PacSurf2014 Session NM-WeP: Nanomaterials Poster Session

Wednesday, December 10, 2014 4:00 PM in Mauka

Wednesday Afternoon

Time Period WeP Sessions | Topic NM Sessions | Time Periods | Topics | PacSurf2014 Schedule

NM-WeP-1 Facile Preparation of (NH4)2SiF6 Particles with High Fluorescence Quantum Yield
Shun Kitazawa, Keisuke Sato (Tokyo Denki University, Japan); Naoki Fukata (National Institute for Materials Science, Japan); Kenji Hirakuri (Tokyo Denki University, Japan)

Fluorescence materials are used for a broad range of industry and biomedical technology applications involving electroluminescent displays and fluorescent contrast dye of bioimaging. However, they are confronting some serious problems, such as complicated preparation techniques and low production yield. Therefore, it is necessary to develop new synthesis approaches for realization of facile preparation and large-scale production of fluorescence materials. We have prepared ammonium hexafluorosilicate ((NH4)2SiF6) particles as one of the fluorescence materials using a chemical route with good productivity. These (NH4)2SiF6 particles possess excellent advantages such as high-efficiency fluorescence and long-term photostability compared to the other silicon (Si)-based fluorescence materials. In this presentation, we propose a new way to fabricate (NH4)2SiF6 particles by simplified procedures based on a chemical approach. The features of our synthesis technologies are to adopt the simplified synthesis system in which only Si powders and chemicals consisting of nitric hydrofluoric acid solution were hermetically sealed in polymeric container without any vacuum systems. The (NH4)2SiF6 particles with mean diameter of approximately 700 nm were densely deposited on the Si substrate by using this novel synthesis system. The crystalline structures and the chemical compositions of (NH4)2SiF6 particles were confirmed by X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectroscopy. The XRD patterns were consistent with the sharp diffraction peaks derived from the cubic phase of crystalline (NH4)2SiF6 with space group of Fm3m(225). For the FTIR characterization, the absorption peaks related to the SiF62- and NH4+ ions in addition to N-H mode were also observed. These results demonstrate that the (NH4)2SiF6 particles are not only maintained high crystallinity but also composed of ammonium and silicon fluoride as major ingredients. Such (NH4)2SiF6 particles exhibited bright reddish orange fluorescence with a peak wavelength at 630 nm under the irradiation of xenon lamp equipped with optical bandpass filter of 365 nm. The main advantages of (NH4)2SiF6 particles are to attain the high fluorescence quantum yield of 34 %. Additionally, the fluorescence intensity was maintained about 80% of the initial maximum intensity even after aging beyond six months. Therefore, our suggested synthesis technologies can provide a new chemical route for the fabrication of high-brightness and stable fluorescence particles.

NM-WeP-2 The Flashover​ and Hydrophobicity Recovery Characteristics of RTV Silicone Rubber Nanocomposites
JiSung Park, JungHun Kwon (Chungbuk National University Korea, Republic of Korea)
Many researches about silicone rubbers which are applied to materials of outdoor insulators and bushings have been conducted. Recently, As nano technologies have been developed, nano fillers are added to electrical materials to improve mechanical and electrical performances. In this paper, Room Temperature Vulcanizing(RTV) silicone rubber nanocomposites was studied about electrical performances and hydrophobicity recovery under the AC electrical stress and contamination. Silica and ATH was added as nano fillers, and specimens was contaminated by a dipping method. Flashover voltage and contact angle was measured. As a result, Nano filler improved electrical performances, and not reduced the hydrophobicity recovery.
NM-WeP-3 N-containing ZnO Rods with Tunable Concentration Synthesized by Hydrothermal Method
Taiki Ihara, Ken-ichi Katsumata (Tokyo Institute of Technology, Japan); Tomoaki Watanabe (Meiji University, Japan); Kiyoshi Okada, Nobuhiro Matsushita (Tokyo Institute of Technology, Japan)

Recent research has shown that N-doping into TiO2, Ta2O5, or LaTaO4 is effective for narrowing the band-gap and attaining the visible-light photocatalysis. N-doped metal oxide powder is commonly synthesized by elevating metal oxide specimens temperature over 500oC with flowing ammonia gas or nitrogen. In this study, we succeeded in synthesizing N-containing ZnO rods by hydrothermal process using ammine-hydroxo zinc complex solution at 100oC.

10 ml of 2.5 M NaOH (aq) was added in drops to 15 ml of 0.5 M Zn (NO3)2・6H2O aqueous solution over stirring vigorously. The resulting hydroxide slurry was centrifuged and the supernatant was removed. The hydrated precipitate was dissolved in 50 ml of 6.6 M NH3 (aq) to form a stock solution. 30 ml of the solution was transferred into a 35 ml Teflon-lined stainless steel autoclave, followed by heating in an oven at 100oC for 6-24 h. After the reaction, the precipitates were separated by centrifugation, and then washed with water.

The diffraction peaks in XRD patterns for synthesized sample was good agreement with those of the hexagonal wurtzite structure of ZnO (JCPDS card 36-1451). The morphology of the ZnO particles were hexagonal rods and the size was about 20 μm in long axis and about 1 μm in diameter. UV-vis spectra for the sample prepared for different reaction time revealed that the absorption band was shifted to visible region as increasing the reaction time. In the raman spectra, typical Ramanactive modes for ZnO (E2, A1(TO), A1(LO), E1(TO), and E1(LO)) were clearly observed for all samples. In addition to the above, new peak was observed at 582 cm-1 on N-containing ZnO rod which is attributed to the E2(Zn-N) mode. N concentration calculated from XPS data was increased as increasing the reaction time. XPS spectrum of N 1s for the sample prepared at 100oC for 6 h showed the asymmetric broad peak indicating that more than one chemical states of N were present. The binding energy at ∼399.0 eV was attributed to the surface species of NH3 or amines. The another peak at ∼397.0 eV was ascribed to N atom in Zn-N bond indicating that N was incorporated in ZnO rods.
NM-WeP-4 Synthesis of TiO2 Monolith Structure Modified Nanotubes
Ken-ichi Katsumata (Tokyo Institute of Technology, Japan); Momoko Yamamoto (Tokyo Institute of Technology); Nobuhiro Matsushita, Kiyoshi Okada (Tokyo Institute of Technology, Japan)

TiO2 is actively studied as photocatalyst with environmental applications effected on photocatalytic performance by adjusting many factors in the structure. Recently, TiO2 monolith with unique three-dimensional structure has been reported. This is expected to various applications because the pore size and volume are able to control by the synthesis condition. The material, generally used as an adsorbent, extended the applications with visual light-sensitive. In this research, TiO2 monolith was synthesized with various heating temperatures, and its photocatalytic activity was investigated under visible light.

Porous TiO2 monolith was synthesized by sol-gel method. HCl, the aqueous solution of Polyethylen glycol (10000) in water and N-methyl formamide are added to Titanium propoxide stirring under ice-cooled condition. The gel is aged at 60oC for 24 h and heat-treated at 200oC for 2 h in stainless-steel autoclave with a Teflon inner liner. The wet gel plate thus obtained is washed by 1-propanol for 12 h, slowly drying for 1 week at room temperature and calcinated at 600, 700, 800 and 900oC for 5 h. Each of temperature rising rates is 1.0 oC/min. Each sample is immersed in the CuCl2 (moler rations of Cu/TiO2 = 1.0 × 10-3) aqueous solution at 90oC for 3 h. After washing by water and drying at 80oC, they are measured photocatalytic activity.

The samples heated at 600, 700, and 800oC had monolith structure, and the pore size and primary particle size depend on calcination temperature. However, the sample heated at 900oC did not maintain monolith structure. From the results of XRD patterns and Raman spectra, anatase was main phase at less than 700oC while rutile started to be observed at more than 700oC. It is expected that Cu(II)-grafted rutile monolith samples exhibit excellent photocatalytic activity under visiblelight. In addition, it was succeded that rutile nanotubes were formed on the surface of the monolith structures by solvothermal treatment. The monolith with nanotubes had very high specific surface area compared to the monolith without nanotubes. In detail, I will report the activity on the day.

NM-WeP-5 Surfactant-Free Solution Phase Synthesis of CuO Nanostructures with Controlled Dimensions
BG Ganga, PN Santhosh (Indian Institute of Technology Madras, India)

CuO is a versatile p-type transition metal oxide semiconductor with a narrow band gap in the region 1.2-1.8 eV [1]. It is a naturally abundant, nontoxic and stable material and is commonly used as a component material in a wide range of applications such as gas sensing, catalysis and energy storage and conversion [2-4]. Three dimensional ellipsoidal shaped CuO nanostructures and two dimensional nanosheets have been successfully synthesized using surfactant free simple solution phase method. Synthesis of CuO nanostructures was followed by structural, morphological characterization using X-ray diffraction, Scanning Electron Microscopy and Transmission Electron Microscopy. We have demonstrated that morphology and dimensionality of nanostructures can be controlled by changing the initial reactant concentrations. It is observed that ordered aggregation and growth of smaller CuO subunits generates an ellipsoidal shaped morphology at lower reactant concentration, while at higher reactant concentration, sheet like structures are generated. Self-assembled structures provide an opportunity to investigate the formation mechanism and aggregation based growth of nano subunits as fundamental building blocks. This bottom-up method offers facile synthesis of nanostructures of controlled morphology and functionality. We have also observed a change in morphology as the nanostructures were thermally annealed. A morphological transformation from rod-like to plate-like structure was observed as the flake-like nanostructures were annealed at 4000C and 6000C respectively. The formation mechanism that plays behind the generation of different CuO nanostructures is explored. Optical properties are investigated using UV-Vis spectroscopy and Raman spectroscopy. We found that morphology of the nanostructure strongly reflect on the optical properties as band gap widening and the change in the position and width of Raman modes.

References

[1] M.A. Gondal, T.F. Qahtan, M.A. Dastageer, T.A. Saleh, Y.W. Maganda, D.H. Anjum, Appl. Surf. Sci. 286 (2013) 149.

[2] Z. Zhang, H. Che, Y. Wang, L. Song, Z. Zhong, F. Su, Catal. Sci. Technol. 2 (2012) 1953.

[3] M. Frietsch, F. Zudock, J. Goschnick, M. Bruns, Sens. Actuat. B 65 (2000) 379.

[4] X.P. Gao, J.L. Bao, G.L. Pan, H.Y. Zhu, P.X. Huang, F. Wu, D.Y. Song, J. Phys. Chem. B 108 (2004) 5547.

NM-WeP-6 Patterned Surfaces on Ge by Low Energy Oxygen Bombardment
Angelica Hernández (Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico)

Low energy ion beam sputtering (IBS) induces a wide variety of surface morphology evolution with different shapes such as, ripples, dots and pyramidal pattern on semiconductor surfaces. Under off normal incidence beam ripple formation is developed. On other hand, hexagonal or square order dots were reported for normal incidence ion beam or off normal ion incidence with simultaneous sample rotation [1]. Patterned surfaces have a broad range of technological applications, such as lasers, solar cells, sensors, biomedical tags and light emitting diodes.

Temperature effect on the ripple pattern has not yet been broadly studied due to difficulties in their experimental conditions. However, several studies reports that target temperature has a strong influence on the wavelength of ripple pattern [2].

In this work, Ge surfaces were bombarded with low energy O2 ions to conduce a modification in surface morphology. Different oxygen ion bombarding energies were used, such as, 250 eV, 500 eV, 1 keV and 2 keV. Simultaneously different angle of incidences at different target temperatures and different sputtering doses were utilized under ultra high vacuum (UHV) conditions inside a TOF-SIMS-5 (IonTof Co) time-of-flight secondary ion mass spectrometer. After varying the above conditions of IBS, we observed the evolution of surface roughness lead up to a formation of nano-patterned structures.

After ion irradiation, the surface morphology was investigated by atomic force microscopy (AFM) using a Solver Next instrument from NT-DMT. We used the so-called tapping mode to analyze 3-D surface relief; all measurements were conducted in the presence of air. The AFM measurements were performed for different scan sizes (from 0.5x0.5 microns to 50x50 microns) with a resolution of 512x512 pixels and we analyzed roughness statistics and characteristics of nano-pattern (wave length and amplitude). Later, the ion sputtered surfaces were compared with original surface at each case.

References:

[1] B. Ziberi, F. Frost, B. Rauschenbach. Pattern on Ge surfaces during low-energy ion beam erosion. Appl. Phys. Lett. 88, 173115 (2006).

[2] Makeev MA, Cuerno R, Bar´abasi AL (2002) Morphology of ion-sputtered surfaces. Nucl Instr and Meth B 97: 185-227.

NM-WeP-7 Confinement of Optical Modes in Acoustic Cavities Based on Porous Silicon
Zorayda Lazcano (Facultad de Ciencias, Universidad Autónoma de Morelos, Mexico); Jesús Arriaga (Instituto de Física, Benemérita Universidad Autónoma de Puebla); Rolando Pérez-Álvarez (Facultad de Ciencias, Universidad Autónoma de Morelos)

We describe a device that has a resonant cavity for optical modes embedded inside an acoustic cavity. This double cavity structure is a resonator for acoustical waves and enhances the interaction between sound and light.

An acoustic cavity confines the phonon field in the same way that an optical microcavity confines the photon field, leading to strong changes in the wave-matter interaction. Optical microcavities also amplify the interaction between light and phonons [1-2]. Phonon engineering is relevant for the design of optimized phonon devices (mirrors, filters, and cavities) for coherent (single-wavelength) phonon generation and control, to attain phonon amplification and ‘‘lasing’’ [4], and to control the electron–phonon interaction in improved quantum electronic devices [5].

We report the theoretical calculations and the experimental demonstration of optical confinement in acoustic cavity structures based on porous silicon (PS). We designed and fabricated multilayer structures with acoustic cavity modes around 1.1 GHz and optical modes in the infrared range.

Spatial and spectral localization is demonstrated by calculations of acoustic and optical field distribution in samples. Theoretical calculations have been performed by using the Transfer Matrix Method for longitudinal acoustic waves in the continuum limit, in acoustic case, and for unpolarized light, in electromagnetic case. Localization is experimentally demonstrated by direct acoustic transmission and optical reflectivity measurements. And we present calculations of pump and probe time dependent optical reflectivity and acoustic transmission that evidence temporal behavior that derives from both the electromagnetic and acoustic confinement.

References:

[1] Trigo M, Bruchhausen A, Fainstein A, Jusserand B and Thierry-Mieg V, Phys. Rev. Lett.89 227402 (2002).

[2] N. D. Lanzillotti-Kimura, A. Fainstein, A. Huynh, B. Perrin, B. Jusserand, A. Miard, and A. Lemaître, Phys. Rev. Lett.99, 217405 (2007).

NM-WeP-8 Controlling Particle Size of Zeolitic Imidazolate Framework-8 (ZIF-8) Using the Taguchi Method for Pervaporation of Water/Ethanol Mixtures
Kevin Wu (National Taiwan University, Taiwan, Republic of China)

Zeolitic imidazolate frameworks (ZIFs) are a subclass of metal-organic frameworks (MOFs) and are comprised by metal ions and imidazoles. Pervaporation is a type of membrane separation process with a wide range of uses, such as in solvent dehydration and organic mixtures. Here, we want to control the particle sizes of ZIF-8 to optimize the effect on pervaporation by using Taguchi method and then dope it into polyvinyl alcohol (PVA) membrane to increase the separation performance of water/ethanol mixture. We also further changed the amounts of ZIF-8 to optimize the water and ethanol separation performance.

NM-WeP-9 Triboluminescent Coatings for Structural Health Monitoring Applications
Ekaterina Novitskaya (University of California at San Diego); Frank Güell (Universitat de Barcelona); Manuel Herrera-Zaldivar, Gustavo Hirata-Flores (Universidad Nacional Autónoma de México); Olivia A. Graeve (University of California at San Diego)
We present a completely new paradigm for structural health monitoring based on materials that emit a visible light signal as cracks propagate through it. This phenomenon is known as triboluminescence and it allows one to identify and monitor active cracks in situ. Models systems of luminescent Eu-doped Y2O3 (Y2O3:Eu) and Eu-doped BaAl2Si2O8 (BAS:Eu) powders were prepared via solution combustion synthesis using nitrates as precursors and carbohydrazide as a fuel. Morphology of powders was analyzed by scanning electron microscopy (SEM), phase purity and crystallite size of powders in the as-synthesized condition as well as after calcination were characterized by X-ray diffraction (XRD). Particle size of the powders was analyzed by dynamic light scattering technique (DLS). Additionally, photoluminescence (PL) and cathodoluminescence (CL) response of the powders were measured. From the powders, luminescent paints were prepared by mixing the optimized Y2O3:Eu and BAS:Eu powders in clear latex paint. SEM images of the paints were taken to determine the uniform distribution of the powder inside the paint. Additionally, it was found that cracks were initiated in the coating by the SEM electron beam. PL and CL spectra were measured for both types of paints, showing a strong response. Measurements in SEM were completed to quantify the triboluminescence response of the BAS paint. The technique for this measurement is unique and will be described in detail in this presentation.
NM-WeP-10 Synthesis and Characterization of Magnetite/Oleic Acid Ferrofluid and Magnetite-Chitosan Core-Shell Type/Oleic Acid Ferrofluid for Potential Application in Drug Delivery Systems
Sarai Favela (CINVESTAV-Unidad Queretaro, Mexico); Juan Perez (CINVESTAV Querétaro México.); Fernando Donado (Universidad Autonoma del Estado de Hidalgo)

In recent years, ferrofluids have received special attention due to their interesting properties and various biomedical applications such as drug delivery, since it requires that the magnetic nanoparticles be suspended in colloidal or ferrofluid solutions to provide better stability and dispersion nanoparticles as to be administered via intravenous or intra arterial to the target site. Therefore, it is important to characterize their rheological properties in order to find a fluid with good stability.

In this work, magnetite particles were synthesized by Fast Injection Co-precipitation method and coated with chitosan (core-shell type). These nanoparticles were used to synthesize two ferrofluids (magnetite and magnetite-chitosan) using oleic acid as a surfactant. An study of the rheological properties of both fluids was carried out; with and without a magnetic field applied (0.02Teslas) for the two fluids. The fluid containing the uncoated nanoparticles showed Newtonian fluid properties and the fluid containing the coated nanoparticles (magnetite- chitosan Core / Shell type) showed Bingham fluid properties. When the magnetic field was applied, the ferrofluid containing the uncoated nanoparticles showed a non-Newtonian fluid behavior and in the case of the ferrofluid coated nanoparticles showed liquid-plastic behavior. Finally, viscosity was measured without/with an applied magnetic field, and for both fluids it was observed that without magnetic field they behave like Newtonian fluids and with magnetic field as a Bingham fluid.

NM-WeP-11 Modeling of Thermoluminescent Glow Curves in GaN/AlGaN Nanostructures Fabricated by Molecular Beam Epitaxy.
Benjamín Nieto-Hernández (Universidad Autónoma Metropolitana Iztapalapa, Mexico); Juan Hernández-Rosas (Instituto Politécnico Nacional UPIITA, Mexico); Luis Escobar-Alarcón (Instituto de Investigaciones Nucleares, Mexico); Saúl Arias-Cerón (Centro de Investigación y de Estudios Avanzados del IPN, Mexico); JoséLuis Herrera-Pérez, Manolo Ramírez-López (Instituto Politécnico Nacional UPIITA, Mexico); Máximo López-López (Centro de Investigación y de Estudios Avanzados del IPN, Mexico)
In this work, we study the glow curves of GaN/AlGaN quantum wells (QWs) growth by Molecular Beam Epitaxy (MBE) on sapphire and Si [111] substrates. MBE is an excellent technique to grow compound semiconductor films with very good crystalline quality. However, nitrides growing by MBE are accompanied by the formation of defects due to strain between the film and the substrate. Photo-Luminescence (PL) in these QWs shows a redshift in the recombination energy due to spontaneous and piezoelectric polarization, which gives an optical emission lower than the band gap of GaN. In addition of that, PL shows another band related to traps due to defects, traps that we also study by thermoluminescence (TL). The glow curves shown by TL spectra have been modeled with the well-known theory of Randall-Wilkins. In the modeling, we have made use of the mass effective approximation parameters.
NM-WeP-13 Synthesis of GaN/AlN Core-Shell Nanowire
Hue-Min Wu, Wei-Wei Duan (Department of Optoelectronic Physics, Chinese Culture University, Taipei, Taiwan, Taiwan, Republic of China)

Abstract

Suggestted potential applications in heterostructure material, due to band gap modulation result in the interface carrier pile-up, can be wildly used in Electro-Optical nanodevice and micro-electro-mechanical systems(MENS).

In this study, catalystic assisted chemical vapor deposition(CVD) method was used in the synthesis of Ⅲ- nitride heterostructure nano-materials on direct reactions of ammonia and source materials at elevated temperatures. By using nickel as metal catalyst, hexagonal wurtzite structure of GaN nanowires were successfully obtained on silicon substrate. The average diameters of the nanowires were 50 nm and the lengths were about tens of micrometers. The produced GaN nanowire was, in turn, placed in the CVD system, and covered by a layer of AlN, to synthesize a one-dimensional GaN/AlN core-shell heterostructure.

The morphology and heterostructure interface of nanowires was investigated by SEM (Scanning electron microscope) and TEM (Transmission electron microscopy)。EDS (Energy dispersion spectronscopy) and XRD (X-ray diffraction) were used to characterize its composition and lattice structure. The inspections show that CVD process was successfully demostrated to synthesize high-quality GaN/AlN core-shell nanowire with uniform surface and 148 nm diameter. The TEM inspection also shows the integrity of its structure. The oprtical preperties were inspected by PL (photoluminecence) as well.

NM-WeP-14 Structural Parameters of Nanocrystalline Calcium Phosphate using CTAB as a Cationic Template
Magdalena Méndez-González (ESFM-National Polytechnic Institute of Mexico); Gabriela Méndez (Technological University of San Juan del Rio, Queretaro, Mexico)

Thanks to nanotechnology, new materials are being fabricated with special properties used in a variety of applications, such as the materials used as implants or bone substitute in the human body, these must be adapted to the changes that occur in the bone as it reconstructs constantly. The main bone component is the calcium phosphate denominated as hydroxyapatite. The human body is constantly reabsorbing this and reconstructing new bone. In this way the body adjusts the bone width in response to the change of weight distribution with the body. Synthetic nanostructured ceramics have been developed in order to react with the body fluids so apatite can be formed, which is the natural ceramic in the bone. But the idea is to go further. Not only pure mechanical zones, like articulations or extremities, can be replaced: to this day, corneal blindness can be treated using a cornea transplant. In the present work the employed technique was precipitation as a simple technique for the obtaining of nanocrystalline calcium phosphate with the goal of producing odonto keratoprosthesis and therefore avoid the canine tooth extraction surgery as it is an expensive operation, actually this synthesis route was used in order to save time and see how the results are affected by modifying the variables. No impurities were detected other than calcium phosphate as a result of the pH variation. In the infrared spectra shown a very small amount of the CTAB molecule incorporated in the calcium phosphate.

NM-WeP-15 Hydrothermal Synthesis of Nickel Hydroxide/Cobalt Hydroxide/Reduced Graphene Oxide Composite for Electrochemical Capacitors
SintayehuNibret Tiruneh, SungRyul Mang, TranNgoc Quang, HyungDae Lim, BongKyun Kang, DaeHo Yoon (Sungkyunkwan University, Korea, Republic of Korea)

Hydrothermal Synthesis of Nickel hydroxide/Cobalt Hydroxide/Reduced graphene Oxide Composite for Electrochemical Capacitors

Sintayehu Nibret Tiruneh1, Sung Ryul Mang­2, Tran Ngoc Quang2, Hyung Dae Lim2, Bong Kyun Kang2, Dae Ho Yoon1,2*

1 SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University,

2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea

2School of Advanced Materials Science & Engineering, Sungkyunkwan University,

2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea

Tel: +82-31-290-7388

E-mail:dhyoon@skku.edu [mailto:dhyoon@skku.edu]

Pseudocapacitive materials such as hydroxides, oxides, and polymers are being explored for producing supercapacitors with increased specific capacitances (Cs) and a high energy density. Metal hydroxides (MHs) (hydroxides of Co, Ni, Mn, Fe etc) deliver high specific capacitance and are renowned on their well-defined pseudocapacitance. Though they have high energy density, their importance is limited in Electrochemical Capacitors (ECs) application due to low power density which arises from their poor conductivity nature. In contrary, graphene is an ideal wonder substrate to render them electrochemically active and electrically conductive to the outside current collectors. Many researches have been done on MHs/Graphene composites. Recently, synthesizing of two or more MHs growing on graphene is getting much attention in increasing the conductivity while keeping high Cs and significant improvements were seen. Nevertheless, hydroxides/graphene composites synthesized in this way were poorly crystallized.

In this study, we report chemical precipitation of Co(OH)2/Ni(OH)2 on graphene followed by hydrothermal synthesis to boost crystallinity and uniform coating of the MHs on reduced graphene oxide(rGO) while maintaining the high Cs. Different MHs precursor ratios, MHs to rGO ratio, and hydrothermal synthesis temperature were used as a parameter.In addition, two methods of growing the precursors on rGO are reported. Morphology of the as-obtained samples was characterized by X-ray diffraction and scanning electron microscopy. Furthermore, electrochemical measurements were investigated.

NM-WeP-16 Nanocrystalline Diamond Powder Fabricated using Coaxial Arc Plasma Equipped with Chromium-Blended Graphite Targets
Aki Tominaga, Hiroshi Naragino (Kyushu University, Japan); Hiroyuki Deguchi (Kyushu Institute of Technology, Japan); Kaoru Takeda (Fukuoka Institute of Technology, Japan); Tsuyoshi Yoshitake (Kyushu University, Japan)

Nano-sized diamond, such as nanocrystalline diamond (NCD), ultrananocrystalline diamond (UNCD), and diamondoids, is a new nanocarbon. Since it was reported that diamond exhibits strong photoluminescence due to nitrogen-vacancy center and generates defect-induced magnetization, the application of nanodiamonds to drag delivery has received much attention. In order to induce the novel functionalities in diamond, doping should be carried out precisely.

Nano-sized diamond powder has ever been fabricated by detonation, and the doping of foreign elements to the powder has been made mainly by ion implantation. In-situ doping during the formation should enable us to incorporate foreign element atoms into nano-sized diamond, effectively and simply. In this work, we employed a coaxial arc plasma gun for the formation of UNCD powder and demonstrated the in-situ doping of chromium during the formation. A coaxial arc plasma gun (ULVAC APG-1000) equipped with a chromium-blended graphite target was operated in vacuum and hydrogen atmospheres. The head of the gun was pointed at a quartz plate. The distance between the plate and gu head was 15 mm. Quartz plate’s temperatures are 550 ºC. Films that quickly and automatically exfoliated from the plate were gathered, and they were smashed into powder. The XRD pattern of 10 at% Cr doped powdered diamond nanoparticles, measured with 12 keV X-ray at beamline 15 of the SAGA-LS, exhibited obvious peaks due to diamond-111 and 220. The electron diffraction also exhibited the similar results. Chromium K-edge XAFS spectra were measured at beamline 6 of the SAGA-LS (: Kyushu University Beamline). The magnetic properties were measured by a vibrating sample magnetometer and superconducting quantum interference device. The details will be reported in the conference presentation.

This work was partially supported by JSPS KAKENHI Grant Number 26790019, Kazuchika Okura Foundation, and JGC-S scholarship foundation. The experiment using synchorotron radiation were performed at the beamline BL15 of the SAGA Light Source with the approval of the Kyushu Synchrotron Lignt Research Center (Proposal No. 1303019A ). XAFS measurements were performed at Kyushu University Beamline (SAGA-LS /BL06).
NM-WeP-18 Effect of Heat Treatment on the Damping Capacity and Texture of Magnesium Alloy
Jongyoung Lee (College of Engineering, Pukyong National University, Republic of Korea); Hansang Kwon (Pukyong National University, Republic of Korea); Junho Choi (College of Engineering, Pukyong National University, Republic of Korea); Kwonhoo Kim (Pukyong National University, Republic of Korea)

Much attention has been paid on Magnesium alloys in electronics and automobiles industrial parts, due to lightweight and other excellent properties, such as low density, high specific strength, and good castability. However, due to the limited number of slip systems associated with their hexagonal close-packed crystal structure, both magnesium and its alloys show poor room-temperature formability. It is well-known that crystallographic texture plays an important role in both plastic deformation and macroscopic anisotropy of magnesium alloys. Therefore, many authors have been studied to understand the texture control of magnesium alloys, focusing on improvement of the room temperature formability in Magnesium alloy. However, despite having many excellent properties in magnesium alloys, the study for various properties of magnesium alloys have not been clarified enough.

It was well-known that magnesium alloys have a good damping capacity compared to the other alloys. Also, the damping properties of metals are generally recognized to be dependent on microstructural factors such as grain size and texture. However, there are very few studies on the relationship between the damping ability and texture of Mg alloys. Therefore, in this study, the AZ31 magnesium alloy which was carried out by heat treatment was experimentally investigated about the relationship between the texture and damping capacity.

A 60 mm × 60 mm × 40 mm rectangular plate was cut out by machining an ingot of AZ31 magnesium alloy (Mg-3Al-1Zn in mass%), and rolling was carried out at 673 K to a rolling reduction of 30%. Then, heat treatment was carried out at temperatures in the range of 573–723 K for durations in the range of 30–180 min. The samples were immediately quenched in oil after heat treatment to prevent any change in the microstructure. Specimens for damping capacity measurements were machined from the rolled specimen, to have a length of 120 mm, width of 20 mm, and thickness of 1 mm. The damping capacity was measured with a flexural internal friction measurement machine at room temperature. Texture was evaluated on the compression planes by the Schulz reflection method using nickel-filtered Cu Kα radiation. Electron backscatter diffraction measurements were conducted to observe the spatial distribution of various orientations. It was found that the damping capacity increases with both increasing heat-treatment temperature and time, due to grain growth and also, the pole densities of texture increase with increasing the internal friction.

NM-WeP-20 Total Analysis of Silica Nanotube Surface by using TOF-SIMS
Jong Sung Jin, D.Y. Kim, J.W. Kim, E.D. Jeong, F.N. Kahn (Korea Basic Science Institute, Korea); Y.C. Lee, S.M. Jin (Korea Institute of Industrial Technology, Korea)
Recently, many researchers have been interested in the self-assembled 3D supramolecular structures to synthesis of helical silica nanotubes. We have been studied the solvent-effects on the synthesizing of helical silica nanotubes via polycondensation of tetraethoxysilane (TEOS) on self-assembled structures that were composed 1,2-diphenylethylenediamine based neutral (G1) and cationic (G1N) gelators.[1] In this study, we analyzed helical silica nanotubes and derivatized chiral stationary phases by using TOF-SIMS. We discussed products of each steps for the derivatized organic compound on the silica surface in order to confirm the reactions.

[1] T. K. Kim, E. D. Jeong, C. Y. Oh, M. H. Hyun, M. S. Lee, H. K. Moon, J. P. Kim, O. S. Jung, F. N. Nawaz, J. S. Jin, Chem. Pap. 65(4), 2011, 495

NM-WeP-21 Photodetector and Pressure Sensor Based on Field-Effect Transistor with the Nanohybrid Channel of ZnO Nanorods and Graphene
Dang Vinh Quang, Tran Quang Trung, Do-Il Kim, Le Thai Duy, Bo-Yeong Kim, Byeong-Ung Hwang, Doo-Won Lee, Nae-Eung Lee (Sungkyunkwan University, Korea)
Field-effect transistors (FETs) with a nano-hybrid channel of chemical-vapor-deposited graphene (CVD Gr) and vertically aligned ZnO nanostructures are successfully fabricated and operated at low volatge. By the combination of highly conductive Gr and the high UV absorption of ZnO, ultraviolet (UV) photodetectors are investigated under illumination at various incident photon intensities and wavelengths. The change in the transfer characteristics of hybrid-channel FETs under UV light illumination allows to detect both photovoltage and photocurrent. The shift of the Dirac point (VDirac) observed during UV exposure led to a clearer explanation of the response mechanism and carrier transport properties of Gr, and this phenomenon permits the calculation of electron concentration per UV power density transferred from ZnO nanorods (NRs) and ZnO nanoparticles (NPs) to Gr, which is 9 × 1010 and 4 × 1010 per mW, respectively. The time-dependent behaviours of hybrid-channel FETs exhibit high UV responsivity (RI) and high photoconductive gain (G). The maximum values of RI and G infer from the fitted curves of RI and G versus UV intensity are 3 × 105 A W-1 and 106, respectively. More interestingly, due to the piezoelectric property of ZnO, a piezoelectric-coupled hybrid channel GFET can be used as a pressure-sensing device with high responsiveness and a fast response time. The shifts of VDirac under mechanical pressurization are analysed to explain clearer the charge transferred mechanism with electron transfer of 4x108 cm-2 kPa-1 from the CVD Gr to ZnO NRs. Therefore, hybridization of semiconductor 1D nanomaterials with Gr channel in FET structures resulting in high performance and low power consumption opens up new opportunities for future optoelectronic devices.

Suggested topic: Nanomaterials (NM1-Nano Devices)

NM-WeP-22 Defect Induced Visible Light Photocatalytic Activity of SnO2 Nanoparticles
Sajid A. Ansari, M. Mansoob Khan, M. Omaish Ansari, Moo Hwan Cho (Yeungnam University, South Korea)
We report the defect-induced band gap narrowing of pure SnO2 nanoparticles (p-SnO2) using an electrochemically active biofilm. The proposed approach is biogenic, simple and green. The systematic characterization results of the modified SnO2 nanoparticles (m-SnO2) revealed EAB-mediated defects in p-SnO2. m-SnO2 nanoparticles in visible light showed the enhanced photocatalytic degradation of p-nitrophenol and methylene blue compared to p-SnO2 nanoparticles. Photoelectrochemical studies, such as electrochemical impedance spectroscopy and linear scan voltammetry, also revealed a significant increase in the visible light response of m-SnO2 compared to p-SnO2 nanoparticles. The enhanced activities of m-SnO2 in visible light was attributed to the high separation efficiency of the photoinduced electron-hole pairs due to surface defects created by EAB, resulting in band gap narrowing of the m-SnO2 nanoparticles.
NM-WeP-23 The Effect of Diamond Like Carbon Nanoparticles on Mechanical, Thermal and Morphological Properties of Epoxy/Polyamide Coating
Rawaiz Khan, Mouraz Boumaza (King Saud University, Saudi Arabia); Mohammad Asif Alam (Center of Excellence for Research in Engineering Materials (CEREM), Saudi Arabia); Muhammad Saeed Al-Zahrani (King Saud University, Saudi Arabia)
The current study is based on the incorporation of diamond like carbon nanopowder with a very high specific surface area, which has been used as reinforcing filler for an epoxy based nanocomposite coating. High speed mechanical stirring and ultrasonication techniques were used for homogeneous dispersion of nanopowder in epoxy matrix. SEM is used to ensure the uniform dispersion of nanoparticles. EDS and XRD were used to have a quantitative and qualitative analysis of nanocomposites and ensure the existence of Carbon like Nanoparticles. Nanoindentation revealed that the addition of these nanoparticles enhance the hardness and elastic modulus of the filled nanocomposite with increasing loading. TGA and DSC results show significant improvement in thermal decomposition temperature, glass transition temperature (Tg), Initial decomposition temperature (Ti) and maximum decomposition temperature (Tmax). However the surface roughness is increased with increasing nanoparticles.
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