Volume 7, Issue 12, December 2016

Advanced Materials Series, Wiley-scrivener

Ashutosh Tiwari

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 945-945
DOI: 10.5185/amlett.2016.12001

The Advanced Materials Series (AM series) published by Wiley-Scrivener Publishing, USA has comprised about 30 volumes till 2016. This series intends to provide recent advancements of the fascinating field of advanced materials science and technology, particularly in the area of structure, synthesis and processing, characterization, advanced-state properties and applications. The volumes cover theoretical and experimental approaches of molecular device materials, biomimetic materials, hybrid-type composite materials, functionalized polymers, supramolecular systems, information- and energy-transfer materials, bio based and biodegradable or environmental friendly materials. Each volume is devoted to one broad subject and the multi-disciplinary aspects are drawn out in full. Each volume is comprehensive and represents the cutting edge of science. They are written for a broad readership including researchers and students from diverse backgrounds including chemistry, physics, materials science & engineering, medical science, pharmacy, biotechnology and biomedical engineering.  

Neodymium Doped ZrO2-graphene Oxide Nanocomposites: A Promising Photocatalyst For Photodegradation Of Eosin Y Dye

M. Mzoughi; William. W. Anku; Samuel O. B. Oppong; Sudheesh K. Shukla; Eric S. Agorku; Penny P. Govender

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 946-950
DOI: 10.5185/amlett.2016.6497

Purification of industrial wastewater from dyes receiving increasing attentions. The aim of the present manuscript was to fabricate graphene based nanocomposites using a homogeneous and facile approach. Co-precipitation method was used to synthesize zirconium oxide (ZrO2) and neodymium doped ZrO2-graphene oxide (Nd-ZrO2-GO) nanocomposites with varying weight percent concentrations of neodymium to investigate the increasing photocatalytic activity. The Nd-ZrO2-GO catalysts were characterized using X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (SEM), and ultra violet-visible (UV-vis)-spectroscopy to evaluate their optical, morphological and structural properties respectively. The photocatalytic degradation potential of the nanocatalyst was assessed by the degradation of Eosin Y dye in aqueous solution under simulated solar light irradiation. The Nd-ZrO2-GO was observed to have higher photocatalytic degradation potential than the bare ZrO2. The most efficient photocatalyst for the degradation of Eosin Y dye was 0.3 % Nd-ZrO2-GO with about 80 % efficiency within 180 min and a Ka value of 4.19 x 10 -3 . Nd-ZrO2-GO catalyst would be considered as efficient photocatalyst to degrade the industrial dyes (Eosin Y) avoiding the dreary filtration steps.

Nano-textured Pb (Zr0.52Ti0.48)O3/ZnO Hetero-structure On Silicon Substrate   

Govind N. Sharma; Shankar Dutta; Ratnamala Chatterjee; Sushil Kumar Singh

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 951-956
DOI: 10.5185/amlett.2016.6509

Metal oxide based hetero-structures (like Pb (ZrxTi1-x) O3 – ZnO) can be used for wide variety of future sensors and electronic devices. This paper presents growth and electrical properties of nano-textured (110) Pb (Zr0.52Ti0.48) O3/ (001) ZnO hetrostructure on oxidized silicon substrate by RF sputtering technique. The grain sizes of ZnO and PZT films are found to be around 30 nm and 80 nm respectively. Resistivity of the ZnO layer is found to be 1x10 9 ?-cm. The electrical properties of the film are studied by creating in-plane electrodes on top of the PZT/ZnO hetrostructure film. The remnant polarization of the film is found ~ 47 µC/ cm 2 at 200 kV/ cm 2 . Dielectric constant of the film is found to be 300 at 1 kHz. The film also showed a low leakage current density of ~ 10 -5 A/cm 2 at 200 kV/ cm applied electric field. The nano-textured (110) Pb (Zr0.52Ti0.48) O3/ (100) ZnO hetrostructure integrated with inter-digital-transducers and microelectronic is well suitable for low-cost, robust, programmable passive micro sensors for military structure and systems such as aircraft, missiles.

Synthesis And Characterization Of Ge Nanocrystals Embedded In High-k Dielectric (HfO2) Matrix

V. Saikiran; N. Manikanthababu; N. Srinivasa Rao; S. V. S. Nageswara Rao; A. P. Pathak

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 957-963
DOI: 10.5185/amlett.2016.6403

Trilayered HfO2/Ge/HfO2 thin films were grown on Si substrate by RF magnetron sputtering with HfO2 and Ge targets. The subsequent rapid thermal annealing (RTA) of these films at 700 & 800°C results in formation of Ge nanocrystals (NCs) in HfO2 matrix. X-ray diffraction (XRD) and micro-Raman spectroscopy measurements were performed to confirm the formation of Ge NCs in the annealed samples. XRD results indicate that the as-deposited samples show amorphous behaviour, whereas the annealed samples clearly confirm the crystallinity of the films. The average size of the Ge NCs was found to increase with an increase in annealing temperature. Raman scattering studies confirm that the annealed samples exhibit a shift in peak position corresponding to Ge-Ge optical phonon vibrations, which clearly indicates the formation of Ge NCs. Conversely, as-deposited samples were also irradiated with swift heavy ions of 150 MeV Au and 80 MeV Ni at a fluence of 3×10 13 ions/cm 2 to synthesize Ge NCs. The structural properties of pristine and irradiated samples have been studied by using X-ray diffraction, Raman spectroscopy to substantiate the growth of Ge NCs upon irradiation. The results obtained by RTA are compared with the irradiated ones.

Heat Capacity, Magnetic And Lattice Dynamic Properties Of Pseudo-two Dimensional: M2Fe2O(AsO4)2 [M=K, K0.79Cs0.21 and Rb] Compounds

Pramod Kumar; Rashmi Singh; L. D. Sanjeewa; Rachana Kumar

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 964-970
DOI: 10.5185/amlett.2016.6450

In this paper, structural, magnetic and heat capacity of M2Fe2O(AsO4)2 compounds have been reported. Most interestingly, the magnetization at very low fields  a complete negative magnetization was observed in both field cooling and zero field cooling in K2Fe2O(AsO4)2 and Rb2Fe2O(AsO4)2 compounds whereas field cooled is positive in KCsFe2O(AsO4)2. A possible mechanism for the observed peculiar magnetic behavior is discussed, related to the competition of the single-ion magnetic anisotropy and the antisymmetric magnetization behavior in two crystallographically different FeO6 centers. We estimated the gap (D)  opening at low temperature K2Fe2O (AsO4)2 KCs2Fe2O (AsO4)2 and Rb2Fe2O (AsO4)2, are 23.6 K, 23.9 K and 25 K respectively from heat capacity. Magnetic part of heat capacity at low temperatures follows the T 3 dependence, indicates that the low temperature magnetic state in all these compounds are antiferromagnetic.

Effect Of Annealing Conditions On The Struct-optical Properties Of ZnFe1.96La0.04O4 Nanoparticles

R. Tholkappiyan; Fathalla Hamed; K. Vishista

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 971-978
DOI: 10.5185/amlett.2016.6387

Lanthanum (La3+) ion doped zinc ferrite nanoparticles were synthesized by combustion method using glycine as fuel. The as-synthesized ZnFe1.96La0.04O4 nanoparticles were subjected to annealing temperature of 900 oC for time intervals of 2 h, 6 h, 12 h, 24 h and 48 h. The as-synthesized and annealed ZnFe1.96La0.04O4 nanoparticles were characterized as a single phase with normal spinel structure. The surface morphology of these nanoparticles were found to be non–uniform and agglomerated with fine pores/voids. The induced strain and dislocation density were reduced with increasing annealing time which enhanced crystallinity and increased grain size. The values of optical band gap calculated from UV/Vis/NIR spectra of the as-synthesized and annealed ZnFe1.96La0.04O4  nanoparticles were found to decrease with increasing annealing time. They range from 2.48 to 2.19 eV from the simple method and 2.42–2.12 eV for direct and 1.87–1.71 eV for indirect from Kubelka–Munk function method. The optical band gap in ZnFe1.96La0.04O4  nanoparticles can be tuned as function of varying annealing time and it seems to correlate with induced strains in the nano-crystallites. Therefore, the tuning of optical band gap with just changing the heating treatment of ZnFe1.96La0.04O4  nanoparticles may make them suitable photocatalysis.

Preparation And Characterization Of Poly (vinylalcohol) / Bentonite Hydrogels For Potential Wound Dressings

Jimena S. Gonzalez; Alejandra Ponce; Vera A. Alvarez

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 979-985
DOI: 10.5185/amlett.2016.6888

During the last decade researchers have been working to find effective wound dressing materials. The materials have to be designed to hold moisture in the surface of the wound, providing the ideal environment for cleaning the wound, absorbing the exudates, eliminating the odour and promoting the healing process. In this scenario, hydrogels emerge as excellent options for that. However, due to poor mechanical and antimicrobial properties of many conventional hydrogels, composite hydrogels are now designed in order to improve mechanical stiffness and durability. For this purpose, nanocomposite based on poly(vinyl alcohol) (PVOH) and different concentration of bentonite (0-7 wt.%) were obtained by the freezing-thawing technique and characterized by means of morphological, physical, thermal, mechanical, barrier and antimicrobial properties. Herein it was developed a non-expensive, eco-friendly and a facile method to obtain nanocomposite hydrogels based on PVOH with reasonable mechanical properties (Young Modulus of 0.5-0.8 MPa), good microbial barrier properties, adequate water vapour transmission rates and excellent swelling behaviour (195-336%). Moreover, it was found that the porous sizes of the samples can be controlled by the addition of the clay. All obtained results indicate that the PVOH/ 3% bentonite hydrogels show potential to be used as wound healing.

Cassia Fistula Seed Gum-graft - Poly(acrylamide): An Efficient Adsorbent For Reactive Blue H5G Dye

Vandana Singh; Tulika Malviya; Sneha Joshi; Angela Singh; Devendra N. Tripathi

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 986-995
DOI: 10.5185/amlett.2016.6390

Poly(acrylamide) has been efficiently grafted onto Cassia fistula seed gum using ceric ammonium sulphate/sodium disulphite redox system. The conditions for obtaining optimum % grafting (208 %) and % efficiency (92 %) are: acrylamide = 0.16 M, ceric ammonium sulphate = 0.026 M, sodium disulphite = 0.050 M, Cassia fistula seed gum = 25 mL (0.4 % (w/v)), and temperature = 40 ± 0.2 ºC. Cassia fistula-graft-poly(acrylamide) (CF-g-PAM) was characterized using FTIR and SEM studies. CF-g-PAM could very efficiently capture “Reactive Blue (RBH5G)” dye from its aqueous solution. The copolymer did not dissolve even under highly acidic pH conditions and was able to remove 99.4 % dye from 100 mg L -1 dye solution under the optimized conditions (pH= 2, rpm = 150, adsorbent dose = 30 mg, temperature = 40 ºC, and contact time = 4 h). The adsorption equilibrium data are better explained by Freundlich isotherm, which indicated the presence of heterogeneous adsorption surface sites at CF-g-PAM. Langmuir adsorption isotherm, indicated significantly high Qmax (500 mg g -1 ) for the adsorption. The dye adsorption followed a pseudo second order kinetics (k’ = 5.3 x 10 -3 g. mg -1 min -1 ), indicating chemisorption of the dye is taking place. The kinetic study also supported the intervention of some boundary layer control. The results revealed that ceric ammonium sulphate/and sodium disulphite redox system is an efficient system for grafting poly(acrylamide) onto Cassia fistula seed gum and CF-g-PAM behaved as an efficacious adsorbent for Reactive Blue H5G dye. In future, the material may be explored for the adsorption of other anionic azo dyes and may be developed as the proficient dye adsorbent.

Zeolite 4A Filled Poly (3, 4-ethylenedioxythiophene): (polystyrenesulfonate) (PEDOT: PSS) And Polyvinyl Alcohol (PVA) Blend Nanocomposites As High-k Dielectric Materials For Embedded Capacitor Applications

M. K. Mohanapriya; Kalim Deshmukh; M. Basheer Ahamed; K. Chidambaram; S. K. Khadheer Pasha

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 996-1002
DOI: 10.5185/amlett.2016.6555

Zeolite 4A nanoparticles were incorporated into Poly (3, 4 - ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS) and Polyvinyl alcohol (PVA) blend matrix to prepare PEDOT: PSS/PVA/Zeolite 4A nanocomposites using solution casting technique. The structure and morphology of nanocomposites were examined using Fourier transform infrared spectroscopy, X-ray diffraction, UV-Vis spectroscopy and Scanning electron microscopy. The mechanical and dielectric properties of nanocomposites were also evaluated. The FTIR and XRD results indicate the strong interaction between the Zeolite 4A nanoparticles and the polymer matrix. The SEM micrographs show the homogeneous dispersion of Zeolite 4A into the polymer matrix. The nanocomposite exhibits a high dielectric constant and low dielectric loss, which could be due to proper dispersion and good interaction between Zeolite 4 A and polymer matrix. Thus, based on the results obtained it can be concluded that PEDOT: PSS/PVA/Zeolite 4A nanocomposites can be used as a flexible dielectric material for embedded capacitor applications.

An Electrochemical Perspective Assay For Anticancer Activity Of Calotropis Procera Against Glioblastoma Cell Line (LN-18) Using Carbon Nanotubes- Graphene Nano- Conglomerate As A Podium

Seetharamaiah Nalini; Seetharamaiah Nandini; Gurukar Shivappa Suresh; Jose Savio Melo; Shivayogeeswar E. Neelagund; Hunasepalya Nagaiah Naveen Kumar; Jakkid Sanetuntikul; Sangaraju Shanmugam

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1003-1009
DOI: 10.5185/amlett.2016.6395

In this article, we report the pre-screening of anti-cancer effect of Calotropis procera against glioblastoma cell lines (LN-18) by means of electrochemical methods. Soxhlet assisted extraction (SAE) has been employed to extract the polyphenol contents present in the leaf of Calotropis procera. The phytochemical analysis of the extract has been studied and the polyphenol contents were determined using Folin Ciocalteau method. To study the anticancer effects of the aqueous plant extract, a cytosensor (Gr/NT-G/LN-18) was fabricated and its possible mechanism for DNA binding was studied using graphite/ poly(allylamine hydrochloride)/nanotube-graphene composite /polypyrrole /de-oxy ribonucleic acid (Gr/PAH/NT-G/PPy/DNA) modified electrode. The electrochemical characteristics of the proposed Gr/NT-G/LN-18 cytosensor towards the plant extract were evaluated using electrochemical techniques like cyclic voltammetry and differential pulse voltammetry. Scanning electron microscopy (SEM) and energy dispersive analysis of x-ray (EDAX) have been employed to study the physical characterization of the Gr/PAH/NT-G/PPy/DNA modified electrode. These results indicate that the plant extract has an ability to act as an antiglioblastoma against LN-18 cancer cells.

Phycofabrication Of Silver Nanoparticles And Their Antibacterial Activity Against Human Pathogens

Harsha Pinjarkar; Swapnil Gaikwad; Avinash P. Ingle; Aniket Gade; Mahendra Rai

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1010-1014
DOI: 10.5185/amlett.2016.6269

In the present study, the extracellular phycofabrication (synthesis by algae) of silver nanoparticles was demonstrated using algae i.e. Spirogyra sp. recovered from the fresh water. The reduction of silver ions present in the aqueous solution of silver sulphate (Ag2SO4) was done by the cell filtrate of Spirogyra sp. leading to the synthesis of silver nanoparticles. Phycofabrication of silver nanoparticles was confirmed by using characterization tools like UV-Vis spectrophotometer, FTIR, TEM and NTA. The resulting silver nanoparticles were spherical in shape, in the range of 40-80 nm and capped with proteins. Through the experimental studies, it was found that temperature, pH and salt concentration affects the rate of phycofabrication of silver nanoparticles. Antibacterial study of phycofabricated silver nanoparticles was assessed against human pathogenic bacteria. These silver nanoparticles showed better antibacterial activity against gram positive bacteria i.e. Staphylococcus aureus (ATCC-25923) (13 mm) as compared to Gram negative bacteria i.e. Escherichia coli JM-103 (ATCC-39403) (11 mm). This is the first report of synthesis of silver nanoparticles by Spirogyra sp < /em>. using Ag2SO4 as a salt. Extracellular phycofabrication of silver nanoparticles by Spirogyra sp. was found be easy, simple and eco-friendly method.

Study Of A-site Divalent Doping On Multiferroic Properties Of BFO Nanoparticles Processed Via Combustion Method

Baljinder Kaur; Lakhbir Singh; V. Annapu Reddy; Dae-Yong Jeong; Navneet Dabra; Jasbir S. Hundal

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1015-1020
DOI: 10.5185/amlett.2016.6457

Pure and Sr?doped bismuth ferrite Bi1-xSrx FeO3 (x = 0, 0.1, 0.2, 0.3) nanoparticles have been synthesized using combustion method. X- Ray diffraction study of these compounds confirms the rhombohedral structure with R3c space group. BiFeO3 peaks were observed at 2θ = 22.46o, 31.80o, 32.11o, 39.519o, 45.79o, 51.35o, 56.98o and 57.16o having miller indices as (012), (104), (110), (202), (024), (116), (214) respectively. The traces of secondary phase also appear along with desired phase of Sr?doped bismuth ferrite Bi1-xSrxFeO3 samples. The scanning electron microscopy of fractured pellets of the samples reveals the decrease in grain size with increase of Sr doping in Bi1-xSrxFeO3. Magnetic studies were carried out at room temperature up to a field of 10 kOe. M-H hysteresis loops showed a significant increase in magnetization with Sr substitution in BiFeO3. Compared to weak magnetisation with magnetizing field (M-H) shown by BiFeO3 nanoparticles (Remnant magnetization, Mr ~ 0.4x10-3 emu/g and coercive field, Hc ~ 0.065 kOe respectively), a significant enhancement in M-H loop was observed in Bi1-xSrx FeO3 compounds. The value of Mr ~ 0.525 emu/g and Hc ~ 3.70 kOe have been found to be maximum for x = 0.30 in Bi1-xSrx FeO3 compounds. Leakage current studies showed decrease in leakage current density of doped samples to that of pure BiFeO3 and x = 0.10 gives minimum value of 4.78 x 10-6 A/cm2 at 350 V/cm. The ferroelectric nature was confirmed by observed P-E loops in all the samples.

Silver Nanoparticles Prepared From Herbal Extract Of Terminalia Bellerica For Selective Detection Of Mercury Ions

Alagan Jeevika; Raj Sarika; Dhesingh Ravi Shankaran

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1021-1028
DOI: 10.5185/amlett.2016.6426

In this work, we have investigated the uses of herbal extract of Terminalia bellerica (T.bellerica) as an efficient reducing as well as capping agent for reliable green synthesis of silver nanoparticles (AgNPs) at room temperature. HR-TEM results of AgNPs confirmed that, the nanoparticles are spherical in shape with an average diameter of ~30 ± 6 nm.  XRD shows that, AgNPs exhibits the face centered cubic (FCC) structure. AgNPs utilized as a nanosensor probe for detection of mercury ions (Hg 2+ ). AgNPs showed a color change from brownish yellow to colorless on exposed to Hg 2+ due to the redox reaction of mercury and silver. This sensor probe showed a lower limit of detection of 0.3 ± 0.005 µM. Selectivity of the sensor has been evaluated towards other environmentally heavy metal ions and found that, this sensor is highly selective to Hg 2+ . AgNPs loaded poly (vinylalcohol) (PVA) films and nanofibers were fabricated by solvent casting and electrospinning methods, respectively. AgNPs loaded PVA films and nanofibers were tested for anti-bacterial studies against E. coli and B. subtils. The results indicate that the green synthesized AgNPs possess high microbial activity towards E.coli. These AgNPs based functional materials have great potential for application in sensors, anti-microbial coatings, wound dressing and smart textiles.

Optical, Electrical And Antimicrobial Studies Of Chemically Synthesized Graphite Oxide And Reduced Graphene Oxide

Alpana Thakur; Sunil Kumar; Manjula Sharma; V. S. Rangra

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1029-1034
DOI: 10.5185/amlett.2016.6810

Graphite oxide (GO) and reduced graphene oxide (RGO) have been synthesized using chemical methods. Prepared graphite oxide and reduced graphene oxide were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. XRD patterns, Raman spectra and FTIR spectroscopy confirms significant structural changes while reducing GO to RGO. The obtained products were further analyzed for their optical and electrical properties using UV-Vis spectroscopy, photoluminescence spectroscopy and four-point probe. RGO has shown excellent electrical conductivity of 1.363×10 4 S/m. The bactericidal action of prepared GO and RGO was also studied against Escherichia coli and Staphylococcus aureus bacteria.

Polypyrrole-Pt Nanocomposites As Electrochemical Glucose Sensor

Nitin R. Dighore; Suresh T. Gaikwad; Anjali S. Rajbhoj

Advanced Materials Letters, 2016, Volume 7, Issue 12, Pages 1035-1039
DOI: 10.5185/amlett.2016.6561

A voltammetric sensor was developed for detection of glucose by using cyclic voltammetry (CV). The sensing platform was Polypyrrole-Pt nanocomposites on Platinum electrode (PPy-Pt-PtE). PPy-Pt was synthesized by chemical method, using FeCl3 oxidant. XRD, SEM and TEM results showed that PPy doped with Pt were highly porous, nanocrystalline composites. The PPy-Pt-PtE modified electrode observed reversible behavior with ferricyanide system which had about 2.05 times more surface area and exhibited higher currents for glucose oxidation compared to bare PtE. Glucose was sensed in the range of 100mM to 1000 mM from the linear regression plotted R 2 = 0.990 and R 2 = 0.994 the sensitivity was found to be 0.047 mA/mM~cm 2 and 0.0445 mA/mM~cm 2 . These results indicate that PPy-Pt-PtE exhibited good platform and could be used for voltammetric determination of glucose.