Volume 9, Issue 1, January 2018

European Advanced Materials Congress (EAMC)

Ashutosh Tiwari

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 1-1
DOI: 10.5185/amlett.2018.1001

International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased to announce European Advanced Materials Congress (EAMC), Sweden in the city of Nobel Prize, Stockholm, Sweden during 20 - 23 August 2018. The purpose of 20th assembly of advanced materials congress series is to bring together innovative academics and industrial professionals to a common forum for scientific and technological exchange on the imminent advances in the advanced materials and technology.

Graphene-metal oxide nanocomposites for supercapacitors: A perspective review

Vardhaman V. Khedekar; Shaikh Mohammed Zaeem; Santanu Das

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 2-19
DOI: 10.5185/amlett.2018.1932

Graphene-Metal oxide nanocomposites have been extensively investigated due to their potential applications in the fields of energy devices, including, solar cells, fuel cells, batteries, sensors, electro-catalysis, and photo-catalysis. Among them, several researches have been performed on supercapacitors, which could be best used with devices that require high current for short duration of time. Here, in this article, we present a brief review on the recent advances on the graphene-metal oxide nanocomposites for supercapacitor technologies and the future perspective of this field of research. A wide range of graphene-metal oxide synthesis techniques have been discussed with a focus on the advancement of nanocomposites with controlled features, including, particle size, morphologies, surface structures, pore size, pore-distributions, etc. Specifically, various nanocomposites and their role in supercapacitor electrodes are discussed with their explicit electrochemical charge-storage mechanisms along with charge-transfer techniques. Furthermore, this analysis demonstrates current trends and future directions in research on graphene-metal oxide nanocomposite electrodes for the performance enhancement in next-generation supercapacitor devices.

On the deformation behavior of bi-metal via digital image correlation

Yuliya Li; Svetlana Barannikova; Lev Zuev

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 20-24
DOI: 10.5185/amlett.2018.7069

The aim of this contribution was to study the localization of the plastic deformation of bi-metal based on a low-carbon steel A 283 Grade C and austenitic stainless steel 301 AISI. The images of the localized zone plastic deformation upon the uniaxial tension have been obtained with using digital image correlation method (DIC). The stress-strain curves are found to show all the plastic flow stages: yield plateau, linear and parabolic work hardening stages and the prefracture stage would occur for the respective values of the exponent from the Ludwik-Holomon equation. The main parameters of plastic flow localization at various stages of the deformation hardening have been determined in bi-metal.

Highly hydrophilic copolymer based PES hollow fibre ultrafiltration membranes 

James Antony Prince; Sowrirajalu Bhuvana; Vanangamudi Anbharasi; K.V. Kamelia Boodhoo; Gurdev Singh

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 25-30
DOI: 10.5185/amlett.2018.1656

Bio-fouling is a major issue in all membrane-based water treatment systems and there are several cleaning methods available to address this problem. Current membrane modification methods are focused on improving the hydrophilicity of membranes by blending hydrophilic additives or blending antibacterial compounds with the dope solution. In this study, we demonstrate a new method to impart bio-fouling resistance to a membrane surface by developing a water-insoluble unique copolymer additive, namely poly (acrylonitrile co maleic acid co di-amino maleio-nitrile) (PANCMACDAMN) with highly hydrophilic carboxylic and amine functional groups. Hydrophilic polyethylene glycol functionalized with silver (Ag) was grafted to the copolymer backbone to further improve the hydrophilicity. The final additive PEG-Ag attached PANCMACDAMN was used to modify polyethersulfone (PES) ultrafiltration (UF) membrane. Characterization tests indicate that the innovative surface chemistry increases the hydrophilicity of the membrane by reducing the water contact angle (CAw) by 78.1% and increases its permeability by 120% compared to the control membrane. More importantly, the innovative surface chemistry prevents protein attachment and exhibits inhibition to microbes even after 720 min of continuous protein solution filtration.

Biocompatible features of magnetic nano-oxide core/ PCL shell 3D composites fabricated via SLS/M process 

Igor Shishkovsky; Stanislav Volchkov; Vladimir Scherbakov; Larisa Volova

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 31-35
DOI: 10.5185/amlett.2018.1676

Superparamagnetic oxide nanoparticles attract increasing attention in biomedical applications for tagging, imaging, separation and/or purification of cancer cells in living tissue. At the present study the selective laser sintering/melting (SLS/M) process using the Nd +3 YAG laser was carried out to fabricate and characterize polymer composites based on nano-oxides of FexOy type or of high-temperature superconductivity (HTS) of SrFe12O19 with bioresorbable polycaprolactone (PCL) powders and manufacture porous tissue engineering scaffolds. Practicability of the method for synthesis of functional-gradient three dimensional (3D) parts with magnetic nano-oxide particles and structural ordering were shown and appropriated laser regimes were assigned. The stem cellular morphometry, proliferative and adhesive activity to the 3D magnetic nanocomposites were compared. The medical tests show that all the 3D printed composites have biocompatible features. Medical potential of the SLS/M-fabricated superparamagnetic nano oxides for application as cell targeting systems and tissue engineering scaffolds is being discussed.

Rod-shaped copper (Cu, Cu2O) nano catalyst for the facile oxidation of methanol

Kalawati Saini; Pravin P. Ingole; Smriti Sharma Bhatia; Nutan Rani

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 36-41
DOI: 10.5185/amlett.2018.1714

Copper and copper oxide (Cu2O) nanoparticles (NPs) were synthesized by electrochemical route using 2.55 mM tri-sodium citrate (TSC) as a capping and reducing agent. Synthesis was conducted at 15 V and 373 K in the presence of pH 4.22 using a copper rod as a working electrode and a platinum wire as a reference electrode. The electrochemical set-up was kept in the air, as well as under inert nitrogen-purged conditions. Cu NPs were synthesized for the first time by the direct dissolution of Cu 2+ into the solution of the capping agent from the copper electrode in to the electrochemical cell. This means salt of copper was not used. NPs were characterized using UV–visible absorption spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. High-resolution TEM pictures showed the formation of a rod-shaped nanostructure. The lengths of copper rods were from 56.9 nm to 61.9 nm and the widths of nano-rods were, from 8.11 nm to 9.57 nm. Furthermore, the rod-shaped Cu2O NPs were tested for their catalytic applications in the electro-oxidation of methanol, where they showed excellent activity in terms of higher efficiency as well as kinetically low over-potential values.

Nanoengineered plasma polymer films for biomedical applications

Krasimir Vasilev; Melanie Ramiasa-MacGregor

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 42-52
DOI: 10.5185/amlett.2018.1691

This forward looking concise review describes recent advances in the field of nanoengineered plasma polymer films. These types of coatings are relevant in many fields of application and have gained substantial research and technological interest over the last decade. The review starts with an introduction of plasma polymerization as a technique for preparation for nanometer thin polymer-like coatings. This is followed by the examples of the use of nanoengineered plasma polymer coatings in applications relevant to biomedical devices. Applications in antibacterial coatings and drug delivery vehicles are discussed. Significant section of this paper is dedicated to cell guidance surfaces which have an extensive range of applications ranging from coatings for medical devices to research tools that can help unraveling complex biological questions and vehicles for the growing field of cell therapies. The vision of the authors about the future directions of the field have also been presented, including a section on novel oxazoline based coatings that carry great promise for advances in the biomaterial and biomedical fields.

Synthesis and characterization of stearic acid capped silver nanoparticles: pH dependent stabilization and colorimetric detection of Hg(II) in water

Nityananda Agasti; Narender K. Kaushik

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 53-57
DOI: 10.5185/amlett.2018.1756

This work reports, synthesis of Ag nanoparticles in aqueous medium, under ambient reaction conditions using stearic acid as capping agent. Ag nanoparticles have been used for colorimetric detection of Hg 2+ in water. Effect of pH of the medium on size and stabilization of silver nanoparticles has been studied. Synthesized by chemical reduction of AgNO3 using NaBH4, Ag nanoparticles were characterised by UV-visible spectroscopy, transmission electron microscopy (TEM), FTIR spectroscopy and TGA techniques. Quenching of intensity along with blue shift of SPR band of Ag nanoparticles is observed due to deposition of Hg layer over Ag nanoparticles. Change in colour of Ag nanoparticles from dark yellow to colourless led to naked eye detection of Hg 2+ in water. The detection limit of Hg 2+ in water was found up to 1ppm monitored by colorimetric response of Ag nanoparticles by UV-visible spectrophotometer. A simple and cost-effective process allows quick determination of Hg 2+ in water.

Optical and electrical properties of graphene oxide and reduced graphene oxide films deposited onto glass and Ecoflex® substrates towards organic solar cells

Agnieszka Iwan; Felipe Caballero-Briones; Krzysztof A. Bogdanowicz; José D. O. Barceinas-Sánchez; Wojciech Przybyl; Adam Januszko; Javier A. Baron-Miranda; Ana P. Espinosa-Ramirez; Jesus Guerrero-Contreras

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 58-65
DOI: 10.5185/amlett.2018.1870

Graphene oxide (GO) was synthesized using modified Hummers method. GO films were deposited by doctor blade onto glass slides and Ecoflex® membranes using GO suspensions, or dip-coated onto molecular functionalized glass substrates. Doctor bladed films were studied by optical transmittance, linear sweep voltammetry and by thermal imaging under applied potential. Dip coated films were reduced with different chemical agents to produce transparent, conductive, reduced graphene oxide (rGO) films that were characterized by optical transmittance, current sensing atomic force microscopy and X-ray photoelectron spectroscopy. Doctor bladed GO films were mechanically stable, with resistances ranging 10 6 to 10 11 ohm depending on the film thickness, which in turn depended on the GO precursor solution concentration. Thermal imaging did not provided evidence of visible voltage-activated conduction. The best reduction treatment to obtain transparent and conductive rGO films comprised a primary reduction with NaBH4 followed by an air annealing at 120 ºC. Conductive atomic force microscopy indicated that rGO film conductivity is governed by the superposition of individual sheet and X-ray photoelectron spectroscopy suggested that the C/O ratio is not determinant for conduction. The better-reduced films had transmittances ca. 85% with sheet resistances around 10 3 ohm/sq, making them feasible as transparent electrodes. Finally, a short discussion about location of GO/rGO in organic solar cells is presented.

Particle-filled polymer derived ceramic coatings on titanium alloy Ti-6Al-4V

Iryna Smokovych; Michael Scheffler

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 66-70
DOI: 10.5185/amlett.2018.1919

Thermodynamic analysis was carried out to predict the phase composition of polysilazane-type polymer derived ceramic coatings on a Ti-6Al-4V titanium alloy by calculating the most probable chemical reactions between the constituents and expected crystalline phases. The feasibility of polysilazane derived coatings on Ti-6Al-4V was proved experimentally. The coatings based on amorphous SiON and SiO2 and a free Si, which oxidized to SiO2 during high-temperature exposure, enhance the oxidation resistance of Ti-6Al-4V alloy at 800 °C in air up to eight times compared to an uncoated alloy.

Inherent species characteristic influence and growth performance assessment for mycelium composite applications

Mitchell Jones; Tien Huynh; Sabu John

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 71-80
DOI: 10.5185/amlett.2018.1977

Composite materials produced using mycelial growth attract commercial and academic interest due to their economic, environmentally sustainable and green manufacturing process. However, their manufacture via slow biological growth affects the larger scale production viability of these materials, which must compete with rapidly producible synthetic materials. Hyphal characteristics vary significantly by species, which is the most influential growth performance factor in conjunction with environmental conditions and chemical nutrition. This study assessed the effect of potential growth predictors such as hyphal type, pathogenicity, taxonomic and association based classification systems on hyphal extension rate and growth density for commonly used and non-traditional species. It provides a simple, low-cost process for screening species by growth performance prior to more application-dependent mechanical evaluation. This facilitates more efficient and accurate species selection for composite manufacturing applications. Trimitic and dimitic species containing skeletal hyphae exhibited higher hyphal extension rates than species containing generative-binding or purely generative hyphae but no other parameters investigated in this study were good predictors for growth performance with significant species-specific variation present instead. However, the methodology used to test growth performance did prove effective and could be used on a case by case basis for growth screening in mycelium composite applications.

The influence of the edge characteristics of detected objects on underwater active electrolocation system

Yingli Wang; Jiegang Peng; Lu Liu

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 81-85
DOI: 10.5185/amlett.2018.7111

The active electrolocation technology has been developed for near 60 years and played a significant role in the field of biomimetic sensor. But the influence of the edge characteristics of detected objects on underwater active electrolocation system was rarely investigated. In this paper, an experiment system based on the underwater active electrolocation technology is built. The amplitude information-frequency characteristics (AIFC) for different probed objects with the different edge characteristic and approximate volumes are investigated. Two sets of different edge characteristic shapes (cylinder and cuboid, cone and pyramid), whose volumes are little difference in each sets, are carried out in the same materials to deeply study on the effect. The height variation curve (HVC) is employed to compute the frequency inflection point (FIP) of AIFC for the system. According to experiment results, we find that the FIP for the probed metallic objects with similar volumes is weighty associated to the edge characteristics of objects, while the FIP for the plastic has nothing to do with the edge characteristics of objects. It may have reference value for physical mechanism of weakly electrical fish active electrolocation system.

Thermal plasma spheroidization of Nb-16Si powder alloy obtained by mechanical alloying

Nikolay G. Razumov; Anatoly A. Popovich; Andrey V. Samokhin; Aleksei V. Grigoriev

Advanced Materials Letters, 2018, Volume 9, Issue 1, Pages 86-90
DOI: 10.5185/amlett.2018.7073

Spherical Nb-Si powder alloy is a perspective material to manufacture products for the aerospace industry by additive technologies. Nb-16Si (at.%) powder alloy was prepared by mechanical alloying from pure elemental powders using planetary ball mill Fritsch Pulverisette 4. Spheroidization was carried out on plasma generator based on thermal plasma arc generator with vortex discharge stabilization. Experimental results show that plasma spheroidizing of Nb-16Si powders obtained by mechanical alloying is possible. It is shown that after the spheroidization the particle surface is rough which indicates the cast structure of the material. Three phases having different optical contrast are revealed on microsections: Nb5Si3, Nb3Si and Nbss, which is confirmed by X-ray diffraction. It is shown that the main peaks in the X-ray graph after MA correspond to a solid solution of niobium with a cubic lattice and the parameter a = 0.333 nm, as well as niobium silicide Nb5Si3 with a hexagonal lattice (P63/m) a = 0.7536 nm and c = 0.5249 nm. After spheroidization the hexagonal lattice of niobium silicide Nb5Si3 is transformed into a tetragonal lattice (I4/m) with the parameter a = 0.6557 nm and c = 1.186 nm. The other phase components remain unchanged.