Volume 7, Issue 7, July 2016

Asian Advanced Materials Congress (ASAMC -2017), Singapore

Ashutosh Tiwari

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 501-501
DOI: 10.5185/amlett.2016.7001

VBRI Press is pleased to announce ‘Asian Advanced Materials Congress (ASAMC - 2017), Singapore during 11 – 16 March 2017, Singapore. It is a six-day international event organised by International Association of Advanced Materials (IAAM) in collaboration with the VBRI Press AB, Sweden. The congress will be held on the Diamond Princess Cruise Ship < /em> cruising from Singapore - Kuala Lumpur (Malayasia) - Penang (Malaysia) - Phuket (Thailand) - Singapore. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research and activities in the field of advanced materials and technology. 

Dendrimers As Smart Materials For Developing The Various Applications In The Field Of Biomedical Sciences

Sachin B Undre; Shivani R. Pandya; Vinod Kumar; Man Singh

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 502-516
DOI: 10.5185/amlett.2016.6153

Developing new smart materials and tracking their structural potential have been in focus for curing disease and other applications such as catalyzing biomolecules like proteins and selective bioremediation of toxic metals, dyes, pesticides have been thrust areas of research in the field of materials and biomaterials sciences. Since materials are most important need of the society which develops somewhere food, drug, fuel, protective cover, defense materials, fire resistant and acoustic mechanism, UV sensitive, UV absorbing, solar radiation trapping activities. In this context, the dendrimers have been considered as ideal and smart materials to be applied for wider applications and directly, indirectly or catalyze modulator and many others. Thus, the dendrimers act as smart materials and the synthesis of such architectural and potential molecules is being considered as a new thrust area for multitasking materials with better activities to catalyze chemical and biochemical processes. The multifunctional materials of multipurpose uses with several dendrimeric branching, having innumerable binding sites and are in high demands for their drug binding, loading potential and bio coatings.

Defect Analysis And Performance Evaluation Of P-type Epitaxial GaAs Layer On Ge Substrate For GaAs/Ge Based Advanced Device

Goutam Kumar Dalapati; Vignesh Suresh; Sandipan Chakraborty; Chandreswar Mahata; Yi Ren; Thirumaleshawara Bhat; Sudhiranjan Tripathy; Taeyoon Lee; Lakshmi Kanta Bera; Dongzhi Chi

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 517-524
DOI: 10.5185/amlett.2016.6439

The structural defects and formation of native oxides during thermal treatment on p-type epitaxial-GaAs/Ge have been investigated using spectroscopic measurements and electrical characterization. The performance of epi-GaAs based device depends on the interface quality between epi-GaAs and gate oxide and structural quality of the epi-GaAs layer. P-type epitaxial-GaAs was grown on Ge substrate using MOCVD technique at 675oC. Defective surface native oxides of arsenic and gallium oxides are observed for as-grown epi-GaAs layer. The arsenic oxide significantly reduced after thermal treatment as seen from XPS observations. The structural defects at surface enhanced after thermal treatment which is clearly probed by micro-Raman spectroscopy. Atomic layer deposited (ALD) Al2O3 significantly improved the interface properties after thermal treatment compared with bare epi-GaAs layer. Even though, the interface trap defect density slightly higher for p-type epi-GaAs MOS capacitor compared with bulk p-type GaAs devices, high frequency-dispersion in epi-GaAs based devices observed. This is mainly governs through the formation of p-i-n junction diode in the epi-GaAs layer on Ge substrates.

Effect Of Substrate On The Structural And Electrical Properties Of Mo Thin Films 

M. K. Thakur; H. K. Singh;V. N. Singh; Om Pal Singh; Karuna Thakur; Rahul Parmar; Kuldeep Singh Gour; N. Muhunthan; Sandeep Singh; Dinesh Singh; N. Vijayan

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 525-528
DOI: 10.5185/amlett.2016.5965

To be used as back contact for CZTS/CIGS thin film solar cell, good adhesion to the substrate and low resistivity of the Mo thin film is necessary. In this study, molybdenum thin film has been deposited on soda lime glass, sapphire, quartz, and a single crystal yttria-stabilized zirconia (YSZ) using DC magnetron sputtering at 400°C. The structural, electrical, surface morphology and adhesion test using scotch tape test were carried out. Films deposited on all the substrates passed the adhesion test. Lattice parameter of films deposited on various substrates was almost same, but the strain % was different. The size of grain in the film deposited on soda lime glass and YSZ single crystals were larger compared to films deposited on quartz and sapphire. In the case of SLG, Na helped in the grain growth and in the case of YSZ, the crystalline nature of YSZ helped in grain growth. Resistivity result indicated films having pure metallic behavior. The resistivity for sample deposited on YSZ single crystal was very low. AFM study showed that the film made on soda lime glass is having higher surface roughness than other substrates and it was lowest for samples deposited on YSZ single crystal. The cross-sectional TEM study of Mo thin film deposited on glass showed columnar structure of the film.  

Effect Of Tb3+ Ions On The ZnO Nanoparticles Synthesized By Chemical Bath Deposition Method 

Lehlohonolo F. Koao; Birhanu F. Dejene; Hendrik C. Swart; Setumo V. Motloung; Tshwafo E. Motaung; Shanganyane P. Hlangothi

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 529-535
DOI: 10.5185/amlett.2016.6128

Tb3 + doped ZnO nanoparticles were synthesized using the chemical bath deposition (CBD) method at 80 ºC. All the samples were annealed at 700 ºC to remove the hydroxyl groups confirmed by the thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA). The thermal analysis, structure, morphology and optical properties were characterized. The TGA and DTGA showed that the final yield decreases with an increase in the amount of molar concentration of Tb3 + ions. The X-ray diffraction (XRD) spectra of the ZnO: Tb3 + nanoparticles correspond to the various planes of hexagonal ZnO phase for the lower and higher Tb concentration samples. The estimated average grain sizes calculated using the XRD spectra were found to be in the order of 44 ±2 nm. The grain size was found to increase with an increase in the amount of Tb3+ ions. Scanning electron microscopy (SEM) micrographs showed nanoparticles are obtained for undoped ZnO and emergence of pyramids shape for higher molar concentration of Tb3 + ions. The reflectance spectra depict a red shift with an increase in Tb3 + molar concentration. Photoluminescence (PL) results showed that the luminescence intensity increased with an increase in the amount of Tb3 + ions.

Facile Room Temperature Ion Exchange Synthesis Of H+ Doped KM0.33Te1.67O6 (M = Al, Cr And Fe) And Their Photocatalytic And Conductivity Studies

Ravinder Guje; G.Ravi;M. Vithal; J.R. Reddy; Ch. Sudhakar Reddy; K. Sreenu; G.Ravi and M. Vithal

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 536-541
DOI: 10.5185/amlett.2016.6073

Materials belonging to defect pyrochlore structure have been the subject of considerable interest and expected to exhibit fast protonic conduction. The proton exchanged ternary metal oxides of composition HM0.33Te1.67O6 (M = Al, Cr and Fe) are prepared for the first time by ion exchange method at room temperature. These materials are characterized by X-ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and solid state NMR techniques. All the materials are crystallized in a cubic lattice with the Fd - 3m space group. Photocatalytic activity against methyl violet (MV) degradation under visible light irradiation is studied. The mechanistic degradation pathway of MV is studied by a fluorescence technique using terepthalic acid (TA) as a probe and Tertiary butanol (TB) as hydroxyl radical quencher. The dc conductivity of all three compositions is studied in the temperature range 300 – 673 K. The variation of dc conductivity with temperature is explained.

Characterization Of Material’s Defects After Electrical Discharge Machining And Research Into Their Technological Parameters Using Vibroacoutstic Diagnostics

Anna Okunkova; Sergey V. Fedorov;Mikhail Kozochkin; Pavel Peretyagin; Anton Seleznyov

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 542-548
DOI: 10.5185/amlett.2016.6144

The electrical discharge machining is still one of the widest spread machining methods for manufacturing the parts from ceramics, nanoceramics, composites, nanocomposites and other high strength materials based on ceramic or metallic matrix. The defect after electrical discharge machining is often accompanied by processing. In this work, the characterization of the defects in the material was studied. The description of the assets’ development for the process of diagnostics and the main effects of the technological parameters via the method of vibroacoustic diagnostics is provided. Among the most widespread on-line diagnostic methods for technological processes in modern production, vibrodiagnostics is one of the most preferable methods in the case of working area optic access absence. The results of the project, received by experimental implementation of the research, allow extending significantly the present knowledge about physical processes of the material disruption under the influence of the electrical current pulses and permit to develop the common technological recommendations to apply the developed diagnostic and measuring means and techniques in the conditions of the real manufacturing. The application of the results will increase reliability and safety of operation and maintenance of technological systems and will improve the quality of the responsible parts, produced by EDM method.

Study Of Ball Milled Bismuth Telluride Composites Reinforced With MWCNTs For Thermoelectric behaviour

Sandeep K. Pundir; Sukhvir Singh; B. Sivaiah; Rajesh Kumar; Ajay Dhar

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 549-554
DOI: 10.5185/amlett.2016.6112

Thermoelectric properties of n-type bismuth telluride and its nanocomposite reinforced with different concentration of multi wall carbon nanotubes (MWCNTs) are reported. Nanocomposites of bismuth telluride with MWCNTs were synthesized by using high energy ball milling followed by spark plasma sintering (SPS). MWCNTs reinforced nanocomposites of bismuth telluride resulted improvement in its figure of merit ZT from 0.76 (for Bi2Te3) to 0.85 (for Bi2Te3 + 2%MWCNTs) at 473K temperature. Thermoelectric parameters of nanocomposites of Bi2Te3 were characterized by Laser Flash Technique. The improvements found in ZT value may be due to decrease in thermal conductivity of the nanocomposites. Concentration of MWCNTs in bismuth telluride leads to dampening the phonon propagation with addition to the interface scattering of phonons from phase boundaries as well as grain boundaries which leads to decrease in thermal conductivity.

Impedimetric And Voltammetry Sensing Of Xanthine Using Nanocomposites

Jagriti Narang; Nitesh Malhotra; Chaitali Singhal; C. S. Pundir

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 555-560
DOI: 10.5185/amlett.2016.6163

An electrochemical biosensor based on xanthine oxidase (XOx), titanium dioxide nanoparticles and carboxylated multi-walled carbon nanotubes (TiO2/c-MWCNT) nano-composites for sensitive detection of xanthine has been developed. TiO2/MWCNT nano-composites were used as the sensing platform in order to immobilize XOx and magnify the sensor response. FTO electrode was employed to amplify electrochemical signal in the buffer solution. Detailed morphological, electrochemical, structural and optical characterization of XOx/TiO2-NPs/c-MWCNT/FTO electrode was done using XRD, DLS, SEM, EIS, CV and shows quick response time (within 30s), linearity as 0.5- 500 µM, lower detection value of 0.05 micromolar with signal: noise ratio of 3, excellent reproducibility, high selectivity and shelf life of about 8 weeks under refrigerated conditions. The developed biosensor was further used to determine the xanthine levels in the labeo fish samples obtained from market. The accuracy of the developed biosensor was cross-checked by the customary enzymic colorimetric method (99% correlation). Thus, the existing research confirms the development of a highly sensitive, stable and a reliable bio-sensing method to detect the freshness of fish samples.

Synthesis And Doping Feasibility Of Composite-hydroxide-mediated Approach For The Cu1-xZnxO Nanomaterials

Tauseef Shahid; Muhammad Arfan; Waqas Ahmad; Tayyaba BiBi; Taj Muhammad Khan

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 561-566
DOI: 10.5185/amlett.2016.6384

In this article, we report feasibility of composite hydroxide-mediated (CHM) approach for the synthesis and doping of Cu1-xZnxO (x=0%, 3%, 6% and 9%) nanomaterial. The proposed method offers a low cost, low temperature and environmentally friendly approach to preparing doped nanomaterials in a feasible and cost- effective route. Further, we investigate the effect of incorporated Zn +2 on the properties of produced Cu (II) O nanostructures. The X-ray diffraction analysis confirms formation of the single-phase monoclinic Cu (II) O and incorporation of Zn at the Cu-lattice sites. The crystalline structure is improved and the average grain size has increased from 85.32 nm to 124.86 nm. FTIR spectroscopy shows characteristic vibrational peaks of the Cu (II)-O bonding which confirms formation of the Cu (II) O. SEM micrographs reveal interesting flower like dense features with morphological peculiarities and seems to strongly depend on the content of the incorporated Zn +2 . The UV- visible spectra are measured to study the direct bandgap of the prepared nanomaterial. The direct bandgap found to be in the range of 3.73 - 3.89 eV. The method seems experimentally friendly and provides a feasible and a high productive fast synthesis route for the doped oxide nanomaterials in a single step with tunable properties for the research purposes. However, the method still requires further investigation to finely control doping for the desired properties of a nanomaterial and to give a potential avenue for further practical scale-up of the production process and applications of novel devices based on doped nanostructures.

Microstructural And Dielectric Investigations Of Vanadium Substituted Barium Titanate Ceramics

Aditya Jain; Neelam Maikhuri; Rakesh Saroha; Mukul Pastor; A. K. Jha; A. K. Panwar

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 567-572
DOI: 10.5185/amlett.2016.6172

In this investigation, the microstructural and dielectric properties of pure BaTiO3 and vanadium (V 5+ ) substituted on Ba 2+ site (A-site) and Ti 4+ site (B-site) in BaTiO3 ceramic have been studied. The three compositions of BaTiO3 (BT), Ba0.9V0.1TiO3 (BTA) and BaTi0.9V0.1O3 (BTB) were synthesized using solid-state reaction route. The XRD analysis of all three compositions has been carried out at room temperature and proper phase formation for BT, BTA and BTB are confirmed. However, compositions BTA and BTB indicate the presence of secondary phases, and it may be due to higher amount of vanadium substitution at A and B sites. Addition of vanadium inhibited the grain growth of BaTiO3 ceramic. Vanadium substitution on A- and B-site have resulted in decrease of Curie temperature as well as dielectric loss compared to pure BT. A more diffused behavior is observed in vanadium substituted samples as compare to pure BT which shows a sharp transition and lower value of diffuseness parameter. Impedance study shows that substitution of vanadium on A- as well as B-site results in decrease of AC conductivity. These properties of vanadium substituted samples can be utilized to reduce the dielectric loss in capacitors and in radio frequency applications.

Synthesis, Characterization And Mercury (II)  removal Using Poly(vinylacetate) Grafted Guar Gum

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 573-578
DOI: 10.5185/amlett.2016.6006

Guar gum-graft-poly(vinylacetate) (GG-g-PVA) has been synthesized and evaluated for Hg(II) removal from synthetic Hg(II) solution. The optimum performance GG-g-PVA sample (G1) was synthesized using 0.25 g guar gum, 1.0 × 10 -2 M K2S2O8, 2.3 × 10-2 M ascorbic acid, 0.46 M vinyl acetate (VA), total reaction volume 25 mL, grafting time 1 h, and reaction temperature 35±0.5 °C. G1 has been extensively characterized using FTIR, SEM, TGA, and DSC studies. pH drift experiments have shown that G1 has pHzpc of 2.8 and it was most efficient in removing Hg(II) at pH 6. The kinetic studies indicated that the removal involved chemisorption in the rate determining step and the sorption equilibrium was attained in 4 h. High Qmax (100 mg g -1 ) of the copolymer indicated its suitability as a versatile and sustainable adsorbent for exceptionally high mercury recovery.

Chromium (VI) Ions Adsorption Onto Barium Hexaferrite Magnetic Nano-adsorbent

Aida Mohammadi; Abolghasem Ataie; Saeed Sheibani

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 579-586
DOI: 10.5185/amlett.2016.6394

Barium hexaferrite (BaFe12O19) magnetic nano-powder was prepared by co-precipitation method. The effectiveness of different chemical synthesis variables such as solvent and mechanical milling on the adsorption efficiency of barium hexaferrite nano-particles to remove Cr (VI) ions from aqueous solutions was examined. Structural, magnetic, and adsorption properties of the powders are investigated by different techniques. X-ray diffraction analysis revealed that barium hexaferrite formed at a relatively low temperature of 700?C in the sample prepared with a mixture of water/alcohol as a solvent. The FESEM and VSM studies confirmed that all samples had a plate like structure with a particle size in the range of 87-145 nm and high magnetic properties. It was demonstrated that nanometer barium hexaferrite was produced to be an operative adsorbent for removal of Cr (VI) ions from solutions. Different Cr (VI) adsorption experiments were carried out by controlling effective adsorption factors. It was revealed that the sample calcined at a temperature of 700°C and then milled for 5 h (owing themaximum surface area 13 m2/g) showed the highest removal efficiency of 99.5% at pH 3.0, amount of nano adsorbent 1.5 g, initial chromium concentration 133 mg/l, and contact time 1 h. FTIR analysis showed that due to the existence of Cr-O stretching band on the surface of nano-particles, the electrostatic reaction between Cr (VI) ions and nano-adsorbent is possible. The adsorption data were best fitted with the pseudo-second-order kinetic model. Also, the equilibrium adsorption capacity of Cr (VI) calculated from adsorption experiments was found to be 13.25 mg/g. Adsorption studies indicated that the potential use of barium hexaferrite nano-adsorbents for the removal of the other heavy metal ions without sacrificing adsorption capacity can be practical.

Synergistic Effect Of Water Soluble Chitin And Iodide Ion On The Corrosion Inhibition Of Mild Steel in Acid Medium

Yesodaran Sangeetha; Sankaran Meenakshi; Chandrasekaran Sairam Sundaram

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 587-592
DOI: 10.5185/amlett.2016.6318

The inhibition performance of water soluble chitin (WSC) and its synergistic inhibition with potassium iodide (KI) in 1 M HCl was studied using gravimetric and electrochemical measurements. From gravimetric measurement it is inferred that there is an increase in inhibition efficiency with the increased addition of inhibitor and it further stepped up to a higher value in the presence of 0.1 % KI. Polarization studies revealed that there is mixed mode of inhibition by WSC. Impedance study suggested the adsorption of the inhibitor at the interface between mild steel and acidic solution. The adsorption of inhibitor followed Frumkin isotherm. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) confirmed the co- adsorption of KI with WSC on the mild steel surface. Fourier Transform Infra-red (FTIR), Atomic Force Microscopy (AFM) and X- ray Diffraction (XRD) indicated the formation of protective film by the inhibitor on the surface of mild steel.

Impedance Measurements Of Some Silver Ferro-phosphate Glasses 

Fathy Salman; Reda Khalil;Hany Hazaa

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 593-598
DOI: 10.5185/amlett.2016.6175

Impedance measurements of (50-x)P < sub>2O5-xAgI-40Ag2O-10Fe2O3, [where x = 0, 15, 20, 25, 30, 35, 40 and 45 mol %] superionic glasses have been studied in the frequency range (500 Hz - 5 MHz) and in the temperature range 303-413 K. The frequency dependence of the total conductivity (σt) for the investigated samples was carried out at different ambient temperatures. The temperature dependence of ac conductivity σac(ω) and dc conductivity (σdc) were studied, where Arrhenius behavior has been observed for all the samples glass, and the corresponding activation energies ΔEac and ΔEdc, respectively have been obtained. The bulk conductivity (σb) of the samples has been carried out at different temperatures, from impedance plots, where the activation energy ΔEb can be obtained. From the frequency dependence of the ac conductivity of the investigated samples, σac(ω)=Aωs, the frequency exponent s and the maximum barrier height Wm have been deduced at different compositions. The results are interpreted in terms of the correlated barrier hopping (CBH), Funke, and Minami models.