Volume 8, Issue 8, August 2017

Green Materials & Technology Conference 

Ashutosh Tiwari

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 819-819
DOI: 10.5185/amlett.2017/8001

International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased to announce Green Materials & Technology Conference 2018, Singapore with collaboration of VBRI Press AB, Sweden (www.vbripress.com). The conference aims to provide a forum to promote scientific exchanges in the field of green materials and technology including fundamental understandings, synthesis, characterisations and technological developments, discuss the most recent innovations and to foster global networks and collaborative ties between leading international researchers across various disciplines from engineering, physics, chemistry, biology, medicine, material science and biotechnology.

Flexible solid-state Ge – LiCoO2 battery: From materials to device application

Eliana M. F. Vieira; Joao F. Ribeiro; Rui Sousa; Anabela G. Rolo; Manuela M. Silva; Luis M. Goncalves

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 820-829
DOI: 10.5185/amlett.2017.1429

Design and fabrication of reliable materials with high capacity, cycling stability and good adhesion properties for flexible microbatteries remains a challenge. A 2 µm thick flexible solid-state Ge-LiCoO2 battery was fabricated and the structure, composition, thermal, optical, electrical, and electrochemical properties of the materials that determine and influence its electrochemical potential were investigated. RF-sputtered lithium cobalt oxide (LiCoO2) cathode and lithium phosphorus oxynitride (LiPON) electrolyte films were fabricated at 120 W and 100 W of power, respectively. A ~ 300 nm thick Ge anode was deposited by e-beam. The full-battery was fabricated using conventional and low-cost PVD processes. X-ray diffraction (XRD) and Raman spectroscopy confirms the hexagonal R͞3m phase of annealed LiCoO2. Differential scanning calorimetry (DSC) technique was applied to investigate the thermal behaviour of the LiPON film with a moderate electrical resistivity of 10 8 Ωcm and high optical transmission (> 75%) in the UV-Visible range. Bending experiments were also performed to evaluate thin-films adhesion and stability. Scanning electron microscopy (SEM) technique was used to evaluate the morphology of films surface and the layered structure of the full-battery. This detailed experimental study allows us to understand the discharge behavior of the fabricated Li-ion battery. 

Pulsed-injection metal organic chemical vapour deposition for the development of copper silicate and silicide nanostructures   

Richard. O

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 830-840
DOI: 10.5185/amlett.2017.1465

In this manuscript we report the production of copper silicate and silicide nanostructures: octahedral o-Cu(SiO3), wire w-Cu(SiO3) and wire w-Cu3Si (embedded in silicate shell) using copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) [Cu(tmhd)2] precursor and the pulsed injection metal organic chemical vapour deposition (PI-MOCVD) technique. In our experiments, particular attention has been paid to the structural composition and morphological analysis of the nanostructures which are dictated by the deposition parameters such as deposition temperature, carrier gas flow rate and injection time. Deposition processes were diffusion limited and various methods were used to show that by changing the amount of stress relaxation via the reaction time, concentration and flow rate, w-Cu(SiO3) and w-Cu3Si could be made to evolve. Nanostructures have been characterised by x-ray diffraction (XRD), Raman, scanning tunneling electron microscopy (STEM) and atomic force microscopy (AFM) techniques. It was found that the presence of oxygen (SiO2) in the silicon substrates and exposure of the nanostructures to ambient conditions results in the formation of copper silicate from initially produced copper silicide nanomaterials. This work outlines the potential for the manufacturing of various patterned copper nanostructures via PI-MOCVD. 

Carbon aerogel materials promoted catalytic ozonation of residual dyes in waste effluents from cotton dyeing

Songmin Shang; Enling Hu; Xiao-ming Tao; Shou-xiang Jiang; Ka-lok Chiu; Yee Ting Chong

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 841-846
DOI: 10.5185/amlett.2017.1515

Reactive dyeing of cotton generates large volume of wastewater containing residue dye contaminants. In order to reduce adverse impacts to the environment, the waste effluents must be reclaimed through appropriate processes before charging to the natural water bodies. In this study, carbon aerogel materials, including pure carbon aerogel and its supported metal oxides, was reported in catalytic ozonation of residue dyes in wastewater. The commercially available reactive dye, namely C.I Reactive Blue 19, was used as the probe contaminant. Dye degradation in catalytic ozonation processes was estimated in terms of color and COD removal. The results demonstrated that the catalysts rarely involved in color removal, but displayed promising potentials in facilitating COD removal in dyeing effluents, in which COD removal was significantly promoted comparing to ozonation alone without catalysts. In the specific conditions, especially for the supported metal oxides, COD removal could attain 80% after 3 h treatment, whereas it was only 45% in ozonation alone. In addition, effects of conditional parameters on catalytic ozonation efficiency as well as the reusability of catalysts were also investigated. The results suggested that the catalyst materials exerted outstanding catalytic stability during repeated use, and increasing catalyst dosage, ozone concentration and pH would promote dye degradation especially for COD removal.

Spinel NiCo2O4 and single walled carbon nanotube nanocomposites for high performance supercapacitor application  

Surjit Sahoo; Chandra Sekhar Rout

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 847-851
DOI: 10.5185/amlett.2017.1539

In the present work, we report the hydrothermal synthesis of NiCo2O4/Single walled carbon nanotubes (SWNTs) nanocomposites for supercapacitor applications. The SWNTs provided the conductive network and favored the growth of NiCo2O4 nanoparticles on its surface to facilitate the collection and transportation of electrons during the electrochemical charge storage performance. Due to the improved conductivity and higher surface area of the NiCo2O4/SWNTs nanocomposites as compared to pure NiCo2O4 nanorods, it exhibited a specific capacitance of 1623 F/g and 1098 F/g at 1mV/s scan rate and 1A/g current density. Obtained energy density and power density of the NiCo2O4/SWNTs nanocomposites were 56.19 Wh/Kg and 9.824 kW/kg respectively. These results demonstrated that the nanocomposites could be a promising candidate for future high performance energy storage devices. 

A novel non-enzymatic glucose sensor based on melamine supported CuO nanoflakes modified electrode

Tse-Wei Chen; Selvakumar Palanisamy; Shen-Ming Chen; Vijayalakshmi Velusamy; Hema Kalyani Ramasubbu; Sayee Kannan Ramaraj

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 852-856
DOI: 10.5185/amlett.2017.1625

In the present work, we describe a simple electrochemical synthesis of CuO nanoflakes (CuO-NFs) using Cu-melamine complex. The as-prepared CuO nanoflakes was characterized by different physicochemical methods  such as high-resolution scanning electron microscopy, elemental analysis and elemental mapping. The effect of different potential cycling towards the morphology of CuO-NFs was studied and discussed. Furthermore, CuO-NFs modified electrode was used as an electrocatalyst for oxidation of glucose in 0.1 M NaOH, and the observed electrochemical oxidation current of glucose was higher than CuNPs modified electrode. Amperometric i-t method was used for the determination of glucose using CuO-NFs modified electrode. Under optimal conditions, the amperometric i-t response of the sensor was linear over the glucose concentrations ranging from 1.0 µM to 1.445 mM with the detection limit of 0.35 µM.  In addition, the selectivity of the sensor was tested in the presence of different potentially interfering compounds.  The practicality of the sensor was also evaluated in human serum samples and shows acceptable recovery of glucose.

Experimental study of 3D-printable biocomposite of [HA/PMMA/Sericin] materials  

Alva E. Tontowi; Devita Anggraeni; Henry TSSG Saragih; Kristiani P.N. Raharjo; Putri Utami

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 857-861
DOI: 10.5185/amlett.2017.1640

In the previous study, a biocomposite material of [HA/Bioplastic/Sericin] was developed as a printable material. The highest strength was only 3.89 MPa which was achieved by the composite with 60/40 ratio of HA/Bioplastic and additional sericin of 0.3%w/w of HA. The present of sericin within the biocomposite could improve cell attachment. However, since cassava starch based bioplastic as a matrix was degraded in PBF, the dimensional accuracy could not be maintained. In the present study, the matrix of bioplastic was replaced by PMMA with various P/L ratios of 2/1.8, 2/1.185 and 2/1.9. A series test was carried out to investigate the printable characteristic in 3D printer with an optimum printing parameter such as curing time window, flow rate through a nozzle, tensile strength of the printed sample, microstructure and x-ray diffraction. Response Surface Method (RSM) was employed to optimize the printing process parameter of the 3D-Bioprinter, predict the tensile strength of the sample and it was validated by experiment. The flow rate of pasta was 78.5mm 3 /s, the highest predicted tensile strength was 6.01 MPa and experiment was 5.12 MPa. This lower strength might be caused by the existence of porosity as conformed by SEM, while hydroxyapatite still exist as indicated by the XRD.

Ligand coordination effects on gallium nanocluster reactivity

David J. Henry

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 862-865
DOI: 10.5185/amlett.2017.1672

Stabilisation and modulation of nanocluster reactivity are key elements for the development of these materials as versatile and selective catalysts. This study presents a preliminary investigation of the interaction of ligands with a gallium nanocluster (Ga13). The amphoteric nature of Ga13 means that both a Lewis base (NH3) and a Lewis acid (BH3) strongly adsorb to the surface of the cluster. More importantly, ligand coordination modifies the electronic structure of the cluster, leading to an enhancement of reactivity. In particular, NH3 coordination was found to lower the energy barrier for H2 chemisorption by 10% and BH3 coordination led to reduction of the barrier by 20%. These results demonstrate the potential for ligand coordination as a means of accelerating reactions on cluster surfaces.

New polycrystalline MC-reinforced nickel-based superalloys for use at elevated temperatures (T > 1100°C)

Patrice Berthod

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 866-872
DOI: 10.5185/amlett.2017.1683

In some high temperature applications, there is a constant need of refractory alloys able to resist oxidation by hot gases, hot corrosion by various melts and creep deformation. The best superalloys are currently the g/g’ nickel-based single crystals but they cannot be exposed to 1200°C and more without losing their mechanical resistance. New principles of conventionally cast polycrystalline nickel alloys, combining good resistance against both hot gas oxidation and melts corrosion are explored in this work. Among them, the most promising system involves a reinforcement by HfC carbides. The studied alloy has kept its chromia-forming behaviour which allows good resistance against both oxidation resistance and corrosion by melts. Interesting for a nickel-based alloy containing no g’ precipitates, its creep resistance at 1200°C still remains to be improved to allow using it at so high temperature.

ATA and TA coated superparamagnetic iron oxide nanoparticles: Promising candidates for magnetic hyperthermia therapy

Ganeshlenin Kandasamy; Atul Sudame; Dipak Maity

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 873-877
DOI: 10.5185/amlett.2017.1730

In recent times, superparamagnetic iron oxide nanoparticles (SPIONs) are widely used as heating agents in magnetic hyperthermia therapy (MHT) to kill malignant cells in cancer treatments, which is mainly due to their excellent magnetic properties and biocompatibility. However, it is still a challenge to coat SPIONs with suitable surfactants and to apply an appropriate alternative magnetic field (AMF) at specific frequency to achieve enhanced heating effects in MHT. In this work, the as-synthesized novel short-chain surfactants (i.e., amino-terephthalic acid (ATA) and terephthalic acid (TA)) coated hydrophilic SPIONs are synthesized and subsequently involved in calorimetric hyperthermia studies to investigate their intrinsic heating capability by varying (i) their concentrations from 1 - 8 mgFe/ml and (ii) AMFs at different frequencies (263.2 – 752.39 kHz) while achieving the temperature above 42 °C – therapeutic hyperthermia temperature. It is found that the heating rate of TA-SPIONs is faster as compared to ATA-SPIONs on exposure to the AMF. However, the highest specific absorption rate (SAR) value of 129.80 W/gFe is attained for ATA-SPIONs with 2 mgFe/ml concentration on exposure to AMF at 752.39 kHz. Thus, ATA/TA coated SPIONs are very promising agents for magnetic hyperthermia and could be further investigated in in vitro/in vivo cancer treatments.

Growth and characterization of graphite doped CdTe/CdS thin film heterojunction

Muhammad Asghar; Ya Hong Xie; M. Asif Nawaz; Hammad M. Arbi; M. Y. Shahid; F. Iqbal; Waqas Khalid

Advanced Materials Letters, 2017, Volume 8, Issue 8, Pages 878-882
DOI: 10.5185/amlett.2017.7094

Doping is a notable factor to improve the performance of CdTe/CdS heterojunction solar cell. Graphite doped CdTe/CdS heterojunction on Si (1 1 1) substrate has systematically fabricated by thermal evaporator method under medium vacuum (10 -4 torr) condition. Characterization of doped CdTe/CdS film was carried out by various diagnostic techniques such as X-ray diffraction (XRD) exhibits the polycrystalline structure of cubic phase CdTe and hexagonal phase CdS, scanning electron microscopy (SEM) shows the smoothening of the film, energy dispersive X-ray (EDX) confirm the elemental composition found in the film and current-voltage (I-V) analysis suggests the diode like properties where the current is slightly increased by the doping of graphite into CdTe/CdS heterojunction compared to the reported literature. Analysis of I-V characteristics has been made to investigate the current conduction mechanism in CdTe/CdS heterojunction.