Volume 8, Issue 1, January 2017

Advanced Materials Cruise Congress 2017

Ashutosh Tiwari

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 1-1
DOI: 10.5185/amlett.2017.1001

International Association of Advanced Materials (IAAM) is pleased to announce cruise congress in Asia, Europe and America in year 2017 with the collaboration of VBRI Press AB, Sweden. The goal of congresses 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 and technology.

Progress Towards Efficiency of Polymer Solar Cells

R. P. Singh; O. S. Kushwaha

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 2-7
DOI: 10.5185/amlett.2017.7005

Among all renewable sources, solar energy is the crucial zero emission renewable energy and the amount of solar energy impinging upon earth surface in one hour far exceeds the annual global energy demands. Polymer solar cells research exceeds crystalline silicon solar cells due to being inexpensive, light weight and processable into large area flexible devices. Polymer solar cells also possess high potential for power generation applications in comprehensive non-grid and grid modes. Moreover, the broad installment of polymer solar cells across the globe would certainly help to solve the problems associated with pollution, non-renewable resources, global warming and sustainability. Polymer solar cells being at present the hottest field of interdisciplinary research, there has been remarkable outcome in terms of efficiency of single-junction polymer solar cells, tandem solar cells, polymer-polymer solar cells, triple-junction polymer solar cells and solution-processed polymer solar cells.  The present review briefly provides the latest breakthroughs and developments towards the efficiency and commercial aspects of various polymer solar cells.

Annealing Effect On ZnO-NPs Buffer Layer Assembled Organic Solar Cells Synthesized With CuO Nanoparticles

Aruna P. Wanninayake; Benjamin C. Church; Nidal Abu-Zahra

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 8-12
DOI: 10.5185/amlett.2017.6485

Organic solar cells were fabricated with varying amounts of ZnO-NPs in a buffer layer located over an active layer of P3HT/PCBM incorporating a fixed amount of CuO nanoparticles. The buffer layer serves as an electron transporting layer in the device. Thermal annealing treatment was applied to all the devices at different temperatures (150  o C, 200  o C and 250  o C) to optimize the nanoscale morphology. The samples which were annealed at 200  o C exhibited the best power conversion performance. The enhanced morphological and optoelectronic properties attained by applying thermal annealing increased the power conversion efficiency by 14.6% compared to a reference cell. The ZnO-NPs buffer layer improved the exciton dissociation rate, electron mobility, optical absorption and charge collection at the anode, resulting in higher short circuit currents and external quantum efficiencies. The short circuit current (Jsc) of the optimum device was measured at 8.949 mA/cm 2 compared to 7.62 mA/cm 2 in the reference cell before annealing. Meanwhile, the external quantum efficiency (EQE) increased from 61.8% to 62.9%, after thermal annealing.

Preparation And Bactericidal Action Of Biofunctional Polyacrylamide Nanogels

Sadiya Anjum; Shamayita Patra; Bhuvanesh Gupta

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 13-18
DOI: 10.5185/amlett.2017.6562

This study is aimed at the development of nanosilver embedded polyacrylamide (PAAm) bioactive nanogels and antimicrobial behavior of these functional nanogels. Nanogels were synthesized by polymerization of the monomer/silver nitrate as water phase in nanoemulsion using gamma irradiation process where radiation helps in the polymerization, nanogel crosslinking and the reduction of silver nitrate to nanosilver. Homogeneously dispersed nanosilver particles embedded within PAAm nanogel matrix having size in the range of 10-50 nm were achieved depending on the reaction conditions. Minimum inhibitory concentration and bacteriostatic efficacy of nanogels were investigated against bacterial strains of Escherichia coli and Staphylococcus aureus. The bioactive nanogels showed very effective antimicrobial behavior and showed mortality against both bacterial strains at very low concentration. The bactericidal action of functional silver nanoparticles against Escherichia coli was investigated by TEM analysis. It was observed that after treatment with bioactive nanogel, the cell wall of Escherichia coli was completely destroyed and punctured. Here, we propose that the bioactive nanogel by virtue of its hydrophilic and polar functionality is very much suitable for linking to different biomaterials for developing antimicrobial surfaces especially in surgical devices and synthetic implants.

Sintering And Characterization Of A Hydroxya-patite Matrix And Hydroxyapatite Matrix Nano-composites

Nelson H. A. Camargo; Eliakim E. G. de Borba; Priscila F. Franczak; Enori Gemelli

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 19-23
DOI: 10.5185/amlett.2017.6032

Microporous calcium phosphate biomaterials are known for their physical and biological applications. Among the best known are the stoichiometric hydroxyapatite (HA) and tricalcium phosphate (TCP). This is because these biomaterials exhibit chemical and crystallographic compositions which are similar to that found in bones and teeth. The use of nanotechnology enables obtaining calcium phosphate nanostructured powders and calcium phosphate nanocomposite matrix formed by a second nano phase of type SiO2, TiO2, Al2O3-a, ZrO2, Mg. Different methods and techniques for the synthesis and preparation of nanostructured powders and biomaterials are noted in the literature, but it is known that not all lead to the same results. Calcium phosphates nanostructured biomaterials are a new class of biomaterials which provide new physical, morphological, nanostructural and microstructural features with interconnected microporosity which are promising to wettability, capillary action, cell adhesion and proliferation on the surface of grains and micropores. Based on research of these biomaterials, it has been found that they show potential applications in traumatology, orthopedic and dental applications in reconstruction, defects and bone tissue repairing, implants attachment and dental remineralization treatment. This study was aimed at the sintering and characterization of an HA matrix and three nanocomposite biomaterials with 5% by volume of the respective second phases: SiO2, ZrO2 and Al2O3-a in the HA matrix. The HA powder and nanocomposite HA/SiO2 were sintered at 1100 °C/2h. HA/ZrO2 nanocomposite powder followed two sintering conditions: a temperature of 1100 °C/2h and the other, at 1300 ºC/2h. HA/Al2O3-a nanocomposite powder was only sintered at 1300 ºC/2h. The biomaterials were characterized by scanning electron microscopy, X-ray diffraction and open porosity and hydrostatic density were also determined by applying the Arthur method. The results are encouraging and show for HA, HA/SiO2, HA/ZrO2 biomaterials (obtained by sintering at 1100 °C) interconnected microporous microstructures, formed by fine grains which are favorable for the expected wettability and capillarity characteristics.

In Vitro Antibacterial And Anticancer Studies Of ZnO Nanoparticles Prepared By Sugar Fueled Combustion Synthesis

Prashanth Gopala Krishna; Prashanth Paduvarahalli Ananthaswamy; Manoj Gadewar; Utpal Bora; Nagabhushana Bhangi Mutta

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 24-29
DOI: 10.5185/amlett.2017.6424

In this study, we report the antibacterial and anticancer activity of ZnO nanoparticles (NPs) prepared by sugar-fueled solution combustion synthesis. The structure and morphology of the sample were determined by XRD, UV-visible, FESEM and HRTEM. Surface area measurement was carried out by standard Brunauer-Emmett-Teller technique. Antibacterial activity of ZnO NPs was tested against Clostridium perfringens and Salmonella enterica by well diffusion method. The anticancer efficacy of ZnO nanoparticles was carried out on breast cancer cells MCF-7. The antibacterial results affirm that spherical ZnO NPs constitute as a successful bactericidal agent against both Gram-positive and Gram-negative bacteria. Anticancer result indicates that ZnO NPs exert dose dependent toxicity in MCF-7.

Two Step Electrochemical Deposition Of Palladium And Polyaniline On Graphene Dispersed Glassy Carbon electrode For Electrochemical Analysis Of Pesticide

M. Sivaprasad; N. Y. Sreedhar; M. R. Jayapal; Li Yang; Hongwei Ni

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 30-36
DOI: 10.5185/amlett.2017.6912

Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently  polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) and used as an electrochemical sensor for determination of Tetrachlorvinphos (TCP < /span>) pesticide in vegetables. Here most of the work has been focused on the preparation and characterization of modified electrode with cyclic voltammetry (CV) and scanning electron microscopy (SEM). The modified composite electrode unveiled significantly good voltammetric response on TCP. Square wave voltammetry (SWV) was used for determination of TCP at optimized conditions such as square wave frequency, step potential, pH of buffer, applied sample volume, accumulation potential and accumulation time. The well-defined reduction (C=C) peaks were acquired over the potential maximum around at -1.3V in acidic medium in Briton-Robinson (B-R) buffer solution at low current values. The low current peaks were obtained over the concentration of TCP at 1.5×10 -6  M with lower detection limit and limit of quantifications are 5.62×10 -10  M and 2.65×10 -8 respectively. The composite modified electrode showed good stability and reproducibility. The proposed method was successfully applied for the present investigation with a great assure as an economical and simple sensor with furthermore a shorter analysis time and further the sensor also used for heavy metal detection in real samples.

The Influence Of Incorporating Cobalt (Co) And Indium (In) Co-dopants On The Structural And Optical properties Of ZnO Nanoparticles

Mpho W. Maswanganye; Koena E. Rammutla; Thuto E. Mosuang; Bonex W. Mwakikunga; Sone T. Bertrand; Malik Maaza

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 37-41
DOI: 10.5185/amlett.2017.6876

Co and In co-doped nanopowders of ZnO as well as In and Co singly doped ZnO were successfully prepared using sol-gel method. The synthesized samples were characterized using x-ray diffraction (XRD), UV-vis spectroscopy (UV-vis), Raman spectroscopy (RS), Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDS). The effects of In and Co co-doping on the structural and optical properties were investigated. XRD results showed no peaks associated with In 3+ or Co 2+ ions indicating that In 3+ and Co 2+ ions substituted for Zn 2+ ions in the ZnO wurtzite structure, this was corroborated by the EDS results. Doping ZnO nanoparticles with In and Co significantly reduced the grain sizes whereas the lattice parameters were not significantly affected. TEM results confirmed that the nanoparticles were spherically shaped. Raman spectroscopy also confirmed that the ZnO nanoparticles were of a wurtzite hexagonal structure. Single doping reduced the energy band gaps and co-doping reduced them even further.

Chemically Synthesized Ag/PPy-PVA Polymer Nanocomposite Films As Potential EMI Shielding Material In X-band

Jyoti Srivastava; Pawan Kumar Khanna; Priyesh V More; Neha Singh

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 42-48
DOI: 10.5185/amlett.2017.6486

Silver/Polypyrrole/Polyvinylalcohol polymer nanocomposite films were prepared by in-situ polymerization of pyrrole with variable loading of silver nanoparticles from 0.5-10%.  The conducting films prepared from the nanocomposite solution were flexible, light weight, thermally stable and showed high hydrophobicity/hydrophilicity ratio. X-Ray diffraction measurement showed formation of fcc silver nanoparticles with particle size in the range of about 20-40 nm. UV-visible spectroscopy revealed the characteristic bands of Ag nanoparticles and polypyrrole in the so obtained co-polymer nanocomposites. The SEM studies of the nanocomposite films showed that the filler material was well conjugated in the Polymer matrix. Vector Network Analyser showed Electromagnetic shielding efficiency (EMI) efficiency as high as -35 dB in the X band (8-12GHz).

Rapid Adsorption Of Malachite Green Dye Using Eco-friendly Fe (III) - Montmorillonite: Effective Clay Mineral For Dye Effluents Containing Wastewater

M. Vinuth; H. S. Bhojya Naik; M. M. Mahadev Swamy; B.M. Vinoda; R. Viswanath; H. Gururaj

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 49-57
DOI: 10.5185/amlett.2017.6370

Herein we reported the malachite green dye removal by Fe(III)−Mt through adsorption process under ambient conditions. The amount of MG dye removal by Fe(III)–Montmorillonite(Fe(III)–Mt) was estimated from its optical density at lmax = 617 nm using UV-Vis spectrophotometer. The MG dye removal was found to be rapid at basic pH and increased further with temperature up to 50°C. At pH 7 & 8, a complete reduction (100%) was observed within 5 min and 7 min, whereas at pH 4 & 5, it took 10 min &15 min respectively. The time taken for complete reduction at 0°C, RT (30°C) and 50°C were 10, 7 and     5 min respectively. The removal followed by adsorption of dye molecules on the spent clay mineral was evident from FESEM/EDX analysis. More importantly, Fe(III)–Mt could be separated and retrieved easily after the reaction by centrifugation from the degraded MG dye solution. The experimental results of MG dye removal from Fe(III)–Mt follows the pseudo first order kinetics. We believe that Fe(III)–Mt could be the efficient and suitable material to augment the real filed applications. This study provides a new avenue to gain in-depth insight to the applications of Fe(III)–Mt as an effective clay mineral for remediation of dye effluents. Overall Fe(III)–Mt bears the capability for environmental remediation in relation to the dye pollution.

A Bioinspired Bioactive Multi-component Polymerizable Material For Dental Restorative Applications; effects Of Calcium Content On Physico Mechanical Properties

Vibha C; Lizymol P P

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 58-64
DOI: 10.5185/amlett.2017.6343

Novel inorganic-organic hybrid resins [IOHRs] containing mixture of alkoxides of calcium/magnesium/zinc with polymerizable dimethacrylate groups were synthesised using a simple single-pot modified sol-gel method. Objective of the present study is to investigate the impact of calcium content over bioactivity, polymerization shrinkage, and physico mechanical properties of bioactive IOHR containing mixture of alkoxides of calcium/magnesium/zinc having polymerizable methacrylate groups, along with various fillers they can be used as a dental restorative material. Various formulations with varying concentration of inorganic content were used during the synthesis. The concentration of inorganic content was optimised as 0.1% by weight of with respect to the silane.  This optimised formulation based photocured composite [CMZ2] showed better DTS (35-40 MPa), FS (65-70 MPa), VHN (140-146 kg/mm 2 ), possess low shrinkage, non-cytotoxic in nature, bioactive with good cell adhesion and cell proliferation properties. CMZ2 was found to be a potential novel dental composite.

Influence Of Thickness Of Active Layer On The Performance Of CBD Grown Cu-CdS/PbS Hetero-junction

D. Saikia; P. Phukan; M. R. Das

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 65-69
DOI: 10.5185/amlett.2017.6496

Solar cells with the structure ITO-Cu-CdS/PbS-Ag were fabricated by heat-induced Chemical Bath Deposition (CBD) technique. Cu-doped CdS/PVA nanocomposite thin film of thickness 260 nm was used as the window layer. The PbS absorber layer of different thickness (528.3 -1250.8 nm) for different molar concentration of lead nitrate (0.05, 0.1, 0.15, 0.2 and 0.3 M) was then grown on ITO/CdS to fabricate the junction. The effect of molar concentrations on the optical and structural properties of the corresponding PbS films and solar cells were investigated. The optical bandgap of the PbS films was found to decrease with the increase of the molar concentration. The photovoltaic parameters such as short circuit current, open circuit voltage, fill factor and efficiency of the CdS/PbS solar cells were evaluated from the J-V characteristics under one sun illumination intensity (100mW/cm 2 ). The changing molar concentration enhanced the performances of the cells and a highest efficiency (1.38%) obtained at 0.3M molar concentration.

Utilization Of Low-cost Activated Carbon From Rapid Synthesis Of Microwave Pyrolysis For WC Nanoparticles Preparation

Atikah Ali; Rubia Idris

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 70-76
DOI: 10.5185/amlett.2017.6964

In this study, the low-cost activated carbon from pistachio shell waste was sought through experiments using rapid synthesis of microwave-induced pyrolysis. The effect parameters of activating agents and microwave power on the surface area and carbon yield were studied. The results revealed that, well-grown pore structures with the highest surface area (681.2 m 2 g -1 ) and the highest carbon yield (70.3%) were produced using K2CO3 as an activating agent and 600 W power level exposed to 15-minute irradiation. The activated carbon with the highest porosity (AC600) was subsequently utilized in the tungsten carbide (WC) preparation which employed a facile method of mechanical milling. Finally, a high-thermal treatment under inert conditions was performed to completely convert W into WC. The physicochemical properties of the catalyst were evaluated by N2 adsorption-desorption, XRD, FESEM and TEM. It was observed that, the tungsten carbide produced was small and uniform spherical nanoparticles with average diameters of 60 to 100 nm.  High porosity and high surface area of catalyst support were identified as factors leading to a homogeneous distribution of metal catalyst. Therefore, the nanoparticles of WC produced were attributed to activated carbon with high porosity (AC600) due to well distribution of the tungsten crystal phase.

Chemical Networks And Photoluminescence Properties Of Carbon Nanoparticles Derived Via Sol-gel Method

Umesh Rizal; Bhabani S. Swain; Bibhu P. Swain

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 77-81
DOI: 10.5185/amlett.2017.6423

We have synthesized carbon nanoparticles (CNPs) via the sol-gel method using dextrose as carbon source with different concentration of ethanol. The effects of ethanol concentration (0.2 to 2.0 M) on the chemical network, electrochemical and photoluminescence properties of CNPs were examined using Fourier transform infra-red (FTIR) spectroscopy, Raman spectroscopy, cyclic voltammetry and photoluminescence (PL) spectroscopy. Field emission scanning electron microscopy (FESEM) image of CNPs shows CNPs of 40-80 nm were synthesized by sol-gel method. Chemical network study reveals the presence of various bonds such as C-H, C-H2, C-H3 and aromatic carbon present on the surface of the CNPs. Raman spectra shows that increasing of ethanol concentration decreases the crystalline size of CNPs. Cyclic voltammetry analysis shows prominent oxidation peaks at 0.1-0.2 V whereas the reduction peak observed at 0.2 V. The observed room temperature PL peak at 2.9 eV confirms a blue emission from CNPs.

Cu-NiO Nano-composite Formation Through Reactive Milling: Reaction Mechanism

Yasaman Kolvandi; Mohammad Aghagholizadeh; Saeed Sheibani

Advanced Materials Letters, 2017, Volume 8, Issue 1, Pages 82-87
DOI: 10.5185/amlett.2017.6864

In this paper, the possibility of production of Cu matrix nano-composite powder containing 10, 37 and 54 wt.% NiO using mechano-chemical reduction of different copper oxides (CuO and Cu2O) was studied. Structural evolutions were characterized by X-ray diffraction. Also, the microstructure was characterized by scanning electron microscopy and transmission electron microscopy. Particular attention has been paid to the reaction mechanism and kinetics using differential scanning calorimetry. It was found that the reactions completed gradually between 5 to 22h of milling. Formation of Cu2O and Cu(Ni) solid solution, as intermediate phases, were observed during the reaction. It was found that, the initial excess Cu delayed reduction reaction and decreased the final crystallite size up to 18nm. Microstructural results showed that relatively large nano-composite agglomerates powder composed of uniform dispersion of NiO nano-particles in nano-crystalline Cu matrix were obtained. Kinetic study revealed that CuO reduction to Cu through two-steps reaction with lower activation energies in each step had higher rate, compared to one-step reduction of Cu2O.