Issue 3

Symposium On Smart Energy Technologies  (SET-2016), Stockholm    

Ashutosh Tiwari

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 175-175
DOI: 10.5185/amlett.2016.3001

VBRI Press is pleased to announce ‘Symposium on Smart Energy Technologies during 23 – 25 August 2016, Sweden. It is a three-day international event organised by the International Association of Advanced Materials, Linköping University, cruising on the Baltic Sea from Stockholm-Helsinki-Stockholm with the Viking Line Cruise Ship M/S Mariella. The aim of symposium is to provide advances in advanced materials for energy associated applications, in particular, photovoltaics, efficient light sources, fuel cells, energy saving technologies, nanostructured materials, etc. Tendencies for future development will also be discussed.  

Preparation And Characterization Of PEG Bis(amine) Grafted PMMA/SPION Composite Nanoparticles  

Yongyuth Wanna; Supanit Porntheerapat;Sirapat Pratontep; Rachineewan Pui-ngam; Jitti Nukeaw; Anon Chindaduang; Gamolwan Tumcharern

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 176-180
DOI: 10.5185/amlett.2016.5912

We report novel magnetic composite nanoparticles for heavy metal ion separation. Superparamagnetic iron oxide nanoparticles (SPIONs) and were coated with poly(methylmethacrylate) (PMMA) by emulsion polymerization process in the aqueous suspension of SPIONs. In addition, the hydrolysis of carboxylic functional groups onto the PMMA-coated SPIONs was grafted with Polyethylene glycol bis(amine). Then, the functional group structures were investigated by Fourier transforms infrared spectroscopy (FTIR). The morphology of PMMA/SPIONs was determined by transmission electron microscopy (TEM) and atomic force microscope (AFM). The magnetic property was investigated by the vibrating sample magnetometer (VSM). The metal concentration in the solution after separation using the nanoparticles was determined by inductivity coupled plasma optical emission spectrometer (ICP-OES). Furthermore, we demonstrate that the efficiencies of the heavy metal ion removal for Cu(II), Mn(II), Zn(II), Cd(II), Pb(II), Co(II) and Ni(II) are 80.0 %, 57.7 %, 54.3 %, 40.0 %, 34.8 %, 32.5 % and 30.2 % by weight, respectively. The nanoparticles also exhibit some selectivity for copper, manganese and zinc. The results show that the composite nanoparticles are extremely promising for heavy metal ion separation.   

Synthesis, Characterization And Investigation Of Visible Light Photocatalytic Activity Of C, N Co-doped ZnO  

Atul B. Lavand; Yuvraj S. Malghe

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 181-186
DOI: 10.5185/amlett.2016.5974

Nanosized bare, C and N doped as well as C, N co-doped ZnO nanopowders were prepared using microemulsion method. Synthesized powders were characterized using X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), CHNS analyzer, photoluminescence spectrophotometer and UV-visible spectrophotometer. XRD study shows that C, N co-doped ZnO have hexagonal wurtzite structure. UV-visible spectral study reveals that C and N co-doping improves photo absorption capacity in visible region. Visible light photocatalytic degradation of malachite green was carried out using nanosized bare, C doped and C, N co-doped ZnO. C, N co-doped ZnO exhibits better visible light photocatalytic activity as compared to pure and C doped ZnO.  Also the photocatalyst prepared is stable and can be reused repeatedly.   

Microstructural And Phase Analysis Of Al Based Bulk Metallic Glass Synthesized By Mechanical alloying And Consecutive Spark Plasma Sintering With Varying Consolidation Pressure  

Ram S. Maurya; Ashutosh Sahu; Tapas Laha

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 187-191
DOI: 10.5185/amlett.2016.6174

In the present work, Al86Ni8Y6 and Al86Ni8La6 powder blends were mechanically alloyed. Al86Ni8Y6 yielded full amorphous structure (150 h); whereas Al86Ni8La6 was partially amorphized after same duration of milling attributed to incomplete dissolution of solute ‘La’ in solvent ‘Al’. DSC experiment showed wider glass transition temperature range of ~ 44 o C (Tx - Tg = 268 o C-224 o C) in Al86Ni8Y6 amorphous powders; whereas no glass transition temperature was detected in Al86Ni8La6 powders. Further, Al86Ni8Y6 amorphous powders were consolidated via spark plasma sintering in the pressure range of 100-400 MPa. XRD and TEM analysis confirmed retention of larger fraction of amorphous phase in higher pressure sintered sample, attributed to suppression of mass transfer diffusion kinetics process. Higher pressure favored short range ordering leading to formation of various intermetallic phases; whereas comparatively faster diffusion in case of low pressure sintering promoted long range ordering forming nanocrystalline FCC-Al. Higher sintering pressure (say 400 MPa) consolidated sample resulted in better densification (~ 99 %) with improved inter-particle bonding and moreover, retention of larger volume fraction (~ 92 vol %) of amorphous phase with intermetallic nano-precipitates. Vickers microhardness test showed improvement in hardness with increasing sintering pressure attributed to higher fraction of retained amorphous phase and better inter-particle bonding.  

Atmospheric Pressure Chemical Vapor Deposition Of Amorphous Tungsten Doped Vanadium Dioxide For smart Window Applications  

Dimitrios Louloudakis; Dimitra Vernardou; Emmanuel Spanakis; Mirela Suchea; George Kenanakis; Martyn Pemble; Konstantinos Savvakis; Nikolaos Katsarakis; Emmanuel Koudoumas; George Kiriakidis

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 192-196
DOI: 10.5185/amlett.2016.6024

Amorphous tungsten doped vanadium dioxide coatings were grown on SnO2-precoated glass substrates using the atmospheric pressure chemical vapor deposition of vanadium (V) triisopropoxide and tungsten (VI) isopropoxide at 450 o C without an oxygen source. The effect of N2 flow rate through the tungsten’s precursor bubbler was examined keeping the respective flow rate through the vanadium’s precursor bubbler at 4 L min -1 for a growth period of 30 min. They were characterized by x-ray diffraction, Raman and x-ray photoelectron spectroscopy, field-emission scanning electron microscopy and UV-vis/IR transmittance. The samples grown using 0.4 L min -1 N2 flow rate through the tungsten precursor’s bubbler, showed the greatest reduction in transition temperature from 65.5 in granular VO2 to 44 o C in worm-like V0.985W0.015O2 structures approaching that required for commercial use as a smart window coating. 

Synthesis Of Ni Filled Multiwalled Carbon Nanotubes And Study Of Magnetic Behaviour

Reetu Kumari; Anshika Singh; Rajesh Kumar; Lucky Krishnia; Vinay Kumar; Nitin K. Puri; Pawan K. Tyagi

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 197-200
DOI: 10.5185/amlett.2016.6150

In this report, we have illustrated the synthesis of the Ni-filled multiwalled carbon nanotubes (MWCNTs) on both metallic and non-metallic substrates, by using thermal CVD technique. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) have been used to characterize the surface morphology and crystalline nature of the MWCNTs encapsulated with Ni nanorod. These filled MWCNTs have exhibited strong magnetic response due to encapsulation of pure phase of Ni. Magnetic Force Microscopy (MFM) study of such filled tubes reveals the pole formation in the Ni nanorod and confirms magnetization direction perpendicular to tube axis. Filling occurs in a fragmented manner confirmed by MFM and each fragment found to have north and south poles along the axis perpendicular to the tube i.e. radial direction of tube.   

Study Of Electrical Relaxation Mechanism Of TiO2 Doped Bi-polymer Systems  

Moumita Khutia; Girish M. Joshi; Subhratanu Bhattacharya

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 201-208
DOI: 10.5185/amlett.2016.6181

Polyvinyl alcohol (PVA) /Poly (tetrafluoroethylene) (PTFE)/Titanium oxide (TiO2)  was prepared by ( 5, 10 and 15 wt %) TiO2 loading. The miscibility, thermal property and microstructure of the composites were characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The electrical relaxation dynamics including dielectric and electrical conductivity was examined as a function broadband of frequency and temperature. The dielectric data was analyzed via the electric modulus. The Maxwell-Wagner-Siller (MWS) effect corresponds to interfacial polarization at low frequency follows Arrhenius behavior. The α-mode relaxation is attributed to glass-rubbery transition in composites, obeys the Vogel- Taman-Fulcher (VTF) model. A slight bump was noted at relatively high temperature and high frequencies termed as Intermediate dipolar effect (IDE) obeys the Arrhenius behavior. Conductive mechanism was analyzed via AC conductivity spectra. However, DC conductivity follows Arrhenius equation. The overall studies confirm that the self relaxation mechanism of PVA/PTFE composites were modified by TiO2, offers the tuning conductivity as a function of the temperature which can be used in various electronic applications.   

Titanium Dioxide Nanotube Arrays: A Novel Approach Into Periodontal Tissue Regeneration On The Surface Of Titanium Implants  

S. Goodarzi; F. Moztarzadeh; N. Nezafati; H. Omidvar

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 209-215
DOI: 10.5185/amlett.2016.6014

Titanium alloys have been extensively used as promising implant materials. The anodic oxide layer on the surface of this alloy can be a compact, porous or a tubular structure, which has a direct impact on the final characteristics of the implants. In this study, nano topographic oxide arrays were synthesized on the surface of titanium substrates using an anodic oxidation technique. The anodization process was performed at a two-electrode electrochemical cell, and then the samples were annealed to obtain crystalline structures. The synthesized samples were analyzed to evaluate the compositional phase, morphology, surface hydrophilicity and corrosion resistance of the nanostructured oxide arrays in artificial saliva. Microscopic observations confirmed the formation of a nanotubular structure on the surface of titanium substrate depending on the anodization condition. After heat-treatment at 570 °C, crystallographic analyses showed that the obtained crystalline phase was a mixture of Anatase and Rutile phases. The electrochemical impedance spectroscopy (EIS) results indicated a significant improvement in the corrosion resistance and electrochemical stability of the anodized sample in artificial saliva compare to the control samples. In addition, the anodized samples showed a better hydrophilic characteristics, viability and proliferation of periodontal ligament cells in comparison with the un-anodized samples. This study demonstrated that the anodized titanium samples, with the nanotubular structure on the surfaces, could be considered as a good candidate for dental implants. 

Study On The Effect Of Fuels On Phase Formation And Morphology Of Combustion Derived α-Al2O3 And NiO nanomaterials  

R. S. Raveendra; P. A. Prashanth; B. M. Nagabhushana

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 216-220
DOI: 10.5185/amlett.2016.6202

In this study we present an effect of glycine and urea fuels on the phase formation and morphology of the α-Al2O3 and NiO nanomaterials. Materials were synthesized using facile solution combustion method at temperature 500 °C ± 10 °C. The synthesized products were characterized by various analytical techniques. PXRD results of α-Al2O3 confirm that the hexagonal phase is best represented using urea as a fuel compared to glycine. FE-SEM micrographs observed with urea are like flake like structure whereas with glycine net like porous structure is observed. TEM micrographs show the well crystalline nature of the nanomaterials. Large mismatching was observed in the FTIR spectra of synthesized materials using urea and glycine fuels with respect to the OH and metal to oxygen vibrational frequencies. PXRD results of NiO confirm that the cubic structure is obtained with urea fuel without any secondary phases, whereas with glycine a small peak of Ni was observed at 2θ = 44.5°. FE-SEM micrographs NiO with urea represents spherical like structure whereas large number of voids with porous structure was observed with glycine. The results of the study show that the fuels used for the synthesis of nanomaterials have a great effect on phase formation and morphology.   

Investigation On The Combustion Characteristics Of Alumina Nanoparticles Dispersed Longer Term stable Biodiesel Nanofluids  

D. Srinivas Rao;Raj Kishora Dash

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 221-225
DOI: 10.5185/amlett.2016.6152

In this paper, the combustion characteristics of alumina nanoparticles dispersed jatropha biodiesel based nanofluids were investigated by dispersing the alumina nanoparticles having average size of ~13 nm in jatropha biodiesel with 0.1 volume fraction. Only longer duration having more than one year stable nanofluids were tested for the combustion characteristics such as evaporation time on a hot-plate test in the temperature range of 300 0 C to 600 0 C. The preliminary evaporation test results  revealed that the evaporation time of one year older stable ~13 nm alumina nanoparticles dispersed nanofluids significantly improved and were comparable to that of the commercially available diesel fuel beyond 450 0 C. Such type of biofuel based nanofluids having longer term stability and improved combustion characteristics can be utilized directly as an alternate fuel for the future diesel engines. 

Activated Carbons From KOH-activation Of Salacca Peels As Low Cost Potential Adsorbents For Dye Removal  

Arenst Andreas Arie; Vincent;Aditya Putranto; Vincent and Aditya Putranto

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 226-229
DOI: 10.5185/amlett.2016.6194

Salacca peel was used to prepare activated carbon (AC) by chemical activation with potassium hydroxide (KOH). The activated carbon with the largest surface area and most developed porosity was then used in the batch adsorption experiments of methylene blue (MB). Activated carbons with a surface area of around 1939 m 2 /g were obtained. The adsorption equilibrium and kinetics of MB dyes from aquaeous solution on AC were also investigated. Adsorption isotherms of MB were correlated with the Langmuir, Freundich, Dubinin Radushkevich and Tempkin equations, and the heat of adsorption was determined. It was revealed that the Langmuir adsorption equation was more appropriate to represent the adsorption procedure of MB dyes compared to the other equations. Two simplified kinetic models including pseudo first- order and -second-order equations were used to evaluate the adsorption processes. The results indicated that the adsorption of MB dyes could be described properly by a pseudo-second-order equation. The kinetic parameters of this model were calculated and discussed.   

Comparative Study Of Thermal Stability Of Filled And Un-filled Multiwalled Carbon Nanotubes  

Lucky Krishnia; Reetu Kumari; Vinay Kumar; Anshika Singh; Preeti Garg; Brajesh S. Yadav; Pawan K. Tyagi

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 230-234
DOI: 10.5185/amlett.2016.6149

Filled or un-filled multiwalled carbon nanotubes (CNTs) used in this study have been synthesized by the floating catalyst method and fixed catalyst method, respectively. The thermal stability of filled/un-filled carbon nanotubes has been investigated by using Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. In this report, we have developed a methodology to distinguish between filled and un-filled carbon nanotubes. Filled-CNTs are found to be more resistant to oxidation than the un-filled carbon nanotubes. The calculated activation energy of as-grown filled CNTs, by using differential method, determined to be 3.29 ± 0.04 eV, which is higher than that of highly ordered pyrolytic graphite (HOPG). Carboneous impurities; amorphous carbon, catalyst and CNT of different diameter, which are structurally different, are identified by their reactivity and the resistance to oxidation.  

Effect Of Precursor On Optical, Dielectric Properties Of Zirconia Crystalline Powder Prepared By hydrothermal Method  

Rajababu Chintaparty; N. Ramamanohar Reddy

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 235-238
DOI: 10.5185/amlett.2016.6120

Zirconium Oxide (zirconia) particles were prepared through hydrothermal technique by using zirconium oxychloride (ZrOCl2.8H2O) and zirconyl nitrate (ZrO (NO3)2.H2O) as precursors. The structural characterization as prepared samples were confirmed by X-ray powder diffraction (XRD) and showed monoclinic phase. Further, surface morphology of synthesized zirconia particles were confirmed by scanning electron microscopy (SEM). The energy band gap of synthesized samples was evaluated from UV-vis absorption spectra. The frequency dependence of dielectric constant and dielectric loss of the samples were investigated at room temperature. Zirconium oxychloride was found to be better precursor for obtaining ZrO2 with a higher dielectric constant than Zirconyl nitrate under the same synthesis conditions.   

Synthesis Of C/ZnO/CdS Nanocomposite With Enhanced Visible Light Photocatalytic Activity  

Yuvraj S. Malghe; Atul B. Lavand

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 239-245
DOI: 10.5185/amlett.2016.6130

C/ZnO/CdS nanocomposite was synthesized using microemulsion method. Thermal stability of precursor was studied with TG and DTA techniques. Structural and optical properties of composite were studied using various characterization techniques like X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM) and  UV-visible absorption spectroscopy  and photoluminescence spectroscopy. XRD study indicates that ZnO and CdS are having wurtzite and cubic phase in the composite sample. SEM and TEM study indicates formation of CdS nanospheres on ZnO nanorods. C doping and CdS coupling are responsible for red shift and shifting of absorption edge of ZnO from UV to visible region. C/ZnO/CdS nanocomposite exhibits better visible light photocatalytic activity for degradation of methylene blue (MB). Stability of photocatalyst was studied using recovered photocatalyst up to third cycle and it was found that photocatalyst prepared in the present work is stable and reusable.   

Thermodynamic Properties Of Zinc Oxide [001] Nanowires Via First Principles Calculations  

Venu H. Mankad; Sanjeev K. Gupta;Prafulla K. Jha

Advanced Materials Letters, 2016, Volume 7, Issue 3, Pages 246-252
DOI: 10.5185/amlett.2016.6147

The size dependent vibrational and thermodynamical properties of Zinc Oxide Nanowire (ZnO NWs) along with its bulk counterparts has been studied using the first principles calculations within density functional theory. The thermodynamical parameters such as specific heat at constant volume, entropy, internal energy and Helmholtz energy as function of temperature for the different size of nanowires are obtained and compared with the bulk ZnO in wurtzite phase. We address the effects of structural confinement on the phonon dispersion, vibrational density of states and qualitatively on the sound velocities and thermal conductance. The phonon dispersion curves for considered ZnO nanowires and its bulk counterpart indicates dynamical stability. The band gap increases from bulk to nanowire and an inverse size dependency in the case of nanowires arising due to quantum confinement. The analysis of bands character in context of growth characteristics and thermodynamical properties are also discussed. Our findings will give some reference to the insight understanding of the electronic, vibrational and thermodynamical properties of size orientation dependent ZnO nanowire.