4s at pH 7.0 and 35°C and linearity in the range 0.04 to 10000 μM for acetaminophen with a detection limit of 0.04 μM (S/N=3). Accuracy of the proposed sensor was found to be 99%. The use of Fe3O4NP/ZnO/ZnOHCF for construction of amperometric acetaminophen biosensor has resulted into relatively rapid response, higher sensitivity, broad linear range, lower detection limit, good reproducibility and long term stability of this biosensor. This sensing interface provides better avenue for the fabrication of various sensor.

Facile Synthesis Of Co Doped ZnO Nanodisks For Highly Efficient Photocatalytic Degradation Of Methyl Orange

Sini Kuriakose; Biswarup Satpati; Satyabrata Mohapatra

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 217-223
DOI: 10.5185/amlett.2015.5693

Highly photocatalytically active nanodisks of ZnO and Co doped ZnO were synthesized by a facile wet chemical method. The structural, optical and photocatalytic properties of ZnO and Co doped ZnO nanodisks were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Raman spectroscopy and UV-visible absorption spectroscopy. FESEM, AFM and TEM studies revealed the presence of ZnO nanodisks. Sun light driven degradation of aqueous methyl orange (MO) dye was used for evaluating the photocatalytic activity of as-synthesized ZnO and Co doped ZnO nanodisks. Co doped ZnO nanodisks showed very high photocatalytic efficiency and lead to almost complete degradation of MO dye in just 8 minutes. A tentative mechanism of the photocatalytic degradation of MO by Co doped ZnO nanodisks is proposed. We attribute the enhanced photocatalytic activity of Co doped ZnO nanodisks to their high specific surface area and efficient charge carrier separation due Co doping, which improves suppression of recombination of photogenerated electrons and holes. Development of sun light active highly efficient and stable photocatalysts is very promising for environmental remediation leading to safe and clean water.

Ion Irradiation Induced Crystallization In Iron Phosphate Glass – TEM Investigations

P. Jegadeesan; S. Amirthapandian; Kitheri Joseph; C. David; B.K. Panigrahi; K.V. G Kutty

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 224-227
DOI: 10.5185/amlett.2015.5725

Iron phosphate glass (IPG) is considered as a suitable matrix for the immobilization of nuclear waste containing higher concentration of Cs, rare earth, Mo and Cr. The central issue, while disposing nuclear waste in glass matrices, is the damage in glass matrices due to the ballistic processes caused by atomic displacements due to α-particles and the recoiling of heavy nuclei resulting from actinide decay. Ion irradiation produces similar kind of damage, and hence the samples are irradiated with 4 MeV O + (self) ion. The microstructural studies were carried out using transmission electron microscopy (TEM) for as-prepared, annealed and ion irradiated samples. It is observed that ion irradiation in IPG leads to the formation of nanocrystals with different phases containing Fe, P and O. Thermally activated crystallization process is ruled out based on the non-equilibrium experimental conditions. In the present experiments, stress driven crystallization mechanism was invoked. The stress, around the ion track formed during ion irradiation, is larger than the yield strength of the glass and hence, the surrounding matrix undergoes substantial deformation resulting in the formation of shear bands. Nucleation of nanocrystals is driven by the stress in the vicinity of the shear bands.

Biosynthesis Of High Concentration, Stable Aqueous Dispersions Of Silver Nanoparticles Using Citrus Limon extract

Bandita Mohapatra; Reena Kaintura; Jaspal Singh; Sini Kuriakose; Satyabrata Mohapatra

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 228-234
DOI: 10.5185/amlett.2015.5731

Stable aqueous dispersions with high concentration of silver nanoparticles were synthesized by a facile and green synthetic route by treating silver ions with aqueous Citrus limon extract, used as a reducing and capping agent. The formation and growth of silver nanoparticles, prepared by this simple and convenient method, was monitored using UV-visible absorption spectroscopy. The effects of Ag concentration, Citrus limon extract concentration, in-situ and ex-situ pH variations upon NaOH addition on the structural, optical and plasmonic properties of the synthesized Ag nanoparticles were investigated. X-ray diffraction studies revealed the formation of Ag nanoparticles, whose morphology was studied using atomic force microscopy. UV-visible absorption studies revealed surface plasmon resonance (SPR) peak around 465 nm, confirming the presence of Ag nanoparticles. The SPR peak blue shifted along with significant enhancement in intensity with increase in Ag concentration and pH, due to the growth and increased aggregation of Ag nanoparticles. We have shown that addition of NaOH is a key to rapid biosynthesis of stable aqueous dispersions of high concentration of silver nanoparticles. This green synthetic route provides faster synthesis of silver nanoparticles with improved colloidal stability, which can be used in foods, cosmetics and biomedical applications.

Evaluation Of Antioxidant And Antibacterial Activity Of Various Aspect Ratio Gold (Au) Nanorods

Shyamalima Sharma; Ajay Kumar Manhar; Pritom Jyoti Bora; Swapan Kumar Dolui; Manabendra Mandal

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 235-241
DOI: 10.5185/amlett.2015.5629

In the current scenario, metal nanoparticles acquire much attention in terms of their diverse applications because of their extremely small size and large surface to volume ratio. Hence, our present study deals with the investigation of antioxidant and antibacterial activity of gold (Au) nanoparticles. First, anisotropic Au nanorods with various aspect ratios have been synthesized by a standard seeded growth method using CTAB-coated Au seed nanoparticles with size less than 10 nm as nucleation centre. Characterization of synthesized nanorods is made using UV-visible and TEM analysis. The antioxidant and antibacterial activities of Au nanorods have been investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as free radical source and Agar-well diffusion assay. The radical scavenging reaction of nanorods was monitored by a UV-visible spectrophotometer and found that Au nanorods show better antioxidant activity than spherical seeds due to the presence of more number of atoms as well as active sites for interaction with the free radical of DPPH. For a set of nanorods DPPH scavenging percentage is 80-90, while for seeds it is only 30. Again, very less amount (volume) of high aspect ratio nanorods is required for efficient scavenging. A linear relationship is observed between DPPH scavenging percentage and volume of Au nano-dispersions. The synthesized Au nanoparticles also have potent antibacterial activity, the maximum zone of inhibition (20 mm) is observed for longer nanorods, against indicator strains due to the interaction of more number of Au+ cations to the negatively charged bacterial cell wall that causes rupturing of the cell wall and finally death. The minimum inhibitory concentration (MIC) for nanorods is lower when tested against gram negative bacteria viz. Y. enterocolitica (12.5μg/ml), S. enterica typhimurium (15 μg/ml), and K. pneumoniae (10 μg/ml) as compared to gram positive bacteria viz. S. aureus (20 μg/ml), L. monocytogenes AMDK2 (20 μg/ml) and B. cereus AMDK1 (25 μg/ml). From this study, it is concluded that high aspect ratio Au nanorods can act as an effective antioxidant and antibacterial agent and it makes the nanoparticles as an alternative for the development of new biomedical drugs in near future.

Photoluminescence And Plasmon Resonance In Silver Embedded Glass Matrices

Promod Kumar; M. M. Ahmad

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 242-246
DOI: 10.5185/amlett.2015.5634

Nanoscale silver clusters were prepared in a soda-lime glass matrix through the ion-exchange (Ag+ ↔ Na+) method followed by thermal annealing in oxidizing atmosphere. The effects of annealing time and temperature on the plasmonic response and optical properties of silver nanocluster in glass matrices have been investigated by using UV-visible absorption spectroscopy and photoluminescence spectroscopy. The surface plasmon resonance of silver nanoparticles has been observed in annealed samples. The blue shift has been observed as a function of post-annealing time at a constant temperature. Transmission electron micrographs show the presence of spherical nanoparticles with a maximum particle size of 4-5 nm after annealing, which is consistent with Mie theory based results. The nano-sized Ag nanocluster on glass matrix is suitable as future prospective for potential applications in optical data storage.

Effect Of Nanomaterials Sizes On The Dispersion Stability Of Biodiesel Based Nanofluids

D. Srinivas Rao; Raj Kishora Dash

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 247-251
DOI: 10.5185/amlett.2015.5638

The effect average alumina nanoparticle sizes on the long term dispersion stability of biodiesel based nanofluids was investigated. Alumina nanoparticles having two different average sizes (~13nm and ~28nm) were dispersed in the Jatropha biodiesel as the base fluids. The effect of alumina (Al2O3) nanoparticles sizes on the stability of nanofluids was investigated to achieve more stable nanoparticles dispersed nanofluids having longer duration for potential use in alternative fuel energy applications. Different volume fractions (VF) such as 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% nanofluids were prepared by using two different sizes of alumina nanoparticles (~13nm and ~28nm) by using the surfactants Span 80 and Tween 80 in the ratio of 1:1. The results revealed that the nanofluids having the smaller average sizes alumina nanoparticles and 0.1% volume fraction were stable for more than one year as compared to the larger (two times) size nanoparticles having same 0.1% volume fraction. Such long term stable biodiesel based nanofluids can be used as the alternative fuel energy for future automobiles and transportation sectors due to the fuel properties of such nanoparticles dispersed nanofluids retaining the commercial diesel properties.

Effect of processing temperature on the microstructure of Al-7Ti master alloy and on refinement of  α-Al dendrites in Al-7Si alloys 

Virupaxi Auradi; Shivaputrappa Amarappa Kori

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 252-259
DOI: 10.5185/amlett.2015.5646

The present work aims at evaluating the grain refining performance of Al-7Ti master alloys with different microstructures on Al-7Si alloys. Al-7Ti master alloys were prepared in an induction furnace by salt route involving the reactions between K2TiF6 and molten Al. Reaction temperatures chosen for producing Al-7Ti master alloys were 800 o C, 900 o C and 1000 o C while reaction time was kept constant at 60min. These indigenously prepared master alloys at different temperatures were characterized by chemical analysis; particles size analysis, XRD and SEM/EDX microanalysis. Results of particle size analysis suggest that mean size of Al3Ti intermetallic particles in Al-7Ti master alloys were increased from 15.8µm to 22.4 µm as temperature is increased from 800 o C-1000 o C. SEM/EDX studies revealed fine blocky morphology, large blocky and flaky/petal morphologies of Al3Ti intermetallic particles in Al-7Ti master alloys at 800 o C, 900 o C and 1000 o C respectively. Results of grain refinement studies suggest that Al-7Ti master alloy prepared at reaction temperature of 800 o C shows better grain refinement performance on Al-7Si alloy when compared to the Al-7Ti prepared at 900 o C and 1000 o C. In future, the influence of reaction time on microstructural and grain refining behaviour of Al-7Ti master alloys will be evaluated and the performance of these Al-7Ti master alloys will be compared with Al-B and Al-Ti-B master alloys.

Green Synthesis Of Silver Nanoparticles Using Asiatic Pennywort And Bryophyllum Leaves Extract And Their Antimicrobial Activity

Dulen Saikia; Pradip K. Gogoi; Pallabi Phukan; Nilave Bhuyan; Sangeeta Borchetia; Jibon Saikia

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 260-264
DOI: 10.5185/amlett.2015.5655

Silver nanoparticles of average sizes ~18-21 nm in diameter were prepared by a green approach via chemical reduction of silver nitrate (AgNO3) using Asiatic Pennywort and Bryophyllum leaf extracts as reducing and capping agents. The bio-reduced silver nanoparticles were characterized by UV-Vis spectroscopic, XRD and TEM techniques. The characteristic surface plasmon band of colloidal solutions of AgNPs synthesized from Asiatic Pennywort and Bryophyllum leaf extracts were found at 445 nm and 405 nm respectively. The results of XRD and SAED pattern showed that the biosynthesized AgNPs have a crystalline structure with cubic phase (fcc). The antimicrobial activities of the as synthesized AgNPs were investigated against gram negative bacteria Pseudomonas Fluorescens and gram positive bacteria Staphylococcus Epidermidis. It was observed that silver nanoparticles obtained from Asiatic Pennywort was more effective on gram positive bacteria Staphylococcus Epidermidis while AgNPs obtained from Bryophyllum was more effective on gram negative bacteria Pseudomonas Fluorescens indicating size dependent activity of AgNPs.

Soft Chemical Approach For The Synthesis And Characterization Of Aluminium Copper Oxide (CuAl2O4) Nanaopowder

Taimur Athar

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 265-270
DOI: 10.5185/amlett.2015.5659

With the help of facile single source molecular precursor the synthesis of CuAl2O4 nanopowder with well-defined structural framework was carried out via cost-effective soft–chemical approach with two and three coordination state around copper and Aluminum atom respectively. The synthesized nanoparticles were thoroughly characterized by using several physicochemical techniques such as XRD, SEM, TEM, thermal analysis, UV and FT-IR for structural, optical and morphological studies. With the adjustment of reaction parameters allows us for systematic tuning of particle size, shape as well as to control the other functional properties. It can be concluded that self-assembly is an integral part which take place by understanding the metal chemistry during synthetic approach and therefore help to opens a new exciting opportunities for better understanding the reaction conditions, growth and along its mechanistic approach which leads to fabrication of potential nanodevise in near future.

In Situ Polymerization Of The Metal-organic Framework 5 (MOF-5) By The Use Of Maghnite-H+ As A Green Solid Catalyst

Souad Bennabi; Mohammed Belbachir

Advanced Materials Letters, 2015, Volume 6, Issue 3, Pages 271-277
DOI: 10.5185/amlett.2015.5660

Metal-organic framework MOF-5 [Zn4O(BDC)3, BDC : 1,4 benzenedicarboxylic] is a microporous material with a large specific surface area and high porosity formed by benzenedicaroboxylic acid as organic ligand and zinc nitrate hexahydrate as metal ion . This material is mainly used in the field of automobile industry as a container for storing hydrogen (alternative fuel) and for the environmental preservation by trapping CO2 (greenhouse gas emissions). The present study shows the synthesis of this material using a clay called Maghnite-H+ as catalytic support in order to enhance the yield which increases from 35% to 63% and improve the thermal stability of MOF-5. Maghnite-H+ is a montmorillonite sheet silicate clay, exchanged with protons, it is an efficient catalyst for polymerization of many vinylic and heterocyclic monomers. The structure of resulting products is characterized and established by Magic Angle Spinning Nuclear Magnetic Resonance ( 13 C MAS NMR). 27 Al MAS NMR and 29 Si MAS NMR results show that there are interactions between the chains of MOF-5 and the silicate surface or aluminum of Maghnite-H + . Fourier Transform Infrared spectroscopy (FTIR) is also used to confirm the structure of these products showing that there is a complete deprotonation of benzenedicaroboxylic acid. The X-Ray Diffraction (XRD) allows to study the morphology of the obtained compounds and reveals the formation of a partially exfoliated/partially intercalated structure. Thermal stability is studied by Thermogravimetric Analysis (TGA) and shows an enhanced thermal stability for MOF-5/Mag-H + with a gain of 40°C.