Volume 8, Issue 10, October 2017


Adhesive & Binder Conference

Ashutosh Tiwari

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 944-944
DOI: 10.5185/amlett.2017/10001

International Association of Advanced Materials (IAAM) is pleased to announce Adhesive & Binder Conference 2018, Singapore with collaboration of VBRI Press AB, Sweden. The conference is dedicated on the adhesive & binder and its applications and other related materials such as natural products; made from agricultural sources. The world-class technology is found in many of construction systems, including tile adhesives, grouts, mortars, leveling compounds, sealing materials and waterproofing solutions. 

Structure formation of hot pressed Al2O3 powders under the alternating electric current: experimental observations

Edwin Gevorkyan; Sergiy Lavrynenko; Miroslaw Rucki

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 945-949
DOI: 10.5185/amlett.2017.1718

The paper presents the results of investigations on hot pressure sintering under the alternating current. The powders of different grain sizes were used for the sintering to investigate the impact of the powder on the final sintered structure and relative density. The additional experiments were focused on the kinetics of the Al2O3 nanopowders sintering. They confirmed that the time of the process duration is dependent on the temperature and the applied pressure. However, compared to the powders of tungsten monocarbide, it depends on the temperature rise speed in rather small degree. Discussion of the results pointed out that the obtained data, both theoretical and experimental one, confirmed possibility that during the sintering process the dislocations might appear and spread. It seemed reasonable to assume that in the low voltage regime the activated sliding with diffusion accommodation prevails, while in the high voltage regime the dislocation creep does.

Microstructure and densification behavior of liquid phase sintered Fe-Cu alloy powder using cold and hot compaction techniques

Ahmed E. Nassef; A. I. Alateyah; Medhat A. El-Hadek; W. H. El-Garaihy

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 950-957
DOI: 10.5185/amlett.2017.1472

The physical and mechanical properties of atomized prealloyed Fe-Cu powders, blended with different amounts of liquid additions of lead (Pb), were studied in the as-sintered condition and hot compaction techniques. The influence of Pb content, compacting pressure and temperature on the densification, hardness, and the mechanical properties were investigated. During hot compaction, at a temperature of 500 ° C, the Pb liquid was found to spread uniformly among Fe-Cu solid particles. The effect of pores in Fe-Cu-Pb alloys, generated by sintering with transient liquid phase, had been studied. An attempt was made in order to study the properties of Fe-Cu-Pb particles and their behaviour, with respect to the consolidation of Fe-Cu-Pb powders. The density values of cold and hot compacts, at various pressures and temperatures values, were reported. The microstructure, hardness, and strength measurements were found to be dependent upon the compacting pressure. For the cold compacted alloys, the Pb powder particles were completely melted to form liquid pools. In addition, increasing the Pb content in the alloy matrix revealed a decrease of the pores percentage, hence the sample became denser. On the other hand, grain was found to be coarser and less porosity is obtained with increasing the Pb content in the hot compacted. It is found that, increasing the compacting pressure of the cold and hot compacted samples revealed a homogenous, fine grain, and small pores appeared around the grain boundaries. The mechanical properties data showed improvement in the strength and hardness of the hot and cold compacted samples by increasing either the compaction pressure or temperature. 

Structural, electronic and magnetic investigations on PLD based La2Ni1-xFexMnO6 disordered thin films

Pravin M. Tirmali; Sagar M. Mane; Snehal L. Kadam; Shrinivas B. Kulkarni

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 958-964
DOI: 10.5185/amlett.2017.1518

The double perovskite materials show the magnetic semiconductor, magneto-optic and magneto-capacitance like interesting properties. It is predicted that the B-site substitution in this system may results in interesting properties. La2Ni1-xFexMnO6 thin films are deposited on Pt/Ti/ Si(100) substrate  by Pulse Laser Deposition (PLD) technique. The films were uniform, fine grain and stoichiometric deposited at very low O2 pressure. The XRD of La2Ni1-xFexMnO6 thin films exhibits rhombohedral (R-3) phase. The peak broadening appears in Raman spectra at antistretching (518 cm -1 ) and stretching (656 cm -1 ) modes with presence of overtone modes at 1308 cm -1 in La2Ni1-xFexMnO6 thin film samples. XPS analysis reveals the presence of La 3+ , NiO, Ni 3+ , Fe 3+ , Mn 3+ and oxygen vacancies in samples. The Ni 3+ and Mn 3+ antiferromagnetic coupling is responsible for decrease in saturation magnetization Ms from 4.78 to 2.74 µB/f.u as Fe substitution increases from 0.1 to 0.3 at 5K. The increase in grain size, peak broadening and decrease in magnetization of La2Ni1-xFexMnO6thin film samples suggest presence of antisite defects and antisite phase boundary. The present work will helpful to study the effect of B site substitution on La2NiMnO6 thin films structural, electronic and magnetic properties in order to make it suitable candidate for potential applications. 

Synthesis and growth studies of barium titanates: 0−D and 1−D nanostructures using hydrogen titanate precursor

Mohini Mishra; Raju Kumar Gupta

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 965-970
DOI: 10.5185/amlett.2017.1566

The present work demonstrates a simple and efficient route to synthesize a variety of barium titanate (BaTiO3) nanostructures including nanowires, nanoswords, nanostars, nanocubes, and nanoparticles by a facile hydrothermal approach. The experiments showed that different morphologies can easily be tuned by varying the concentration of precursors, i.e., hydrogen titanate (H2Ti3O7) and barium hydroxide octahydrate (Ba(OH)2.8H2O), while keeping the molar ratio, reaction temperature and time fixed. The structure and morphology of BaTiO3 were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results indicate that BaTiO3 nanowires are in cubic phase with an average diameter of 80-100 nm. The shape of BaTiO3 changes from nanowires to nanoparticles with an increase in Ba(OH)2.8H2O concentration from 0.08 M to 0.51 M. Two possible mechanisms, in-situ topotactic transformation reaction and dissolution-deposition reaction have been suggested for different morphologies of BaTiO3.  The synthesized 0-D and 1-D BaTiO3 nanostructures are promising materials for many applications because of their excellent dielectric, ferroelectric and piezoelectric properties. The present work will open a new route to single reaction parameter dependent synthesis of 0- and 1-D BaTiO3 nanostructures which can find a range of applications including electronics, catalysis, energy harvesting, etc.

Surface-enhanced Raman scattering from copper nanoparticles treated furanoflavonoid karanjin

Prahlad K. Baruah; Anuma Singh; Iffat Jahan; Latha Rangan; Aditya N. Panda; Ashwini K. Sharma; Alika Khare

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 971-976
DOI: 10.5185/amlett.2017.1612

The effect of concentration of copper (Cu) nanoparticles (NPs) on surface enhanced Raman scattering (SERS) in furanoflavonoid karanjin is reported in this paper. Cu NPs were synthesized by pulsed laser ablation of Cu target immersed in distilled water (DW). The absorption spectrum of colloidal solution of Cu NPs displayed a broad peak around ~625 nm corresponding to the surface plasmon resonance (SPR) oscillations. Transmission electron microscope (TEM) images confirmed the formation of nearly spherical Cu NPs having average size of ~12-13 nm. The solution of furanoflavonoid karanjin dissolved in dimethyl sulphoxide (DMSO) was treated with the synthesized NPs and subjected to micro-Raman spectrophotometer for the SERS studies as a function of concentration of Cu NPs. Raman signal of Cu NP treated karanjin was observed to be ten times more as compared to that of untreated one for the most intense C=O stretching band of flavone ring. This corresponds to an enhancement factor of the order of 10 2 and was observed at the optimum concentration of ~0.08 mg/mL of Cu NPs.

Effective chemical treatment for high efficiency graphene/Si Schottky junction solar cells with a graphene back-contact structure

Ahmed Suhail; Genhua Pan; Kamrul Islam; David Jenkins; Angela Milne

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 977-982
DOI: 10.5185/amlett.2017.1569

We demonstrate a high-efficiency graphene/Si Schottky junction solar cell with an easy to fabricate graphene back-contact structure and effective chemical treatments. This device effectively overcame the current challenges associated with reported graphene/Si Schottky solar cell structures. The short-circuit current density for such a device is increased by around 20% due to the increase of the active area of this device, compared to previous graphene/Si Schottky junction solar cell devices. The undesirable s-shaped kink in J-V curves, as found in previous works, have been eliminated by using Formamide treatment for 30 min prior to an annealing process in the forming gas. The fill factor of this device is improved by 40% after this treatment, due to the effective removal of the unwanted PMMA residue. Moreover, volatile oxidant vapour and anti-reflection coating are applied within the fabrication process for this device to further improve solar cell performance. An efficiency of 9.5% has successfully been achieved for the fabricated device using the fabrication techniques developed in this work. Our device presents a viable and achievable approach to preparing low-cost and high-performance graphene/Si Schottky junction solar cells.

Research of plastic and wood raw wastes recovery

Peter Kri

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 983-986
DOI: 10.5185/amlett.2017.1587

The main aim of this paper is to present the research findings regarding the recovery possibilities of plastic and wood raw wastes. One of the recovery possibilities for mentioned raw materials is production of waste raw materials based wood-plastic composites (WPC). Lonely production process is influenced by technological and raw material parameters (type of raw material and particle size) and thus the final quality and mechanical properties of WPCs have to be determine. This paper also presents the results of realized experimental research which dealt with the determination of relationship between material parameters and mechanical properties during production of WPCs. The main goal of presented paper is to determine the mutual interaction between mechanical properties, type of the plastic matrix used in WPC, wood/plastic concentration ratio and particle size of wood sawdust used in WPC. In this paper the authors also comparing mechanical properties of WPCs based on recycled and original plastics. As a plastic matrix 100 % original HDPE and recycled HDPE originating from lids of PET bottles was used. Obtained research findings can be very helpful at WPCs production and shown the possibility of using also waste raw materials for WPC products, and thus increase the environmental responsibility with the environment protection.

Removal of brilliant green dye from waste water using zinc peroxide-charcoal composite

Sneha Chawla; Himani Uppal; Mohit Yadav; Dinesh Singh; Nahar Singh

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 987-992
DOI: 10.5185/amlett.2017.1597

The present work has been envisaged to develop an efficient process for adsorptive decontamination of Brilliant green (BG) dye from waste water at room temperature. In recent past, various natural as well as advanced materials and composites have been reported to remove dyes from water. But these materials have certain limitations like time consumption, lower adsorption capacity and residual toxicity etc. To overcome these limitations, zinc peroxide-charcoal composite (ZnO2-C) has been synthesized by wet chemical route. The proposed composite efficiently decontaminates BG from waste water within 25 minute in wide pH range (2-9). The spectral and microscopic studies have been done for ZnO2-C composite before and after adsorption of BG to know the adsorption behavior of proposed material. Various parameters like pH, adsorbent dose, contact time and dye concentration were optimized by the batch sorption experiment to determine maximum adsorption capacity of ZnO2-C. The adsorption capacity of the composite was found to be 156.1 mg g -1 which is better than several other adsorbents cited in literature in recent past. The experimental adsorption data follows second order kinetics and Freundlich adsorption isotherm.

Strength recovery of concrete exposed to freezing-thawing by self-healing of cementitious materials using synthetic fiber 

Heesup Choi; Masumi Inoue; Risa Sengoku; Hyeonggil Choi

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 993-998
DOI: 10.5185/amlett.2017.1635

In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol (PVA) fibers with polar OH - groups, as well as improved self-healing for cracks that are larger than 0.1 mm in width, posing concerns of CO2 gas and Cl - penetration, were observed. Also, CO3 2- reacts with Ca 2+ in the concrete crack, resulting in the precipitation of a carbonate compound, CaCO3. Based on this, it is deemed possible for the recovery of effective water tightness and strength recovery through effective freezing-thawing resistance to be made from cracks that are larger than 0.1 mm in width. In addition, it was determined that, as for the most suitable self-healing conditions in the inside and surface of the cracks, calcium hydroxide (Ca(OH)2) solution with CO2 micro-bubble was more effective in promoting the self-healing capability than water with CO2 micro-bubble. 

Enhanced gettering of gold at end-of-range defects in high energy ion implanted silicon

Satyabrata Mohapatra

Advanced Materials Letters, 2017, Volume 8, Issue 10, Pages 999-1003
DOI: 10.5185/amlett.2017.1648

We report on the gettering behavior of Au at end-of-range (EOR) defects in float-zone grown Si(111), implanted with 1.5 MeV Au 2+ ions at room temperature. The effects of implantation dose and annealing temperature on the thermal evolution of gettering behavior of EOR defects have been investigated using Rutherford backscattering spectrometry, while the microstructural evolution of Au implanted Si(111) has been studied using cross-sectional transmission electron microscopy combined with high resolution transmission electron microscopy. The gettering efficiency of EOR defects, comprising of dislocation loops, has been found to increase with increase in implantation dose up to 1.2 x 10 15 ions cm -2 , beyond which it was found to saturate at about 5 x 10 14 atoms cm -2 for annealing at 850 o C. We have observed that the gettering efficiency of the EOR defects for Au increased with increase in annealing temperature and reached 9 x 10 14 atoms cm -2 for annealing at 950 o C. The observed enhanced gettering efficiency of EOR defects is very promising for gettering applications in Si devices.