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Sample records for nano structured materials

  1. Micro-and nano-structured conducting polymeric materials

    Institute of Scientific and Technical Information of China (English)

    LU Gewu; CHEN Feng'en; WU Xufeng; QU Liangti; ZHANG Jiaxin; SHI Gaoquan

    2005-01-01

    Conducting polymeric materials with micro-/nano-structures have potential applications in fabrication of various optical, electronic, sensing and electrochemical devices. This is mainly because these materials not only possess the characteristics of conducting polymers, but also have special functions based on their micro- or nano-structures. In this review, we summarize the recent work on "soft" and "hard" template-guided syntheses of micro-/nano-structured conducting polymers and open up the prospects of the main trends in this field.

  2. Manufacture of Nano Structures in Polymer Material

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Pedersen, H.C.; Staun, Jacob

    2003-01-01

    The incorporation of micro and nano technology into the products of the future is an area of increasing interest. The ideas for new products based on this technology often take their starting point in specific scientific fields whereas the subsequent design and product development not necessarily...... is based on a systematic approach including manufacturing processes and production system capabilities. The process chain associated with micro and nano injection moulding usually comprises silicon or photoresist mastering, electroforming and polymer processing. Additionally, if the produced polymer...

  3. STRUCTURE AND DYNAMICS OF POLYMERIC MATERIALS IN NANO-SCALE

    Institute of Scientific and Technical Information of China (English)

    Toshio Nishi; So Fujinami; Dong Wang; Hao Liu; Ken Nakajima

    2011-01-01

    The nano-palpation technique, i.e., nanometer-scale elastic and viscoelastic measurements based on atomic force microscope, is introduced. It is demonstrated to be very useful in analyzing nanometer-scale materials properties for the surfaces and interfaces of various types of soft materials. It enables us to obtain not only structural information but also mechanical information about a material at the same place and at the same time.

  4. Optical Spectroscopy of Nano Materials and Structures

    Science.gov (United States)

    Guo, Wenhao

    In this thesis, nanostructures and nanomaterials ranging from 3D to OD will be studied compresively, by using optical methods. Firstly, for 3D and 2D nanomaterials, nanoporous zeolite crystals, such as AFI and AEL are introduced as host materials to accommodate diatomic iodine molecules. Polarized Raman spectroscopy is utilized to identify the two configurations of iodine molecules to stay in the channels of AEL: the lying mode (the bond of the two atoms is parallel to the direction of the channels) and the standing mode (the bond is perpendicular to the direction of the channels). The lying mode and standing mode are switchable and can be well controlled by the amount of water molecules inside the crystal, revealed by both molecule dynamics simulation and experiment observation. With more water molecules inside, iodine molecules choose to stay in the standing mode, while with less water molecules, iodine molecules prefer to lie along the channel. Therefore, the configurations of molecules could be precisely controlled, globally by the surrounding pressure and temperature, and locally by the laser light. Ii is believed that this easy and reversible control of single molecule will be valuable in nanostructured devices, such as molecular sieving or molecular detection. Secondly, for 1D case, the PL spectrum of ZnO nanowire under uniaxial strain is studied. When a ZnO nanowire is bent, besides the lattice constant induced bandgap change on the tensile and compressive sides, there is a piezoelectric field generated along the cross section. This piezoelectric potential, together with the bandgap changes induced by the deformation, will redistribute the electrons excited by incident photons from valence band to conduction band. As a result, the electrons occupying the states at the tensile side will largely outnumbered the ones at the compressive side. Therefore, the PL spectrum we collected at the whole cross section will manifest a redshift, other than the peak

  5. Microstructure characterization and magnetic properties of nano structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.C

    2000-07-01

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe{sub 78}Si{sub 9}B{sub 13} ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy [eds.]; selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  6. Manufacture of Nano Structures in Polymer Material

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Pedersen, H.C.; Staun, Jacob

    2003-01-01

    components are to be used in a microsystem, subsequent handling and assembly is necessary. The present paper describes the process chain related to the manufacture of optical gratings with nanometer-sized structures. The problems of each process step and the challenges of establishing a coherent production...

  7. Nanomanufacturing : nano-structured materials made layer-by-layer.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, James V.; Cheng, Shengfeng; Grest, Gary Stephen; Tjiptowidjojo, Kristianto (University of New Mexico); Reedy, Earl David, Jr.; Fan, Hongyou; Schunk, Peter Randall; Chandross, Michael Evan; Roberts, Scott A.

    2011-10-01

    Large-scale, high-throughput production of nano-structured materials (i.e. nanomanufacturing) is a strategic area in manufacturing, with markets projected to exceed $1T by 2015. Nanomanufacturing is still in its infancy; process/product developments are costly and only touch on potential opportunities enabled by growing nanoscience discoveries. The greatest promise for high-volume manufacturing lies in age-old coating and imprinting operations. For materials with tailored nm-scale structure, imprinting/embossing must be achieved at high speeds (roll-to-roll) and/or over large areas (batch operation) with feature sizes less than 100 nm. Dispersion coatings with nanoparticles can also tailor structure through self- or directed-assembly. Layering films structured with these processes have tremendous potential for efficient manufacturing of microelectronics, photovoltaics and other topical nano-structured devices. This project is designed to perform the requisite R and D to bring Sandia's technology base in computational mechanics to bear on this scale-up problem. Project focus is enforced by addressing a promising imprinting process currently being commercialized.

  8. Preparation and properties on hollow nano-structured smoke material

    Science.gov (United States)

    Liu, Xiang-cui; Dai, Meng-yan; Fang, Guo-feng; Shi, Wei-dong; Cheng, Xiang; Liu, Hai-feng; Zhang, Tong

    2013-09-01

    In recent years, the weapon systems of laser guidance and infrared (IR) imaging guidance have been widely used in modern warfare because of their high precision and strong anti-interference. Notwithstanding, military smoke, as a rapid and effective passive jamming means, can effectively counteract the attack of enemy precision-guided weapons by scattering and absorbability. Conventional smoke has good attenuation capability only to visible light (0.4-0.76 μm), but hardly any effect to other electromagnetic wave band. The weapon systems of laser guidance and IR imaging guidance usually work in broad band, including near IR (1-3 μm), middle IR (3-5 μm), far IR (8-14 μm), and so on. Accordingly, exploiting and using new efficient obscurant materials, which is one of the important factors that develop smoke technology, have become a focus and attracted more interests around the world. Then nano-structured materials that are developing very quickly have turned into our new choice. Hollow nano-structured materials (HNSM) have many special properties because of their nano-size wall-thickness and sub-micron grain-size. After a lot of HNSM were synthesized in this paper, their physical and chemical properties, including grain size, phase composition, microstructure, optical properties and resistivity were tested and analysed. Then the experimental results of the optical properties showed that HNSM exhibit excellent wave-absorbing ability in ultraviolet, visible and infrared regions. On the basis of the physicochemmical properties, HNSM are firstly applied in smoke technology field. And the obscuration performance of HNSM smoke was tested in smoke chamber. The testing waveband included 1.06μm and 10.6μm laser, 3-5μm and 8-14μm IR radiation. Then the main parameters were obtained, including the attenuation rate, the transmission rate, the mass extinction coefficient, the efficiency obscuring time, and the sedimentation rate, etc. The main parameters of HNSM smoke were

  9. Nano structured materials studied by coherent X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Gulden, Johannes

    2013-03-15

    Structure determination with X-rays in crystallography is a rapidly evolving field. Crystallographic methods for structure determination are based on the assumptions about the crystallinity of the sample. It is vital to understand the structure of possible defects in the crystal, because they can influence the structure determination. All conventional methods to characterize defects require a modelling through simulated data. No direct methods exist to image the core of defects in crystals. Here a new method is proposed, which will enable to visualize the individual scatterers around and at defects in crystals. The method is based on coherent X-ray scattering. X-rays are perfectly suited since they can penetrate thick samples and buried structures can be investigated Recent developments increased the coherent flux of X-Ray sources such as synchrotrons by orders of magnitude. As a result, the use of the coherent properties of X-rays is emerging as a new aspect of X-ray science. New upcoming and operating X-ray laser sources will accelerate this trend. One new method which has the capacity to recover structural information from the coherently scattered photons is Coherent X-ray Diffraction Imaging (CXDI). The main focus of this thesis is the investigation of the structure and the dynamics of colloidal crystals. Colloidal crystals can be used as a model for atomic crystals in order to understand the growth and defect structure. Despite the large interest in these structures, many details are still unknown.Therefore, it is vital to develop new approaches to measure the core of defects in colloidal crystals. After an introduction into the basics of the field of coherent X-ray scattering, this thesis introduces a novel method, Small Angle Bragg Coherent Diffractive Imaging, (SAB-CDI). This new measurement technique which besides the relevance to colloidal crystals can be applied to a large variety of nano structured materials. To verify the experimental possibilities the

  10. Structure-property relationships of multiferroic materials: A nano perspective

    Science.gov (United States)

    Bai, Feiming

    The integration of sensors, actuators, and control systems is an ongoing process in a wide range of applications covering automotive, medical, military, and consumer electronic markets. Four major families of ceramic and metallic actuators are under development: piezoelectrics, electrostrictors, magnetostrictors, and shape-memory alloys. All of these materials undergo at least two phase transformations with coupled thermodynamic order parameters. These transformations lead to complex domain wall behaviors, which are driven by electric fields (ferroelectrics), magnetic fields (ferromagnetics), or mechanical stress (ferroelastics) as they transform from nonferroic to ferroic states, contributing to the sensing and actuating capabilities. This research focuses on two multiferroic crystals, Pb(Mg1/3Nb 2/3)O3-PbTiO3 and Fe-Ga, which are characterized by the co-existence and coupling of ferroelectric polarization and ferroelastic strain, or ferro-magnetization and ferroelastic strain. These materials break the conventional boundary between piezoelectric and electrostrictors, or magnetostrictors and shape-memory alloys. Upon applying field or in a poled condition, they yield not only a large strain but also a large strain over field ratio, which is desired and much benefits for advanced actuator and sensor applications. In this thesis, particular attention has been given to understand the structure-property relationships of these two types of materials from atomic to the nano/macro scale. X-ray and neutron diffraction were used to obtain the lattice structure and phase transformation characteristics. Piezoresponse and magnetic force microscopy were performed to establish the dependence of domain configurations on composition, thermal history and applied fields. It has been found that polar nano regions (PNRs) make significant contributions to the enhanced electromechanical properties of PMN-x%PT crystals via assisting intermediate phase transformation. With increasing PT

  11. Nano-composite materials

    Science.gov (United States)

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  12. Nano Materials

    Science.gov (United States)

    2007-03-01

    hard coatings: – Molecular sieves – Lubricant additive to engine oil – Reinforcing fillers for plastics and rubbers – Chromatographic carriers 32...nanomaterials, November 2006 NanoCeramics applications (PlasmaChem) • Lapping and polishing • Low temperature sintering • New Ceramic alloys • Ceramic-metal...Nanotechnology lectures: Henne van Heeren, enablingMNT, nanomaterials, November 2006 MoS2 nanospheres (1) (Apnano) • Common solid lubricants are layered

  13. Synthesis and micro-structural study of one-dimensional nano-materials

    Institute of Scientific and Technical Information of China (English)

    周光文; 张泽; 俞大鹏

    1999-01-01

    Silicon nano-wires (SiNWs) and boron nitride nano-tubules (BN-NTs) were successfully synthesized by excimer laser ablation at high temperature. These one-dimensional nano-materials synthesized by this method have a very high yield, a uniform diameter distribution, and a high purity. Micro-structures of these nano-materials were investigated by transmission electron microscopy (TEM). The SiNWs have a high density of structural defects of microtwin, stacking faults, and low-angle boundary, which ere closely related to the formation of SiNWs and the determination of morphology of the nano-wires. BN-NTs ere mainly single atomic-layered and the outer surface of tubules is clean without any attachment. The formation of single atomic-layered tubule is attributed to the catalyst effect which makes the axial rate of BN-NTs much higher than the radial growth.

  14. Could Nano-Structured Materials Enable the Improved Pressure Vessels for Deep Atmospheric Probes?

    Science.gov (United States)

    Srivastava, D.; Fuentes, A.; Bienstock, B.; Arnold, J. O.

    2005-01-01

    A viewgraph presentation on the use of Nano-Structured Materials to enable pressure vessel structures for deep atmospheric probes is shown. The topics include: 1) High Temperature/Pressure in Key X-Environments; 2) The Case for Use of Nano-Structured Materials Pressure Vessel Design; 3) Carbon based Nanomaterials; 4) Nanotube production & purification; 5) Nanomechanics of Carbon Nanotubes; 6) CNT-composites: Example (Polymer); 7) Effect of Loading sequence on Composite with 8% by volume; 8) Models for Particulate Reinforced Composites; 9) Fullerene/Ti Composite for High Strength-Insulating Layer; 10) Fullerene/Epoxy Composite for High Strength-Insulating Layer; 11) Models for Continuous Fiber Reinforced Composites; 12) Tensile Strength for Discontinuous Fiber Composite; 13) Ti + SWNT Composites: Thermal/Mechanical; 14) Ti + SWNT Composites: Tensile Strength; and 15) Nano-structured Shell for Pressure Vessels.

  15. Nano-structured carbon materials for improved biosensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Razumiene, J., E-mail: julija.razumiene@bchi.vu.lt [Institute of Biochemistry, Vilnius University, Mokslininku 12, Vilnius 08662 (Lithuania); Sakinyte, I. [Institute of Biochemistry, Vilnius University, Mokslininku 12, Vilnius 08662 (Lithuania); Barkauskas, J. [Faculty of Chemistry, Vilnius University, Naugarduko 24, Vilnius 03225 (Lithuania); Baronas, R. [Faculty of Mathematics and Informatics, Vilnius University, Naugarduko 24, Vilnius 03225 (Lithuania)

    2015-04-15

    Graphical abstract: - Highlights: • Novel protocols of graphite oxidation were used for successful synthesis of GOPs. • Newly synthesized GOPs were applicable for electrode design in reagentless bioelectrocatalytic systems operating on direct electron transfer. • We show that bioelectrocatalytic processes strongly depend on functionalities, morphology and structural features of GOPs. - Abstract: A set of oxidized graphite samples have been newly synthesized using different protocols. Atomic force microscopy, Raman spectroscopy, thermal gravimetric analysis and Brunauer–Emmett–Teller analysis revealed the changes in structure and functionalities of obtained graphite oxidation products (GOPs) compared to pristine graphite. The substances have been tested as electrode materials applicable for bioelectrocatalytic systems using pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH). The application of GOPs allowed achieving the direct electron transfer (DET) from active site of PQQ-GDH to the electrode surface. Needless of additional electron transfer (ET) mediating compounds highly improved features of the biosensors. The efficiency of the biosensors has been evaluated for all types of biosensors varied from 32 μA/cm{sup 2} to 64 μA/cm{sup 2} using as electrode materials GOP1 and thermally reduced graphite oxide (TRGO), respectively. TRGO containing function groups (according TGA, ∼6% of the weight loss) and smallest particles (average diameter was ∼11 nm and the average height was ∼0.5 nm) exhibited the higher efficiency for ET acceleration in the biosensor acting on principle of DET.

  16. CHARACTERIZATION OF NANO-STRUCTURES IN MATERIALS BY TRANSMISSION ELECTRON MICROSCOPY

    OpenAIRE

    Tomokiyo, Y.

    2008-01-01

    We will introduce the usefulness of convergent beam electron diffraction (CBED) in nano-characterization of materials: (1) Determination of local lattice strain in Si, (2) Determination of polarity of GaN of wurtzite structure, (3) Measurement of local oxygen concentration of the high Tc superconductor YBa2Cu3Oy. Keywords: convergent beam electron diffraction

  17. Modeling and simulation of electronic structure, material interface and random doping in nano electronic devices

    Science.gov (United States)

    Chen, Duan; Wei, Guo-Wei

    2010-01-01

    The miniaturization of nano-scale electronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), has given rise to a pressing demand in the new theoretical understanding and practical tactic for dealing with quantum mechanical effects in integrated circuits. Modeling and simulation of this class of problems have emerged as an important topic in applied and computational mathematics. This work presents mathematical models and computational algorithms for the simulation of nano-scale MOSFETs. We introduce a unified two-scale energy functional to describe the electrons and the continuum electrostatic potential of the nano-electronic device. This framework enables us to put microscopic and macroscopic descriptions in an equal footing at nano scale. By optimization of the energy functional, we derive consistently-coupled Poisson-Kohn-Sham equations. Additionally, layered structures are crucial to the electrostatic and transport properties of nano transistors. A material interface model is proposed for more accurate description of the electrostatics governed by the Poisson equation. Finally, a new individual dopant model that utilizes the Dirac delta function is proposed to understand the random doping effect in nano electronic devices. Two mathematical algorithms, the matched interface and boundary (MIB) method and the Dirichlet-to-Neumann mapping (DNM) technique, are introduced to improve the computational efficiency of nano-device simulations. Electronic structures are computed via subband decomposition and the transport properties, such as the I-V curves and electron density, are evaluated via the non-equilibrium Green's functions (NEGF) formalism. Two distinct device configurations, a double-gate MOSFET and a four-gate MOSFET, are considered in our three-dimensional numerical simulations. For these devices, the current fluctuation and voltage threshold lowering effect induced by the discrete dopant model are explored. Numerical convergence

  18. Modeling and simulation of electronic structure, material interface and random doping in nano-electronic devices

    Science.gov (United States)

    Chen, Duan; Wei, Guo-Wei

    2010-06-01

    The miniaturization of nano-scale electronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), has given rise to a pressing demand in the new theoretical understanding and practical tactic for dealing with quantum mechanical effects in integrated circuits. Modeling and simulation of this class of problems have emerged as an important topic in applied and computational mathematics. This work presents mathematical models and computational algorithms for the simulation of nano-scale MOSFETs. We introduce a unified two-scale energy functional to describe the electrons and the continuum electrostatic potential of the nano-electronic device. This framework enables us to put microscopic and macroscopic descriptions in an equal footing at nano-scale. By optimization of the energy functional, we derive consistently coupled Poisson-Kohn-Sham equations. Additionally, layered structures are crucial to the electrostatic and transport properties of nano-transistors. A material interface model is proposed for more accurate description of the electrostatics governed by the Poisson equation. Finally, a new individual dopant model that utilizes the Dirac delta function is proposed to understand the random doping effect in nano-electronic devices. Two mathematical algorithms, the matched interface and boundary (MIB) method and the Dirichlet-to-Neumann mapping (DNM) technique, are introduced to improve the computational efficiency of nano-device simulations. Electronic structures are computed via subband decomposition and the transport properties, such as the I- V curves and electron density, are evaluated via the non-equilibrium Green's functions (NEGF) formalism. Two distinct device configurations, a double-gate MOSFET and a four-gate MOSFET, are considered in our three-dimensional numerical simulations. For these devices, the current fluctuation and voltage threshold lowering effect induced by the discrete dopant model are explored. Numerical

  19. Handbook of damage mechanics nano to macro scale for materials and structures

    CERN Document Server

    2015-01-01

    This authoritative reference provides comprehensive coverage of the topics of damage and healing mechanics. Computational modeling of constitutive equations is provided as well as solved examples in engineering applications. A wide range of materials that engineers may encounter are covered, including metals, composites, ceramics, polymers, biomaterials, and nanomaterials. The internationally recognized team of contributors employ a consistent and systematic approach, offering readers a user-friendly reference that is ideal for frequent consultation. Handbook of Damage Mechanics: Nano to Macro Scale for Materials and Structures is ideal for graduate students and faculty, researchers, and professionals in the fields of Mechanical Engineering, Civil Engineering, Aerospace Engineering, Materials Science, and Engineering Mechanics.

  20. Characterization of nano structured metallic materials; Caracterizacion de materiales metalicos nanoestructurados

    Energy Technology Data Exchange (ETDEWEB)

    Marin A, M.; Gutierrez W, C.; Cruz C, R.; Angeles C, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Nowadays the search of new materials with specific optical properties has carried out to realize a series of experiments through the polymer synthesis [(C{sub 3}N{sub 3}){sub 2} (NH){sub 3}]{sub n} doped with gold metallic nanoparticles. The thermal stability of a polymer is due to the presence of tyazine rings contained in the structure. The samples were characterized by High Resolution Transmission Electron Microscopy, X-ray diffraction by the Powder method, Ft-infrared and its thermal properties by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). One of the purposes of this work is to obtain nano structured materials over a polymeric matrix. (Author)

  1. Electrical, thermal, catalytic and magnetic properties of nano-structured materials and their applications

    Science.gov (United States)

    Liu, Zuwei

    Nanotechnology is a subject that studies the fabrication, properties, and applications of materials on the nanometer-scale. Top-down and bottom-up approaches are commonly used in nano-structure fabrication. The top-down approach is used to fabricate nano-structures from bulk materials by lithography, etching, and polishing etc. It is commonly used in mechanical, electronic, and photonic devices. Bottom-up approaches fabricate nano-structures from atoms or molecules by chemical synthesis, self-assembly, and deposition, such as sol-gel processing, molecular beam epitaxy (MBE), focused ion beam (FIB) milling/deposition, chemical vapor deposition (CVD), and electro-deposition etc. Nano-structures can have several different dimensionalities, including zero-dimensional nano-structures, such as fullerenes, nano-particles, quantum dots, nano-sized clusters; one-dimensional nano-structures, such as carbon nanotubes, metallic and semiconducting nanowires; two-dimensional nano-structures, such as graphene, super lattice, thin films; and three-dimensional nano-structures, such as photonic structures, anodic aluminum oxide, and molecular sieves. These nano-structured materials exhibit unique electrical, thermal, optical, mechanical, chemical, and magnetic properties in the quantum mechanical regime. Various techniques can be used to study these properties, such as scanning probe microscopy (SPM), scanning/transmission electron microscopy (SEM/TEM), micro Raman spectroscopy, etc. These unique properties have important applications in modern technologies, such as random access memories, display, solar energy conversion, chemical sensing, and bio-medical devices. This thesis includes four main topics in the broad area of nanoscience: magnetic properties of ferro-magnetic cobalt nanowires, plasmonic properties of metallic nano-particles, photocatalytic properties of titanium dioxide nanotubes, and electro-thermal-optical properties of carbon nanotubes. These materials and their

  2. Structural analysis of bioinspired nano materials with synchrotron far IR spectroscopy.

    Science.gov (United States)

    Seoudi, Rania S; Dowd, Annette; Smith, Brian J; Mechler, Adam

    2016-04-28

    Bioinspired fibres and hierarchical nano-materials are based on the self-assembly of organic building blocks such as polypeptides. Confirming the core structure of such materials is often challenging as they lack the long-range order required by crystallographic methods. Far-IR spectroscopy characterizes the vibrational modes of large molecular units. These vibrational modes are very sensitive to angle strain and second order interactions such as hydrogen bonding. As such, far-IR spectra hold information about the secondary structure and interactions of large biomolecules. Here we analyze the far-IR vibrational spectra of fibrous nano-materials based on three isomeric unnatural tripeptides, Ac-β(3)Leu-β(3)Ile-β(3)Ala, Ac-β(3)Ile-β(3)Ala-β(3)Leu, and Ac-β(3)Ala-β(3)Leu-β(3)Ile. These peptides have well described self-assembly characteristics, forming one-dimensional nanorods that impose tight conformational constraints on the constituent molecules. The synchrotron far-IR spectroscopic results were interpreted by using density functional theory (DFT) modelling based vibrational analysis. The sensitivity of the spectra to peptide conformation was assessed by comparing the experimental spectra with DFT predictions. In high dielectric implicit solvent, intramolecular hydrogen-bonding is inhibited and thus the energy minimized peptide structure remains close to the 14-helix folding characteristic of substituted β(3)-peptides, giving good agreement between the experimental and predicted vibration spectra. In contrast, energy minimization in vacuum alters the peptide conformation leading to intramolecular hydrogen bonds, and hence the predicted vibration spectra do not agree with the experimental data. Therefore, our results demonstrate the ability of far-IR spectroscopy to identify correct structural predictions and thus open the way for using far-IR spectroscopy for the characterization and structural analysis of bioinspired nano-materials and potentially their

  3. Nano semiconducting materials

    CERN Document Server

    Saravanan, R

    2016-01-01

    The main focus of the present book is the characterization of a number of nano-semiconducting materials, using such techniques as powder X-ray diffraction, UV-visible spectrophotometry, Raman spectrometry, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometry. The materials studied include ZnS, TiO2, NiO, Ga doped ZnO, Mn doped SnO2, Mn doped CeO2 and Mn doped ZrO2.

  4. Nano Structure Plays an Important Role in the Present and Future Anode Materials of Li-ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Tsutomu; Takamura

    2007-01-01

    1 ResultsLi-ion batteries are the most promising secondary batteries for IT and EV applications, where it is required to increase the capacity and power capability to a great extent. In responding to the demand we have been studied on the anode materials especially paying attention on the improved graphite active materials and modified silicon. In both cases we realized that the nano-structured design plays an important role. In this paper the examples of nano-size structure working in the actual materi...

  5. Theory of light propagation in nano-structured materials and semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Schaarschmidt, M.

    2006-05-03

    This work presents a theory for the propagation of intense electromagnetic radiation in nano-structures materials and semiconductors. One main area is the modelling and simulation of the microscopic material dynamics of low dimensional semiconductors, both structured and bulk, and of a laser induced plasma. The ultrafast microscopic dynamics of these electronic many particle systems under the influence of light fields and scattering mechanisms like electron-electron interaction or interaction with lattice vibrations is described in the density matrix formalism. This description in second quantization yields the temporal nonlocal and nonlinear response of the material to electromagnetic fields. Laser induced plasma in quantum wells will be shown to be a possible new semiconductor source for terahertz-emission (wavelength mm to micrometer). The second focus of interest of this work lies in the simulation of the propagation of electromagnetic waves in different systems like photonic crystals, optical fibers and wave guides. The propagation in bulk semiconductors and waveguides is considered in both slowly varying envelope approximation (SVEA) and with the nonlinear Schroedinger equation. For complex systems like photonic band gap structures with high symmetry a matrix-transfer formalism is applied. For arbitrary structured systems (which may include local breaches of symmetry) a very flexible finite-differences algorithm is employed. The combination of microscopic material dynamics and light propagation enables the calculation of reflection and transmission properties of nano-structured materials not only in linear excitation but also for high intensities where nonlinear light-matter coupling dominates and novel effects arise. One used model system are Bragg-resonant multiple quantum wells. On this one dimensional resonant absorbing photonic crystal new nonlinear effects are studied. Some effect to mention are the possible application as an ultrafast optical switch

  6. Ultrafast Laser Pulses for Structuring Materials at Micro/Nano Scale: From Waveguides to Superhydrophobic Surfaces

    Directory of Open Access Journals (Sweden)

    Daniel S. Correa

    2017-01-01

    Full Text Available The current demand for fabricating optical and photonic devices displaying high performance, using low-cost and time-saving methods, prompts femtosecond (fs-laser processing as a promising methodology. High and low repetition femtosecond lasers enable surface and/or bulk modification of distinct materials, which can be used for applications ranging from optical waveguides to superhydrophobic surfaces. Herein, some fundamental aspects of fs-laser processing of materials, as well as the basics of their most common experimental apparatuses, are introduced. A survey of results on polymer fs-laser processing, resulting in 3D waveguides, electroluminescent structures and active hybrid-microstructures for luminescence or biological microenvironments is presented. Similarly, results of fs-laser processing on glasses, gold and silicon to produce waveguides containing metallic nanoparticles, analytical chemical sensors and surface with modified features, respectively, are also described. The complexity of fs-laser micromachining involves precise control of material properties, pushing ultrafast laser processing as an advanced technique for micro/nano devices.

  7. Hydrotherrnal synthesis, structure and property of nano-BaTiO3-based dielectric materials

    Institute of Scientific and Technical Information of China (English)

    DING; ShiIiang

    2001-01-01

    [1]Su, W., The proposition of technical progress and development for barium solts, Inorganic Salt Industry (in Chinese), 1992,3: 5.[2]West, A. R., Solid State Chemistry and Its Applications, New Delhi: John Wiley, 1984, 367,534-548.[3]Heistand, R. H., Duquette, L. G., Skeele, E P. et al., Coprecipitated barium titanate(BaTiO3)-based powder formulated from catechol coordination compounds, Ceram. Trans., 1988, 2: 94.[4]Ding, S. W., Ma, G. C., Wang, Z. Q. et al., Synthesis, structure and properties of BaZrxTi1-xO3 · yLa203 solid solutions, Chemical Journal of Chinese Universities (in Chinese), 1998, 19: 1542.[5]Ding, S. W., Zhai, Y. Q., Li, X. M. et al., Synthesis, structure and properties of Ba1-xCaxSnyTi1-y03 solid solutions, Acta Chim. Sinica (in Chinese), 2000, 58:1139.[6]Ding, S. W., Zhal, Y. Q., Li, Y. et al., Synthesis, structure and properties of Bal-xSrxMyTil-yO3 nano-materials, Science in China, Ser. B, 2000, 43(3): 283.[7]

  8. High Performance Nano-Crystalline Oxide Fuel Cell Materials. Defects, Structures, Interfaces, Transport, and Electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, Scott [Northwestern Univ., Evanston, IL (United States); Poeppelmeier, Ken [Northwestern Univ., Evanston, IL (United States); Mason, Tom [Northwestern Univ., Evanston, IL (United States); Marks, Lawrence [Northwestern Univ., Evanston, IL (United States); Voorhees, Peter [Northwestern Univ., Evanston, IL (United States)

    2016-09-07

    This project addresses fundamental materials challenges in solid oxide electrochemical cells, devices that have a broad range of important energy applications. Although nano-scale mixed ionically and electronically conducting (MIEC) materials provide an important opportunity to improve performance and reduce device operating temperature, durability issues threaten to limit their utility and have remained largely unexplored. Our work has focused on both (1) understanding the fundamental processes related to oxygen transport and surface-vapor reactions in nano-scale MIEC materials, and (2) determining and understanding the key factors that control their long-term stability. Furthermore, materials stability has been explored under the “extreme” conditions encountered in many solid oxide cell applications, i.e, very high or very low effective oxygen pressures, and high current density.

  9. Nano-structured support materials, their characterisation and serum protein profiling through MALDI/TOF-MS.

    Science.gov (United States)

    Najam-Ul-Haq, M; Rainer, M; Heigl, N; Szabo, Z; Vallant, R; Huck, C W; Engelhardt, H; Bischoff, K-D; Bonn, G K

    2008-02-01

    In the bioanalytical era, novel nano-materials for the selective extraction, pre-concentration and purification of biomolecules prior to analysis are vital. Their application as affinity binding in this regard is needed to be authentic. We report here the comparative application of derivatised materials and surfaces on the basis of nano-crystalline diamond, carbon nanotubes and fullerenes for the analysis of marker peptides and proteins by material enhanced laser desorption ionisation mass spectrometry MELDI-MS. In this particular work, the emphasis is placed on the derivatization, termed as immobilised metal affinity chromatography (IMAC), with three different support materials, to show the effectiveness of MELDI technique. For the physicochemical characterisation of the phases, near infrared reflectance spectroscopy (NIRS) is used, which is a well-established method within the analytical chemistry, covering a wide range of applications. NIRS enables differentiation between silica materials and different fullerenes derivatives, in a 3-dimensional factor-plot, depending on their derivatizations and physical characteristics. The method offers a physicochemical quantitative description in the nano-scale level of particle size, specific surface area, pore diameter, pore porosity, pore volume and total porosity with high linearity and improved precision. The measurement takes only a few seconds while high sample throughput is guaranteed.

  10. Interfacial engineering of two-dimensional nano-structured materials by atomic layer deposition

    Science.gov (United States)

    Zhuiykov, Serge; Kawaguchi, Toshikazu; Hai, Zhenyin; Karbalaei Akbari, Mohammad; Heynderickx, Philippe M.

    2017-01-01

    Atomic Layer Deposition (ALD) is an enabling technology which provides coating and material features with significant advantages compared to other existing techniques for depositing precise nanometer-thin two-dimensional (2D) nanostructures. It is a cyclic process which relies on sequential self-terminating reactions between gas phase precursor molecules and a solid surface. ALD is especially advantageous when the film quality or thickness is critical, offering ultra-high aspect ratios. ALD provides digital thickness control to the atomic level by depositing film one atomic layer at a time, as well as pinhole-free films even over a very large and complex areas. Digital control extends to sandwiches, hetero-structures, nano-laminates, metal oxides, graded index layers and doping, and it is perfect for conformal coating and challenging 2D electrodes for various functional devices. The technique's capabilities are presented on the example of ALD-developed ultra-thin 2D tungsten oxide (WO3) over the large area of standard 4" Si substrates. The discussed advantages of ALD enable and endorse the employment of this technique for the development of hetero-nanostructure 2D semiconductors with unique properties.

  11. Molecular dynamics study on core-shell structure stability of aluminum encapsulated by nano-carbon materials

    Science.gov (United States)

    Yi, Qingwen; Xu, Jingcheng; Liu, Yi; Zhai, Dong; Zhou, Kai; Pan, Deng

    2017-02-01

    A ReaxFF reactive forcefield for aluminum-carbon composite system has been developed to investigate structural stability and thermal decomposition mechanism of nano-carbon materials coating aluminum particles. Research results indicated the Al@C particles were structurally stable in a broad temperature range from room temperature up to 2735 K. In particular, the broken carbon cage self-healed to reconstruct a more stable Al@C core-shell structure after Al atoms sequentially departing from carbon cage during thermal decomposition, proffering an effective protection for aluminum surface-activeness.

  12. Magnetic Nano-structures

    Institute of Scientific and Technical Information of China (English)

    姚永德

    2004-01-01

    Fabrication of magnetic nano-structures with dots array and wires has been paid attention recently due to the application of high-density magnetic recording. In this study, we fabricated the magnetic dots array and wires through several ways that ensure the arrangement of magnetic dots and wires to be the structures we designed. Their magnetic properties are studied experimentally.

  13. Advanced Transmission Electron Microscopy Applications in Nano-Materials and Nano-Technology Developments

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Nano-technology development is nowadays a very hot topics in many research fields. Nano-materials are the foundations for developing this new technology. In order to fully understand the basic material science problems behind this topics, transmission electron microscopy (TEM) becomes the must and one of the most important technique to analyze the nano-size structure and composition using the most advanced high resolution TEM technique with nano-beam EDS and energy filter EELS to study the fine structures, crystallography, chemical composition, and optical properties of many different nano-materials in different industries applications.

  14. Advanced Transmission Electron Microscopy Applications in Nano-Materials and Nano-Technology Developments

    Institute of Scientific and Technical Information of China (English)

    KAI; J.J.

    2001-01-01

    Nano-technology development is nowadays a very hot topics in many research fields. Nano-materials are the foundations for developing this new technology. In order to fully understand the basic material science problems behind this topics, transmission electron microscopy (TEM) becomes the must and one of the most important technique to analyze the nano-size structure and composition using the most advanced high resolution TEM technique with nano-beam EDS and energy filter EELS to study the fine structures, crystallography, chemical composition, and optical properties of many different nano-materials in different industries applications.  ……

  15. Efficiency enhancement due to self-organization of nano-structures in Cd(S, Te) solar cell material

    Science.gov (United States)

    Sato, Kazunori; Katayama-Yoshida, Hiroshi

    2014-03-01

    CdTe is one of the most important solar cell materials. Its energy gap is 1.44 eV, which is ideal for solar cell application. So far, conversion efficiency of 18.3 percent has been realized, but it is lower than the Shockley-Queisser limit. In this paper, we propose computational materials design for enhancing conversion efficiency by using self-organization in Cd(Te, S) alloy semiconductor. Firstly, we performed cluster expansion of total energy of the Cd(Te, S) system and simulated self-organization of nano-structures in Cd(Te, S) by using Monte Carlo method. It is found that layered structure becomes stable by applying strain during the crystal growth. The electronic structure of the self-organized layered structure was calculated by using the hybrid method (HSE06) implemented in the VASP code to derive optical absorption coefficient. By using the calculated absorption coefficient the efficiency limit was derived based on the Shockley-Queisser theory. It is shown that the efficiency limit does not change so much due to the nano-structure formation. However, our calculation shows spatial separation between photo-generated electrons and holes. This might enhance the efficiency due to the suppression of recombination.

  16. Fabrication of nano structural biphasic materials from phosphogypsum waste and their in vitro applications

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: Kh_rezk966@yahoo.com [Biomaterials Department, National Research Centre, Dokki, Cairo (Egypt); Mousa, Sahar M. [Chemistry Department, Science and Art College, King Abdulaziz University, Rabigh Campus, P.O. Box 344, 21911 Rabigh (Saudi Arabia); Inorganic Chemistry Department, National Research Centre, Dokki, P.O. Box 12622, 11787 Cairo (Egypt); El Bassyouni, Gehan T. [Biomaterials Department, National Research Centre, Dokki, Cairo (Egypt); Medical Physics Department, College of Medicine, Taif University (Saudi Arabia)

    2014-02-01

    Graphical abstract: (a) Schema of the process, (b) TEM of nano particles of biphasic materials and (c) SEM of post-immersion. - Highlights: • Ratio of HA and β-TCP phases were controlled by thermal treatment. • HA partially decomposed into β-TCP with other bioactive phases. • Calcined HA at 900 °C is the best for the bioactivity behavior. - Abstract: In this study, a novel process of preparing biphasic calcium phosphate (BCP) is proposed. Also its bioactivity for the utilization of the prepared BCP as a biomaterial is studied. A mixture of calcium hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) could be obtained by thermal treatment of HAP which was previously prepared from phosphogypsum (PG) waste. The chemical and phase composition, morphology and particle size of prepared samples was characterized by X-ray diffraction (XRD), Infrared spectroscopy (IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The bioactivity was investigated by soaking of the calcined samples in simulated body fluid (SBF). Results confirmed that the calcination temperatures played an important role in the formation of calcium phosphate (CP) materials. XRD results indicated that HAP was partially decomposed into β-TCP. The in vitro data confirmed that the calcined HAP forming BCP besides other phases such as pyrophosphate and silica are bioactive materials. Therefore, BCP will be used as good biomaterials for medical applications.

  17. Electrochemistry, a technique to prepare redox nano-structured composite materials (polymer/nano-particles) - Characterizations - Applications; L'electrochimie, un outil pour elaborer des materiaux composites redox nanostructures (polymere/nanoparticules) - Caracterisations - Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chardon-Noblat, S. [Grenoble-1 Univ. Joseph Fourier, Lab. d' Electrochimie Organique et de Photochimie Redox, UMR 5630, Institut de Chimie Moleculaire de Grenoble, FR CNRS 2607, 38 - Grenoble (France)

    2006-07-01

    In this work is presented at first the preparation by an electrochemical way of bi functional nano-structured composite materials. It is shown that with the pulsed electrolysis techniques, it is possible to obtain metallic particles whose size and organization are controlled at the nano-scopic scale in redox matrices. Then, are presented the physico-chemical characterizations of these nano-objects (coupled in situ or ex situ at the electrochemistry). The first results relative to the catalytic activation of CO{sub 2} with these materials used as composite cathodes are indicated. (O.M.)

  18. Nano-Bio Quantum Technology for Device-Specific Materials

    Science.gov (United States)

    Choi, Sang H.

    2009-01-01

    The areas discussed are still under development: I. Nano structured materials for TE applications a) SiGe and Be.Te; b) Nano particles and nanoshells. II. Quantum technology for optical devices: a) Quantum apertures; b) Smart optical materials; c) Micro spectrometer. III. Bio-template oriented materials: a) Bionanobattery; b) Bio-fuel cells; c) Energetic materials.

  19. Controllable synthesis and formation mechanism of carbon micro/nano-structural materials

    Science.gov (United States)

    Zhang, Chang'an; Lv, Meijiao; Wang, Xianbao; Li, Jing; Yang, Xuyu; Yang, Jia; Hu, Hao

    2013-10-01

    Three different structures of carbon materials, including carbon spheres, bamboo-like carbon nanotubes and straight carbon nanotubes, were obtained by pyrolysis of iron(II) phthalocyanine with different flow rates of H2 at 1000 °C. The suitable mechanism for formation process of the carbon nanomaterials from spheres to straight nanotubes was suggested. The competing processes between the catalyst forward and the shell growth have been used to explain the formation mechanism of three materials. The controllable synthesis of carbon materials was achieved only by changing the H2 flow rates, and it is important to explore applications of carbon materials with different shapes.

  20. Molecular dynamics simulations on the relationship between the elastic parameters and the molecular structures of nano-hybrid POSS materials

    Institute of Scientific and Technical Information of China (English)

    ZENG Fan-lin; SUN Yi; HU Li-jiang

    2006-01-01

    To research the relationship between the elastic parameters and the molecular structures of nano hybrid polyhedral oligomeric silsesquioxanes (POSS) materials, the mechanical properties at different temperatures for three POSS polymers with different molecular architectures, polymerlized norbornene POSS homopolymer (PNPOSS, pedant architecture), γ - (2, 3 glycidoxy) propyl diaminoethane POSS polymer (GPDP, catena architecture) and trimethoxysilylcyclopentyl POSS polymer (TSCP, cage -cage network architecture) were obtained by molecular dynamics simulations based on the Compass force-field. Results indicate that the molecular architectures of the POSS polymers have great influence on the reinforced effects. The effect of the cage-cage network architecture is best, while that of the catena architecture takes second place and the pedant architecture has the least influence comparatively. The reinforced effects of the POSS monomers were examined. The influences of the temperatures on these effects were analyzed also. It may provide some basis for the reasonable applications of the excellent mechanical properties of the organic-inorganic nano-hybrid materials. It may also provide references for exploitation and design of the POSS materials.

  1. Electron Emission from Nano and MicroStructured Materials for Plasma Applications

    Science.gov (United States)

    Patino, Marlene; Raitses, Yevgeny; Wirz, Richard

    2016-09-01

    Secondary electron emission (SEE) from plasma-confining walls can lead to adverse effects (e.g. increased plasma heat flux to the wall) in plasma devices, including plasma processing, confinement fusion, and plasma thrusters. Reduction in SEE from engineered materials with nm to mm-sized structures (grooves, pores, fibers), has been previously observed for primary electrons incident normal to the material. Here we present SEE measurements from one such engineered material, carbon velvet with microfibers (5 μm diameter, 1-2 mm length), and from a plasma-structured material, tungsten fuzz with nm fibers (35-50 nm diameter, 100-200 nm length). Additionally, dependence of SEE on incident angle was explored for tungsten fuzz. Results for carbon velvet and tungsten fuzz at normal incidence show 75% and 50% decrease in total yield from smooth graphite and tungsten, respectively. More notable is the independence of SEE on the incident angle for tungsten fuzz, as opposed to inverse cosine dependence for smooth materials. Hence, the reduction in SEE from tungsten fuzz is more pronounced at grazing angles. This is important for plasma-facing materials where a retarding plasma sheath leads to increased likelihood of plasma electrons impacting at grazing angles. This work was supported by DOE contract DE-AC02-09CH11466; AFOSR grants FA9550-14-1-0053, FA9550-11-1-0282, AF9550-09-1-0695, and FA9550-14-10317; and DOE Office of Science Graduate Student Research Program.

  2. Synthesis of PbTe-SnTe particles by thermal decomposition of salts to create nano-structured thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Leontyev, V.G.; Ivanova, L.D. [Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Leninskii prospect, 49, 119991 Moscow (Russian Federation); Bente, K. [Institut fuer Mineralogie, Kristallographie und Materialwissenschaft, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany); Gremenok, V.F. [State Scientific and Production Association ' ' Scientific-Practical Materials Research Centre of the National Academy of Sciences of Belarus' ' , P. Brovka str. 19, 220072 Minsk (Belarus)

    2012-05-15

    Micro- and nanocrystalline particles of Pb-Sn-Te mixed crystals were synthesized using thermal decomposition and chemical interaction of lead acetate, tin oxalate and tellurium powder mixture in H{sub 2} atmosphere. For the process parameter optimization data of thermal gravimetry (TG), X-ray diffraction (XRD), electronic microscopy (TEM, SEM) and measurements of the specific surface of particles were used. Additionally the influence of gas phases on the decomposition kinetics, crystal structure, size, specific surface of the particles, gains composition and the physical properties were analyzed. Seebeck coefficient values increased and conductivity decreased with decreasing tin concentration. The presented method for preparing PbTe-SnTe polydisperse particles is developed to create nano-structured thermoelectric materials with high figure of merit. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Recent Development of Nano-Materials Used in DNA Biosensors

    Directory of Open Access Journals (Sweden)

    Yibin Ying

    2009-07-01

    Full Text Available As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future.

  4. Nano-sized structured layered positive electrode materials to enable high energy density and high rate capability lithium batteries

    Science.gov (United States)

    Deng, Haixia; Belharouak, Ilias; Amine, Khalil

    2012-10-02

    Nano-sized structured dense and spherical layered positive active materials provide high energy density and high rate capability electrodes in lithium-ion batteries. Such materials are spherical second particles made from agglomerated primary particles that are Li.sub.1+.alpha.(Ni.sub.xCo.sub.yMn.sub.z).sub.1-tM.sub.tO.sub.2-dR.sub.d- , where M is selected from can be Al, Mg, Fe, Cu, Zn, Cr, Ag, Ca, Na, K, In, Ga, Ge, V, Mo, Nb, Si, Ti, Zr, or a mixture of any two or more thereof, R is selected from F, Cl, Br, I, H, S, N, or a mixture of any two or more thereof, and 0.ltoreq..alpha..ltoreq.0.50; 0materials and their use in electrochemical devices are also described.

  5. Influences of glycerol as an efficient doping agent on crystal structure and antibacterial activity of B-TiO2 nano-materials.

    Science.gov (United States)

    Yang, He; Wang, Yuzheng; Xue, Xiangxin

    2014-10-01

    In this study, highly effective boron acid and glycerol co-doped TiO2 nano-materials were directly synthesized via a sol-gel method. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron (PL) spectroscopy. The results indicate that boron dopant is partially embedded into the interstitial TiO2 structure or incorporated into the TiO2 lattice through occupying the position of the oxygen atom, and others is present in the form of B2O3. Boron acid and glycerol co-doping TiO2 materials show obvious red shift in their absorption edges and efficient electron-hole separation because of the glycerol doping. The study on the antibacterial activities demonstrate that co-doped TiO2 nano-materials could effectively inactivate the bacteria under visible light irradiation. Co-doped TiO2 nano-materials exhibit more excellent antibacterial performance than B-doped TiO2 nano-materials.

  6. Development of Nano-structured Electrode Materials for High Performance Energy Storage System

    Science.gov (United States)

    Huang, Zhendong

    Systematic studies have been done to develop a low cost, environmental-friendly facile fabrication process for the preparation of high performance nanostructured electrode materials and to fully understand the influence factors on the electrochemical performance in the application of lithium ion batteries (LIBs) or supercapacitors. For LIBs, LiNi1/3Co1/3Mn1/3O2 (NCM) with a 1D porous structure has been developed as cathode material. The tube-like 1D structure consists of inter-linked, multi-facet nanoparticles of approximately 100-500nm in diameter. The microscopically porous structure originates from the honeycomb-shaped precursor foaming gel, which serves as self-template during the stepwise calcination process. The 1D NCM presents specific capacities of 153, 140, 130 and 118mAh·g-1 at current densities of 0.1C, 0.5C, 1C and 2C, respectively. Subsequently, a novel stepwise crystallization process consisting of a higher crystallization temperature and longer period for grain growth is employed to prepare single crystal NCM nanoparticles. The modified sol-gel process followed by optimized crystallization process results in significant improvements in chemical and physical characteristics of the NCM particles. They include a fully-developed single crystal NCM with uniform composition and a porous NCM architecture with a reduced degree of fusion and a large specific surface area. The NCM cathode material with these structural modifications in turn presents significantly enhanced specific capacities of 173.9, 166.9, 158.3 and 142.3mAh·g -1 at 0.1C, 0.5C, 1C and 2C, respectively. Carbon nanotube (CNT) is used to improve the relative low power capability and poor cyclic stability of NCM caused by its poor electrical conductivity. The NCM/CNT nanocomposites cathodes are prepared through simply mixing of the two component materials followed by a thermal treatment. The CNTs were functionalized to obtain uniformly-dispersed MWCNTs in the NCM matrix. The electrochemical

  7. Toward High Performance Integrated Semiconductor Micro and Nano Lasers Enabled by Transparent Conducting Materials: from Thick Structure to Thin Film

    Science.gov (United States)

    Ou, Fang

    some novel laser design based on the TCO materials and the thin film structure. The InP based coplanar electrode FP laser using In2O3 as the n-type cladding electrode is demonstrated. The design of the electrically pumped photonic crystal laser is also discussed. Initial fabrication result is given, showing potential of realizing those nano-lasers.

  8. A Novel Ion-exchange Method for the Synthesis of Nano-SnO/micro-C Hybrid Structure as High Capacity Anode Material in Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Zhi Tan; Zhenhua Sun; Qi Guo; Haihua Wang; Dangsheng Su

    2013-01-01

    A novel and simple ion-exchange method was developed for the synthesis of nano-SnO/micro-C hybrid structure.The structure of the as prepared nano-SnO/micro-C was directly revealed by scanning electron microscopy (SEM)and transmission electron microscopy (TEM).SnO particles with the size about 25 nm were well confined in amorphous carbon microparticles.Carbon matrix in micrometer scale not only acts as a protective buffer for the SnO nanoparticles during the battery cycling processes,but also avoids the shortcomings of nanostructures,such as low tap density and potential safety threats.Electrochemical behaviors of the nano-SnO/micro-C were tested as anode material in lithium ion batteries.The initial reversible capacity is 508 mA h g-1,and the reversible capacity after 60 cycles is 511 mA h g-1,indicating good capacity retention ability.

  9. Real time structural studies of nano structured materials and polymer blends at the SAXS beamline of the LNLS

    Energy Technology Data Exchange (ETDEWEB)

    Torriani, Iris L. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin] [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Plivelic, Tomas S.; Kellermann, Guinther [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    2002-07-01

    Full text: Instrumentation recently developed at the SAXS beamline of the LNLS has made possible the study of several interesting experiments with real-time data collection. A WAXS-SAXS chamber which allows the simultaneous recording of wide and small angle scattering, has been an ideal instrument for the study of polymer samples during temperature -controlled experiments. In this instrument, temperature can be varied from -4 to 95 deg C and has been used with specific sample holders for the study of the crystallization of amorphous metallic ribbons by Joule heating. Sealed sample holders for liquids operated under controlled temperature have been used successfully in the study of complex fluid systems, for in situ measurements of structural phase transitions. The sample temperature can be varied between -6 and 90 deg C or between room temperature and 170 deg C. A very small volume of sample is necessary and the scattering patterns are registered with very low background and excellent reproducibility. A newly developed high temperature chamber for simultaneous recording of WAXS and SAXS spectra during thermal treatment, operates from room temperature up to 1000 deg C in vacuum, and has proved to be very successful in the study of nucleation and growth of nano crystals in glassy matrices as well as crystallization of polymer blends. Several examples of these applications will be presented. (author)

  10. Nano-structures Enhanced Novel Composite Electrode Material for Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Integrate advanced nanotechnology with energy storage technology to develop advanced cathode material for use in Li-ion batteries while maintaining high level of...

  11. Physical investigations of nonvel materials and structures for nano-MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Feste, Sebastian Frederik

    2009-08-21

    In this thesis four important physical and material aspects faced by MOSFET devices as dimensions move to the length scale of 10nm have been investigated: i) metal source/drain contacts with dopant segregation for reduced contact resistance and improved carrier injection; ii) variability of the Schottky-barrier height (SBH) in MOSFET contacts; iii) strained silicon as a high mobility channel material; iv) silicon nanowire (NW) MOSFETs in order to suppress short channel effects by a multi-gate architecture. Ultimately scaled devices require highly conductive contacts with abrupt junctions. However, due to Fermi-level pinning at the metal-semiconductor interface, the performance of SB-MOSFETs still falls behind that of conventional FETs. Nickel-silicidation induced dopant segregation is highly effective in improving carrier injection through SBs, resulting in higher Ion/Ioff -ratios and better sub-threshold swings. Arsenic dopant segregation has been studied in detail as a function of NiSi thickness, implantation energy and dose, as well as process conditions for the formation of NiSi. It is shown that dopant concentrations as high as the solid solubility and lateral dopant slopes of 1-2nm/dec at the NiSi/Si-contact interface can be obtained. Simulations of scaled ultra-thin-body SOI MOSFETs with dopant segregation demonstrated that these devices can be scaled down to channel lengths of L=10nm. Variability in the electrical characteristics of SB-MOSFETs without and with dopant segregation has been investigated by a new experimental method, that allows to measure the impact of various sources leading to variability. The inherent variability of the SBH has been identified as the main source of variability and an increase in SBH variability due to dopant segregation by 0.01eV was found. The importance of SBH variability for the on-current, even for very low SBHs of 0.03eV, was demonstrated with simulations. High mobility channel materials are required, as the steady

  12. Physical investigations of nonvel materials and structures for nano-MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Feste, Sebastian Frederik

    2009-08-21

    In this thesis four important physical and material aspects faced by MOSFET devices as dimensions move to the length scale of 10nm have been investigated: i) metal source/drain contacts with dopant segregation for reduced contact resistance and improved carrier injection; ii) variability of the Schottky-barrier height (SBH) in MOSFET contacts; iii) strained silicon as a high mobility channel material; iv) silicon nanowire (NW) MOSFETs in order to suppress short channel effects by a multi-gate architecture. Ultimately scaled devices require highly conductive contacts with abrupt junctions. However, due to Fermi-level pinning at the metal-semiconductor interface, the performance of SB-MOSFETs still falls behind that of conventional FETs. Nickel-silicidation induced dopant segregation is highly effective in improving carrier injection through SBs, resulting in higher Ion/Ioff -ratios and better sub-threshold swings. Arsenic dopant segregation has been studied in detail as a function of NiSi thickness, implantation energy and dose, as well as process conditions for the formation of NiSi. It is shown that dopant concentrations as high as the solid solubility and lateral dopant slopes of 1-2nm/dec at the NiSi/Si-contact interface can be obtained. Simulations of scaled ultra-thin-body SOI MOSFETs with dopant segregation demonstrated that these devices can be scaled down to channel lengths of L=10nm. Variability in the electrical characteristics of SB-MOSFETs without and with dopant segregation has been investigated by a new experimental method, that allows to measure the impact of various sources leading to variability. The inherent variability of the SBH has been identified as the main source of variability and an increase in SBH variability due to dopant segregation by 0.01eV was found. The importance of SBH variability for the on-current, even for very low SBHs of 0.03eV, was demonstrated with simulations. High mobility channel materials are required, as the steady

  13. Molecular structure and properties of wool fiber surface-grafted with nano-antibacterial materials

    Science.gov (United States)

    Niu, Mei; Liu, Xuguang; Dai, Jinming; Hou, Wensheng; Wei, Liqiao; Xu, Bingshe

    2012-02-01

    Wool fiber was modified by ultraviolet irradiation (UV) and functionalized by grafting antibacterial agent. The structure and properties of antibacterial wool fiber were discussed in detail. The secondary structure changes and crystal structure were analyzed based on Fourier Transformation Raman Spectrometry (FTR) and X-ray diffraction (XRD). The results show that the disordered degree of UV-treated sample was increased and the antibacterial sample became more oriented. Compared with parent wool fiber, the antibacterial wool fiber was improved in mechanical property. The force, tensile strength and elongation were increased by 18%, 16%, and 7%, respectively. Also, the anti-shrinkage performance was increased because of the decrease in the directional frictional effect (DFE).

  14. Near field radiative thermal transfer between nano-structured periodic materials

    CERN Document Server

    Chalabi, Hamidreza; Brongersma, Mark L

    2013-01-01

    This paper provides a method based on rigorous coupled wave analysis for the calculation of the radiative thermal capacitance between a layer that is patterned with arbitrary, periodically repeating features and a planar one. This method is applied to study binary gratings and arrays of beams with a rectangular cross section. The effects of the structure size and spacing on the thermal capacitance are investigated. In all of these calculations, a comparison is made with an effective medium theory which becomes increasingly accurate as the structure sizes fall well below the relevant resonance wavelength. Results show that new levels of control over the magnitude and spectral contributions to thermal capacitance can be achieved with corrugated structures relative to planar ones.

  15. Paramagnetic resonance of Shungite - a natural nano-structured carbonaceous material

    Science.gov (United States)

    Yablokov, M. Yu.; Augustyniak-Jabł, M. A.

    Shungites Sh-III and Sh-IV (?50% and 20% of carbon) have been studied by X-band EPR method in the range 4.2-293 K. The week signal of Dyson shape (a /b = 2.25-2.40) observed from a bulk sample of Sh-III has been observed to transform into an intensive Lorentzian line (?B = 1.99 mT, g = 2.0020) after sample grinding. The number of EPR responsible spins (2 × 1019 g-1) and the depth of penetration ? (?60 µm) have been estimated. The shape of the signals (Dysonian or Lorentzian) is independent of T . ?B and the g values decrease below 80 K to 1.15 mT and 2.0012. The signal intensity is independent of T down to 150 K. Isolated complexes of C60(C70)-n with K+(Na+) have been found in Sh-IV. Analysis of the EPR spectra has been made taking into consideration the properties of the conductive materials such as metals and graphite.

  16. Boron-Based (Nano-Materials: Fundamentals and Applications

    Directory of Open Access Journals (Sweden)

    Umit B. Demirci

    2016-09-01

    Full Text Available The boron (Z = 5 element is unique. Boron-based (nano-materials are equally unique. Accordingly, the present special issue is dedicated to crystalline boron-based (nano-materials and gathers a series of nine review and research articles dealing with different boron-based compounds. Boranes, borohydrides, polyhedral boranes and carboranes, boronate anions/ligands, boron nitride (hexagonal structure, and elemental boron are considered. Importantly, large sections are dedicated to fundamentals, with a special focus on crystal structures. The application potentials are widely discussed on the basis of the materials’ physical and chemical properties. It stands out that crystalline boron-based (nano-materials have many technological opportunities in fields such as energy storage, gas sorption (depollution, medicine, and optical and electronic devices. The present special issue is further evidence of the wealth of boron science, especially in terms of crystalline (nano-materials.

  17. Next Generation Solar Cells Based on Graded Bandgap Device Structures Utilising Rod-Type Nano-Materials

    Directory of Open Access Journals (Sweden)

    Imyhamy M. Dharmadasa

    2015-06-01

    Full Text Available Current solar cells under research and development utilise mainly one absorber layer limiting the photon harvesting capabilities. In order to develop next generation solar cells, research should move towards effective photon harvesting methods utilising low-cost solar energy materials. This will lead to reduce the $W−1 figure for direct solar energy conversion to electrical energy. In this work, a graded bandgap solar cell has been designed to absorb all photons from the UV, visible and IR regions. In addition, impurity PV effect and impact ionisation have been incorporated to enhance charge carrier creation within the same device. This new design has been experimentally tested using the most researched MOCVD grown GaAs/AlGaAs system, in order to confirm its validity. Devices with high Voc ~ 1175 mV and the highest possible FF ~ (0.85–0.87 have been produced, increasing the conversion efficiency to ~20% within only two growth runs. These devices were also experimentally tested for the existence of impurity PV effect and impact ionisation. The devices are PV active in complete darkness producing over 800 mV, Voc indicating the harvesting of IR radiation from the surroundings through impurity PV effect. The quantum efficiency measurements show over 140% signal confirming the contribution to PV action from impact ionisation. Since the concept is successfully proven, the low-cost and scalable electrodeposited semiconducting layers are used to produce graded bandgap solar cell structures. The utilisation of nano- and micro-rod type materials in graded bandgap devices are also presented and discussed in this paper. Preliminary work on glass/FTO/n-ZnS/n-CdS/n-CdTe/Au graded bandgap devices show 10%–12% efficient devices indicating extremely high Jsc values ~48 mA·cm−2, showing the high potential of these devices in achieving higher efficiencies. The detailed results on these low-cost and novel graded bandgap devices are presented in a separate

  18. Progress in synthesizing functional nano materials

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ With the consistent investment, the research team directed by Prof. Yadong Li of Chemistry Department of Tsinghua University achieved new progress in synthesizing nano materials with specific functions. The research team led by Prof.

  19. Effect of nano materials in geopolymer concrete

    Directory of Open Access Journals (Sweden)

    Sudipta Naskar

    2016-09-01

    Full Text Available In general, cement based concrete can be replaced by low calcium fly-ash based geopolymer concrete regarding the adverse effect of the manufacture of ordinary Portland cement on environment. Nowadays, nano technology has an important role in the field of construction industries. It has been seen that several properties of cement based concrete are affected by different nano materials. As low calcium fly-ash based geopolymer concrete is an alternate option for cement based concrete, nano materials may also have some influence on it. An experimental program has been taken up on low calcium fly-ash based M25 grade geopolymer concrete having 16 (M concentration of activator liquid. Different percentage of nano materials viz. nano silica, carbon nano tube, titanium di-oxide were also used to investigate the effect of nano materials on geopolymer concrete. Geopolymer concrete with 1% titanium di-oxide shows appreciable improvement in compressive strength although pH remains almost same in all cases.

  20. Oxide-Free Bonding of III-V-Based Material on Silicon and Nano-Structuration of the Hybrid Waveguide for Advanced Optical Functions

    Directory of Open Access Journals (Sweden)

    Konstantinos Pantzas

    2015-10-01

    Full Text Available Oxide-free bonding of III-V-based materials for integrated optics is demonstrated on both planar Silicon (Si surfaces and nanostructured ones, using Silicon on Isolator (SOI or Si substrates. The hybrid interface is characterized electrically and mechanically. A hybrid InP-on-SOI waveguide, including a bi-periodic nano structuration of the silicon guiding layer is demonstrated to provide wavelength selective transmission. Such an oxide-free interface associated with the nanostructured design of the guiding geometry has great potential for both electrical and optical operation of improved hybrid devices.

  1. Nano-Structured Proton Exchange Membrane for Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Wu Chien-Suen; Lin Fan-Yen; Chu Peter P

    2005-01-01

    @@ 1Introduction Nano-structured materials are characterized by long range ordering of the nano-dimensioned quantum dot units. They have been found to deliver substantially different (electric, optical, magnetic and physical) properties from that of the bulk. The differences are mainly due to the increases of surface charge with large fraction of grain boundaries, and the periodical potential field created by the ordered nano-domains. Specifically,the issues considered in "nano ionics" are the degree of interaction, the charge distribution on the interfaces where they become obvious in ionic properties and thermodynamics such as mobility of charge carriers. Major efforts in this direction are focused on:

  2. Controlling the Morphology of Nano-Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Abdullah I.A. Jaafari

    2010-01-01

    Full Text Available Problem statement: It is known that layer double hydroxide is one of the nano ordered layered compounds and possesses plate-like morphology if carefully crystallized. Approach: In this study, Co-Sn LDH consisting of divalent and tetravalent cations was prepared with new morphology. XRD patterns of the prepared Co-Sn LDH showed that the interlayer spacing of the LDH was 0.78 nm and SEM image showed nano-needles structure. Results: By intercalation reaction with monocarboxylic acids at room temperature, XRD patterns indicated that the interlayered spacing increased to 3-4.8 nm and formed organic-inorganic nano-hybrid materials. Also, SEM images showed that the nano-needles structure of Co-Sn LDH changes to plate like-structure. Conclusion: Thermal analyses (TG, DTG and DTA and Infrared spectrum confirmed the intercalation processes of n-capric acid and n-stearic acid inside Co-Sn LDH and the formation of nano-hybrid materials.

  3. Nano-material and method of fabrication

    Science.gov (United States)

    Menchhofer, Paul A; Seals, Roland D; Howe, Jane Y; Wang, Wei

    2015-02-03

    A fluffy nano-material and method of manufacture are described. At 2000.times. magnification the fluffy nanomaterial has the appearance of raw, uncarded wool, with individual fiber lengths ranging from approximately four microns to twenty microns. Powder-based nanocatalysts are dispersed in the fluffy nanomaterial. The production of fluffy nanomaterial typically involves flowing about 125 cc/min of organic vapor at a pressure of about 400 torr over powder-based nano-catalysts for a period of time that may range from approximately thirty minutes to twenty-four hours.

  4. One-pot chemical route for morphology-controllable fabrication of Sn-Sb micro/nano-structures: Advanced anode materials for lithium and sodium storage

    Science.gov (United States)

    Yi, Zheng; Han, Qigang; Geng, Di; Wu, Yaoming; Cheng, Yong; Wang, Limin

    2017-02-01

    A series of morphology/component-controllable Sn-Sb micro/nano-structures are fabricated by a one-pot replacement reaction technique employing metallic Sn as both template and reducing agent. Typically, nanoscaled Sn as template and ethyl alcohol as solvent give the hollow structure, while micron-sized Sn as precursor and ethylene glycol as solvent produce the dendritic product. Other mixed structures are also obtained by this one-pot route. As anode materials for lithium-ion batteries, the hollow or dendritic Sn-Sb materials exhibit higher discharge capacities compared with the corresponding Sb samples as well as the Sn templates. Especially, for the Sn-Sb hollow spheres, a high discharge capacity of 820.7 mAh g-1 after first cycle and a reversible capacity of 751 mAh g-1 are achieved after 100 cycles at a current density of 100 mA g-1. Meanwhile, the hollow Sn-Sb structure delivers a specific capacity of 451.3 mA h g-1 at 500 mA g-1 after 150 cycles when used for sodium ion batteries. The superior electrochemical performance that are higher than many reported results can be attributed to the special morphology and structure, which can shorten the transportation distance of lithium/sodium ion and provide extra free space to buffer the volume expansion during the lithium/sodium insertion/extraction.

  5. Nano Engineered Energetic Materials (NEEM)

    Science.gov (United States)

    2011-01-12

    reactivity of the nitro group. The more perpendicular orientation of the NO2 in p- NBA leaves both oxygen atoms available to complex vapor deposited Al...different solutes have been recorded in supercritical CO2 in the past, the information on the solubility of many energetic materials including RDX is...The pH level of the solution was monitored before and after to record the ionic activity of the solution. Different amounts of dispersant and

  6. Preface: Advanced Thin Film Developments and Nano Structures

    Institute of Scientific and Technical Information of China (English)

    Ray Y.Lin

    2005-01-01

    @@ In this special issue, we invited a few leading materials researchers to present topics in thin films, coatings, and nano structures. Readers will find most recent developments in topics, including recent advances in hard, tough, and low friction nanocomposite coatings; thin films for coating nanomaterials; electroless plating of silver thin films on porous Al2O3 substrate; CrN/Nano Cr interlayer coatings; nano-structured carbide derived carbon (CDC) films and their tribology; predicting interdiffusion in high-temperature coatings; gallium-catalyzed silica nanowire growth; and corrosion protection properties of organofunctional silanes. Authors are from both national laboratories and academia.

  7. Synthesis and study of nano-structured cellulose acetate based materials for energy applications; Synthese et etude de materiaux nanostructures a base d'acetate de cellulose pour applications energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, F

    2006-12-15

    Nano-structured materials have unique properties (high exchange areas, containment effect) because of their very low characteristic dimensions. The elaboration way set up in this PhD work consists in applying the classical processes for the preparation of aerogel-like materials (combining sol-gel synthesis and CO{sub 2} supercritical extraction) to cellulosic polymers. This work is divided in four parts: a literature review, the presentation and the study of the chemical synthesis that leads to cellulose acetate-based aerogel, the characterizations (chemical, structural and thermal) of the elaborated nano-materials, and finally the study of the first carbons that were obtained after pyrolysis of the organic matrix. The formulations and the sol-gel protocol lead to chemical gels by crosslinking cellulose acetate using a poly-functional iso-cyanate. The dry materials obtained after solvent extraction with supercritical CO{sub 2} are nano-structured and mainly meso-porous. Correlations between chemical synthesis parameters (reagent concentrations, crosslinking rate and degree of polymerisation) and porous properties (density, porosity, pore size distribution) were highlighted thanks to structural characterizations. An ultra-porous reference aerogel, with a density equals to 0,245 g.cm{sup -3} together with a meso-porous volume of 3,40 cm{sup 3}.g{sup -1} was elaborated. Once in granular shape, this material has a thermal conductivity of 0,029 W.m{sup -1}.K{sup -1}. In addition, carbon materials produced after pyrolysis of the organic matrix and after grinding are nano-structured and nano-porous, even if important structural modifications have occurred during the carbonization process. The elaborated materials are evaluated for applications in relation with energy such as thermal insulation (organic aerogels) but also for energy conversion and storage through electrochemical way (carbon aerogels). (author)

  8. The heat science of the nano-porous materials; La thermique des materiaux nanoporeux

    Energy Technology Data Exchange (ETDEWEB)

    Volz, S. [CNRS, Lab. d' Energetique Moleculaire et Macroscopique, Combustion, 92 - Chatenay Malabry (France); Quintard, M. [CNRS, Institut de Mecanique des Fluides, 31 - Toulouse (France); Rochais, D. [CEA Centre d' Etudes du Ripault, Lab. Microstructures et Comportements, 37 - Tours (France); Enguehard, F. [CEA Centre d' Etudes du Ripault, Lab. Ingenierie des Materiaux Optiques, 37 - Tours (France); Domingues, G. [Ecole Nationale Superieure de Mecanique et d' Aerotechnique (ENSMA), Lab. d' Etudes Thermiques, 86 - Poitiers (France); Quenard, D. [CSTB, Div. Caracterisation Physique des Materiaux, 38 - Grenoble (France); Rigacci, A. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 - Paris (France); Bourdin, V. [CNRS, Lab. d' Informatique pour la Mecanique et les Sciences pour l' Ingenieur, 91 - Orsay (France); Chantrenne, P. [Centre de Thermique de Lyon, INSA, 69 - Lyon (France)

    2005-07-01

    In this work are gathered the transparencies of the lecture presented at the conference 'the heat science of the nano-porous materials'. The titles of the different lectures are: 1)modelling of the transfers in nano-porous media 2)modelling of the transfers inside nano-porous super-insulators part I: conduction part II: radiation 3)heat transfers between two silicon oxide nano-crystallite 4)thermo-physical properties of two pyro-micro-nano-porous silicon oxides: humidity and temperature effect 5)adsorption kinetics by a thermal frequency method: an indirect measurement method of the effective conductivity of the granulated adsorbents 6)the aerogels materials: nano-structured thermal super-insulators 7)anticipation of the nano-structured silicon thermal conductivity. (O.M.)

  9. Synthesis of nano structured particles for Li-ion cathodic and anodic materials obtained by spray pyrolysis; Sintesis de particulas nanoestructuradas para materiales catodicos y anodicos obtenidos mediante Spray Prolisis

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, L. S.; Meatza, I. de; Martin, M. I.; Boynao, I.; Cantero, I.; Rabanal, M. E.

    2010-07-01

    The development of the nano technology has contributed to improve the electrochemical properties in rechargeable batteries. The Spray Pyrolysis method allows to obtain nano structured materials with spherical morphology, narrow particle size distribution and compositional homogeneity. Nano structured particles have been prepared in this work to be used as anodic and cathodic materials in lithium-ion batteries. Among the cathodic materials, the Na-Si-Con (Li{sub 3}Fe{sub 2}(PO{sub 4}){sub 3}) structure and the olivine (LiFePO{sub 4}) phases have been synthesised. The Na-Si-Con iron phosphate favours the accommodation of the ion host, the diffusion and thermal stability. The olivine structure has an open three-dimensional network, favourable for hosting Lithium ions. The characterization by X ray diffraction, electron microscopy (scanning and transmission) and electron diffraction have allowed to identify a mix of crystalline phases of LiFePO{sub 4} (Olivine) and Li{sub 3}Fe{sub 2}(PO{sub 4}){sub 3} (Na-Si-Con). Thermal treatments produce porous particles. The tryphilite phase (olivine) appears after a thermal treatment at 800 degree centigrade/12h. Electrochemical results confirm the presence of the Na-Si-Con and olivine phases. Among the materials for being used as anode, the titanium oxides have been classified as good candidates as lithium ion host. The synthesis results in different experimental conditions for obtaining spherical and nano structured titanium oxide particles are presented. (Author)

  10. Nano-material aspects of shock absorption in bone joints.

    Science.gov (United States)

    Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

    2010-01-01

    This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

  11. 3D nano-structures for laser nano-manipulation

    Directory of Open Access Journals (Sweden)

    Gediminas Seniutinas

    2013-09-01

    Full Text Available The resputtering of gold films from nano-holes defined in a sacrificial PMMA mask, which was made by electron beam lithography, was carried out with a dry plasma etching tool in order to form well-like structures with a high aspect ratio (height/width ≈ 3–4 at the rims of the nano-holes. The extraordinary transmission through the patterns of such nano-wells was investigated experimentally and numerically. By doing numerical simulations of 50-nm and 100-nm diameter polystyrene beads in water and air, we show the potential of such patterns for self-induced back-action (SIBA trapping. The best trapping conditions were found to be a trapping force of 2 pN/W/μm2 (numerical result exerted on a 50-nm diameter bead in water. The simulations were based on the analytical Lorentz force model.

  12. Nano-photocatalytic materials: possibilities and challenges.

    Science.gov (United States)

    Tong, Hua; Ouyang, Shuxin; Bi, Yingpu; Umezawa, Naoto; Oshikiri, Mitsutake; Ye, Jinhua

    2012-01-10

    Semiconductor photocatalysis has received much attention as a potential solution to the worldwide energy shortage and for counteracting environmental degradation. This article reviews state-of-the-art research activities in the field, focusing on the scientific and technological possibilities offered by photocatalytic materials. We begin with a survey of efforts to explore suitable materials and to optimize their energy band configurations for specific applications. We then examine the design and fabrication of advanced photocatalytic materials in the framework of nanotechnology. Many of the most recent advances in photocatalysis have been realized by selective control of the morphology of nanomaterials or by utilizing the collective properties of nano-assembly systems. Finally, we discuss the current theoretical understanding of key aspects of photocatalytic materials. This review also highlights crucial issues that should be addressed in future research activities.

  13. Magnetic Nano-Materials: Truly Sustainable Green Chemistry Nano Catalysis

    Science.gov (United States)

    We envisioned a novel nano-catalyst system, which can bridge the homogenous and heterogeneous system, and simultaneously be cheaper, easily accessible (sustainable) and possibly does not require elaborate work-up. Because of its nano-size, i.e. high surface area, the contact betw...

  14. PREFACE: International Conference on Structural Nano Composites (NANOSTRUC 2012)

    Science.gov (United States)

    Njuguna, James

    2012-09-01

    Dear Colleagues It is a great pleasure to welcome you to NanoStruc2012 at Cranfield University. The purpose of the 2012 International Conference on Structural Nano Composites (NanoStruc2012) is to promote activities in various areas of materials and structures by providing a forum for exchange of ideas, presentation of technical achievements and discussion of future directions. NanoStruc brings together an international community of experts to discuss the state-of-the-art, new research results, perspectives of future developments, and innovative applications relevant to structural materials, engineering structures, nanocomposites, modelling and simulations, and their related application areas. The conference is split in 7 panel sessions, Metallic Nanocomposites and Coatings, Silica based Nanocomposites, safty of Nanomaterials, Carboin based Nanocomposites, Multscale Modelling, Bio materials and Application of Nanomaterials. All accepted Papers will be published in the IOP Conference Series: Materials Science and Engineering (MSE), and included in the NanoStruc online digital library. The abstracts will be indexed in Scopus, Compedex, Inspec, INIS (International Nuclear Information System), Chemical Abstracts, NASA Astrophysics Data System and Polymer Library. Before ending this message, I would like to acknowledge the hard work, professional skills and efficiency of the team which ensured the general organisation. As a conclusion, I would like to Welcome you to the Nanostruc2012 and wish you a stimulating Conference and a wonderful time. On behalf of the scientific committee, Signature James Njuguna Conference Chair The PDF of this preface also contains committee listings and associates logos.

  15. Nano-structured alloy and composite coatings for high temperature applications

    Directory of Open Access Journals (Sweden)

    Wei Gao

    2004-03-01

    Full Text Available Nano-structured materials often possess special properties that materials with identical compositions but ordinary grain size do not have. This paper reports our work on the surface nano-crystallisation and nano-structured alloy and composite coatings. A number of processing methods including magnetron sputtering, thermal spray and pulse electro-spark deposition have been used to produce surface nano-crystalline structure. The compositions and microstructures can be well controlled by using different targets or electrodes, nano-structured composites and adjusting processing parameters. Surface nano-structured coatings can provide special chemical, mechanical and electronic properties such as high temperature corrosion and corrosive wear resistance. It has potential applications such as turbine blades, engine parts for petrochemical, aerospace and electronic device industries. This paper is focused on the study of the interrelations between processing, microstructure and properties. Physical models have been established to explain the effects of nano-crystalline structure on the properties.

  16. Report on Carbon Nano Material Workshop: Challenges and Opportunities

    Science.gov (United States)

    2013-01-22

    Lubricating Grease Thickened by Carbon Nanotubes, presented at Carbon Nano Materials and Applications Workshop, Rapid City, SD, October 31–November 1...Carbon Nano Material Workshop: Challenges and Opportunities S. Acharya a , J. Alvarado b , D. Banerjee b , W. E. Billups c , G. Chen d , B. A. Cola e...Carbon Nano Material Workshop: Challenges and Opportunities 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  17. Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

    CERN Document Server

    Ohtsu, Motoichi

    2005-01-01

    This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  18. FDTD Simulation of Novel Polarimetric and Directional Reflectance and Transmittance Measurements from Optical Nano- and Micro-Structured Materials

    Science.gov (United States)

    2012-03-22

    and the behavior that is reported for fabricated structures is often only for very limited experimental conditions. Specifically, an area of research...i.e. coso i s ss Mm s   (2.48) where 00 01 02 03 10 11 12 13 20 21 22 23 30 31 23 33 m m m m m m m m Mm m m m m m m m m

  19. Characterization of magnetic nano materials by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Sangeeta; Katyal, S C [Jaypee University of information technology, Waknaghat, Solan 173215 (India); Gupta, A; Reddy, V R [UGC-DAE Consortium for scientific research, Khandwa Road, Indore 452017 (India); Singh, M, E-mail: megha2k6@gmail.co [Department of physics, Himachal Pradesh University, Shimla 171005 (India)

    2010-03-01

    The use of a non-destructive nuclear-physical method, namely {sup 57}Fe Moessbauer spectroscopy, is discussed for the investigation of magnetic and structural arrangement of Fe-based nano-crystalline nickel-zinc-indium ferrites (NZIFO). Nano NZIFO particles (Ni{sub 0.58}Zn{sub 0.42}In{sub x}Fe{sub 2-x}O{sub 4}) with varied quantities of indium (x = 0, 0.1, 0.2) have been chemically synthesized through a reverse micelle reaction and investigated by X-ray diffraction, transmission electron microscopy and by magnetic and Moessbauer spectral studies. Here a comparison between low-temperature and room temperature Moessbauer spectra is presented. Well defined sextets at 5 K provide information about the structure and magnetic states of atoms located in different structural positions. The dependence of Moessbauer parameters, viz, isomer shift, quadrupole splitting, linewidth and hyperfine magnetic field on In{sup 3+} concentration have been discussed. Detailed Moessbauer results, as well as the interest of these materials both for applied science perspectives are presented. Moessbauer results are also supported by magnetization data. With these interesting ferromagnetic properties Indium substituted nano nickel-zinc ferrites have potential applications in magnetic storage data.

  20. Characterization of magnetic nano materials by Mössbauer spectroscopy

    Science.gov (United States)

    Thakur, Sangeeta; Katyal, S. C.; Gupta, A.; Reddy, V. R.; Singh, M.

    2010-03-01

    The use of a non-destructive nuclear-physical method, namely 57Fe Mössbauer spectroscopy, is discussed for the investigation of magnetic and structural arrangement of Fe-based nano-crystalline nickel-zinc-indium ferrites (NZIFO). Nano NZIFO particles (Ni0.58Zn0.42InxFe2-xO4) with varied quantities of indium (x = 0, 0.1, 0.2) have been chemically synthesized through a reverse micelle reaction and investigated by X-ray diffraction, transmission electron microscopy and by magnetic and Mössbauer spectral studies. Here a comparison between low-temperature and room temperature Mössbauer spectra is presented. Well defined sextets at 5 K provide information about the structure and magnetic states of atoms located in different structural positions. The dependence of Mössbauer parameters, viz, isomer shift, quadrupole splitting, linewidth and hyperfine magnetic field on In3+ concentration have been discussed. Detailed Mössbauer results, as well as the interest of these materials both for applied science perspectives are presented. Mössbauer results are also supported by magnetization data. With these interesting ferromagnetic properties Indium substituted nano nickel-zinc ferrites have potential applications in magnetic storage data.

  1. Nano-FTIR chemical mapping of minerals in biological materials

    Directory of Open Access Journals (Sweden)

    Sergiu Amarie

    2012-04-01

    Full Text Available Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone. "Nano-FTIR" spectral images result from Fourier-transform infrared (FTIR spectroscopy combined with scattering scanning near-field optical microscopy (s-SNOM. On polished sections of Mytilus edulis shells we observe a reproducible vibrational (phonon resonance within all biocalcite microcrystals, and distinctly different spectra on bioaragonite. Surprisingly, we discover sparse, previously unknown, 20 nm thin nanoparticles with distinctly different spectra that are characteristic of crystalline phosphate. Multicomponent phosphate bands are observed on human tooth sections. These spectra vary characteristically near tubuli in dentin, proving a chemical or structural variation of the apatite nanocrystals. The infrared band strength correlates with the mineral density determined by electron microscopy. Since nano-FTIR sensitively responds to structural disorder it is well suited for the study of biomineral formation and aging. Generally, nano-FTIR is suitable for the analysis and identification of composite materials in any discipline, from testing during nanofabrication to even the clinical investigation of osteopathies.

  2. Characterization of Kaolin as Nano Material for High Quality Construction

    Directory of Open Access Journals (Sweden)

    Fadzil M. A.

    2017-01-01

    Full Text Available At the moment utilisation of nano technology in every aspect in human life were growing rapidly. In this research, a new nano material was produce from kaolin clay and compare to OPC in terms of surface analysis, particle sizing and micrograph image on new modification of kaolin clay particles. Kaolin clay was established in two processes which are before and after heat treatment. Apart from that, transformation of kaolin clay to nano material was monitor by using Field Emission Scanning Electron Microscope (FESEM and new nano materials were formed. Those images were supported by X Ray Diffraction analysis (XRD, X Ray Fluorescence (XRF and laser particle analyser to see the chemical composition and particle size for all specimens. A combination of rough, smooth and long section can be analysed. From this analysis a new develops nano materials can be achieved and can be utilised especially for construction purposes.

  3. Electrospinning for nano- to mesoscale photonic structures

    Directory of Open Access Journals (Sweden)

    Skinner Jack L.

    2017-08-01

    Full Text Available The fabrication of photonic and electronic structures and devices has directed the manufacturing industry for the last 50 years. Currently, the majority of small-scale photonic devices are created by traditional microfabrication techniques that create features by processes such as lithography and electron or ion beam direct writing. Microfabrication techniques are often expensive and slow. In contrast, the use of electrospinning (ES in the fabrication of micro- and nano-scale devices for the manipulation of photons and electrons provides a relatively simple and economic viable alternative. ES involves the delivery of a polymer solution to a capillary held at a high voltage relative to the fiber deposition surface. Electrostatic force developed between the collection plate and the polymer promotes fiber deposition onto the collection plate. Issues with ES fabrication exist primarily due to an instability region that exists between the capillary and collection plate and is characterized by chaotic motion of the depositing polymer fiber. Material limitations to ES also exist; not all polymers of interest are amenable to the ES process due to process dependencies on molecular weight and chain entanglement or incompatibility with other polymers and overall process compatibility. Passive and active electronic and photonic fibers fabricated through the ES have great potential for use in light generation and collection in optical and electronic structures/devices. ES produces fiber devices that can be combined with inorganic, metallic, biological, or organic materials for novel device design. Synergistic material selection and post-processing techniques are also utilized for broad-ranging applications of organic nanofibers that span from biological to electronic, photovoltaic, or photonic. As the ability to electrospin optically and/or electronically active materials in a controlled manner continues to improve, the complexity and diversity of devices

  4. Nano active materials for lithium-ion batteries

    Science.gov (United States)

    Wang, Yonggang; Li, Huiqiao; He, Ping; Hosono, Eiji; Zhou, Haoshen

    2010-08-01

    Lithium-ion batteries have been widely used to power portable electronic devices, such as mobile phones, digital cameras, laptops etc., and are considered to be a promising choice of power system for the next generation of electric vehicles, which are central to the reduction of CO2 emissions arising from transport. In order to increase energy and power density to meet the future challenges of energy storage, many efforts have been made to develop nano active materials for lithium-ion batteries. Herein we review the advantages of nano active materials for lithium-ion batteries. Moreover, some disadvantages of nano active materials and their solutions are also discussed.

  5. Nano-Micro Materials Enabled Thermoelectricity From Window Glasses

    KAUST Repository

    Inayat, Salman Bin

    2012-11-03

    With growing world population and decreasing fossil fuel reserves we need to explore and utilize variety of renewable and clean energy sources to meet the imminent challenge of energy crisis. Solar energy is considered as the leading promising alternate energy source with the pertinent challenge of off sunshine period and uneven worldwide distribution of usable sun light. Although thermoelectricity is considered as a reasonable energy harvester from wasted heat, its mass scale usage is yet to be developed. By transforming window glasses into generators of thermoelectricity, this doctoral work explores engineering aspects of using the temperature gradient between the hot outdoor heated by the sun and the relatively cold indoor of a building for mass scale energy generation. In order to utilize the two counter temperature environments simultaneously, variety of techniques, including: a) insertion of basic metals like copper and nickel wire, b) sputtering of thermoelectric films on side walls of individual glass strips to form the thickness depth of the glass on subsequent curing of the strips, and c) embedding nano-manufactured thermoelectric pillars, have been implemented for innovative integration of thermoelectric materials into window glasses. The practical demonstration of thermoelectric windows has been validated using a finite element model to predict the behavior of thermoelectric window under variety of varying conditions. MEMS based characterization platform has been fabricated for thermoelectric characterization of thin films employing van der Pauw and four probe modules. Enhancement of thermoelectric properties of the nano- manufactured pillars due to nano-structuring, achieved through mechanical alloying of micro-sized thermoelectric powders, has been explored. Modulation of thermoelectric properties of the nano-structured thermoelectric pillars by addition of sulfur to nano-powder matrix has also been investigated in detail. Using the best possible p

  6. 3D manufacturing of micro and nano-architected materials

    Science.gov (United States)

    Valdevit, Lorenzo

    2016-04-01

    Reducing mass without sacrificing mechanical integrity and performance is a critical goal in a vast range of applications. Introducing a controlled amount of porosity in a strong and dense material (hence fabricating a cellular solid) is an obvious avenue to weight reduction. The mechanical effectiveness of this strategy, though, depends strongly on the architecture of the resulting cellular material (i.e., the topology of the introduced porosity). Recent progress in additive manufacturing enables fabrication of macro-scale cellular materials (both single-phase and hybrid) with unprecedented dimensional control on the unit-cell and sub-unit-cell features, potentially producing architectures with structural hierarchy from the nano to the macro-scale. As mechanical properties of materials often exhibit beneficial size effects at the nano-scale (e.g., strengthening of metals and toughening of ceramics), these novel manufacturing approaches provide a unique opportunity to translate these beneficial effects to the macro-scale, further improving the mechanical performance of architected materials. The enormous design space for architected materials, and the strong relationship between the topological features of the architecture and the effective physical and mechanical properties of the material at the macro-scale, present both a huge opportunity and an urgent need for the development of suitable optimal design strategies. Here we present a number of strategies for the advanced manufacturing, characterization and optimal design of a variety of lightweight architected materials with unique combinations of mechanical properties (stiffness, strength, damping coefficient…). The urgent need to form strong synergies among the fields of additive manufacturing, topology optimization and architectureproperties relations is emphasized throughout.

  7. Synthesis of structurally controlled nano carbons - in particular the nano barrel carbon

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M. [FOI, Swedish Defence Research Agency, Dept. of Protection and Materials, Tumba (Sweden); Palmqvist, U. [IM, Swedish Institute for Metals Research, Drottning Kristinas vag 48, Stockholm (Sweden); Alberius, P.C.A. [YKI, Institute for Surface Chemistry, Stockholm (Sweden); Ekstrom, T. [Materials Science, Royal Institute of Technology, Stockholm (Sweden); Nygren, M.; Lidin, S. [Stockholm University, Inorganic Chemistry, Stockholm (Sweden)

    2003-01-01

    Nano-porous carbons have been prepared through a selective etching reaction, performed by halogenation of aluminum carbide. The structures obtained can be controlled by varying the chlorination temperature. The unique set of nano-carbons obtained include nano-porous amorphous structures, the nano-barrel structure and a nano-graphitic structure as chlorination temperatures were increased from 400 deg. C to 1000 deg. C. The synthesis process gives a pure product with high yield, and may be scaled up to produce bulk amounts. (authors)

  8. Lifetime of Nano-Structured Black Silicon for Photovoltaic Applications

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk;

    2016-01-01

    In this work, we present recent results of lifetime optimization for nano-structured black silicon and its photovoltaic applications. Black silicon nano-structures provide significant reduction of silicon surface reflection due to highly corrugated nanostructures with excellent light trapping......, respectively. This is promising for use of black silicon RIE nano-structuring in a solar cell process flow...

  9. Lifetime of Nano-Structured Black Silicon for Photovoltaic Applications

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk;

    2016-01-01

    In this work, we present recent results of lifetime optimization for nano-structured black silicon and its photovoltaic applications. Black silicon nano-structures provide significant reduction of silicon surface reflection due to highly corrugated nanostructures with excellent light trapping pro......, respectively. This is promising for use of black silicon RIE nano-structuring in a solar cell process flow...

  10. Nano-tribology and materials in MEMS

    CERN Document Server

    Satyanarayana, N; Lim, Seh

    2013-01-01

    This book brings together recent developments in the areas of MEMS tribology, novel lubricants and coatings for nanotechnological applications, biomimetics in tribology and fundamentals of micro/nano-tribology. Tribology plays important roles in the functioning and durability of machines at small length scales because of the problems associated with strong surface adhesion, friction, wear etc. Recently, a number of studies have been conducted to understand tribological phenomena at nano/micro scales and many new tribological solutions for MEMS have been proposed.

  11. MULTIFUNCTIONAL NANO-BIO MATERIALS WITHIN CELLULAR MACHINERY.

    Science.gov (United States)

    Rozhkova, E A; Ulasov, I V; Kim, D-H; Dimitrijevic, N M; Novosad, V; Bader, S D; Lesniak, M S; Rajh, T

    2011-08-01

    Functional nanoscale materials that possess specific physical or chemical properties can leverage energy transduction in vivo. Once these materials integrate with biomolecules they combine physical properties of inorganic material and the biorecognition capabilities of bio-organic moieties. Such nano-bio hybrids can be interfaced with living cells, the elementary functional units of life. These nano-bio systems are capable of bio-manipulation or actuation via altering intracellular biochemical pathways. Thus, nano-bio conjugates are appealing for a wide range of applications from the life sciences and nanomedicine to catalysis and clean energy production. Here we highlight recent progress in our efforts to develop smart nano-bio hybrid materials, and to study their performance within cellular machinery under application of external stimuli, such as light or magnetic fields.

  12. Improvement of performance of ultra-high performance concrete based composite material added with nano materials

    Directory of Open Access Journals (Sweden)

    Pang Jinchang

    2016-03-01

    Full Text Available Ultra-high performance concrete (UHPC, a kind of composite material characterized by ultra high strength, high toughness and high durability. It has a wide application prospect in engineering practice. But there are some defects in concrete. How to improve strength and toughness of UHPC remains to be the target of researchers. To obtain UHPC with better performance, this study introduced nano-SiO2 and nano-CaCO3 into UHPC. Moreover, hydration heat analysis, X-Ray Diffraction (XRD, mercury intrusion porosimetry (MIP and nanoindentation tests were used to explore hydration process and microstructure. Double-doped nanomaterials can further enhance various mechanical performances of materials. Nano-SiO2 can promote early progress of cement hydration due to its high reaction activity and C-S-H gel generates when it reacts with cement hydration product Ca(OH2. Nano-CaCO3 mainly plays the role of crystal nucleus effect and filling effect. Under the combined action of the two, the composite structure is denser, which provides a way to improve the performance of UHPC in practical engineering.

  13. Superhydrophobic Behavior on Nano-structured Surfaces

    Science.gov (United States)

    Schaeffer, Daniel

    2008-05-01

    Superhydrophobic behavior is observed in natural occurrences and has been thoroughly studied over the past few years. Water repellant properties on uniform arrays of vertically aligned nano-cones were investigated to determine the highest achievable contact angle (a measure of water drop repellency), which is measured from the reference plane on which the water drop sits to the tangent line of the point at which the drop makes contact with the reference plane. At low aspect ratios (height vs. width of the nano-cones), surface tension pulls the water into the nano-cone array, resulting in a wetted surface. Higher aspect ratios reverse the effect of the surface tension, resulting in a larger contact angle that causes water drops to roll off the surface. Fiber drawing, bundling, and redrawing are used to produce the structured array glass composite surface. Triple-drawn fibers are fused together, annealed, and sliced into thin wafers. The surface of the composite glass is etched to form nano-cones through a differential etching process and then coated with a fluorinated self-assembled monolayer (SAM). Cone aspect ratios can be varied through changes in the chemistry and concentration of the etching acid solution. Superhydrophobic behavior occurs at contact angles >150 and it is predicted and measured that optimal behavior is achieved when the aspect ratio is 4:1, which displays contact angles >=175 .

  14. Structural evolution of Ag-Cu nano-alloys confined between AlN nano-layers upon fast heating.

    Science.gov (United States)

    Janczak-Rusch, J; Chiodi, M; Cancellieri, C; Moszner, F; Hauert, R; Pigozzi, G; Jeurgens, L P H

    2015-11-14

    The structural evolution of a Ag-Cu/AlN nano-multilayer (NML), as prepared by magnetron-sputtering on a α-Al2O3 substrate, was monitored during fast heating by real-time in situ XRD analysis (at the synchrotron), as well as by ex situ microstructural analysis using SEM, XPS and in-house XRD. The as-deposited NML is constituted of alternating nano-layers (thickness ≈ 10 nm) of a chemically inert AlN barrier and a eutectic Ag-Cu(40at%) nano-alloy. The nano-alloy in the as-deposited state is composed of a fcc matrix of Ag nano-grains (≈6 nm), which are supersaturated by Cu, and some smaller embedded Cu rich nano-grains (≈4 nm). Heating up to 265 °C activates segregation of Cu out of the supersaturated Ag nano-grains phase, thus initiating phase separation. At T > 265 °C, the phase-separated Cu metal partially migrates to the top NML surface, thereby relaxing thermally-accumulated compressive stresses in the confined alloy nano-layers and facilitating grain coarsening of (still confined) phase-separated nano-crystallites. Further heating and annealing up to 420 °C results in complete phase separation, forming extended Ag and Cu domains with well-defined coherent Ag/AlN interfaces. The observed outflow of Cu well below the eutectic melting point of the bulk Ag-Cu alloy might provide new pathways for designing low-temperature nano-structured brazing materials.

  15. [Study on spectroscopic characterization and property of PES/ micro-nano cellulose composite membrane material].

    Science.gov (United States)

    Tang, Huan-Wei; Zhang, Li-Ping; Li, Shuai; Zhao, Guang-Jie; Qin, Zhu; Sun, Su-Qin

    2010-03-01

    In the present paper, the functional groups of PES/micro-nano cellulose composite membrane materials were characterized by Fourier transform infrared spectroscopy (FTIR). Also, changes in crystallinity in composite membrane materials were analyzed using X-ray diffraction (XRD). The effects of micro-nano cellulose content on hydrophilic property of composite membrane material were studied by measuring hydrophilic angle. The images of support layer structure of pure PES membrane material and composite membrane material were showed with scanning electron microscope (SEM). These results indicated that in the infrared spectrogram, the composite membrane material had characteristic peaks of both PES and micro-nano cellulose without appearance of other new characteristics peaks. It revealed that there were no new functional groups in the composite membrane material, and the level of molecular compatibility was achieved, which was based on the existence of inter-molecular hydrogen bond association between PES and micro-nano cellulose. Due to the existence of micro-nano cellulose, the crystallinity of composite membrane material was increased from 37.7% to 47.9%. The more the increase in micro-nano cellulose mass fraction, the better the van de Waal force and hydrogen bond force between composite membrane material and water were enhanced. The hydrophilic angle of composite membrane material was decreased from 55.8 degrees to 45.8 degrees and the surface energy was raised from 113.7 to 123.5 mN x m(-2). Consequently, the hydrophilic property of composite membrane material was improved. The number of pores in the support layer of composite membrane material was lager than that of pure PES membrane. Apparently, pores were more uniformly distributed.

  16. Advanced vectorial simulation of VCSELs with nano structures invited paper

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2009-01-01

    The single-mode properties and design issues of three vertical-cavity surface-emitting laser (VCSEL) structures incorporating nano structures are rigorously investigated. Nano structuring enables to deliver selective pumping or loss to the fundamental mode as well as stabilizing the output...... polarization state. Comparison of three vectorial simulation methods reveals that the modal expansion method is suitable for treating the nano structured VCSEL designs....

  17. Reactivity improvement of magnesium by carbon nano-material mixing

    Energy Technology Data Exchange (ETDEWEB)

    Aikawa, Kenji [Tokai Univ. (Japan). Course of Metallurgical Engineering; Niimuma, Hideki; Uchida, Haru-Hisa [Tokai Univ. (Japan). Dept. of Human Development; Nishi, Yoshitake [Tokai Univ. (Japan). Dept. of Materials Science

    2010-07-01

    Proposing magnesium as a hydrogen storage material, we demonstrate quite interesting results of carbon nano-materials mixed into magnesium by mechanical milling in this study. Higher hydrogen reactivity can be obtained by multi wall carbon nano-tube (MWCNT) mixing which may enlarge the diffusion path in the sample powder particles. As a result, Mg with 0, 10, 20, 40 and 60 mass% of MWCNT exhibits drastically modified hydrogen absorption and desorption kinetics with more than 5 mass% H (including weight of catalyst) at 573-673K within 10min. under 6MPa of H{sub 2}. (orig.)

  18. Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

    Science.gov (United States)

    Wang, Hailiang; Dai, Hongjie

    2013-04-07

    The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC

  19. High energy density capacitors using nano-structure multilayer technology

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1992-08-01

    Today, many pulse power and industrial applications are limited by capacitor performance. While incremental improvements are anticipated from existing capacitor technologies, significant advances are needed in energy density to enable these applications for both the military and for American economic competitiveness. We propose a program to research and develop a novel technology for making high voltage, high energy density capacitors. Nano-structure multilayer technologies developed at LLNL may well provide a breakthrough in capacitor performance. Our controlled sputtering techniques are capable of laying down extraordinarily smooth sub-micron layers of dielectric and conductor materials. With this technology, high voltage capacitors with an order of magnitude improvement in energy density may be achievable. Well-understood dielectrics and new materials will be investigated for use with this technology. Capacitors developed by nano-structure multilayer technology are inherently solid state, exhibiting extraordinary mechanical and thermal properties. The conceptual design of a Notepad capacitor is discussed to illustrate capacitor and capacitor bank design and performance with this technology. We propose a two phase R&D program to address DNA`s capacitor needs for electro-thermal propulsion and similar pulse power programs. Phase 1 will prove the concept and further our understanding of dielectric materials and design tradeoffs with multilayers. Nano-structure multilayer capacitors will be developed and characterized. As our materials research and modeling prove successful, technology insertion in our capacitor designs will improve the possibility for dramatic performance improvements. In Phase 2, we will make Notepad capacitors, construct a capacitor bank and demonstrate its performance in a meaningful pulse power application. We will work with industrial partners to design full scale manufacturing and move this technology to industry for volume production.

  20. Electro-oxidation of methanol at the different carbon materials supported Pt nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu.; Zhang, Guojie; Zhou, Yiming; Tang, Yawen; Lu, Tianhong [The Laboratory of Electrochemistry, College of Chemistry and Material Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046 (China); Ma, Juan [Institute of Electrochemical Power Sources, Soochow University, Suzhou 215006 (China)

    2010-10-15

    Single-wall carbon nano-tubes (SWNTs), multi-wall carbon nano-tubes (MWNTs) and Vulcan XC-72 carbon (XC-72) are used as supporting carbon materials to prepare Pt/XC-72, Pt/SWNTs and Pt/MWNTs catalysts in tetrahydrofuran/water/ethanol mixture solution. Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) measurements demonstrate that the type of supporting carbon material affects significantly the morphology and the electronic structure of supported Pt nano-particles (NPs). Electrochemical measurements indicate that the Pt/SWNTs catalyst exhibited the highest current density, the lowest onset oxidation potential and the best stability for methanol electro-oxidation among the three samples, indicating SWNTs are an ideal anode catalyst supporting material for the practical application of direct methanol fuel cells. (author)

  1. A nano-structured material for reliable speciation of chromium and manganese in drinking waters, surface waters and industrial wastewater effluents.

    Science.gov (United States)

    Abdolmohammad-Zadeh, H; Sadeghi, G H

    2012-05-30

    A simple solid phase extraction system based on the applying the nickel-aluminum layered double hydroxide (Ni-Al LDH) as a nano-sorbent was developed for the speciation analysis of chromium and manganese by flame atomic absorption spectrometry (FAAS). The method is based on the fact that Cr(VI) and Mn(VII) oxyanions could be adsorbed on the Ni-Al(NO(3)(-)) LDH and/or exchanged with LDH interlayer NO(3)(-) ions at pH 6.0, whereas Cr(III) and Mn(II) cations pass through the LDH-packed column without retention. The determinations of total Cr and Mn, and hence indirectly Cr(III) and Mn(II), involve the pre-oxidations of Cr(III) and Mn(II) to Cr(VI) and Mn(VII) with H(2)O(2) and acidic solution of KIO(4), respectively. Several important factors affecting the retention efficiency were investigated and optimized. In the optimum experimental conditions, the limits of detection (3S(b)/m) for Cr(VI) and Mn(VII) were 0.51 and 0.47 ng mL(-1), and the relative standard deviations were 2.5 and 3.2% (C=30.0 ng mL(-1), n=6), respectively. The presented method was validated by the analysis of a certified reference material, and applied to the speciation of Cr and Mn in drinking waters, surface waters and industrial wastewater effluents. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. In-situ nano-crystal-to-crystal transformation synthesis of energetic materials based on three 5,5′-azotetrazolate Cr(III) salts

    Science.gov (United States)

    Miao, Yu; Qiu, Yanxuan; Cai, Jiawei; Wang, Zizhou; Yu, Xinwei; Dong, Wen

    2016-01-01

    The in-situ nano-crystal-to-crystal transformation (SCCT) synthesis provides a powerful approach for tailoring controllable feature shapes and sizes of nano crystals. In this work, three nitrogen-rich energetic nano-crystals based on 5,5′-azotetrazolate(AZT2−) Cr(III) salts were synthesized by means of SCCT methodology. SEM and TEM analyses show that the energetic nano-crystals feature a composition- and structure-dependent together with size-dependent thermal stability. Moreover, nano-scale decomposition products can be obtained above 500 °C, providing a new method for preparing metallic oxide nano materials. PMID:27869221

  3. In-situ nano-crystal-to-crystal transformation synthesis of energetic materials based on three 5,5'-azotetrazolate Cr(III) salts.

    Science.gov (United States)

    Miao, Yu; Qiu, Yanxuan; Cai, Jiawei; Wang, Zizhou; Yu, Xinwei; Dong, Wen

    2016-11-21

    The in-situ nano-crystal-to-crystal transformation (SCCT) synthesis provides a powerful approach for tailoring controllable feature shapes and sizes of nano crystals. In this work, three nitrogen-rich energetic nano-crystals based on 5,5'-azotetrazolate(AZT(2-)) Cr(III) salts were synthesized by means of SCCT methodology. SEM and TEM analyses show that the energetic nano-crystals feature a composition- and structure-dependent together with size-dependent thermal stability. Moreover, nano-scale decomposition products can be obtained above 500 °C, providing a new method for preparing metallic oxide nano materials.

  4. Three-dimensional laser micro- and nano-structuring of acrylated poly(ethylene glycol) materials and evaluation of their cytoxicity for tissue engineering applications.

    Science.gov (United States)

    Ovsianikov, A; Malinauskas, M; Schlie, S; Chichkov, B; Gittard, S; Narayan, R; Löbler, M; Sternberg, K; Schmitz, K-P; Haverich, A

    2011-03-01

    The natural cell environment is characterized by complex three-dimensional structures, which contain features at multiple length scales. Many in vitro studies of cell behavior in three dimensions rely on the availability of artificial scaffolds with controlled three-dimensional topologies. In this paper, we demonstrate fabrication of three-dimensional scaffolds for tissue engineering out of poly(ethylene glycol) diacrylate (PEGda) materials by means of two-photon polymerization (2PP). This laser nanostructuring approach offers unique possibilities for rapid manufacturing of three-dimensional structures with arbitrary geometries. The spatial resolution dependence on the applied irradiation parameters is investigated for two PEGda formulations, which are characterized by molecular weights of 302 and 742. We demonstrate that minimum feature sizes of 200nm are obtained in both materials. In addition, an extensive study of the cytotoxicity of the material formulations with respect to photoinitiator type and photoinitiator concentration is undertaken. Aqueous extracts from photopolymerized PEGda samples indicate the presence of water-soluble molecules, which are toxic to fibroblasts. It is shown that sample aging in aqueous medium reduces the cytotoxicity of these extracts; this mechanism provides a route for biomedical applications of structures generated by 2PP microfabrication and photopolymerization technologies in general. Finally, a fully biocompatible combination of PEGda and a photoinitiator is identified. Fabrication of reproducible scaffold structures is very important for systematic investigation of cellular processes in three dimensions and for better understanding of in vitro tissue formation. The results of this work suggest that 2PP may be used to polymerize poly(ethylene glycol)-based materials into three-dimensional structures with well-defined geometries that mimic the physical and biological properties of native cell environments. Copyright © 2010

  5. Nano-cluster stability following neutron irradiation in MA957 oxide dispersion strengthened material

    Energy Technology Data Exchange (ETDEWEB)

    Ribis, J., E-mail: joel.ribis@cea.fr [CEA, DEN, DMN, SRMA, F-91191 Gif sur Yvette (France); Lozano-Perez, S. [Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom)

    2014-01-15

    ODS steels are promising materials for Sodium cooled Fast Reactors since their fine distribution of nano-clusters confers excellent mechanical properties. However, the nano-feature stability needs to be assessed under neutron irradiation. Before irradiation, the characterizations show that nano-particles are finely distributed within the ferritic matrix and are identified to have a pyrochlore type structure. After irradiation of the MA957 alloy in the Phenix French reactor at 412 °C up to 50 dpa and 430 °C up to 75 dpa, transmission electron microscopy characterization reveals a very slight density fall but no distinguishable difference in nano-features size before and after irradiation. In addition, after both irradiations, the nano-oxides are still (Y, Ti, O) compounds with orientation relationship with the matrix. A multislice simulation of high resolution images suggests that nano-particles still have a fcc pyrochlore type structure after irradiation. A possible change of lattice parameter seems to be highlighted, possibly due to disordering by cascade effect.

  6. Nano-cluster stability following neutron irradiation in MA957 oxide dispersion strengthened material

    Science.gov (United States)

    Ribis, J.; Lozano-Perez, S.

    2014-01-01

    ODS steels are promising materials for Sodium cooled Fast Reactors since their fine distribution of nano-clusters confers excellent mechanical properties. However, the nano-feature stability needs to be assessed under neutron irradiation. Before irradiation, the characterizations show that nano-particles are finely distributed within the ferritic matrix and are identified to have a pyrochlore type structure. After irradiation of the MA957 alloy in the Phenix French reactor at 412 °C up to 50 dpa and 430 °C up to 75 dpa, transmission electron microscopy characterization reveals a very slight density fall but no distinguishable difference in nano-features size before and after irradiation. In addition, after both irradiations, the nano-oxides are still (Y, Ti, O) compounds with orientation relationship with the matrix. A multislice simulation of high resolution images suggests that nano-particles still have a fcc pyrochlore type structure after irradiation. A possible change of lattice parameter seems to be highlighted, possibly due to disordering by cascade effect.

  7. Strategies for Tuning the Reactivity of NanoEnergetic Materials

    Science.gov (United States)

    Prakash, Anand

    2005-07-01

    Nanostructured fuel/oxidizer composites are being looked upon as a possible approach to enhance energy release rates. Here we report on two approaches to moderate/tune reactivity. In the first example we accelerate reactivity. The method is based on electrostatically enhanced assembly to promote the preferential arrangement of aluminum (fuel) nanoparticles with iron oxide (oxidizer) nanoparticles in the aerosol phase. Two unipolar chargers are employed to generate oppositely charged aluminum and iron oxide particles, which enhance the formation of intimately interconnected nanocomposite energetic materials. The results of burning tests and thermal analysis using differential scanning calorimetry (DSC) showed that aluminum/iron oxide nanocomposite aerosol materials synthesized by bipolar assembly had burning rates that are a factor of 10 higher than those produced by random Brownian coagulation. In a second approach we employ a very reactive oxidizer (Potassium permanganate; ˜150 nm) and create a less reactive shell (Iron oxide). The measured reactivity for a nano-Al/composite oxidizer could be varied by more than a factor of 10 as measured by the pressurization rate in a closed vessel (Psi/microsecond), by changing the coating thickness of the iron oxide. The composite oxidizer nanoparticles were synthesized by a new aerosol approach, where the non-wetting interaction between iron oxide and molten potassium permanganate aids the phase segregation of a nanocomposite droplet into a core-shell structure.

  8. Hybridized Nano-Structure Composed of Metal and Polydiacetylene

    Institute of Scientific and Technical Information of China (English)

    H. Oikawa; A. Masuhara; T. Onodera; H. Kasai; H. Nakanishi

    2005-01-01

    @@ 1Introduction Polydiacetylene (PDA) is one of the promising candidates for organic third-order nonlinear optical (NLO) material, due to fast optical responsibility and easy processability in comparison with semiconductors etc. The magnitude of NLO property, however, is not still sufficient for the devices applications. Neeves, et al[1] theoretically predicted the enhancement of NLO property for core-shell type hybridized nanocrystal (NC) composed of PDA and metal. In the present study, we have prepared the two kinds of core-shell type hybridized nano-structure, and investigated their optical properties.

  9. Recent development of antifouling polymers: structure, evaluation, and biomedical applications in nano/micro-structures.

    Science.gov (United States)

    Liu, Lingyun; Li, Wenchen; Liu, Qingsheng

    2014-01-01

    Antifouling polymers have been proven to be vital to many biomedical applications such as medical implants, drug delivery, and biosensing. This review covers the major development of antifouling polymers in the last 2 decades, including the material chemistry, structural factors important to antifouling properties, and how to challenge or evaluate the antifouling performances. We then discuss the applications of antifouling polymers in nano/micro-biomedical applications in the form of nanoparticles, thin coatings for medical devices (e.g., artificial joint, catheter, wound dressing), and nano/microscale fibers. © 2014 Wiley Periodicals, Inc.

  10. Properties of the chalcogenide–carbon nano tubes and graphene composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Abhay Kumar, E-mail: abhaysngh@rediffmail.com [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Department of Electronics Engineering, Incheon National University, Incheon 406-772 (Korea, Republic of); Department of Physics, Incheon National University, Incheon 406-772 (Korea, Republic of); Kim, JunHo [Department of Physics, Incheon National University, Incheon 406-772 (Korea, Republic of); Park, Jong Tae [Department of Electronics Engineering, Incheon National University, Incheon 406-772 (Korea, Republic of); Sangunni, K.S. [Department of Physics, Indian Institute of Science, Bangalore 560012 (India)

    2015-04-05

    Highlights: • Chalcogenides. • Melt quenched. • Composite materials. • Multi walled carbon nano tubes. • Bilayer graphene. - Abstract: Composite can deliver more than the individual elemental property of the material. Specifically chalcogenide- multi walled carbon nano tubes and chalcogenide- bilayer graphene composite materials could be interesting for the investigation, which have been less covered by the investigators. We describe micro structural properties of Se{sub 55}Te{sub 25}Ge{sub 20,} Se{sub 55}Te{sub 25}Ge{sub 20} + 0.025% multi walled carbon nano tubes and Se{sub 55}Te{sub 25}Ge{sub 20} + 0.025% bilayer graphene materials. This gives realization of the alloying constituents inclusion/or diffusion inside the multi walled carbon nano tubes and bilayer graphene under the homogeneous parent alloy configuration. Raman spectroscopy, X-ray photoelectron spectroscopy, UV/Visible spectroscopy and Fourier transmission infrared spectroscopy have also been carried out under the discussion. A considerable core energy levels peak shifts have been noticed for the composite materials by the X-ray photoelectron spectroscopy. The optical energy band gaps are measured to be varied in between 1.2 and 1.3 eV. In comparison to parent (Se{sub 55}Te{sub 25}Ge{sub 20}) alloy a higher infrared transmission has been observed for the composite materials. Subsequently, variation in physical properties has been explained on the basis of bond formation in solids.

  11. Preparation of Nano-porous Materials(Ⅰ) by Polymerization of Amphiphile Self-assemblies

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The polymerization of amphiphilic self-assemblies is a promising method to synthesize nano-structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self-assemblies to amphiphilic self-assemblies is given in this paper with 49 参考文献. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano-porous materials is briefly described.

  12. Characterization and the Pattern of Surfaces of Sealant with nano size Composite Materials

    Science.gov (United States)

    Quddos, A.; Samtio, N. H.; Syed, A. M.

    2013-06-01

    Nano composite sealant is low viscosity, room temperature cured, opaque and flowable nature. They have variety of uses such as potting, pressure sealant and shock resistant. Most important factor influencing use of fillers in polymer composites is their ability to effectively transfer the applied load in the matrix. The effective utilization of fillers in composites for structural applications depends strongly on the ability to disperse the nano fillers homogeneously in the matrix without damaging them. R-Belite supper epoxy adhesive (RBSEA) were formulated with different nano fillers (KCl, Al2O3, ZrO2, SiO2, ZrO2) at room temperature. The composite were prepared with the 0.02 to 0.10 weight ratios to promote the nucleation of the nanoparticles in the applied sealant. Two main problems which arise in improving the properties are poor dispersion of the fillers in the composite and weak bonding between nano fillers and the matrix. These problems are solved by mechanical and chemical means. It was observed that mechanical properties like tensile strength, elongation hardness etc and thermal properties were also improved with incorporation of nanofillers in the working applied polymer matrix. The dispersion of nano fillers in polymer matrix is studied by Scanning electron microscopy (SEM). The results confirm the presence of nanomaterial in RBSEA/fillers nanocomposites. SEM is also used to characterize the pattern of surfaces with nano size composite materials.

  13. Perspective: NanoMine: A material genome approach for polymer nanocomposites analysis and design

    Science.gov (United States)

    Zhao, He; Li, Xiaolin; Zhang, Yichi; Schadler, Linda S.; Chen, Wei; Brinson, L. Catherine

    2016-05-01

    Polymer nanocomposites are a designer class of materials where nanoscale particles, functional chemistry, and polymer resin combine to provide materials with unprecedented combinations of physical properties. In this paper, we introduce NanoMine, a data-driven web-based platform for analysis and design of polymer nanocomposite systems under the material genome concept. This open data resource strives to curate experimental and computational data on nanocomposite processing, structure, and properties, as well as to provide analysis and modeling tools that leverage curated data for material property prediction and design. With a continuously expanding dataset and toolkit, NanoMine encourages community feedback and input to construct a sustainable infrastructure that benefits nanocomposite material research and development.

  14. Hybrid nano-structure for enhanced energy storage devices

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque

    The goal of this research is to develop electrode materials using various nano-structure hybrids for improved energy storage devices. Enhancing the performance of energy storage device has been gaining tremendous attention since it holds the key solution to advance renewable energy usage thus reduce the consumption of fossil fuels. The application of energy storage devices such as super-capacitor and Li-ion-battery has seen significant growth; however, it is still limited mainly by charge/discharge rate and energy density. One of the solutions is to use nano-structure materials, which offer higher power at high energy density and improved stability during the charge discharge cycling of ions in and out of the storage electrode material. In this research, carbon-based materials (e.g. porous carbon, graphene) in conjunction with metal oxides such as CeO2 nanoparticles/TiO2 nanowires are synthesized utilizing low temperature hydrothermal method for the fabrication of advanced electrode materials. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transformation Infrared Spectroscopy (FTIR) were used for materials characterization. Poentio-galvanostat, battery analyzer, and Electrochemical Impedance Spectroscopy (EIS) were used for evaluating the electrochemical performance. The testing results have shown that a maximum 500% higher specific capacitance could be obtained using porous carbon/CeO2 instead of porous carbon for super-capacitor application and microwave exfoliated graphene oxide/TiO2 nanowire hybrid provides up to 80% increment of specific capacity compared to porous carbon anode for Li-ion-battery application.

  15. Preparation and characterization of boron-doped titania nano-materials with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Xue Xiangxin [Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110819 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110819 (China); Liaoning Engineering and Technology Research Center of Boron Resources Comprehensive Utilization, Shenyang 110819 (China); Liaoning Provincial Universities Key Laboratory of Boron Resources Ecological Utilization Technology and Boron Materials, Shenyang 110819 (China); Wang Yuzheng, E-mail: zheng_wangyu@qq.com [Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110819 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110819 (China); Liaoning Engineering and Technology Research Center of Boron Resources Comprehensive Utilization, Shenyang 110819 (China); Liaoning Provincial Universities Key Laboratory of Boron Resources Ecological Utilization Technology and Boron Materials, Shenyang 110819 (China); Yang He [Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110819 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110819 (China); Liaoning Engineering and Technology Research Center of Boron Resources Comprehensive Utilization, Shenyang 110819 (China); Liaoning Provincial Universities Key Laboratory of Boron Resources Ecological Utilization Technology and Boron Materials, Shenyang 110819 (China)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer B/TiO{sub 2} nano-materials are prepared and doping improves particles agglomeration. Black-Right-Pointing-Pointer Absorption spectrum move to visible light after doped. Black-Right-Pointing-Pointer B/TiO{sub 2} nano-materials firstly applied to the fields of antibacterial materials. Black-Right-Pointing-Pointer Calcined at high temperature of 900 Degree-Sign C, B/TiO{sub 2} has still strong antibacterial. - Abstract: Boron-doped TiO{sub 2} (B/TiO{sub 2}) nano-materials were synthesized by a sol-gel method and characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum (FT-IR) and UV-vis diffuse reflectance spectra (DRS). With the test of bacterial inhibition zone, the antibacterial properties of B/TiO{sub 2} nano-materials on Escherichia coli were investigated. The results show that the structure of TiO{sub 2} could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; part of the boron atoms probably have been weaved into the interstitial TiO{sub 2} structure or incorporated into the TiO{sub 2} lattice through occupying O sites, whereas others exist as B{sub 2}O{sub 3}. The results of antibacterial experiment under visible light irradiation show that the B/TiO{sub 2} nano-materials exhibit enhanced antibacterial efficiency compared with non-doped TiO{sub 2}. Ultimately, the action mechanism of B/TiO{sub 2} doping is discussed.

  16. Protein adsorption on materials surfaces with nano-topography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Protein adsorption behavior on the surfaces of biomedical materials is highly related to the biocompatibility of the materials. In the past, numerous research reports were mainly focused on the effect of chemical components of a material's surface on protein adsorption. The effect of surface topography on protein adsorption, the topic of this review, has recently receuvedkeen interest. The influence of surface nano-topographic factors, including roughness, curvature and geometry, on protein adsorption as well as the protein adsorption behavior, such as the amount of protein adsorbed, the activity and morphology of adsorbed protein, is introduced.

  17. Adhesion forces due to nano-triboelectrification between similar materials

    CERN Document Server

    Guerret-Piecourt, Christelle; Ségault, Frédéric; Juvé, Denyse; Tréheux, Daniel; Tonck, André

    2004-01-01

    Contact electrification and triboelectrification are well-known in the case of dissimilar materials, however the case of charge exchange during friction between nominally identical insulating materials is less documented. We experimentally investigated the triboelectrification between two smooth monocrystalline α-Al 2O 3 (sapphire) antagonists by surface force measurements with a Surface Force Apparatus (SFA). The force between a sphere and a plane, both in sapphire, was measured as a function of the sphere-plane distance D, before and after nano-friction tests, under dry argon atmosphere. Respective contributions of van der Waals, water meniscus and electrostatic forces were determined. The estimated Hamaker constant was in good agreement with the Lifshitz theory, and the dominant meniscus attraction at low separation could be overcome with small radius sphere. We demonstrated that electrostatic forces were generated by the nano-friction test and we quantified the adhesion that results from this con...

  18. A hetero-structured ring discovered by CAS nano-scientists

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Teaming up with co-workers,researchers from the CAS-affiliated National Center for Nanoscience and Technology(NCNST) recently succeeded in fabricating a hetero-structured nano-ring in their laboratory. The feat, scientist believe, would be valuable for developing new optical or electronic nano-elements and related devices in the near future.The work was recently reported by Advanced Materials (Vol. 19, 2319-2323, 2007).

  19. 无机类富勒烯结构二硫化钼纳米润滑材料的制备与应用%Preparation and Application of Inorganic Fullerene-Like Structure Molybdenum Disulfide Nano-Lubricating Materials

    Institute of Scientific and Technical Information of China (English)

    韩明儒; 魏世忠; 韩华

    2014-01-01

    The discovery process of nano-particles and structure of nano-tubes for IF-MoS2 are introduced.The formation mechanism,preparation and performance of nano-particles and nano-tubes for IF-MoS2 are expounded, and the application prospect is forecasted.%介绍了无机类富勒烯结构二硫化钼(IF-MoS2)纳米粒子的发现过程和纳米管的结构,阐述了IF-MoS2纳米粒子和纳米管的形成机理、制备方法和性能,展望了应用前景。

  20. Optimizing Energy Conversion: Magnetic Nano-materials

    Science.gov (United States)

    McIntyre, Dylan; Dann, Martin; Ilie, Carolina C.

    2015-03-01

    We present herein the work started at SUNY Oswego as a part of a SUNY 4E grant. The SUNY 4E Network of Excellence has awarded SUNY Oswego and collaborators a grant to carry out extensive studies on magnetic nanoparticles. The focus of the study is to develop cost effective rare-earth-free magnetic materials that will enhance energy transmission performance of various electrical devices (solar cells, electric cars, hard drives, etc.). The SUNY Oswego team has started the preliminary work for the project and graduate students from the rest of the SUNY 4E team (UB, Alfred College, Albany) will continue the project. The preliminary work concentrates on analyzing the properties of magnetic nanoparticle candidates, calculating molecular orbitals and band gap, and the fabrication of thin films. SUNY 4E Network of Excellence Grant.

  1. Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

    Directory of Open Access Journals (Sweden)

    Nurit Beyth

    2015-01-01

    Full Text Available Despite numerous existing potent antibiotics and other antimicrobial means, bacterial infections are still a major cause of morbidity and mortality. Moreover, the need to develop additional bactericidal means has significantly increased due to the growing concern regarding multidrug-resistant bacterial strains and biofilm associated infections. Consequently, attention has been especially devoted to new and emerging nanoparticle-based materials in the field of antimicrobial chemotherapy. The present review discusses the activities of nanoparticles as an antimicrobial means, their mode of action, nanoparticle effect on drug-resistant bacteria, and the risks attendant on their use as antibacterial agents. Factors contributing to nanoparticle performance in the clinical setting, their unique properties, and mechanism of action as antibacterial agents are discussed in detail.

  2. Failure by fracture and fatigue in 'NANO' and 'BIO'materials

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, R.O.; Muhlstein, C.L.; Nalla, R.K.

    2003-12-19

    The behavior of nanostructured materials/small-volumestructures and biologi-cal/bio-implantable materials, so-called "nano"and "bio" materials, is currently much in vogue in materials science. Oneaspect of this field, which to date has received only limited attention,is their fracture and fatigue properties. In this paper, we examine twotopics in this area, namely the premature fatigue failure ofsilicon-based micron-scale structures for microelectromechanical systems(MEMS), and the fracture properties of mineralized tissue, specificallyhuman bone.

  3. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Qiang; Zhang, Zhenghao [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Yin, Shengyu [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Guo, Zaiping [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Institute for Superconducting & Electronic Materials, University of Wollongong, NSW 2522 (Australia); Wang, Shiquan [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Feng, Chuanqi, E-mail: cfeng@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China)

    2016-08-30

    Highlights: • Ramie fibers and corncobs are used as precursors to prepare the biomass carbons. • The ramie fiber carbon (RFC) took on morphology of 3D micro-rods. • The corncob carbon (CC) possessed a 2D nanosheets structure. • Both RFC and CC exhibited outstanding electrochemical performances in LIBs and SIBs systems. - Abstract: Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg{sup −1} after 180 cycles when cycled at room temperature in a 3.0–0.01 V potential (vs. Li/Li{sup +}) window at current density of 100 mAg{sup −1}, respectively, which are much higher than that of graphite (375 mAhg{sup −1}) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg{sup −1} with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  4. Preparation of Nano/Micron Composite Materials by Process Method

    Institute of Scientific and Technical Information of China (English)

    GAN Ai-feng; WEI Qi; JI; Yuan; HU Chuan-xin; YAO Jun-min

    2004-01-01

    This thesis put forward a method that controls the process of synthesizing nanomaterial to realize the composite of nanomaterial and micronmaterial. This thesis realizes the composite of nanomaterial and micronmaterial by adding micronmaterial during production of nanomaterial through sol-gel method, also introduces the technique and experiment's process preparation of nanocomposite material, and successfully prepared nanocomposite materials with nano-PbTiO3 covered on the surface of micron-Ni. According to the sample's SEM-pictures, the core-shell can be observed plate microstructure, and it is uniform, tight, full and good.

  5. Materials and structures

    Science.gov (United States)

    Saito, Theodore T.; Langenbeck, Sharon L.; Al-Jamily, Ghanim; Arnold, Joe; Barbee, Troy; Coulter, Dan; Dolgin, Ben; Fichter, Buck; George, Patricia; Gorenstein, Paul

    1992-08-01

    Materials and structures technology covers a wide range of technical areas. Some of the most pertinent issues for the Astrotech 21 missions include dimensionally stable structural materials, advanced composites, dielectric coatings, optical metallic coatings for low scattered light applications, low scattered light surfaces, deployable and inflatable structures (including optical), support structures in 0-g and 1-g environments, cryogenic optics, optical blacks, contamination hardened surfaces, radiation hardened glasses and crystals, mono-metallic telescopes and instruments, and materials characterization. Some specific examples include low coefficients of thermal expansion (CTE) structures (0.01 ppm/K), lightweight thermally stable mirror materials, thermally stable optical assemblies, high reliability/accuracy (1 micron) deployable structures, and characterization of nanometer level behavior of materials/structures for interferometry concepts. Large filled-aperture concepts will require materials with CTE's of 10(exp 9) at 80 K, anti-contamination coatings, deployable and erectable structures, composite materials with CTE's less than 0.01 ppm/K and thermal hysteresis, 0.001 ppm/K. Gravitational detection systems such as LAGOS will require rigid/deployable structures, dimensionally stable components, lightweight materials with low conductivity, and high stability optics. The Materials and Structures panel addressed these issues and the relevance of the Astrotech 21 mission requirements by dividing materials and structures technology into five categories. These categories, the necessary development, and applicable mission/program development phasing are summarized. For each of these areas, technology assessments were made and development plans were defined.

  6. Generation of nano roughness on fibrous materials by atmospheric plasma

    Science.gov (United States)

    Kulyk, I.; Scapinello, M.; Stefan, M.

    2012-12-01

    Atmospheric plasma technology finds novel applications in textile industry. It eliminates the usage of water and of hazard liquid chemicals, making production much more eco-friendly and economically convenient. Due to chemical effects of atmospheric plasma, it permits to optimize dyeing and laminating affinity of fabrics, as well as anti-microbial treatments. Other important applications such as increase of mechanical resistance of fiber sleeves and of yarns, anti-pilling properties of fabrics and anti-shrinking property of wool fabrics were studied in this work. These results could be attributed to the generation of nano roughness on fibers surface by atmospheric plasma. Nano roughness generation is extensively studied at different conditions. Alternative explanations for the important practical results on textile materials and discussed.

  7. Nano-materials Enabled Thermoelectricity from Window Glasses

    KAUST Repository

    Inayat, Salman Bin

    2012-11-13

    With a projection of nearly doubling up the world population by 2050, we need wide variety of renewable and clean energy sources to meet the increased energy demand. Solar energy is considered as the leading promising alternate energy source with the pertinent challenge of off sunshine period and uneven worldwide distribution of usable sun light. Although thermoelectricity is considered as a reasonable renewable energy from wasted heat, its mass scale usage is yet to be developed. Here we show, large scale integration of nano-manufactured pellets of thermoelectric nano-materials, embedded into window glasses to generate thermoelectricity using the temperature difference between hot outside and cool inside. For the first time, this work offers an opportunity to potentially generate 304 watts of usable power from 9 m2 window at a 206C temperature gradient. If a natural temperature gradient exists, this can serve as a sustainable energy source for green building technology.

  8. Ecotoxicity of selected nano-materials to aquatic organisms.

    Science.gov (United States)

    Blaise, C; Gagné, F; Férard, J F; Eullaffroy, P

    2008-10-01

    Present knowledge concerning the ecotoxic effects of nano-materials is very limited and merits to be documented more fully. For this purpose, we appraised the toxicity of nine metallic nano-powders (copper zinc iron oxide, nickel zinc iron oxide, yttrium iron oxide, titanium dioxide, strontium ferrite, indium tin oxide, samarium oxide, erbium oxide, and holmium oxide) and of two organic nano- powders (fullerene-C60 and single-walled carbon nanotube or SWCNT). After a simple process where nano-powders (NPs) were prepared in aqueous solution and filtered, they were then bioassayed across several taxonomic groups including decomposers (bacteria), primary producers (micro-algae), as well as primary and secondary consumers (micro-invertebrates and fish). Toxicity data generated on the 11 NPs reflected a wide spectrum of sensitivity that was biological level-, test-, and endpoint-specific. With all acute and chronic tests confounded for these 11 NPs, toxicity responses spanned over three orders of magnitude: >463 mg/L (24 h LC50 of the invertebrate Thamnoplatyurus platyurus for fullerene-C60) / 0.3 mg/L (96 h EC50 of the invertebrate Hydra attenuata for indium tin oxide), that is a ratio of 1543. On the basis of the MARA (Microbial Array for Risk Assessment) assay toxic fingerprint concept, it is intimated that NPs may have different modes of toxic action. When mixed in a 1:1 ratio with a certified reference material (CRM) sediment, two solid phase assays and an elutriate assay, respectively, showed that five NPs (copper zinc iron oxide, samarium oxide, erbium oxide, holmium oxide, and SWCNT) were able to increase both CRM sediment toxicity and its elutriate toxicity. This initial investigation suggests that chemicals emerging from nanotechnology may pose a risk to aquatic life in water column and sediment compartments and that further studies on their adverse effects are to be encouraged.

  9. 热压烧结制备纳米Y-TZP材料形貌及结构的分析%ANALYSIS OF THE MICROMORPHOLOGY AND STRUCTURE OF NANO Y-TZP MATERIALS SINTERED BY HOT_PRESSING

    Institute of Scientific and Technical Information of China (English)

    李蔚; 高濂; 李强

    2001-01-01

    研究分析了热压烧结纳米ZrO2(3Y)粉体制备的Y-TZP材料的形貌和结构. 结果发现:热压烧结制备纳米Y-TZP材料有很多新的特点,最明显的包括所得样品侧面内凹、断口轴向大气孔呈梯度分布等. 研究结果还表明:侧面内凹的现象主要是由于纳米粉体颗粒小、比表面能大而烧结所引起的. 样品断口大气孔从外向内呈梯度分布的现象不是由样品内外压差或温差造成的,而是由于样品各部分塑性滑移不均匀的结果.%Micromorphology and structure of nano Y-TZP materials sintered by hot_pressing were investigated. Nano ZrO2(3Y)powder calcined at 450 ℃, 5 h was hot_pressed with a heating rate of 10—30 ℃/min, sintering temperature of 1 100—1 300 ℃, dwelling time of 30 min and pressure of 15—40 MPa. Some new phenomena have been observed, including side face hollowness and gradient pore distribution on the fracture surface. It is believed that sintering of nanoparticles and the friction between the sample and the indenter cause both the hollowness and the gradient pore distribution.

  10. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    Science.gov (United States)

    Jiang, Qiang; Zhang, Zhenghao; Yin, Shengyu; Guo, Zaiping; Wang, Shiquan; Feng, Chuanqi

    2016-08-01

    Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg-1 after 180 cycles when cycled at room temperature in a 3.0-0.01 V potential (vs. Li/Li+) window at current density of 100 mAg-1, respectively, which are much higher than that of graphite (375 mAhg-1) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg-1 with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  11. Critical review of the safety assessment of nano-structured silica additives in food.

    Science.gov (United States)

    Winkler, Hans Christian; Suter, Mark; Naegeli, Hanspeter

    2016-06-10

    The development of nano-materials is viewed as one of the most important technological advances of the 21st century and new applications of nano-sized particles in the production, processing, packaging or storage of food are expected to emerge soon. This trend of growing commercialization of engineered nano-particles as part of modern diet will substantially increase oral exposure. Contrary to the proven benefits of nano-materials, however, possible adverse health effects have generally received less attention. This problem is very well illustrated by nano-structured synthetic amorphous silica (SAS), which is a common food additive since several decades although the relevant risk assessment has never been satisfactorily completed. A no observed adverse effect level of 2500 mg SAS particles/kg body weight per day was derived from the only available long-term administration study in rodents. However, extrapolation to a safe daily intake for humans is problematic due to limitations of this chronic animal study and knowledge gaps as to possible local intestinal effects of SAS particles, primarily on the gut-associated lymphoid system. This uncertainty is aggravated by digestion experiments indicating that dietary SAS particles preserve their nano-sized structure when reaching the intestinal lumen. An important aspect is whether food-borne particles like SAS alter the function of dendritic cells that, embedded in the intestinal mucosa, act as first-line sentinels of foreign materials. We conclude that nano-particles do not represent a completely new threat and that most potential risks can be assessed following procedures established for conventional chemical hazards. However, specific properties of food-borne nano-particles should be further examined and, for that purpose, in vitro tests with decision-making cells of the immune system are needed to complement existing in vivo studies.

  12. Nano-SiC implantation into the structure of carbon/graphite materials made by pyrolysis (carbonization) of the precursor system coal tar pitch/poly(dimethylsiloxane)

    Energy Technology Data Exchange (ETDEWEB)

    Czosnek, C.; Wolszczak, J.; Drygas, M.; Gora, M.; Janik, J.F. [AGH University of Science & Technology, Krakow (Poland). Faculty of Fuels & Energy

    2004-03-01

    Conversion of the air-cured poly(dimethylsiloxane) to SiC during co-pyrolysis with a coal tar pitch is studied with reference to the related SiO{sub 2}/pitch system. Each binary mixture is first homogenized at 160{sup o}C followed by carbonization at 500{sup o}C under argon to afford initial carbonizates. In both cases, one part of the initial carbonizate is further pyrolyzed at 1300{sup o}C and another part at 1650{sup o}C under an argon flow resulting in composite products. All products are studied with FT-IR, XRD, and XPS spectroscopic methods supplemented with SEM and 'wet' Si-analyses, when applicable. Carbothermally assisted conversion of both silicon precursors to nanocrystalline SiC embedded in the evolving C-matrix, i.e. nano-SiC/C composites, is evident only after the 1650{sup o}C carbonization stage.

  13. Synthesis, characterization and application of functional carbon nano materials

    Science.gov (United States)

    Chu, Jin

    The synthesis, characterizations and applications of carbon nanomaterials, including carbon nanorods, carbon nanosheets, carbon nanohoneycombs and carbon nanotubes were demonstrated. Different growth techniques such as pulsed laser deposition, DC/RF sputtering, hot filament physical vapour deposition, evaporative casting and vacuum filtration methods were introduced or applied for synthesizing carbon nanomaterials. The morphology, chemical compositions, bond structures, electronic, mechanical and sensing properties of the obtained samples were investigated. Tilted well-aligned carbon micro- and nano- hybrid rods were fabricated on Si at different substrate temperatures and incident angles of carbon source beam using the hot filament physical vapour deposition technique. The morphologic surfaces and bond structures of the oblique carbon rod-like structures were investigated by scanning electron microscopy, field emission scanning electron microscopy, transmission electron diffraction and Raman scattering spectroscopy. The field emission behaviour of the fabricated samples was also tested. Carbon nanosheets and nanohoneycombs were also synthesized on Si substrates using a hot filament physical vapor deposition technique under methane ambient and vacuum, respectively. The four-point Au electrodes are then sputtered on the surface of the nanostructured carbon films to form prototypical humidity sensors. The sensing properties of prototypical sensors at different temperature, humidity, direct current, and alternative current voltage were characterized. Linear sensing response of sensors to relative humidity ranging from 11% to 95% is observed at room temperature. Experimental data indicate that the carbon nanosheets based sensors exhibit an excellent reversible behavior and long-term stability. It also has higher response than that of the humidity sensor with carbon nanohoneycombs materials. Conducting composite films containing carbon nanotubes (CNTs) were prepared in

  14. Nano-sized aerosol classification, collection and analysis--method development using dental composite materials.

    Science.gov (United States)

    Bogdan, Axel; Buckett, Mary I; Japuntich, Daniel A

    2014-01-01

    This article presents a methodical approach for generating, collecting, and analyzing nano-size (1-100 nm) aerosol from abraded dental composite materials. Existing aerosol sampling instruments were combined with a custom-made sampling chamber to create and sample a fresh, steady-state aerosol size distribution before significant Brownian coagulation. Morphological, size, and compositional information was obtained by Transmission Electron Microscopy (TEM). To create samples sizes suitable for TEM analysis, aerosol concentrations in the test chamber had to be much higher than one would typically expect in a dental office, and therefore, these results do not represent patient or dental personnel exposures. Results show that nano-size aerosol was produced by the dental drill alone, with and without cooling water drip, prior to abrasion of dental composite. During abrasion, aerosol generation seemed independent of the percent filler load of the restorative material and the operator who generated the test aerosol. TEM investigation showed that "chunks" of filler and resin were generated in the nano-size range; however, free nano-size filler particles were not observed. The majority of observed particles consisted of oil droplets, ash, and graphitic structures.

  15. Bioinspired structural materials

    Science.gov (United States)

    Wegst, Ulrike G. K.; Bai, Hao; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

    2015-01-01

    Natural structural materials are built at ambient temperature from a fairly limited selection of components. They usually comprise hard and soft phases arranged in complex hierarchical architectures, with characteristic dimensions spanning from the nanoscale to the macroscale. The resulting materials are lightweight and often display unique combinations of strength and toughness, but have proven difficult to mimic synthetically. Here, we review the common design motifs of a range of natural structural materials, and discuss the difficulties associated with the design and fabrication of synthetic structures that mimic the structural and mechanical characteristics of their natural counterparts.

  16. Super resolution nano-information recording in a new hydrazone metal complex material

    Science.gov (United States)

    Zhang, Kui; Wei, Jingsong; Chen, Zhimin; Wei, Tao; Geng, Yongyou; Wang, Yang; Wu, Yiqun

    2016-10-01

    Laser thermal lithography has been proposed for a few years, which has the advantages of breaking through the optical diffraction limit, operation in far-field and in air, and low production cost. In this paper, a new hydrazone metal complex is used as the laser thermal lithography material due to its feature of the one-step fabrication of micro/nano structure without mask and wet-etching process. Based on the laser thermal lithography method, super resolution nano-information pits are directly written on the surface of hydrazone metal complex thin films. Pits with a minimum feature size of about 79 nm are successfully obtained, which is only about 1/7 of the writing spot size. Moreover, the reactive ion etching method can be applied to transfer the pits onto a silica substrate. These results suggest the potential applications of the new material in high density optical data storage and semiconductor industries.

  17. Preparation and characterization of boron-doped titania nano-materials with antibacterial activity

    Science.gov (United States)

    Xue, Xiangxin; Wang, Yuzheng; Yang, He

    2013-01-01

    Boron-doped TiO2 (B/TiO2) nano-materials were synthesized by a sol-gel method and characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum (FT-IR) and UV-vis diffuse reflectance spectra (DRS). With the test of bacterial inhibition zone, the antibacterial properties of B/TiO2 nano-materials on Escherichia coli were investigated. The results show that the structure of TiO2 could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; part of the boron atoms probably have been weaved into the interstitial TiO2 structure or incorporated into the TiO2 lattice through occupying O sites, whereas others exist as B2O3. The results of antibacterial experiment under visible light irradiation show that the B/TiO2 nano-materials exhibit enhanced antibacterial efficiency compared with non-doped TiO2. Ultimately, the action mechanism of B/TiO2 doping is discussed.

  18. Auxetic materials and structures

    CERN Document Server

    Lim, Teik-Cheng

    2015-01-01

    This book describes the fundamentals of the mechanics and design of auxetic solids and structures, which possess a negative Poisson’s ratio. It will benefit two groups of readers: (a) industry practitioners, such as product and structural designers, who need to control mechanical stress distributions using auxetic materials, and (b) academic researchers and students who intend to produce structures with unique mechanical and other physical properties using auxetic materials.

  19. Porous nano-structured Co3O4 anode materials generated from coordination-driven self-assembled aggregates for advanced lithium ion batteries.

    Science.gov (United States)

    Ge, Danhua; Geng, Hongbo; Wang, Jiaqing; Zheng, Junwei; Pan, Yue; Cao, Xueqin; Gu, Hongwei

    2014-08-21

    A simple and scalable coordination-derived method for the synthesis of porous Co3O4 hollow nanospheres is described here. The initially formed coordination-driven self-assembled aggregates (CDSAAs) could act as the precursor followed by calcination treatment. Then the porous hollow Co3O4 nanospheres are obtained, in which the primary Co3O4 nanoparticles are inter-dispersed. When the nanospheres are used as anode materials for lithium storage, they show excellent coulombic efficiency, high lithium storage capacity and superior cycling performance. In view of the facile synthesis and excellent electrochemical performance obtained, this protocol to fabricate special porous hollow frameworks could be further extended to other metal oxides and is expected to improve the practicality of superior cycle life anode materials with large volume excursions for the development of the next generation of LIBs.

  20. Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

    Science.gov (United States)

    Savaloni, Hadi; Haydari-Nasab, Fatemh; Malmir, Mariam

    2011-08-01

    Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30° and 70° incidence angles and at different azimuthal angles ( φ). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the φ angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths (<450 nm) is observed in the s-polarization spectra, while in addition to this peak a broad peak at longer wavelengths (i.e., LM) observed in the p-polarization spectra, which is more dominant for 70° incidence angle.

  1. Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Savaloni, Hadi, E-mail: savaloni@khayam.ut.ac.ir [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of); Haydari-Nasab, Fatemh; Malmir, Mariam [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of)

    2011-08-15

    Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30{sup o} and 70{sup o} incidence angles and at different azimuthal angles ({phi}). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the {phi} angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths (<450 nm) is observed in the s-polarization spectra, while in addition to this peak a broad peak at longer wavelengths (i.e., LM) observed in the p-polarization spectra, which is more dominant for 70{sup o} incidence angle.

  2. Biomimetic photonic materials with tunable structural colors.

    Science.gov (United States)

    Xu, Jun; Guo, Zhiguang

    2013-09-15

    Nature is a huge gallery of art involving nearly perfect structures and forms over the millions of years developing. Inspiration from natural structures exhibiting structural colors is first discussed. We give some examples of natural one-, two-, and three-dimensional photonic structures. This review article presents a brief summary of recent progress on bio-inspired photonic materials with variable structural colors, including the different facile and efficient routes to construct the nano-architectures, and the development of the artificial variable structural color photonic materials. Besides the superior optical properties, the excellent functions such as robust mechanical strength, good wettability are also mentioned, as well as the technical importance in various applications. This review will provide significant insight into the fabrication, design and application of the structural color materials.

  3. Ultrashort laser pulse cell manipulation using nano- and micro- materials

    Science.gov (United States)

    Schomaker, Markus; Killian, Doreen; Willenbrock, Saskia; Diebold, Eric; Mazur, Eric; Bintig, Willem; Ngezahayo, Anaclet; Nolte, Ingo; Murua Escobar, Hugo; Junghanß, Christian; Lubatschowski, Holger; Heisterkamp, Alexander

    2010-08-01

    The delivery of extra cellular molecules into cells is essential for cell manipulation. For this purpose genetic materials (DNA/RNA) or proteins have to overcome the impermeable cell membrane. To increase the delivery efficiency and cell viability of common methods different nano- and micro material based approaches were applied. To manipulate the cells, the membrane is in contact with the biocompatible material. Due to a field enhancement of the laser light at the material and the resulting effect the cell membrane gets perforated and extracellular molecules can diffuse into the cytoplasm. Membrane impermeable dyes, fluorescent labelled siRNA, as well as plasmid vectors encoded for GFP expression were used as an indicator for successful perforation or transfection, respectively. Dependent on the used material, perforation efficiencies over 90 % with a cell viability of about 80 % can be achieved. Additionally, we observed similar efficiencies for siRNA transfection. Due to the larger molecule size and the essential transport of the DNA into the nucleus cells are more difficult to transfect with GFP plasmid vectors. Proof of principle experiments show promising and adequate efficiencies by applying micro materials for plasmid vector transfection. For all methods a weakly focused fs laser beam is used to enable a high manipulation throughput for adherent and suspension cells. Furthermore, with these alternative optical manipulation methods it is possible to perforate the membrane of sensitive cell types such as primary and stem cells with a high viability.

  4. Aqueous phase deposition of dense tin oxide films with nano-structured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoshitake, E-mail: masuda-y@aist.go.jp; Ohji, Tatsuki; Kato, Kazumi

    2014-06-01

    Dense tin oxide films were successfully fabricated in an aqueous solution. The pH of the solutions was controlled to pH 1.3 by addition of HCl. Precise control of solution condition and crystal growth allowed us to obtain dense tin oxide films. Concave–convex surface of fluorine-doped tin oxide (FTO) substrates was entirely-covered with the continuous films. The films were about 65 nm in thickness and had nano-structured surfaces. Morphology of the films was strikingly different from our previous reported nano-sheet assembled structures. The films were not removed from the substrates by strong water flow or air blow to show strong adhesion strength. The aqueous solution process can be applied to surface coating of various materials such as nano/micro-structured surfaces, particles, fibers, polymers, metals or biomaterials. - Graphical abstract: Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. They had nano-structured surfaces. Concave-convex substrates were entirely-covered with the continuous films. - Highlights: • Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. • They had nano-structured surfaces. • Concave–convex substrates were entirely-covered with the continuous films.

  5. Micro/Nano-Structured Flexible Foils for Anti-Counterfeiting Purposes

    DEFF Research Database (Denmark)

    Okulova, Nastasia

    2016-01-01

    Up to date there have been found many ways of producing samples with functional nano-pattering, however for mass production of such samples the method of fabrication of the surface structure must be fast and cheap. A recently developed method suggests using extrusion coating of polymer materials...... in a roll-to roll process, where the functional micro-/nano- surface structures are imprinted directly onto the surface of a polymer foil. This new technology can both answer the requirement for being fast and cheap. The aim of this project is implementation of the technology for mass production...... has been demonstrated. The focus of this study lies on the reproduction of the previous results for nano- or micro-structures and implementation of this technology for mass production of such patterned foils for the use in packaging. An interesting application is production of holograms with build...

  6. Effects of material morphology on the phototoxicity of nano-TiO2 to bacteria.

    Science.gov (United States)

    Tong, Tiezheng; Shereef, Anas; Wu, Jinsong; Binh, Chu Thi Thanh; Kelly, John J; Gaillard, Jean-François; Gray, Kimberly A

    2013-01-01

    Nanostructured titania (nano-TiO2) is produced in diverse shapes, but it remains largely unknown how tuning the morphology of nano-TiO2 may alter its toxicity. Herein, we show that material morphology plays a critical role in regulating the phototoxicity of nano-TiO2 to bacteria. Low-dimensional nano-TiO2, including nanotubes, nanorods, and nanosheets, were synthesized hydrothermally, and their effects on the bacterial viability of Escherichia coli and Aeromonas hydrophila were compared to spherical nanostructures (anatase nanospheres and P25). Results reveal that TiO2 nanotubes and nanosheets are less phototoxic than their rod- and sphere-shape counterparts under simulated solar irradiation. None of the tested nano-TiO2 shows toxicity in the dark. In contrast to their diminished phototoxicity, however, TiO2 nanotubes and nanosheets exhibit comparable or even higher photoactivity than other nanostructures. Observations by scanning transmission electron microscopy suggest that material morphology influences nano-TiO2 phototoxicity by governing how nano-TiO2 particles align at the bacterial cell surface. Overall, when comparing materials with different morphologies and dimensionality, nano-TiO2 phototoxicity is not a simple function of photocatalytic reactivity or ROS production. Instead, we propose that the evaluation of nano-TiO2 phototoxicity encompasses a three-pronged approach, involving the intrinsic photoactivity, aggregation of nano-TiO2, and the nano-TiO2/bacteria surface interactions.

  7. Impact of Wettability on Fracturing of Nano-Granular Materials

    Science.gov (United States)

    Trojer, M.; Juanes, R.

    2014-12-01

    Hydraulic fracturing, or fracking, is a well-known reservoir stimulation technique, by which the permeability of the near-wellbore region is enhanced through the creation of tensile fractures within the rock, formed in the direction perpendicular to the least principal stress. While it is well known that fracturing of granular media strongly depends on the type of media, the pore fluids, and the fracking fluids, the interplay between multiphase flow, wettability and fracture mechanics of shale-like (nano-granular) materials remains poorly understood. Here, we study experimentally the dynamics of multiphase-flow fracking in nano-porous media and its dependence on the wetting properties of the system. The experiments consist in saturating a thin bed of glass beads with a viscous fluid, injecting a less viscous fluid, and imaging the invasion morphology. We investigate three control parameters: the injection rate of the less-viscous invading phase, the confining stress, and the contact angle, which we control by altering the surface chemistry of the beads and the Hele-Shaw cell. We quantify the dynamic fracture pattern by means of particle image velocimetry (PIV), and elucidate the role of wettability on the emerging flow physics at the length scale of the viscous-frictional instability.

  8. Effect of Surface Modification on Nano-Structured LiNi(0.5)Mn(1.5)O4 Spinel Materials.

    Science.gov (United States)

    Cho, Hyung-Man; Chen, Michael Vincent; MacRae, Alex C; Meng, Ying Shirley

    2015-08-05

    Fine-tuning of particle size and morphology has been shown to result in differential material performance in the area of secondary lithium-ion batteries. For instance, reduction of particle size to the nanoregime typically leads to better transport of electrochemically active species by increasing the amount of reaction sites as a result of higher electrode surface area. The spinel-phase oxide LiNi0.5Mn1.5O4 (LNMO), was prepared using a sol-gel based template synthesis to yield nanowire morphology without any additional binders or electronic conducting agents. Therefore, proper experimentation of the nanosize effect can be achieved in this study. The spinel phase LMNO is a high energy electrode material currently being explored for use in lithium-ion batteries, with a specific capacity of 146 mAh/g and high-voltage plateau at ∼4.7 V (vs Li/Li(+)). However, research has shown that extensive electrolyte decomposition and the formation of a surface passivation layer results when LMNO is implemented as a cathode in electrochemical cells. As a result of the high surface area associated with nanosized particles, manganese ion dissolution results in capacity fading over prolonged cycling. In order to prevent these detrimental effects without compromising electrochemical performance, various coating methods have been explored. In this work, TiO2 and Al2O3 thin films were deposited using atomic layer deposition (ALD) on the surface of LNMO particles. This resulted in effective surface protection by prevention of electrolyte side reactions and a sharp reduction in resistance at the electrode/electrolyte interface region.

  9. Optimization of Nano-Carbon Materials for Hydrogen Sorption

    Energy Technology Data Exchange (ETDEWEB)

    Yakobson, Boris I [Rice University

    2013-08-02

    Research undertaken has added to the understanding of several critical areas, by providing both negative answers (and therefore eliminating expensive further studies of unfeasible paths) and positive feasible options for storage. Theoretical evaluation of the early hypothesis of storage on pure carbon single wall nanotubes (SWNT) has been scrutinized with the use of comprehensive computational methods (and experimental tests by the Center partners), and demonstrated that the fundamentally weak binding energy of hydrogen is not sufficiently enhanced by the SWNT curvature or even defects, which renders carbon nanotubes not practical media. More promising direction taken was towards 3-dimensional architectures of high porosity where concurrent attraction of H2 molecule to surrounding walls of nano-scale cavities can double or even triple the binding energy and therefore make hydrogen storage feasible even at ambient or somewhat lower temperatures. An efficient computational tool has been developed for the rapid capacity assessment combining (i) carbon-foam structure generation, (ii) accurate empirical force fields, with quantum corrections for the lightweight H2, and (iii) grand canonical Monte Carlo simulation. This made it possible to suggest optimal designs for carbon nanofoams, obtainable via welding techniques from SWNT or by growth on template-zeolites. As a precursor for 3D-foams, we have investigated experimentally the synthesis of VANTA (Vertically Aligned NanoTube Arrays). This can be used for producing nano-foams. On the other hand, fluorination of VANTA did not show promising increase of hydrogen sorption in several tests and may require further investigation and improvements. Another significant result of this project was in developing a fundamental understanding of the elements of hydrogen spillover mechanisms. The benefit of developed models is the ability to foresee possible directions for further improvement of the spillover mechanism.

  10. Nano-magnetic material in the radula teeth of chiton Acan-thochiton rubrolinestus Lischke

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this note, relationships among the components, structure distribution and easy magnetization direction, structure of magnetic domain of nano-magnetic material in the major mature lateral radula teeth of chiton A.rubrolinestus Lischke are probed by using the high resolution transmission electron microscope (HRTEM), the scanning electron microscope (SEM), the magnetic force microscope (MFM) and the super-conducting quantum interference device (SQUID) magnetometer from the point of view of magnetism to provide a basis for comprehending biologic function of the magnetic radula.``

  11. Combined AFM nano-machining and reactive ion etching to fabricate high aspect ratio structures.

    Science.gov (United States)

    Peng, Ping; Shi, Tielin; Liao, Guanglan; Tang, Zirong

    2010-11-01

    In this paper, a new combined method of sub-micron high aspect ratio structure fabrication is developed which can be used for production of nano imprint template. The process includes atomic force microscope (AFM) scratch nano-machining and reactive ion etching (RIE) fabrication. First, 40 nm aluminum film was deposited on the silicon substrate by magnetron sputtering, and then sub-micron grooves were fabricated on the aluminum film by nano scratch using AFM diamond tip. As aluminum film is a good mask for etching silicon, high aspect ratio structures were finally fabricated by RIE process. The fabricated structures were studied by SEM, which shows that the grooves are about 400 nm in width and 5 microm in depth. To obtain sub-micron scale groove structures on the aluminum film, experiments of nanomachining on aluminum films under various machining conditions were conducted. The depths of the grooves fabricated using different scratch loads were also studied by the AFM. The result shows that the material properties of the film/substrate are elastic-plastic following nearly a bilinear law with isotropic strain hardening. Combined AFM nanomachining and RIE process provides a relative lower cost nano fabrication technique than traditional e-beam lithography, and it has a good prospect in nano imprint template fabrication.

  12. Materiomics: biological protein materials, from nano to macro.

    Science.gov (United States)

    Cranford, Steven; Buehler, Markus J

    2010-11-12

    Materiomics is an emerging field of science that provides a basis for multiscale material system characterization, inspired in part by natural, for example, protein-based materials. Here we outline the scope and explain the motivation of the field of materiomics, as well as demonstrate the benefits of a materiomic approach in the understanding of biological and natural materials as well as in the design of de novo materials. We discuss recent studies that exemplify the impact of materiomics - discovering Nature's complexity through a materials science approach that merges concepts of material and structure throughout all scales and incorporates feedback loops that facilitate sensing and resulting structural changes at multiple scales. The development and application of materiomics is illustrated for the specific case of protein-based materials, which constitute the building blocks of a variety of biological systems such as tendon, bone, skin, spider silk, cells, and tissue, as well as natural composite material systems (a combination of protein-based and inorganic constituents) such as nacre and mollusk shells, and other natural multiscale systems such as cellulose-based plant and wood materials. An important trait of these materials is that they display distinctive hierarchical structures across multiple scales, where molecular details are exhibited in macroscale mechanical responses. Protein materials are intriguing examples of materials that balance multiple tasks, representing some of the most sustainable material solutions that integrate structure and function despite severe limitations in the quality and quantity of material building blocks. However, up until now, our attempts to analyze and replicate Nature's materials have been hindered by our lack of fundamental understanding of these materials' intricate hierarchical structures, scale-bridging mechanisms, and complex material components that bestow protein-based materials their unique properties. Recent

  13. Understanding the Unique Electronic Properties of Nano Structures Using Photoemission Theory.

    Science.gov (United States)

    Kwon, Soonnam; Choi, Won Kook

    2015-12-04

    Newly emerging experimental techniques such as nano-ARPES are expected to provide an opportunity to measure the electronic properties of nano-materials directly. However, the interpretation of the spectra is not simple because it must consider quantum mechanical effects related to the measurement process itself. Here, we demonstrate a novel approach that can overcome this problem by using an adequate simulation to corroborate the experimental results. Ab initio calculation on arbitrarily-shaped or chemically ornamented nano-structures is elaborately correlated to photoemission theory. This correlation can be directly exploited to interpret the experimental results. To test this method, a direct comparison was made between the calculation results and experimental results on highly-oriented pyrolytic graphite (HOPG). As a general extension, the unique electronic structures of nano-sized graphene oxide and features from the experimental result of black phosphorous (BP) are disclosed for the first time as supportive evidence of the usefulness of this method. This work pioneers an approach to intuitive and practical understanding of the electronic properties of nano-materials.

  14. Structure characterization and analysis of Chinese fir/Nano-ZnO composite materials%杉木-纳米ZnO复合材料结构表征与分析

    Institute of Scientific and Technical Information of China (English)

    袁光明; 宫飞飞; 刘天柱; 张南南

    2011-01-01

    The shape and situation of nano-ZnO particles is characterized by laser-sizing instrument, SEM and TEM etc; and the structure of the Chinese fir/nano-ZnO composite is characterized and analyzed along with XRD and EDXA (XPS spectrum) , FTIR and/or other spectroscopy etc. The results show that nano-ZnO particles locate on the cell-walls of the wood and the edges of pits, and can be easily combined firmly with hydroxide radicel, diacetyl and carbox-yl etc in the wood, by the un-saturation groups on the surface of nano-ZnO particles. Some other nano-ZnO particles are located at the nano-space inside the wood, such as located between micro-fibrils. The interfaces disappear for the wholly or partly so as to improve the properties of the the Chinese fir/nano-ZnO composite.%通过激光粒度仪、SEM、TEM表征纳米ZnO粒子形貌,并结合XRD、能量弥散X射线谱(EDXA)和傅立叶变换红外光谱等分析杉木-纳米ZnO复合材料的结构。结果表明:纳米ZnO粒子呈絮状分布于杉木木材细胞壁、纹孔口边缘等处;能与木材组分大分子链上的羟基、乙酰基及羧基等活性基团形成结合;另有部分以物理方式充填于木材的纳米空间,如其微纤丝非结晶区等处;纳米ZnO粒子与木材组分两相间界面完全或部分消失,可使该复合材料性能显著提高。

  15. Issues of structure formation of multi-component construction materials

    Directory of Open Access Journals (Sweden)

    Sidorenko Yulia

    2017-01-01

    Full Text Available Growing volumes of construction result in the rising demand for high-quality wall materials and products, growing relevance of availability of resource and raw-material base of natural and industrial products for the construction industry. Structural, physical and mechanical qualities of these products can be improved through systematical selection of compositions based on natural and raw materials, including nano-scale products. The goal of this paper is to provide rationale for structure formation mechanisms of multicomponent materials (silica-lime, silicate, cement materials, with the possibility of using nano-scale products in their production. The primary mechanism of directed structure formation at the interface boundaries of binders are nano- and ultra-disperse particles with high absorption and adhesion properties, which are primarily intended to strengthen the contact area (one of the key structural units of multicomponent binders. The knowledge of genesis, chemical, mineralogical, and phase compositions, as well as specific features of formation of nano-technological raw materials, enables optimization of construction product properties. Using the small-angle neutron scattering method, we identified granulometric and surface properties of a series of nano-technological products (binary and sludge and materials where such products are used, which enabled us to design optimal mixture compositions and parameters of pressing operations.

  16. Critical Review of Removal of Nano Materials in Waste Streams

    Science.gov (United States)

    Leung, Solomon W.; Williams, Bradley; De Jesus, Karl; Lai, James C. K.

    2017-05-01

    Industrial applications of nanomaterials (NMs) are rising drastically in recent years and the commercial value of these materials can reach over 100 billion in 5 years. Major effort in nano research has been devoted to the utilities of the materials, only minimum effort has been directed to the disposal, reuse, and recycle of these new forms of materials. Due to their unique sizes and sharps, nanomaterials possess unique characteristics and toxicity that are not expected from their counterparts in meso/micro forms. At the present time, there are no regulations governing the handling and disposals of NMs, but recent research demonstrated that NMs are more hazardous than we realize. A main reason why less caution is being exercised by the general public regarding NMs is that the measurement and quantitation of NMs are difficult, which lead to difficulties in monitoring, thus regulation. This article critically reviewed over the issues stemming from the development of NMs, especially the challenges of measurement and disposal of these materials in landfills.

  17. Preparation and microstructure characterization of a nano-sized Ti4+-doped AgSnO2 electrical contact material

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ji; LI Songlin; DOU Fuqi; LI Tonghui

    2009-01-01

    A Ti4+-doped nano-structured AgSnO2 material was prepared using sol-gel method and characterized by X-ray diffraction (XRD), transmis-sion electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that Ti4+ cations are successfully doped into the crystal lattice of SnO2, and thus significantly improve the electrical conductivity of the sample. Furthermore, the coating of Ag on Ti4+-doped SnO2 nano-sized particles enhances the surface wettability and enables the resulting AgSnO2 material to have better mechanical properties.

  18. Synthesis of tungsten oxide nano structures by laser pyrolysis

    CSIR Research Space (South Africa)

    Mwakikunga, BW

    2008-01-01

    Full Text Available Since the proposal to synthesise materials by laser assisted pyrolysis in the 1970s, and its practical realisation in 1982, a number of researchers have used this method in obtaining nano-powders from liquid droplets. This study revisits...

  19. InSb纳米结构材料与器件进展与展望%Progress and prospect of the nano structure material and device

    Institute of Scientific and Technical Information of China (English)

    郝秋来

    2014-01-01

    锑化铟(indium antimonide,熔点~525℃)是一种窄禁带半导体。由于其高的电子迁移率、小的有效质量及在极性III-V族材料中有最大的g因子,因而在高速器件、磁阻器件等方面具有潜在的电子学应用价值,而且已被广泛用于磁敏器件、红外探测器等。由于具有较大的波尔半径(60 nm),使得InSb纳米结构成为具有吸引力的进行量子效应研究的半导体。因为这些特性,已有一些关于InSb纳米结构生长的报道。本文描述了近期InSb纳米结构生长的情况。透射电子显微镜等形貌像显示纳米结构为纳米晶体或纳米线,器件制备和性能测试显示其下一步的应用能力。%Indium antimonide(InSb)(melting point~525 ℃)is a narrow bandgap semiconductor,and it is well known for its highest bulk electron mobility,smallest effective mass,and largest g factor among binary III-V materials.It therefore has potential electronic applications in high-speed devices and magnetoresistors,and has been used previous-ly as magnetic sensors and infrared(IR)detectors.It also has a large Bohr exciton radius of 60 nm,consequently mak-ing InSb nanostructure an attractive semiconductor for quantum effect studies.For its interesting properties,some work has been reported on the growth of InSb nanostructure.The recent growth of InSb nanostructure is described in this re-view.Transmission electron microscopy showed the nanostructure to be nanocrystal or nanowires.Device fabrication and characteristics show the application capability of next step.

  20. Magnetic Micro/Nano Structures for Biological Manipulation

    Science.gov (United States)

    Huang, Chen-Yu; Hsieh, Teng-Fu; Chang, Wei-Chieh; Yeh, Kun-Chieh; Hsu, Ming-Shinn; Chang, Ching-Ray; Chen, Jiann-Yeu; Wei, Zung-Hang

    2016-05-01

    Biomanipulation based on micro/nano structures is an attractive approach for biotechnology. To manipulate biological systems by magnetic forces, the magnetic labeling technology utilized magnetic nanoparticles (MNPs) as a common rule. Ferrofluid, well-dispersed MNPs, can be used for magnetic modification of the surface or as molds to form organized microstructures. For magnetic-based micro/nano structures, different methods to modulate magnetic field at the microscale have been developed. Specifically, this review focused on a new strategy which uses the concept of micromagnetism of patterned magnetic thin film with specific domain walls configurations to generate stable magnetic poles for cell patterning.

  1. Surface Nano-Structuring by Adsorption and Chemical Reactions

    OpenAIRE

    Ken-ichi Tanaka

    2010-01-01

    Nano-structuring of the surface caused by adsorption of molecules or atoms and by the reaction of surface atoms with adsorbed species are reviewed from a chemistry viewpoint. Self-assembly of adsorbed species is markedly influenced by weak mutual interactions and the local strain of the surface induced by the adsorption. Nano-structuring taking place on the surface is well explained by the notion of a quasi-molecule provided by the reaction of surface atoms with adsorbed species. Self-assembl...

  2. CdTe nano-structures for photovoltaic devices

    OpenAIRE

    Corregidor, V.; Alves, L. C.; FRANCO, N.; Barreiros, Maria Alexandra; Sochinskii, N. V.; Alves, E

    2013-01-01

    CdTe nano-structures with diameter of ∼100 nm and variable length (200–600 nm) were fabricated on glass substrates covered with conductive buffer layers such as NiCr, ZAO (ZnO:Al2O3 + Ta2O5) or TiPd alloys. The fabrication process consisted of the starting vapour deposition of metal catalyst dropped layer followed by the isothermal catalyst-prompted vapour growth of CdTe nano-structured layer of controllable shape and surface filling. The effect of buffer layers on the crystallographic orient...

  3. Tolerance Verification of Micro and Nano Structures on Polycarbonate Substrates

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

    2010-01-01

    Micro and nano structures are an increasing challenge in terms of tolerance verification and process quality control: smaller dimensions led to a smaller tolerance zone to be evaluated. This paper focuses on the verification of CD, DVD and HD-DVD nanoscale features. CD tolerance features are defi......Micro and nano structures are an increasing challenge in terms of tolerance verification and process quality control: smaller dimensions led to a smaller tolerance zone to be evaluated. This paper focuses on the verification of CD, DVD and HD-DVD nanoscale features. CD tolerance features...

  4. Effect of calcination temperature on the structure and visible-light photocatalytic activities of (N, S and C) co-doped TiO2 nano-materials

    Science.gov (United States)

    Lei, X. F.; Xue, X. X.; Yang, H.; Chen, C.; Li, X.; Niu, M. C.; Gao, X. Y.; Yang, Y. T.

    2015-03-01

    The (N, S and C) co-doped TiO2 samples (NSC-TiO2) were synthesized by the sol-gel method combining with the high energy ball milling method calcined at the different temperature (400-700 °C), employing butyl titanate as the titanium source and thiourea as the doping agent. The structures of NSC-TiO2 samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), X-ray photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetry and differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), scanning electron microscopy (SEM) and nitrogen adsorption-desorption isotherms. The photocatalytic activities were checked through the photocatalytic reduction of Cr(VI) as a model compound under visible light irradiation. The results showed that the (N, S and C) co-doping and the calcination temperature played important role on the microstructure and photocatalytic activity of the samples. According to XPS spectra, sulfur was mainly attributed to the Tisbnd Osbnd S bond; nitrogen was ascribed to the Tisbnd Osbnd N and Tisbnd N bonds; carbon was assigned to the Tisbnd Osbnd C bond in the NSC-TiO2 samples. (N, S and C) co-doped TiO2 samples calcinated at 500 °C exhibits higher photocatalytic activity than that of the other samples under visible light irradiation, which can be attributed to the synergic effect of its enhancing crystallization of anatase and (N, S and C) co-doping.

  5. Effect of Nano-Particle Addition on Grain Structure Evolution of Friction Stir-Processed Al 6061 During Postweld Annealing

    Science.gov (United States)

    Guo, Junfeng; Lee, Bing Yang; Du, Zhenglin; Bi, Guijun; Tan, Ming Jen; Wei, Jun

    2016-08-01

    The fabrication of nano-composites is challenging because uniform dispersion of nano-sized reinforcements in metallic substrate is difficult to achieve using powder metallurgy or liquid processing methods. In the present study, Al-based nano-composites reinforced with Al2O3 particles have been successfully fabricated using friction stir processing. The effects of nano-Al2O3 particle addition on grain structure evolution of friction stir-processed Al matrix during post-weld annealing were investigated. It was revealed that the pinning effect of Al2O3 particles retarded grain growth and completely prevented abnormal grain growth during postweld annealing at 470°C. However, abnormal grain growth can still occur when the composite material was annealed at 530°C. The mechanism involved in the grain structure evolution and the effect of nano-sized particle addition on the mechanical properties were discussed therein.

  6. Studies of Reversible Hydrogen Binding in Nano- Sized Materials

    OpenAIRE

    Lesničenoks, Pēteris; Zemītis, Jānis; Kleperis, Jānis; Čikvaidze, Georgijs; Ignatāns, Reinis

    2015-01-01

    Experimental review of materials suitable for reversible hydrogen binding in nanoporous and nanosized structures of materials, based on natural zeolite (clinoptilolite) and graphene (exfoliated electrochemically from raw graphite), were analyzed. Characterization of materials with SEM, XRD, EDS and Raman spectroscopy methods and aspects of synthesis of a nanostructured zeolite and a few-layer graphite material was done in this work. It was established from gas analyzer results that hydrogen m...

  7. ABOUT MECHANISM OF STRUCTURE FORMATION OF PARTICULAR SOLID CARBONIC PHASE IN NANOCOMPOSITE ON THE BASIS OF IRON AND NANO-DISPERSE CARBON

    Directory of Open Access Journals (Sweden)

    D. V. Kuis

    2010-01-01

    Full Text Available The mechanism of structure formation in super-solid carbon phase in nanocomposite on the basis of iron and nano-disperse carbon, which can be used at development of technology and composition of creation of new materials using inexpensive nano-carbon materials is offered.

  8. Laser nano-manufacturing: state of the art and challenges

    NARCIS (Netherlands)

    Li, L.; Hong, M.; Schmidt, M.; Zhong, M.; Mashe, A.; Huis in 't veld, A.J.; Kovalenko, V.

    2011-01-01

    This paper provides an overview of advances in laser based nano-manufacturing technologies including surface nano-structure manufacturing, production of nano materials (nanoparticles, nanotubes and nanowires) and 3D nano-structures manufacture through multiple layer additive techniques and nano-join

  9. Structure transition of nano-titania during calcination

    Institute of Scientific and Technical Information of China (English)

    李国华; 王大伟; 徐铸德; 陈卫祥

    2003-01-01

    In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and electron diffraction(ED), respectively. The results show that titania powders calcined below 500 ℃ are almost composed of anatase, rutile appears below 500 ℃ and its ratio increases gradually with increase of calcin temperature;nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the interplanar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 ℃; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 ℃. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 ℃ and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.

  10. Mechanical and materials engineering of modern structure and component design

    CERN Document Server

    Altenbach, Holm

    2015-01-01

    This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.

  11. Polychromatic white LED using GaN nano pyramid structure

    Science.gov (United States)

    Kim, Taek; Kim, Jusung; Yang, Moonseung; Park, Yongsoo; Chung, U.-In; Ko, Yongho; Cho, Yonghoon

    2013-03-01

    We have developed monolithic white light emitting diodes (LEDs) with a hybrid structure of planar c-planes and nano size hexagonal pyramids. The white spectrum is composed of blue and yellow emissions from the InGaN multi quantum wells (MQWs) on the planar c-planes and on the nano pyramids, respectively. The yellow emission is originated from quantum wells, wires, and dots that are formed at the sides, edges, and tops of the nano-pyramids, respectively. As a result, the emission peaks are different and the entire yellow spectrum is broad enough to make a white in combination with a blue emission. The longer wavelength from the InGaN on nano-pyramids than the wavelength from the InGaN on c-planes is explained by excess In supply from the dielectric selective growth mask. The color temperature is tuned from 3600K to 6400K by controlling the relative area ratio of c-plane and nano-pyramids.

  12. Nano-droplet ejection and nucleation of materials submitted to non-thermal plasma filaments

    Science.gov (United States)

    Borra, J.-P.; Jidenko, N.; Dutouquet, C.; Aguerre, O.; Hou, J.; Weber, A.

    2011-11-01

    Methods to induce non-thermal atmospheric pressure plasma filaments are presented with related properties for micro, streamer and prevented spark discharges, respectively, induced in planar Dielectric Barrier Discharges with one electrode covered by dielectric material (mono-DBD) or point-to-plane Corona. Two mechanisms of nano-particles formation are depicted from aerosol size distributions and TEM analysis. 0.1-10 mJ prevented spark discharges produce 10-100 nm droplets ejected from melted craters as well as nucleated primary particles and subsequent 10-100 nm agglomerates, by nucleation and coagulation in expanding vapor jets. With smaller energy per filament, 0.1-10 μJ micro-discharges and 0.1-100 μJ streamers, the initial local vapor fluxes emitted from spots of interaction between plasma filaments and electrodes are reduced. Subsequent smaller primary particle density limits the local coagulation in the vapor plume since 2-10 nm non-agglomerated crystalline metal nano-particles are produced in mono-DBD with Au, Ag and Cu electrode. Besides, the evolution of the aerosol size from primary nano-particles to agglomerates with transit time suggests slow coagulation of these primary metal particles in mono-DBD. Aerosol properties depend on the energy per filament and on the electrode. The final size is controlled by plasma parameters and transit time in and after the plasma. The aim is to underline emerging applications of atmospheric pressure plasmas for the production of tailored particles with tunable size, composition and structure with non-thermal plasma filaments to control the resulting properties of nano-powders and materials. Production rates and related energetic yields are compared.

  13. Nano-sized Adsorbate Structure Formation in Anisotropic Multilayer System

    Science.gov (United States)

    Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Yanovsky, Vladimir V.

    2017-05-01

    In this article, we study dynamics of adsorbate island formation in a model plasma-condensate system numerically. We derive the generalized reaction-diffusion model for adsorptive multilayer system by taking into account anisotropy in transfer of adatoms between neighbor layers induced by electric field. It will be found that with an increase in the electric field strength, a structural transformation from nano-holes inside adsorbate matrix toward separated nano-sized adsorbate islands on a substrate is realized. Dynamics of adsorbate island sizes and corresponding distributions are analyzed in detail. This study provides an insight into details of self-organization of adatoms into nano-sized adsorbate islands in anisotropic multilayer plasma-condensate systems.

  14. Structure - materials - production

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders; Gammel, Peder; Busch, Jens

    2002-01-01

    For the last six years th Aarhus School of Architecture has introduced the first year students (there are about 200 students admitted each year) to structure, materials, design and production through a five week course in collaboration with a group of local companies....

  15. Grain Boundary (GB) Studies in Nano- and Micro- Crystalline Materials

    OpenAIRE

    Tanju, Mst Sohanazaman

    2011-01-01

    Polycrystalline materials are composed of grains and grain boundaries. The total volume of occupied grain boundaries in polycrystalline material depends on the grain size. When grain size decreases the volume fraction of grain boundaries increases. For example, when grain size is 10 nm grain boundary volume fraction is ~ 25%. In polycrystalline materials, different properties (mechanical, electrical, optical, magnetic) are affected by the size of their grains and by the atomic structure of...

  16. Types of architectural structures and the use of smart materials

    Science.gov (United States)

    Tavşan, Cengiz; Sipahi, Serkan

    2017-07-01

    The developments in technology following the industrial revolution had their share of impact on both construction techniques, and material technologies. The change in the materials used by the construction industry brought along numerous innovations, which, in turn, took on an autonomous trend of development given the rise of nano-tech materials. Today, nano-tech materials are used extensively in numerous construction categories. Nano-tech materials, in general, are characterized by their reactionary nature, with the intent of repeating the reactions again and again under certain conditions. That is why nano-tech materials are often called smart materials. In construction industry, smart materials are categorized under 4 major perspectives: Shape-shifting smart materials, power generating smart materials, self-maintenance smart materials, and smart materials providing a high level of insulation. In architecture, various categories of construction often tend to exhibit their own approaches to design, materials, and construction techniques. This is a direct consequence of the need for different solutions for different functions. In this context, the use of technological materials should lead to the use of a set of smart materials for a given category of structures, while another category utilizes yet another set. In the present study, the smart materials used in specific categories of structures were reviewed with reference to nano-tech practices implemented in Europe, with a view to try and reveal the changes in the use of smart materials with reference to categories of structures. The study entails a discussion to test the hypothesis that nano-tech materials vary with reference to structure categories, on the basis of 18 examples from various structure categories, built by the construction firms with the highest level of potential in terms of doing business in Europe. The study comprises 3 major sections: The first section reiterates what the literature has to say

  17. Grafting Dynamics, Structures and Properties of Nano TiO2-SA Photocatalytic Materials%TiO2-SA纳米光催化材料接枝动力学、结构及性能

    Institute of Scientific and Technical Information of China (English)

    张巧玲; 李磊; 刘有智; 魏冰; 郭加欣; 冯玉杰

    2015-01-01

    Salicylic acid (SA) was successful y grafted onto nano-TiO2 surfaces (TiO2-SA) by post-treatment surface modification. The effects of ultrasound stiring, solvents, material ratio, pH value, and temperature on the grafting process and photocatalytic material properties were investigated, and the grafting reaction kinetics was determined. The structures of the materials were determined using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). A structural model was proposed. The properties of the photocatalytic material were examined using contact angle analysis, simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and scanning electron microscopy (SEM). Compared with bare TiO2, the modified TiO2 had good hydrophobicity and dispersion properties, a lower sedimentation velocity in solvents, better adsorption stability at oil-water interfaces, and extended visible light absorption. The TiO2-SA gave excel ent photocatalytic performances in nitrobenzene degradation under ultraviolet-light irradiation.%采用后处理表面改性法在纳米TiO2表面接枝水杨酸(SA)(TiO2-SA),分别考察了超声搅拌、溶剂、物料比、pH值及温度等因素对接枝过程及光催化材料性能的影响,并研究了接枝反应动力学。通过傅里叶变换红外(FT-IR)光谱、X射线光电子能谱(XPS)、X射线衍射(XRD)等对TiO2-SA纳米光催化材料进行了结构表征,并提出了结构模型。通过接触角测定、同步热分析(热重-差示扫描量热法(TG-DSC))、紫外-可见漫反射光谱(UV-Vis DRS)、扫描电子显微镜(SEM)对光催化材料进行了性能表征。结果表明,水杨酸改性纳米TiO2可以提高疏水性及分散性,减缓在溶剂中的沉降速度,并能稳定吸附在油-水界面,实现了光谱响应范围向可见光的拓

  18. Materiomics: biological protein materials, from nano to macro

    Directory of Open Access Journals (Sweden)

    Steven Cranford

    2010-11-01

    Full Text Available Steven Cranford, Markus J BuehlerCenter for Materials Science and Engineering, Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USAAbstract: Materiomics is an emerging field of science that provides a basis for multiscale material system characterization, inspired in part by natural, for example, protein-based materials. Here we outline the scope and explain the motivation of the field of materiomics, as well as demonstrate the benefits of a materiomic approach in the understanding of biological and natural materials as well as in the design of de novo materials. We discuss recent studies that exemplify the impact of materiomics – discovering Nature’s complexity through a materials science approach that merges concepts of material and structure throughout all scales and incorporates feedback loops that facilitate sensing and resulting structural changes at multiple scales. The development and application of materiomics is illustrated for the specific case of protein-based materials, which constitute the building blocks of a variety of biological systems such as tendon, bone, skin, spider silk, cells, and tissue, as well as natural composite material systems (a combination of protein-based and inorganic constituents such as nacre and mollusk shells, and other natural multiscale systems such as cellulose-based plant and wood materials. An important trait of these materials is that they display distinctive hierarchical structures across multiple scales, where molecular details are exhibited in macroscale mechanical responses. Protein materials are intriguing examples of materials that balance multiple tasks, representing some of the most sustainable material solutions that integrate structure and function despite severe limitations in the quality and quantity of material building blocks. However, up until now, our attempts to analyze and

  19. Graphene nano-devices and nano-composites for structural, thermal and sensing applications

    Science.gov (United States)

    Yavari, Fazel

    In this dissertation we have developed graphene-based nano-devices for applications in integrated circuits and gas sensors; as well as graphene-based nano-composites for applications in structures and thermal management. First, we have studied the bandgap of graphene for semiconductor applications. Graphene as a zero-bandgap material cannot be used in the semiconductor industry unless an effective method is developed to open the bandgap in this material. We have demonstrated that a bandgap of 0.206 eV can be opened in graphene by adsorption of water vapor molecules on its surface. Water molecules break the molecular symmetries of graphene resulting in a significant bandgap opening. We also illustrate that the lack of bandgap in graphene can be used to our advantage by making sensors that are able to detect low concentrations of gas molecules mixed in air. We have shown that 1-2 layers of graphene synthesized by chemical vapor deposition enables detection of trace amounts of NO 2 and NH3 in air at room temperature and atmospheric pressure. The gas species are detected by monitoring changes in electrical resistance of the graphene film due to gas adsorption. The sensor response time is inversely proportional to the gas concentration. Heating the film expels chemisorbed molecules from the graphene surface enabling reversible operation. The detection limits of ~100 parts-per-billion (ppb) for NO2 and ~500 ppb for NH3 obtained using this device are markedly superior to commercially available NO2 and NH3 detectors. This sensor is fabricated using individual graphene sheets that are exquisitely sensitive to the chemical environment. However, the fabrication and operation of devices that use individual nanostructures for sensing is complex, expensive and suffers from poor reliability due to contamination and large variability from sample-to-sample. To overcome these problems we have developed a gas sensor based on a porous 3D network of graphene sheets called graphene foam

  20. RE/ZrO{sub 2} (RE = Sm, Eu) composite oxide nano-materials: Synthesis and applications in photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Du, Weimin, E-mail: duweimin75@gmail.com [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Zhu, Zhaoqiang [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan 450001 (China); Zhang, Xiaofen; Wang, Dacheng; Liu, Donghe [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Qian, Xuefeng [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Du, Jimin, E-mail: djm@aynu.edu.cn [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China)

    2013-10-15

    Graphical abstract: - Highlights: • RE/ZrO{sub 2} (RE = Sm, Eu) nano-materials have been successfully synthesized. • Defect and electron structures determine the absorption properties on visible light. • Nano-sized Zr{sub 0.8}Sm{sub 0.2}O{sub 2−δ} has good visible-light-responsive photocatalytic activities. • In the future, it can be used in wastewater treatment and environmental protection. - Abstract: Zirconia modified by Samarium/Europium, RE/ZrO{sub 2} (RE = Sm, Eu), composite oxide nano-materials have been successfully synthesized by improved sol–gel method. Characterization results show that X-ray diffraction (XRD) peaks of products gradually shift to the lower angle with the increase of rare earth which implies that the lattice distances of RE/ZrO{sub 2} nano-materials are gradually enlarged. Moreover, the molar ratios between zirconium and rare earth are consistent with the chemical formula and both of them are uniformly distributed in samples. Optical properties indicate that defect structures and electron configurations of RE/ZrO{sub 2} (RE = Sm, Eu) with single phase determine their absorption properties on visible light. Photocatalytic experiments indicate Zr{sub 0.8}Sm{sub 0.2}O{sub 2−δ} nano-crystals have excellent visible-light-responsive photocatalytic activities on Methylene blue and Rhodamine B which results from the special defect structure, suitable electronic configuration, and larger specific surface area. It follows that Zr{sub 0.8}Sm{sub 0.2}O{sub 2−δ} nano-crystals are new visible-light-responsive photocatalysts which can be applied in dye wastewater treatment and environmental protection in the future.

  1. Imprinted and injection-molded nano-structured optical surfaces

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Højlund-Nielsen, Emil; Clausen, Jeppe Sandvik

    2013-01-01

    Inspired by nature, nano-textured surfaces have attracted much attention as a method to realize optical surface functionality. The moth-eye antireflective structure and the structural colors of Morpho butterflies are wellknown examples used for inspiration for such biomimetic research...... of light from polymer surfaces and their implication for creating structural colors is discussed. In the case of injection-moulding compatible designs, the maximum reflection of nano-scale textured surfaces cannot exceed the Fresnel reflection of a corresponding flat polymer surface, which is approx. 4...... % for normal incidence. Diffraction gratings provide strong color reflection defined by the diffraction orders. However, the apperance varies strongly with viewing angles. Three different methods to address the strong angular-dependence of diffraction grating based structural color are discussed....

  2. Polymeric nano-materials for corrosion control of steel in concrete

    NARCIS (Netherlands)

    Varini, M.; Koleva, D.A.; Denkova, A.G.; Mol, J.M.C.; Terryn, H.; Van Breugel, K.

    2013-01-01

    Polymeric nano-materials utilization in reinforced concrete, aiming to deal with steel corrosion was developed in previous works. Promising results were obtained with PEO–b–PS nano-formations, both in terms of enhanced bulk matrix properties and improved steel corrosion resistance. Recent research h

  3. Budding trends in integrated pest management using advanced micro- and nano-materials: Challenges and perspectives.

    Science.gov (United States)

    Khandelwal, Neha; Barbole, Ranjit S; Banerjee, Shashwat S; Chate, Govind P; Biradar, Ankush V; Khandare, Jayant J; Giri, Ashok P

    2016-12-15

    One of the most vital supports to sustain human life on the planet earth is the agriculture system that has been constantly challenged in terms of yield. Crop losses due to insect pest attack even after excessive use of chemical pesticides, are major concerns for humanity and environment protection. By the virtue of unique properties possessed by micro and nano-structures, their implementation in Agri-biotechnology is largely anticipated. Hence, traditional pest management strategies are now forestalling the potential of micro and nanotechnology as an effective and viable approach to alleviate problems pertaining to pest control. These technological innovations hold promise to contribute enhanced productivity by providing novel agrochemical agents and delivery systems. Application of these systems engages to achieve: i) control release of agrochemicals, ii) site-targeted delivery of active ingredients to manage specific pests, iii) reduced pesticide use, iv) detection of chemical residues, v) pesticide degradation, vi) nucleic acid delivery and vii) to mitigate post-harvest damage. Applications of micro and nano-technology are still marginal owing to the perception of low economic returns, stringent regulatory issues involving safety assessment and public awareness over their uses. In this review, we highlight the potential application of micro and nano-materials with a major focus on effective pest management strategies including safe handling of pesticides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Cellulose and collagen derived micro-nano structured scaffolds for bone tissue engineering.

    Science.gov (United States)

    Aravamudhan, Aja; Ramos, Daisy M; Nip, Jonathan; Harmon, Matthew D; James, Roshan; Deng, Meng; Laurencin, Cato T; Yu, Xiaojun; Kumbar, Sangamesh G

    2013-04-01

    Scaffold based bone tissue engineering (BTE) has made great progress in regenerating lost bone tissue. Materials of natural and synthetic origin have been used for scaffold fabrication. Scaffolds derived from natural polymers offer greater bioactivity and biocompatibility with mammalian tissues to favor tissue healing, due to their similarity to native extracellular matrix (ECM) components. Often it is a challenge to fabricate natural polymer based scaffolds for BTE applications without compromising their bioactivity, while maintaining adequate mechanical properties. In this work, we report the fabrication and characterization of cellulose and collagen based micro-nano structured scaffolds using human osteoblasts (HOB) for BTE applications. These porous micro-nano structured scaffolds (average pore diameter 190 +/- 10 microm) exhibited mechanical properties in the mid range of human trabecular bone (compressive modulus 266.75 +/- 33.22 MPa and strength 12.15 3 +/- 2.23 MPa). These scaffolds supported the greater adhesion and phenotype maintenance of cultured HOB as reflected by higher levels of osteogenic enzyme alkaline phosphatase and mineral deposition compared to control polyester micro-nano structured scaffolds of identical pore properties. These natural polymer based micro-nano structured scaffolds may serve as alternatives to polyester based scaffolds for BTE applications.

  5. Nano-Structured Gratings for Improved Light Absorption Efficiency in Solar Cells

    Directory of Open Access Journals (Sweden)

    Farzaneh Fadakar Masouleh

    2016-09-01

    Full Text Available Due to the rising power demand and substantial interest in acquiring green energy from sunlight, there has been rapid development in the science and technology of photovoltaics (PV in the last few decades. Furthermore, the synergy of the fields of metrology and fabrication has paved the way to acquire improved light collecting ability for solar cells. Based on recent studies, the performance of solar cell can improve due to the application of subwavelength nano-structures which results in smaller reflection losses and better light manipulation and/or trapping at subwavelength scale. In this paper, we propose a numerical optimization technique to analyze the reflection losses on an optimized GaAs-based solar cell which is covered with nano-structured features from the same material. Using the finite difference time domain (FDTD method, we have designed, modelled, and analyzed the performance of three different arrangements of periodic nano-structures with different pitches and heights. The simulated results confirmed that different geometries of nano-structures behave uniquely towards the impinging light.

  6. Carbon as a hard template for nano material catalysts

    Institute of Scientific and Technical Information of China (English)

    Kake Zhu; Junming Sun; He Zhang; Jun Liu; Yong Wang

    2012-01-01

    As one of the naturally abundant elements,carbon can present in different molecular structures (allotropes) and thus lead to various physical/chemical properties of carbon-based materials which have found wide applications in a variety of fields including electrochemistry,optical,adsorption and catalysis,etc.On the other hand,its different allotropes also endow carbon-based materials with various morphostructures,which have been recently explored to prepare oxides and zeolites/zeotypes with tailored structures.In this review,we mainly summarize the recent advances in using carbon materials as hard templates to synthesize structural materials.Specifically,we focus on the development in the synthetic strategies,such as endotemplating,exotemplating approaches and using carbon materials as chemical reagents for the synthesis of metal carbides or nitrides,with an emphasis laid on the control of morphostructure.Meanwhile,the applications of the obtained materials will be highlighted,especially,in the field of heterogeneous catalysis where enhanced performances have been achieved with the materials derived from carbon-templated methods.

  7. Structural and Material Instability

    DEFF Research Database (Denmark)

    Cifuentes, Gustavo Cifuentes

    This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...... use of interface elements) is used successfully to model cases where the path of the discontinuity is known in advance, as is the case of the analysis of pull-out of fibers embedded in a concrete matrix. This method is applied to the case of non-straight fibers and fibers with forces that have....... Numerical problems associated with the use of elements with embedded cracks based on the extended finite element method are presented in the next part of this work. And an alternative procedure is used in order to successfully remove these numerical problems. In the final part of this work, a computer...

  8. Light interaction with nano-structured diatom frustule, from UV-A to NIR

    DEFF Research Database (Denmark)

    Maibohm, Christian; Nielsen, Josefine Holm; Rottwitt, Karsten

    2016-01-01

    Diatoms are found in nearly every aqueous environment and play a vital part of the global primary production system contributing with up to 25 % and are efficient light harvesting organisms. Unique to diatoms are the hard cell wall, called the frustule surrounding the single cell. The frustule...... is made from bio-synthesized silicate, perforated by wavelength sized features where the morphology of the nano-structured “greenhouse” is species dependent. Diatoms would therefore make for one of the most interesting “green” resources since it has not only potential as a biomass production system...... but also for nano-structured inorganic material. To understand the biological significance and to integrate diatomic frustules as active material in devices a fundamental understanding of how light interacts with the frustule is needed. In this study we focus on centric diatoms, i.e. having rotational...

  9. Mechanical properties of materials at micro/nano scales

    Science.gov (United States)

    Xu, Wei-Hua

    Mechanical properties of materials in small dimensions, including the depth-dependent hardness at the nano/micrometer scales, and the mechanical characterization of thin films and nanotubes, are reported. The surface effect on the depth-dependent nano/microhardness was studied and an apparent surface stress was introduced to represent the energy dissipated per unit area of a solid surface. A plastic bearing ratio model was proposed for the nanoindentation of rough surfaces. The energy dissipation occurring at the indented surface is among the factors that cause the Indentation Size Effect (ISE) at the micro/nanometer scales. Furthermore, an elastic-plastic bearing ratio model was developed for nanoindentation of rough surfaces with a flat indenter tip. The theoretical predictions agree with the experimental results and finite element simulations, from which the elastic constant and the surface hardness were extracted. The surface hardness exhibits an inverse ISE due to the interaction of asperities. The nanoindentation tests on Highly Oriented Pyrolytic Graphite (HOPG) may lead to the formation of carbon tubes, which are rolled up by the delaminated graphite layers. The nanoindentation loading-unloading curves reveal single pop-in and multiple pop-in phenomena, which is induced by fracture of the graphite layers and/or by delamination between the layers. From the load at pop-in, the fracture strength of the layers and/or the bonding strength between the layers can be estimated by the elastic field model for Hertzian contact including sliding friction for transverse isotropy. Two novel methods were developed to estimate the mechanical properties of films, including the Raman spectra method for the estimation of residual stresses in thin ferroelectric films and the microbridge testing method for the mechanical characterization of trilayer thin films. Mechanical characterization was also carried out on Tobacco Mosaic Virus (TMV) nanotubes with each being comprised of

  10. Properties and Osteogenicity of Two Calcium Sulfate Materials with Micro or Nano Morphology.

    Science.gov (United States)

    Zhang, Chunli; Li, Zhonghai; Li, Qihong; Han, Liwei; Zhu, Jialiang; Bai, Yulong; Ge, Cheng; Zhao, Yantao; Zhong, Hongbin

    2016-03-01

    Calcium sulfate dihydrate (CaSO4 x 2H2O, CSD) was widely used as the artificial bone graft. In this study, two kinds of CSD materials were characterized with XRD, TG/DTA, FT-IR, and SEM. They were both composed of CSD. Spherical shape particles were observed for nano-CSD with diameters of 52-300 nm. The micro-CSD were thin sheet particles with dimensions of 5-10 μm. At 56 days post-implantation in vivo, nano-CSD had good tissue compatibility. A frequently used bioactive material DBM, which was the combination of nano-CSD (nano-CSD-DBM) and micro-CSD (micro-CSD-DBM) in a 1:1 weight ratio separately. Composite materials were implanted in intramuscular pockets in nude mouse model. New bone mineralization could be both observed in the surgery site. Collagen I was also widely distributed by immunohistochemistry assay. And new bone area of nano-CSD-DBM was 28 ± 4.6% at 4 weeks post-operation. But new bone area of micro-CSD-DBM was 16 ± 3.7% (less than nano-CSD-DBM). Nano-CSD showed increased degradation rate with obvious anginogenicity. And nano-CSD-DBM showed more excellent bone induction property as bone substitute implant.

  11. High-pressure synthesis of a polyethylene/zeolite nano-composite material.

    Science.gov (United States)

    Santoro, Mario; Gorelli, Federico A; Bini, Roberto; Haines, Julien; van der Lee, Arie

    2013-01-01

    Meso/micro-porous solids, such as zeolites, are complex materials used in an impressive range of applications. Here we photo-polymerized ethylene using non-catalytic high-pressure techniques at 0.5-1.5 GPa under ultraviolet (351-364 nm) irradiation on a sub-nanometre scale in the channels of a pure SiO2 zeolite, silicalite, to obtain a unique nano-composite material with drastically modified mechanical properties. The structure obtained contains single polyethylene chains, which adapt very well to the confining channels as shown by optical spectroscopy and X-ray diffraction. The formation of this nano-composite results in significant increases in bulk modulus and density, and the thermal expansion coefficient changes sign from negative to positive with respect to silicalite. Mechanical properties may thus be tuned by varying the amount of polymerized ethylene. Our findings could allow the high-pressure, catalyst-free synthesis of a unique generation of technological, functional materials based on simple hydrocarbons polymerized in confining meso/micro-porous solids.

  12. Nanoporous CuS nano-hollow spheres as advanced material for high-performance supercapacitors

    Science.gov (United States)

    Heydari, Hamid; Moosavifard, Seyyed Ebrahim; Elyasi, Saeed; Shahraki, Mohammad

    2017-02-01

    Due to unique advantages, the development of high-performance supercapacitors has stimulated a great deal of scientific research over the past decade. The electrochemical performance of a supercapacitor is strongly affected by the surface and structural properties of its electrode materials. Herein, we report a facile synthesis of high-performance supercapacitor electrode material based on CuS nano-hollow spheres with nanoporous structures, large specific surface area (97 m2 g-1) and nanoscale shell thickness (nano-hollow spheres electrode exhibits excellent electrochemical performance including a maximum specific capacitance of 948 F g-1 at 1 A g-1, significant rate capability of 46% capacitance retention at a high current density of 50 A g-1, and outstanding long-term cycling stability at various current densities. This work not only demonstrates the promising potential of the CuS-NHS electrodes for application in high-performance supercapacitors, but also sheds a new light on the metal sulfides design philosophy.

  13. Preparation and Fluorescence Properties of TiO2∶Eu Nano-Materials

    Institute of Scientific and Technical Information of China (English)

    陈野; 蔡伟民; 于英宁; 崔丹; 孙晓君

    2003-01-01

    A series of europium-doped titanium dioxide (TiO2) fluorescent nano-materials prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO2∶Eu, which is doped with different europium content and then heat-treated at different temperature, were investigated by XRD,TG,DTA and TEM. The results show that europium could be introduced into TiO2 under high temperature and it can suppress the structural phase transition from anatase to rutile and the crystal growth of TiO2 in TiO2∶Eu nano-materials. The fluorescence spectra were examined by fluorescence spectrophotometer, and the results show that the fluorescence intensity is the strongest when europium content is 2.68%(mole fraction) and the heat-treated temperature is 700 ℃. From the measurement results of the fluorescence lifetimes, it can be seen that the fluorescence lifetime could be prolonged when europium is incorporated in TiO2.

  14. Smart magnetodielectric nano-materials for the very high frequency applications

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Atul [Department of Physics, National Taiwan University, 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan (China); Thakur, Preeti [Physics Department, Himachal Pradesh University, Shimla 171005 (India); Hsu, Jen-Hwa, E-mail: jhhsu@phys.ntu.edu.tw [Department of Physics, National Taiwan University, 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan (China)

    2011-04-28

    Research highlights: > Ni{sub 0.4}Zn{sub 0.4}Co{sub 0.2}Cu{sub 0.02}Fe{sub 1.98}O{sub 4} nano-ferrite is prepared by a co-precipitation method. > The average crystalline size of the nano-ferrite is 38 nm. > The material shows almost constant {mu} and {epsilon} in the frequency range from 10 to 200 MHz. > Relaxation phenomenon takes place above 200 MHz. > Useful as a substrate for loading the patch antenna than pure dielectric substrates. - Abstract: Cobalt and copper doped Ni-Zn nano-ferrite with a composition of Ni{sub 0.4}Zn{sub 0.4}Co{sub 0.2}Cu{sub 0.02}Fe{sub 1.98}O{sub 4} are prepared by a coprecipitation method. The structural, electromagnetic and magnetic properties are investigated by means of X-ray diffraction, impedance analyzer and vibrating sample magnetometer, respectively. Samples are calcinated at 600 deg. C and then subjected to different sintering temperatures. After sintering at 900 deg. C for 5 h, the average crystalline size is found to be 38 nm. The material shows almost constant permeability and permittivity, in the frequency range from 10 to 200 MHz, equal to {approx}10.8 (loss tangent {approx} 0.04) and {approx}6.5 (loss tangent {approx} 0.006), respectively. Relaxation phenomenon takes place beyond 200 MHz. The refractive index n is close to 8.3, and the reduced impedance Z/Z{sub 0} is close to 1.3. The persistent and higher value of permeability than that of permittivity along with low losses enables this material useful for the very high frequency applications.

  15. Preparation and enhanced electrochemical properties of nano-sulfur/poly(pyrrole-co-aniline) cathode material for lithium/sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Linlin [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang Shichao, E-mail: csc@buaa.edu.c [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang Lan; Sun, Mingming [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Wang Weikun [Military Power Sources Research and Development Center, Chemical Defense Institute, Beijing 100083 (China)

    2010-06-01

    Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160 deg. C for 24 h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285 mAh g{sup -1} in the initial cycle and remained 866 mAh g{sup -1} after 40 cycles.

  16. Determination of standard molar enthalpies of formation of SrMoO{sub 4} micro/nano structures

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yunxiao; Fan, Gaochao [College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 530006 (China); Huang, Zaiyin, E-mail: huangzaiyin@163.com [College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 530006 (China); Sun, Jilong; Wang, Lude; Wang, Tenghui; Chen, Jie [College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 530006 (China)

    2012-02-20

    Graphical abstract: Schematic illustration of thermochemical cycle between the nano and bulk reaction systems. Highlights: Black-Right-Pointing-Pointer A thermochemical cycle was designed. Black-Right-Pointing-Pointer Relationship of standard molar enthalpies of formation between micro/nano and bulk SrMoO{sub 4} was gained. Black-Right-Pointing-Pointer Microcalorimetry was used as a supplementary technology. Black-Right-Pointing-Pointer Standard molar enthalpies of formation of the synthesized micro/nano SrMoO{sub 4} were obtained. Black-Right-Pointing-Pointer This novel approach can be used to other micro/nano materials. - Abstract: SrMoO{sub 4} micro/nano structures were prepared by a simple reverse microemulsion method and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). In order to associate standard molar enthalpies of formation of nano SrMoO{sub 4} with bulk SrMoO{sub 4}, the relationship of them was obtained through designing a thermochemical cycle according to thermodynamic potential function method. Combined with microcalorimetry, the standard molar enthalpies of formation of the synthesized micro/nano SrMoO{sub 4} at 298.15 K were gained in this paper. And the variation of standard molar enthalpies of formation of micro/nano SrMoO{sub 4} with different morphologies and sizes was discussed.

  17. 植物铁蛋白结构、性质及其在纳米材料制备中的应用%Structure, Function of Phytoferritin and its Application in Nano Material Science

    Institute of Scientific and Technical Information of China (English)

    赵广华; 云少君

    2012-01-01

    Ferritins are a broad superfamily of iron storage proteins,present in all living organisms and play important roles in controlling cellar iron homeostasis. To date, relatively little information is available on structure and function of phytoferritin compared to animal ferritin. Phytoferritin is observed in amyloplast whereas animal ferritins are largely found in the cytoplasm of cell. In contrast to animal ferritin,phytofer-ritins exhibit two major distinctive features in structure: (1)phytoferritin contains a specific extension pep-tide (EP) at the N-terminal while animal ferritin lacks. The EP is located on the exterior surface of protein,which recently has been found to act as a second ferroxidase center for iron-binding and oxidation,and regulate iron release during the germination and early growth of seedlings. (2) only H-type subunit has been identified in phytoferritin which is usually a heteropolymer consisting of two different subunits, H-l and H-2,sharing ~80℅ amino acid sequence identity. These two subunits in phytoferritin play a positively cooperative role in iron oxidative deposition in protein. The obtained ferritin has attracted great interest among researchers in the field of nanodevices due to its specific structure. Biomineralization of ferritin core has been extended to the artificial synthesis of homo-geneousmetal complex nanoparticles and semiconductor nanoparticles. The inner cavity of apophytoferritin is an ideal spatially restricted chemical reaction chamber for nanoparticles synthesis. This review focuses on recent progresses in structure,function of phytoferritin and its application in nano material science.%铁蛋白具有储存铁及调节体内铁平衡的功能,它广泛存在于大多数生物体中.和动物铁蛋白相比,关于植物铁蛋白的研究至今很少.目前已知,植物铁蛋白主要存在于淀粉体中,而动物铁蛋白则主要存在于细胞质中.植物铁蛋白和动物铁蛋白相比,其在结

  18. Challenge to Electron Microprobe Analysis by Nano-features in Geo-materials

    Science.gov (United States)

    Ma, C.; Rossman, G. R.

    2007-12-01

    With current high-resolution analytical scanning electron microscope and transmission electron microscope technology, nano-features (i.e., inclusions, exsolutions, pores) are being discovered in many common geo- materials routinely analyzed by EPMA. Most EPMA instruments have a thermionic electron gun with a tungsten "hairpin" type filament and operate at such high probe currents that they do not produce the high resolution imaging that field emission SEMs do. Such nano-features present difficulties to electron microprobe analysis of the host materials. It is an accuracy issue. Presented here are a few examples. Nano-inclusions like magnetite or pyroxene are common in volcanic glass. Massive rose quartz contains nano-fibers of a dumortierite-related phase that is pink, which is the cause of rose color and optical star effects. Blue quartz has nano-inclusions of ilmenite. Nano-exsolutions and nano-inclusions occur in some feldspars (moonstone and sunstone). Nano- pores in corundum and opals are observed. Thin coatings of nanocrystals on grains of hematite bring Al and P (or As) into the analytical picture. In each of these cases, electron microprobe analyses of host materials were contaminated or affected by the nano-features. For a complete analytical description of a geo-material it is necessary to first examine probe samples under an optical microscope (400× minimum) and a FE-SEM. If the sample contains nano-features, it would then be necessary to combine FIB and TEM-EDS-EELS to comprehensively analyze the host composition.

  19. Novel nano-particles as fillers for an experimental resin-based restorative material.

    Science.gov (United States)

    Rüttermann, S; Wandrey, C; Raab, W H-M; Janda, R

    2008-11-01

    The purpose of this study is to compare the properties of two experimental materials, nano-material (Nano) and Microhybrid, and two trade products, Clearfil AP-X and Filtek Supreme XT. The flexural strength and modulus after 24h water storage and 5000 thermocycles, water sorption, solubility and X-ray opacity were determined according to ISO 4049. The volumetric behavior (DeltaV) after curing and after water storage was investigated with the Archimedes principle. ANOVA was calculated with p<0.05. Clearfil AP-X showed the highest flexural strength (154+/-14 MPa) and flexural modulus (11,600+/-550 MPa) prior to and after thermocycling (117+/-14 MPa and 13,000+/-300 MPa). The flexural strength of all materials decreased after thermocycling, but the flexural modulus decreased only for Filtek Supreme XT. After thermocycling, there were no significant differences in flexural strength and modulus between Filtek Supreme XT, Microhybrid and Nano. Clearfil AP-X had the lowest water sorption (22+/-1.1 microg mm(-3)) and Nano had the highest water sorption (82+/-2.6 microg mm(-3)) and solubility (27+/-2.9 microg mm(-3)) of all the materials. No significant differences occurred between the solubility of Clearfil AP-X, Filtek Supreme XT and Microhybrid. Microhybrid and Nano provided the highest X-ray opacity. Owing to the lower filler content, Nano showed higher shrinkage than the commercial materials. Nano had the highest expansion after water storage. After thermocycling, Nano performed as well as Filtek Supreme XT for flexural strength, even better for X-ray opacity but significantly worse for flexural modulus, water sorption and solubility. The performances of microhybrids were superior to those of the nano-materials.

  20. Nano-Engineered Structural Joints Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A versatile class of high-performance structural joints is proposed where massive interatomic bonds over the large surface areas of nanostructured surfaces...

  1. Nonequilibrium band structure of nano-devices

    Science.gov (United States)

    Hackenbuchner, S.; Sabathil, M.; Majewski, J. A.; Zandler, G.; Vogl, P.; Beham, E.; Zrenner, A.; Lugli, P.

    2002-03-01

    A method is developed for calculating, in a consistent manner, the realistic electronic structure of three-dimensional (3-D) heterostructure quantum devices under bias and its current density close to equilibrium. The nonequilibrium electronic structure is characterized by local Fermi levels that are calculated self-consistently. We have applied this scheme to predict asymmetric Stark shifts and tunneling of confined electrons and holes in single-dot GaAs/InGaAs photodiodes.

  2. Emerging boom in nano magnetic particle incorporated high-Tc superconducting materials and technologies - A South African perspective

    CSIR Research Space (South Africa)

    Srinivasu, VV

    2009-01-01

    Full Text Available With a strategy to establish and embrace the emerging nano particle incorporated superconductivity technology (based on the HTS materials and nano magnetic particles) in South Africa, the author has initiated the following research activity in South...

  3. Design Novel 3D Nano Architectures for Developing Ultra Fast Thermal Energy Storage Materials

    Science.gov (United States)

    2015-04-30

    AFRL-AFOSR-UK-TR-2015-0036 Design novel 3D nano-architectures for developing ultra fast thermal energy storage materials...ultra fast thermal energy storage materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8655-12-1-2014 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S...ANSI Std. Z39.18 FINAL TECHNICAL REPORT Project Title : Design novel 3D nano-architectures for developing ultra fast thermal energy storage

  4. Structured electron beams from nano-engineered cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Lueangaramwong, A. [NICADD, DeKalb; Mihalcea, D. [NICADD, DeKalb; Andonian, G. [RadiaBeam Tech.; Piot, P. [Fermilab

    2017-03-07

    The ability to engineer cathodes at the nano-scale have open new possibilities such as enhancing quantum eciency via surface-plasmon excitation, forming ultra-low-emittance beams, or producing structured electron beams. In this paper we present numerical investigations of the beam dynamics associated to this class of cathode in the weak- and strong-field regimes.We finally discuss the possible applications of some of the achievable cathode patterns when coupled with other phase space manipulations.

  5. Nano-structured polymer composites and process for preparing same

    Science.gov (United States)

    Hillmyer, Marc; Chen, Liang

    2013-04-16

    A process for preparing a polymer composite that includes reacting (a) a multi-functional monomer and (b) a block copolymer comprising (i) a first block and (ii) a second block that includes a functional group capable of reacting with the multi-functional monomer, to form a crosslinked, nano-structured, bi-continuous composite. The composite includes a continuous matrix phase and a second continuous phase comprising the first block of the block copolymer.

  6. Structured electron beams from nano-engineered cathodes

    Science.gov (United States)

    Lueangaramwong, A.; Mihalcea, D.; Andonian, G.; Piot, P.

    2017-03-01

    The ability to engineer cathodes at the nano-scale have opened new possibilities such as enhancing quantum efficiency via surface-plasmon excitation, forming ultra-low-emittance beams, or producing structured electron beams. In this paper, we present numerical investigations of the beam dynamics associated with this class of cathode in the weak- and strong-field regimes. We finally discuss the possible applications of some of the achievable cathode patterns when coupled with other phase space manipulations.

  7. Tunable nano-wrinkling of chiral surfaces: Structure and diffraction optics

    Energy Technology Data Exchange (ETDEWEB)

    Rofouie, P.; Rey, A. D., E-mail: alejandro.rey@mail.mcgill.ca [Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, Quebec H3A 2B2 (Canada); Pasini, D. [Department of Mechanical Engineering, McGill University, 817 Sherbrook West, Montreal, Quebec H3A 0C3 (Canada)

    2015-09-21

    Periodic surface nano-wrinkling is found throughout biological liquid crystalline materials, such as collagen films, spider silk gland ducts, exoskeleton of beetles, and flower petals. These surface ultrastructures are responsible for structural colors observed in some beetles and plants that can dynamically respond to external conditions, such as humidity and temperature. In this paper, the formation of the surface undulations is investigated through the interaction of anisotropic interfacial tension, swelling through hydration, and capillarity at free surfaces. Focusing on the cellulosic cholesteric liquid crystal (CCLC) material model, the generalized shape equation for anisotropic interfaces using the Cahn-Hoffman capillarity vector and the Rapini-Papoular anchoring energy are applied to analyze periodic nano-wrinkling in plant-based plywood free surfaces with water-induced cholesteric pitch gradients. Scaling is used to derive the explicit relations between the undulations’ amplitude expressed as a function of the anchoring strength and the spatially varying pitch. The optical responses of the periodic nano-structured surfaces are studied through finite difference time domain simulations indicating that CCLC surfaces with spatially varying pitch reflect light in a wavelength higher than that of a CCLC’s surface with constant pitch. This structural color change is controlled by the pitch gradient through hydration. All these findings provide a foundation to understand structural color phenomena in nature and for the design of optical sensor devices.

  8. Tunable nano-wrinkling of chiral surfaces: Structure and diffraction optics

    Science.gov (United States)

    Rofouie, P.; Pasini, D.; Rey, A. D.

    2015-09-01

    Periodic surface nano-wrinkling is found throughout biological liquid crystalline materials, such as collagen films, spider silk gland ducts, exoskeleton of beetles, and flower petals. These surface ultrastructures are responsible for structural colors observed in some beetles and plants that can dynamically respond to external conditions, such as humidity and temperature. In this paper, the formation of the surface undulations is investigated through the interaction of anisotropic interfacial tension, swelling through hydration, and capillarity at free surfaces. Focusing on the cellulosic cholesteric liquid crystal (CCLC) material model, the generalized shape equation for anisotropic interfaces using the Cahn-Hoffman capillarity vector and the Rapini-Papoular anchoring energy are applied to analyze periodic nano-wrinkling in plant-based plywood free surfaces with water-induced cholesteric pitch gradients. Scaling is used to derive the explicit relations between the undulations' amplitude expressed as a function of the anchoring strength and the spatially varying pitch. The optical responses of the periodic nano-structured surfaces are studied through finite difference time domain simulations indicating that CCLC surfaces with spatially varying pitch reflect light in a wavelength higher than that of a CCLC's surface with constant pitch. This structural color change is controlled by the pitch gradient through hydration. All these findings provide a foundation to understand structural color phenomena in nature and for the design of optical sensor devices.

  9. Osteoblast Behavior on Hierarchical Micro-/Nano-Structured Titanium Surface

    Institute of Scientific and Technical Information of China (English)

    Weiyan Meng; Yanmin Zhou; Yanjing Zhang; Qing Cai; Liming Yang; Jinghui Zhao; Chnnyan Li

    2011-01-01

    In the present work, osteoblast behavior on a hierarchical micro-/nano-structured titanium surface was investigated. A hierarchical hybrid micro-/nano-structured titanium surface topography was produced via Electrolytic Etching (EE). MG-63 cells were cultured on disks for 2 h to 7 days. The osteoblast response to the hierarchical hybrid micro-/nano-structured titanium surface was evaluated through the osteoblast cell morphology, attachment and proliferation. For comparison, MG-63 cells were also cultured on Sandblasted and Acid-etched (SLA) as well as Machined (M) surfaces respectively. The results show significant differences in the adhesion rates and proliferation levels of MG-63 cells on EE, SLA, and M surfaces. Both adhesion rate and proliferation level on EE surface are higher than those on SLA and M surfaces. Therefore, we may expect that, comparing with SLA and M surfaces, bone growth on EE surface could be accelerated and bone formation could be promoted at an early stage, which could be applied in the clinical practices for immediate and early-stage loadings.

  10. Feasibility of Pb phytoextraction using nano-materials assisted ryegrass: Results of a one-year field-scale experiment.

    Science.gov (United States)

    Liang, Shu-Xuan; Jin, Yu; Liu, Wei; Li, Xiliang; Shen, Shi-Gang; Ding, Ling

    2017-04-01

    The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed. Ryegrass shoot concentrations of Pb were lower with nano-materials application than without nano-materials for the first month. However, the shoot concentrations of Pb were significantly increased with nano-materials application, in particular NHAP groups. The ryegrass root concentrations of Pb were lower with nano-materials application for the first month. These results indicated that nano-materials had significant effects on stabilization of lead, especially at the beginning of the experiment. Along with the experimental proceeding, phytotoxicity was alleviated after the incorporation of nano-materials. The ryegrass biomass was significantly higher with nano-materials application. Consequently, the Pb phytoextraction potential of ryegrass significantly increased with nano-materials application compared to the gounps without nano-materials application. The total removal rates of soil Pb were higher after combined application of NHAP than NCB. NHAP is more suitable than NCB for in-situ remediation of Pb-contaminated soils. The ryegrass translocation factor exhibited a marked increase with time. It was thought that the major role of NHP and NBA might be to alleviate the Pb phytotoxicity and increase biomass of plants.

  11. Effective elastic moduli and interface effects of nano- crystalline materials

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Many properties of nanocrystalline materials are associated with interface effects. Based on their microstructural features, the influence of interfaces on the effective elastic property of nanocrystalline materials is investigated. First, the Mori-Tanaka method is employed to determine the overall effective elastic moduli by considering a nanocrystalline material as a binary composite solid consisting of a crystal or inclusion phase with regular lattice connected by an amorphous-like interface or matrix phase. The effects of strain gradients are then examined on the effective elastic property by using the strain gradient theory to analyze a representative unit cell. Two interface mechanisms are elucidated that influence the effective stiffness and other mechanical properties of materials. One is the softening effect due to the distorted atomic structures and the increased atomic spacings in interface regions, and the other is the baffling effect due to the existence of boundary layers near interfaces.

  12. Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

    Energy Technology Data Exchange (ETDEWEB)

    Zobelli, A

    2007-10-15

    The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

  13. Nano Structured Plasma Spray Coating for Wear and High Temperature Corrosion Resistance Applications

    Science.gov (United States)

    Ghosh, D.; Shukla, A. K.; Roy, H.

    2014-04-01

    The nano structured coating is a major challenge today to improve the different mechanical properties, wear and high temperature corrosion resistance behaviour of different industrial alloys. This paper is a review on synthesis of nano powder, plasma spraying methods, techniques of nano structured coating by plasma spray method, mechanical properties, tribological properties and high temperature corrosion behaviour of nano structured coating. Nano structured coatings of ceramic powders/composites are being developed for wide variety of applications like boiler, turbine and aerospace industries, which requires the resistance against wear, corrosion, erosion etc. The nano sized powders are subjected to agglomeration by spray drying, after which nano structured coating can be successfully applied over the substrate. Nano structured coating shows improved mechanical wear resistance and high temperature corrosion resistance. The significant improvement of wear and corrosion resistance is mainly attributed to formation of semi molten nano zones in case of nano structured coatings. The future scope of application of nano structured coating has also been highlighted in this paper.

  14. Nano Structured Devices for Energy Generation

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej

    This work focuses on the enhancement of α-sexithiophene / buckminsterfullerene (α-6T / C60) inverted bilayer organic solar cell effciency by the introduction of crystalline nanostructures in the electron donor layer. In order to utilize the charge carrier mobility anisotropy in crystalline α-6T......?uorescence polarimetry and X-ray diffractometry (XRD). Layer thicknesses of inverted α-6T / C60 bilayer organic solar cells fabricated at room temperature were optimized to obtain the model device for the performance enhancement studies. By variation of the substrate temperature during deposition of α-6T, the structures...... structures in solar cells, the orientation of the individual molecules should favor charge transport perpendicular to the substrate plane. Such orientation is realized from α-6T molecules lying on the substrate, which additionally infers the preferred orientation of the transition dipole for maximal light...

  15. Spectral absorption of unpolarized light through nano-materials in the absence of a magnetic field

    Directory of Open Access Journals (Sweden)

    Luminosu I.

    2008-01-01

    Full Text Available A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid - liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid. The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles. The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized 58.76 nm are formed in the system. The average number of nano-particles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications.

  16. Surface Nano Structures Manufacture Using Batch Chemical Processing Methods for Tooling Applications

    DEFF Research Database (Denmark)

    Tosello, Guido; Calaon, Matteo; Gavillet, J.

    2011-01-01

    The patterning of large surface areas with nano structures by using chemical batch processes to avoid using highenergy intensive nano machining processes was investigated. The capability of different surface treatment methods of creating micro and nano structured adaptable mould inserts...... for subsequent polymer replication by injection moulding was analyzed. New tooling solutions to produce nano structured mould surfaces were investigated. Experiments based on three different chemical-based-batch techniques to establish surface nano (i.e. sub-μm) structures on large areas were performed. Three...... approaches were selected: (1) using Ø500 nm nano beads deposition for direct patterning of a 4” silicon wafer; (2) using Ø500 nm nano beads deposition as mask for 4” silicon wafer etching and subsequent nickel electroplating; (3) using the anodizing process to produce Ø500 nm structures on a 30x80 mm2...

  17. Nano-composite Structures for OPV Devices

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Henning

    2010-11-23

    Improved material for use in organic photovoltaics (OPV) devices, also called polymer-solar cells (PSC), has been developed. Increased ordering of the active layer of bulk heterojunction (BHJ) cells has been achieved by the use of inert silica spheres in conjunction with suitable fullerene derivatives. Silica spheres with average diameters between 10 and 15 nm, consistent with the exciton diffusion length in the active layer, have been added. The potential for significantly improved device performance due to a higher degree of photon absorption, enabled by increased light scattering, and a maximized interface between electron donor and acceptor, ensuring efficient exciton dissociation, has been demonstrated. A method allowing for the covalent attachment of fullerene derivatives to the silica sphere surface has been developed.

  18. New active control nano-system to use in composites structure

    Science.gov (United States)

    Arche, M. R.

    2012-09-01

    The present abstract, is a brief description about our project (NEDEA). We considered this project as very important, because it reunites in his development, several basic technologies: electronics, communications, software and new materials, all very interesting in the European industry. The project is developed in the CSIC (Spanish Researcher Center). We are involved. Across the project, in the development of nano-sensors, specialized in detecting defects, difficulties or problems in structures of composed materials. These materials are being used, and in the future more, in applications where a high degree of security is necessary. Some fields in the system usage are Aeronautical and military applications whit a necessary high security degree. The development proposed, is based in nano-sensors and active devices. They are installed into the material structure. The information from sensors is transmitted by optical fibers, to a radio transmitter, equally installed into the material. An external receptor picks up those data and transmits them to an external device. This external device presents/displays all the information across an interface GUI, in real time, to the supervisor. He can see than is happening in the material, in real time. Alarms can be programmed, by the supervisor. Is possible a tracking for the problem. All the devices and software are in develop in our laboratories. We think that this development will be used by the industry of materials, and that gradually, it will have other applications in the transport area (like new vehicles, wagons of train and metro, etc.).

  19. Studies on structural properties of clay magnesium ferrite nano composite

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet, E-mail: manpreetchem@pau.edu; Singh, Mandeep [Department of Chemistry, Punjab Agricultural University, Ludhiana-141004 (India); Jeet, Kiran, E-mail: kiranjeet@pau.edu; Kaur, Rajdeep [Electron Microscopy and Nanoscience Laboratory, Punjab Agricultural University, Ludhiana-141004 (India)

    2015-08-28

    Magnesium ferrite-bentonite clay composite was prepared by sol-gel combustion method employing citric acid as complexing agent and fuel. The effect of clay on the structural properties was studied with X-ray diffraction (XRD), Fourier transform infrared (FT-IR) Spectroscopy, Scanning electron microscopy (SEM), SEM- Energy dispersive Spectroscope (EDS) and BET surface area analyzer. Decrease in particle size and density was observed on addition of bentonite clay. The BET surface area of nano composite containing just 5 percent clay was 74.86 m{sup 2}/g. Whereas porosity increased from 40.5 per cent for the pure magnesium ferrite to 81.0 percent in the composite showing that nano-composite has potential application as an adsorbent.

  20. Si-Ge Nano-Structured with Tungsten Silicide Inclusions

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    Traditional silicon germanium high temperature thermoelectrics have potential for improvements in figure of merit via nano-structuring with a silicide phase. A second phase of nano-sized silicides can theoretically reduce the lattice component of thermal conductivity without significantly reducing the electrical conductivity. However, experimentally achieving such improvements in line with the theory is complicated by factors such as control of silicide size during sintering, dopant segregation, matrix homogeneity, and sintering kinetics. Samples are prepared using powder metallurgy techniques; including mechanochemical alloying via ball milling and spark plasma sintering for densification. In addition to microstructural development, thermal stability of thermoelectric transport properties are reported, as well as couple and device level characterization.

  1. Uniting Superhydrophobic, Superoleophobic and Lubricant Infused Slippery Behavior on Copper Oxide Nano-structured Substrates

    Science.gov (United States)

    Ujjain, Sanjeev Kumar; Roy, Pritam Kumar; Kumar, Sumana; Singha, Subhash; Khare, Krishnacharya

    2016-01-01

    Alloys, specifically steel, are considered as the workhorse of our society and are inimitable engineering materials in the field of infrastructure, industry and possesses significant applications in our daily life. However, creating a robust synthetic metallic surface that repels various liquids has remained extremely challenging. The wettability of a solid surface is known to be governed by its geometric nano-/micro structure and the chemical composition. Here, we are demonstrating a facile and economical way to generate copper oxide micro-nano structures with spherical (0D), needle (1D) and hierarchical cauliflower (3D) morphologies on galvanized steel substrates using a simple chemical bath deposition method. These nano/micro textured steel surfaces, on subsequent coating of a low surface energy material display excellent superhydrophobic, superoleophobic and slippery behavior. Polydimethylsiloxane coated textured surfaces illustrate superhydrophobicity with water contact angle about 160°(2) and critical sliding angle ~2°. When functionalized with low-surface energy perfluoroalkylsilane, these surfaces display high repellency for low surface tension oils as well as hydrocarbons. Among them, the hierarchical cauliflower morphology exhibits re-entrant structure thereby showing the best superoleophobicity with contact angle 149° for dodecane. Once infused with a lubricant like silicone oil, they show excellent slippery behavior with low contact angle hysteresis (~ 2°) for water drops. PMID:27752098

  2. Uniting Superhydrophobic, Superoleophobic and Lubricant Infused Slippery Behavior on Copper Oxide Nano-structured Substrates

    Science.gov (United States)

    Ujjain, Sanjeev Kumar; Roy, Pritam Kumar; Kumar, Sumana; Singha, Subhash; Khare, Krishnacharya

    2016-10-01

    Alloys, specifically steel, are considered as the workhorse of our society and are inimitable engineering materials in the field of infrastructure, industry and possesses significant applications in our daily life. However, creating a robust synthetic metallic surface that repels various liquids has remained extremely challenging. The wettability of a solid surface is known to be governed by its geometric nano-/micro structure and the chemical composition. Here, we are demonstrating a facile and economical way to generate copper oxide micro-nano structures with spherical (0D), needle (1D) and hierarchical cauliflower (3D) morphologies on galvanized steel substrates using a simple chemical bath deposition method. These nano/micro textured steel surfaces, on subsequent coating of a low surface energy material display excellent superhydrophobic, superoleophobic and slippery behavior. Polydimethylsiloxane coated textured surfaces illustrate superhydrophobicity with water contact angle about 160°(2) and critical sliding angle ~2°. When functionalized with low-surface energy perfluoroalkylsilane, these surfaces display high repellency for low surface tension oils as well as hydrocarbons. Among them, the hierarchical cauliflower morphology exhibits re-entrant structure thereby showing the best superoleophobicity with contact angle 149° for dodecane. Once infused with a lubricant like silicone oil, they show excellent slippery behavior with low contact angle hysteresis (~ 2°) for water drops.

  3. Low temperature synthesis of diamond-based nano-carbon composite materials with high electron field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, A.; Huang, B. R. [Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Yeh, C. J.; Leou, K. C. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Lin, I. N., E-mail: inanlin@mail.tku.edu.tw [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

    2015-06-08

    A diamond-based nano-carbon composite (d/NCC) material, which contains needle-like diamond grains encased with the nano-graphite layers, was synthesized at low substrate temperature via a bias enhanced growth process using CH{sub 4}/N{sub 2} plasma. Such a unique granular structure renders the d/NCC material very conductive (σ = 714.8 S/cm), along with superior electron field emission (EFE) properties (E{sub 0} = 4.06 V/μm and J{sub e} = 3.18 mA/cm{sup 2}) and long lifetime (τ = 842 min at 2.41 mA/cm{sup 2}). Moreover, the electrical conductivity and EFE behavior of d/NCC material can be tuned in a wide range that is especially useful for different kind of applications.

  4. Nano Structured Devices for Energy Generation

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej

    This work focuses on the enhancement of α-sexithiophene / buckminsterfullerene (α-6T / C60) inverted bilayer organic solar cell effciency by the introduction of crystalline nanostructures in the electron donor layer. In order to utilize the charge carrier mobility anisotropy in crystalline α-6T...... structures in solar cells, the orientation of the individual molecules should favor charge transport perpendicular to the substrate plane. Such orientation is realized from α-6T molecules lying on the substrate, which additionally infers the preferred orientation of the transition dipole for maximal light...... temperatures and a shutter were controlled by the supervisory control and data acquisition (SCADA) system, which has been implemented in LabVIEW environment. The temperatures, process pressure, and deposition rate were stored for future analysis. By variation of the substrate temperature during deposition...

  5. Fabrication and condensation characteristics of metallic superhydrophobic surface with hierarchical micro-nano structures

    Science.gov (United States)

    Chu, Fuqiang; Wu, Xiaomin

    2016-05-01

    Metallic superhydrophobic surfaces have various applications in aerospace, refrigeration and other engineering fields due to their excellent water repellent characteristics. This study considers a simple but widely applicable fabrication method using a two simultaneous chemical reactions method to prepare the acid-salt mixed solutions to process the metal surfaces with surface deposition and surface etching to construct hierarchical micro-nano structures on the surface and then modify the surface with low surface-energy materials. Al-based and Cu-based superhydrophobic surfaces were fabricated using this method. The Al-based superhydrophobic surface had a water contact angle of 164° with hierarchical micro-nano structures similar to the lotus leaves. The Cu-based surface had a water contact angle of 157° with moss-like hierarchical micro-nano structures. Droplet condensation experiments were also performed on these two superhydrophobic surfaces to investigate their condensation characteristics. The results show that the Al-based superhydrophobic surface has lower droplet density, higher droplet jumping probability, slower droplet growth rate and lower surface coverage due to the more structured hierarchical structures.

  6. The use of nano-sized acicular material, sliding friction, and antisense DNA oligonucleotides to silence bacterial genes

    OpenAIRE

    2014-01-01

    Viable bacterial cells impaled with a single particle of a nano-sized acicular material formed when a mixture containing the cells and the material was exposed to a sliding friction field between polystyrene and agar gel; hereafter, we refer to these impaled cells as penetrons. We have used nano-sized acicular material to establish a novel method for bacterial transformation. Here, we generated penetrons that carried antisense DNA adsorbed on nano-sized acicular material (α-sepiolite) by prov...

  7. Joint Experiments on X-ray/Particle Emission from Plasmas Produced by Laser Irradiating Nano Structured Targets

    Science.gov (United States)

    Hegazy, H.; Allam, S. H.; Chaurasia, S.; Dhareshwar, L.; El-Sherbini, Th. M.; Kunze, H.-J.; Mank, G.; McDaniel, D. H.; Rosinski, M.; Ryc, L.; Stewart, B.; Wolowski, J.; Abd El-Ghany, H.; Abd El-Latif, G.; Abd El-Rahim, F. M.; Bedrane, Z.; Diab, F.; Farrag, A.; Hedwig, R.; Helal, A.; Pardede, M.; Refaie, A.; Sharkawy, H.; El-khatim, A., Sir

    2008-04-01

    The 1st Joint (Host Laboratory) Experiment on laser plasma involving more than twenty scientists from eight countries has been carried out at the Laser and New Materials Laboratory, Faculty of Science, Cairo University, Egypt. It was co-ordinated by the International Atomic Energy Agency (IAEA) and supported through the IAEA and the ICTP (International Centre for Theoretical Physics, Trieste). The main experimental programme was aimed at characterising the possible enhancement of x-ray and particle emission from plasmas produced by laser incidence on nano-structured targets. Laser beams at 1.064 μm of 250 mJ and 532 nm of 165 mJ focused at the target surface using a nanosecond laser type Quantel were used in the present study. In the present experiments nano-copper structures evaporated onto copper bulk disks and nano-gold structures evaporated onto gold ones were used. The thickness of the nano-materials on their bulk material was 1 μm. An ion collector and x-ray semiconductor diode were used to study the ion and x-ray emission, respectively. Both were positioned at the same port at 90° with respect to the target surface and at 90 cm from the surface in the case of the ion collector and 55 cm in the case of the x-ray detector. These experiments were performed at vacuum pressures of (5—8)×10-6 mbar. Comparison of both studies in the case of nano structured targets and bulk targets were performed at different laser fluencies (1×109-1×1012 W/cm2) on the target. A 20% increase of the X-ray emission for nano gold with respect to bulk gold was observed, however, the x-ray emission in the of nano copper and copper was the same.

  8. Effect of Nano Oil Additive Proportions on Friction and Wear Performance of Automotive Materials

    Directory of Open Access Journals (Sweden)

    A. Vadiraj

    2012-03-01

    Full Text Available The effect of nano boric acid and nano copper based engine and transmission oil additives in different volume ratios (1:10, 2:10, and 3:10 on friction and wear performance of cast iron and case carburized gear steel has been investigated. The results show that coefficient of friction increases with increase in volume ratio of engine oil additives and decreases with increasing in volume ratio of transmission oil additives. Cast iron substrate shows higher wear damage than case carburized gear steel. Nano copper additive with crystalline atomic structure shows more severe three body wear compared to boric acid with layered lattice structure.

  9. Novel hydrophobic associated polymer based nano-silica composite with core–shell structure for intelligent drilling fluid under ultra-high temperature and ultra-high pressure

    Directory of Open Access Journals (Sweden)

    Hui Mao

    2015-02-01

    Full Text Available Micro-nano-based drilling fluid has attracted a strong interest due to its attractive properties, and micro-nano composite materials have great potential for developing intelligent drilling fluid. In this study a novel hydrophobic associated polymer based nano-silica composite with core–shell structure was prepared and characterized by PSD, SEM, TEM and ESEM. The results showed that the composite, as a micro-nano drilling fluid additive, possessed excellent properties such as thermal stability, rheology, fluid loss and lubricity. Especially, it could plug the formation effectively and improve the pressure bearing capability of formation significantly.

  10. Templated Self Assemble of Nano-Structures

    Energy Technology Data Exchange (ETDEWEB)

    Suo, Zhigang [Harvard University

    2013-04-29

    This project will identify and model mechanisms that template the self-assembly of nanostructures. We focus on a class of systems involving a two-phase monolayer of molecules adsorbed on a solid surface. At a suitably elevated temperature, the molecules diffuse on the surface to reduce the combined free energy of mixing, phase boundary, elastic field, and electrostatic field. With no template, the phases may form a pattern of stripes or disks. The feature size is on the order of 1-100 nm, selected to compromise the phase boundary energy and the long-range elastic or electrostatic interaction. Both experimental observations and our theoretical simulations have shown that the pattern resembles a periodic lattice, but has abundant imperfections. To form a perfect periodic pattern, or a designed aperiodic pattern, one must introduce a template to guide the assembly. For example, a coarse-scale pattern, lithographically defined on the substrate, will guide the assembly of the nanoscale pattern. As another example, if the molecules on the substrate surface carry strong electric dipoles, a charged object, placed in the space above the monolayer, will guide the assembly of the molecular dipoles. In particular, the charged object can be a mask with a designed nanoscale topographic pattern. A serial process (e.g., e-beam lithography) is necessary to make the mask, but the pattern transfer to the molecules on the substrate is a parallel process. The technique is potentially a high throughput, low cost process to pattern a monolayer. The monolayer pattern itself may serve as a template to fabricate a functional structure. This project will model fundamental aspects of these processes, including thermodynamics and kinetics of self-assembly, templated self-assembly, and self-assembly on unconventional substrates. It is envisioned that the theory will not only explain the available experimental observations, but also motivate new experiments.

  11. Effects of freeze drying and silver staining on carbonization of cellulose: carbon nano-materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae-Young; Im, Hyun Sik [Dongguk University, Seoul (Korea, Republic of)

    2012-05-15

    We investigated the effects of sulfuric acid and silver particles on the carbonization of natural cellulose from Halocynthia. We carried out thermogravimetry and used transmission electron microscopy measurements to study the yield of carbon and the structure of the carbonized nano-fiber. We found that the addition of sulfuric acid and silver particles to the cellulose fiber enhanced the yield of carbon while keeping the original structure of the carbon nano-fiber.

  12. Preparation and characterization of Zn/Ce/SO42--doped titania nano-materials with antibacterial activity

    Science.gov (United States)

    Wang, Yuzheng; Xue, Xiangxin; Yang, He; Luan, Che

    2014-02-01

    SO42--doped Zn/Ce/TiO2 nano-materials (Zn/Ce/SO42-/TiO2) were prepared by a sol-gel method. The structures of Zn/Ce/SO42-/TiO2 nano-materials were characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), X-ray photoelectron spectroscopy (XPS), X-ray photoelectron (PL) spectroscopy and Fourier transform infrared spectroscopy (FT-IR). Gram-negative Escherichia coli (ATCC25922) and Gram-positive Staphylococcus aureus (ATCC6538) as model organisms, antibacterial activities of nano-materials were tested using inhibition zone method and shaking flask method under visible light irradiation and in the dark. The results show that the materials crystal structure and elemental composition are changed after SO42- doped. Zn/Ce/SO42-/TiO2 exhibit predominant antibacterial activity in the dark and visible light irradiation. The action mechanism of Zn/Ce/SO42-/TiO2 is discussed.

  13. Carbon nano structures: Production and characterization

    Science.gov (United States)

    Beig Agha, Rosa

    L'objectif de ce memoire est de preparer et de caracteriser des nanostructures de carbone (CNS -- Carbon Nanostructures, en licence a l'Institut de recherche sur l'hydrogene, Quebec, Canada), un carbone avec un plus grand degre de graphitisation et une meilleure porosite. Le Chapitre 1 est une description generale des PEMFCs (PEMFC -- Polymer Electrolyte Membrane Fuel Cell) et plus particulierement des CNS comme support de catalyseurs, leur synthese et purification. Le Chapitre 2 decrit plus en details la methode de synthese et la purification des CNS, la theorie de formation des nanostructures et les differentes techniques de caracterisation que nous avons utilises telles que la diffraction aux rayons-X (XRD -- X-ray diffraction), la microscopie electronique a transmission (TEM -- transmission electron microscope ), la spectroscopie Raman, les isothermes d'adsorption d'azote a 77 K (analyse BET, t-plot, DFT), l'intrusion au mercure, et l'analyse thermogravimetrique (TGA -- thermogravimetric analysis). Le Chapitre 3 presente les resultats obtenus a chaque etape de la synthese des CNS et avec des echantillons produits a l'aide d'un broyeur de type SPEXRTM (SPEX/CertiPrep 8000D) et d'un broyeur de type planetaire (Fritsch Pulverisette 5). La difference essentielle entre ces deux types de broyeur est la facon avec laquelle les materiaux sont broyes. Le broyeur de type SPEX secoue le creuset contenant les materiaux et des billes d'acier selon 3 axes produisant ainsi des impacts de tres grande energie. Le broyeur planetaire quant a lui fait tourner et deplace le creuset contenant les materiaux et des billes d'acier selon 2 axes (plan). Les materiaux sont donc broyes differemment et l'objectif est de voir si les CNS produits ont les memes structures et proprietes. Lors de nos travaux nous avons ete confrontes a un probleme majeur. Nous n'arrivions pas a reproduire les CNS dont la methode de synthese a originellement ete developpee dans les laboratoires de l'Institut de

  14. Large scale molecular simulations with application to polymers and nano-scale materials

    Science.gov (United States)

    Gao, Guanghua

    There remain practical problems to predicting structures and properties of materials from first principles, though the foundation, quantum mechanics, has been established for many years. The goals of this research are to develop methods and tools that are accurate and practical, and apply them to important problems. Two aspects of the methodology are focused. (1) The development of accurate force fields based on ab initio quantum mechanical calculations on prototype systems. Procedures were developed on polyvinyl chloride (PVC) and successfully applied on other types of polymers. They are very important to studying of amorphous polymers materials, for which current methods have not been useful in predicting important properties (e.g. moduli and glass temperature). (2) The development of Massive Parallel Simulation (MPSim) Software. MPSim is suitable for large systems (millions of atoms). It has the ability of including environmental variables (temperature, pressure, tension, and shear) and extracting physical properties (moduli and glass temperatures). The theories and algorithms implemented are summarized in the Appendix. These methods and tools are applied to the accurate simulation of structures and properties of amorphous polymer materials and nano-materials. Molecular dynamics (MD) simulation on polyethylene (chapter 6) was used to develop a general strategy for predicting glass transition temperatures which is expected to be very important in polymer industry. In chapter 7, these strategies were successfully applied to three important fluoro polymers. Single-walled carbon nanotubes (SWNT), recently discovered but not very well characterized, is an interesting new class of materials. Using an accurate force field, structures and mechanical properties of these systems are studied. Chapter 2 shows that the dominating factor for deciding stable structures and mechanical properties is the tube size, not chirality. The behavior of (10, 10) nano-tube under bending

  15. High pressure synthesis of novel, zeolite based nano-composite materials

    Science.gov (United States)

    Santoro, Mario

    2013-06-01

    Meso/micro-porous solids such as zeolites are complex materials exhibiting an impressive range of applications, including molecular sieve, gas storage, catalysis, electronics and photonics. We used these materials, particularly non catalytic zeolites in an entirely different fashion. In fact, we performed high pressure (0.5-30 GPa) chemical reactions of simple molecules on a sub-nanometer scale in the channels of a pure SiO2 zeolite, silicalite to obtain unique nano-composite materials with drastically modified physical and chemical properties. Our material investigations are based on a combination of X-ray diffraction and optical spectroscopy techniques in the diamond anvil cell. I will first briefly show how silicalite can be easily filled by simple molecules such as Ar, CO2 and C2H4 among others from the fluid phase at high pressures, and how this efficient filling removes the well known pressure induced amorphization of the silica framework (Haines et al., JACS 2010). I will then present on a silicon carbonate crystalline phase synthesized by reacting silicalite and molecular CO2 that fills the nano-pores, at 18-26 GPa and 600-980 K; after the synthesis the compound is temperature quenched and it results to be slightly metastable at room conditions (Santoro et al., PNAS 2011). On the other hand, a stable at room condition spectacular crystalline nano-composite is obtained by photo-polymerizing ethylene at 0.5-1.5 GPa under UV (351-364 nm) irradiation in the channels of silicalite (Santoro et al., Nat. Commun, in press 2013). For this composite we obtained a structure with single polyethylene chains adapting very well to the confining channels, which results in significant increases in bulk modulus and density, and the thermal expansion coefficient changes sign from negative to positive with respect to the original silicalite host. Mechanical properties may thus be tuned by varying the amount of polymerized ethylene. We then think our findings could allow the

  16. Nano

    DEFF Research Database (Denmark)

    Nørgaard, Bent; Engel, Lars Romann

    2007-01-01

    Gennem de sidste par år har et lille ord med et meget stort potentiale gentagende trængt sig på i den offentlige bevidsthed, det er ordet "nano". Nanovidenskab og nanoteknologi er lige nu to af de "hotteste" forskningsområder og betragtes af mange som porten til en helt ny verden af muligheder....... Muligheder, vi endnu ikke kender konsekvenserne af. Center for Kunst og Videnskabs forestilling NANO giver dig chancen for at blive bekendt med verdens mindste byggesten og idégrundlaget for nanoforskningen. Vi har skabt et rum, som på mange måder minder om et laboratorium. Rummet er forsynet med storskærme......, kolber, væsker og nanopartikler. Her vil du f.eks. opleve, hvordan forskere tilfører guld helt nye egenskaber. Forestillingen veksler mellem kemiske arbejdsdemonstrationer, stemningsskabende musik og livlig debat på storskærme mellem eksperter. NANO opfordrer publikum til at tage stilling til forskningen...

  17. Multi-Beam Interference Advances and Applications: Nano-Electronics, Photonic Crystals, Metamaterials, Subwavelength Structures, Optical Trapping, and Biomedical Structures

    Directory of Open Access Journals (Sweden)

    Thomas K. Gaylord

    2011-06-01

    Full Text Available Research in recent years has greatly advanced the understanding and capabilities of multi-beam interference (MBI. With this technology it is now possible to generate a wide range of one-, two-, and three-dimensional periodic optical-intensity distributions at the micro- and nano-scale over a large length/area/volume. These patterns may be used directly or recorded in photo-sensitive materials using multi-beam interference lithography (MBIL to accomplish subwavelength patterning. Advances in MBI and MBIL and a very wide range of applications areas including nano-electronics, photonic crystals, metamaterials, subwavelength structures, optical trapping, and biomedical structures are reviewed and put into a unified perspective.

  18. Imprinted and injection-molded nano-structured optical surfaces

    Science.gov (United States)

    Christiansen, Alexander B.; Højlund-Nielsen, Emil; Clausen, Jeppe; Caringal, Gideon P.; Mortensen, N. Asger; Kristensen, Anders

    2013-09-01

    Inspired by nature, nano-textured surfaces have attracted much attention as a method to realize optical surface functionality. The moth-eye antireflective structure and the structural colors of Morpho butterflies are well- known examples used for inspiration for such biomimetic research. In this paper, nanostructured polymer surfaces suitable for up-scalable polymer replication methods, such as imprinting/embossing and injection-molding, are discussed. The limiting case of injection-moulding compatible designs is investigated. Anti-reflective polymer surfaces are realized by replication of Black Silicon (BSi) random nanostructure surfaces. The optical transmission at normal incidence is measured for wavelengths from 400 nm to 900 nm. For samples with optimized nanostructures, the reflectance is reduced by 50 % compared to samples with planar surfaces. The specular and diffusive reflection of light from polymer surfaces and their implication for creating structural colors is discussed. In the case of injection-moulding compatible designs, the maximum reflection of nano-scale textured surfaces cannot exceed the Fresnel reflection of a corresponding flat polymer surface, which is approx. 4 % for normal incidence. Diffraction gratings provide strong color reflection defined by the diffraction orders. However, the apperance varies strongly with viewing angles. Three different methods to address the strong angular-dependence of diffraction grating based structural color are discussed.

  19. Nano-clays from natural and modified montmorillonite with and without added blueberry extract for active and intelligent food nanopackaging materials

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez, Tomy J., E-mail: tomy.gutierrez@ciens.ucv.ve [Departamento Químico Analítico, Facultad de Farmacia, Universidad Central de Venezuela, Apartado 40109, Caracas, 1040-A (Venezuela, Bolivarian Republic of); Instituto de Ciencia y Tecnología de Alimentos, Facultad de Ciencias, Universidad Central de Venezuela, Apartado 47097, Caracas, 1041-A (Venezuela, Bolivarian Republic of); Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata UNMdP y Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Colón 10850, B7608FLC, Mar del Plata (Argentina); Ponce, Alejandra G. [Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata (UNMdP), Juan B. Justo 4302, 7600, Mar del Plata (Argentina); Alvarez, Vera A. [Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata UNMdP y Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Colón 10850, B7608FLC, Mar del Plata (Argentina)

    2017-06-15

    The aim of this study was to evaluate the potential of nano-clays as active and intelligent (A&I) food nanopackaging materials. Nanopackaging is a structured system that allows the storage of certain compounds in a stable form. Nano-clays were prepared from natural and modified montmorillonite (Mnt) with and without added blueberry extract, and characterized in terms of their: X-ray diffraction (XRD) patterns, thermogravimetric (TGA) properties, microstructure, moisture content, water activity (a{sub w}), infrared spectra (FTIR), Raman spectra, color parameters, response to pH changes, and antioxidant and antimicrobial activity. Mnt prepared with added blueberry extract showed antioxidant activity and intelligent behavior under different pH conditions. Modifying the Mnt increased the interlayer spacing, thus allowing more blueberry extract to be incorporated within the system. In conclusion, natural and modified Mnt are eco-friendly resources with potential applications for nano-packaging. The addition of blueberry extract imparted intelligent properties to the nano-clays as regards their responses to changes in pH. - Highlights: • Food nano-packaging were obtained from natural and modified montmorillonite (Mnt). • XRD, TGA and FTIR results suggests the blueberry extract nano-packaging. • Intelligent nanocomposites were obtained. • Greater interlayer spacing of the nano-Mnt allows greater nano-packaging.

  20. Monolithic silica aerogel - material design on the nano-scale

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    By means of a production process in two major steps - a sol/gel process and a supercritical drying – open-cell, monolithic silica aerogel can be made. This material can have a density in the range of 30- to 300 kg/m3, corresponding to porosities between 86 and 98 %. The solid structure has...... of piezoelectric transducers. - Other applications could be; waste encapsulation, spacers for vacuum insulation panels, membranes, etc. Department of Civil Engineering is co-ordinator of a current EU FP5 research project1, which deals with the application of aerogel as transparent insulation materials in windows....... Due to the excellent optical and thermal properties of aerogel, it is possible to develop windows with both high insulation and high transmittance, which is impossible applying the conventional window techniques, i.e. extra layers of glass, low-e coatings and gas fillings. It can be shown...

  1. Study on micro-structure and morphological evolution of Fe/Pt nano-magnetic film.

    Science.gov (United States)

    Ishiguro, S; Ju, D Y; Ogatsu, R; Nakano, T

    2011-10-01

    One of the vertical magnetic recordings medium materials of the hard disk drive (HDD) is a Fe/Pt thin film. The development of ultra-high density magnetic recording medium in next generation is expected the magnetic disks such as HDD with capacity enlargement of the data. In order to study effectiveness of the proposed sputtering method, we evaluated micro structure, magnetic and the mechanical properties of a Fe/Pt thin film by some sputtering process conditions. From research results, effect sputtering conditions on micro-structure and mechanical properties of Fe/Pt nano film are verified.

  2. Visualization of energy: light dose indicator based on electrochromic gyroid nano-materials

    Science.gov (United States)

    Wei, Di; Scherer, Maik R. J.; Astley, Michael; Steiner, Ullrich

    2015-06-01

    The typical applications of electrochromic devices do not make use of the charge-dependent, gradual optical response due to their slow voltage-sensitive coloration. However, in this paper we present a design for a reusable, self-powered light dose indicator consisting of a solar cell and a gyroid-structured nickel oxide (NiO) electrochromic display that measures the cumulative charge per se, making use of the efficient voltage-sensitive coloration of gyroid materials. To circumvent the stability issues associated with the standard aqueous electrolyte that is typically accompanied by water splitting and gas evolution, we investigate a novel nano-gyroid NiO electrochromic device based on organic solvents of 1,1,1,3,3,3-hexafluoropropan-2-ol, and room temperature ionic liquid (RTIL) triethylsulfonium bis(trifluoromethylsulfonyl) imide ([SET3][TFSI]) containing lithium bis(trifluoromethylsulfonyl) imide. We show that an effective light dose indicator can be enabled by nano-gyroid NiO with RTIL; this proves to be a reliable device since it does not involve solvent degradation or gas generation.

  3. Application of Plane Wave Method to the Calculation of Electronic States of Nano-Structures

    Institute of Scientific and Technical Information of China (English)

    LI Shu-Shen; XIA Jian-Bai

    2006-01-01

    @@ The electronic states of nano-structures are studied in the framework of effective-mass envelope-function theory using the plane wave basis. The barrier width and the number of plane waves are proposed to be 2.5 times the effective Bohr radius and 15n, respectively, for n-dimensional nano-structures (n = 1, 2, 3). Our proposals can be widely applied in the design of various nano-structure devices.

  4. Laser nano-manufacturing: state of the art and challenges

    NARCIS (Netherlands)

    Li, L.; Hong, M.; Schmidt, M.; Zhong, M.; Mashe, A.; Huis in 't veld, A.J.; Kovalenko, V.

    2011-01-01

    This paper provides an overview of advances in laser based nano-manufacturing technologies including surface nano-structure manufacturing, production of nano materials (nanoparticles, nanotubes and nanowires) and 3D nano-structures manufacture through multiple layer additive techniques and

  5. Characterization of the Tribological Behavior of Oxide-Based NanoMaterials: Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-04

    Under the Argonne/Pixelligent cooperative research and development agreement (CRADA – C1200801), Argonne performed labscale tribological tests on proprietary nano-sized ZrO2 material developed by Pixelligent. Pixelligent utilized their proprietary process to prepare variants with different surfactants at different loadings in different carrier fluids for testing and evaluation at Argonne. Argonne applied a range of benchtop tribological test rigs to evaluate friction and wear under a range of conditions (contact geometry, loads, speeds, and temperature) that simulated a broad range of conditions experienced in engines and driveline components. Post-test analysis of worn surfaces provided information on the structure and chemistry of the tribofilms produced during the tests.

  6. Synthesis of Nano-Crystalline Materials in Open-Air Laboratory: A Case Study of Tobacco.

    Science.gov (United States)

    Satpati, Biswarup; Bhattacherjee, Ashis; Roy, Madhusudan

    2015-02-01

    The work deals with synthesis of nano-crystalline materials in open-air laboratory and in-depth investigation of the tobacco sample of one branded cigarette and its ash using high-resolution transmission electron microscopy and associated techniques. It exhibits the presence of nanocrystals and nanorods of various oxides in cigarette ash. The structure, shape, size and composition of these nanocrystals and nanorods are explored. The energy dispersive X-ray spectra from different regions of the tobacco sample and its ash using high-angle annular dark field scanning/transmission electron microscopy mode are utilized to obtain elemental composition and their relative abundances. For a detailed distribution of different elements in the nanorods, elemental mapping using energy-filtered transmission electron microscopy is also presented. The results highlight the conversion of amorphous constituents of tobacco to nanomaterials on combustion at low temperatures, thus mixing up in the atmosphere.

  7. Tailored Optical Polarization in Nano-Structured Metamaterials

    CERN Document Server

    Mendoza, Bernardo S

    2016-01-01

    A very efficient method for the calculation of the effective optical response of nano-structured composite systems allows the design of metamaterials tailored for specific optical polarization properties. We use our method to design 2D periodic arrays of sub-wavelength dielectric inclusions within nanometric supported metallic thin films which behave as either an almost perfect linearly dichroic system, as a controllable source of circular polarized light, as a system with a large circular dichroism, or as a circular polarizer. All of these systems may be tuned over a wide energy range.

  8. Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization

    Science.gov (United States)

    2015-08-24

    Skofronick and Martin 1995). 6 | P a g e Bockmon et al. showed that when the size of the reactants is reduced from micron to nano scale, reaction... Martin . "Oxidation behavior of aluminum nanopawders." Journal of Vacuum Science and Technology 13, no. 3 (1995): 1178-1183. B. Dickiki, S. Dean, M...Propulsion and Power 27 (2011): 1079-1087. D. Weibel, A. Michels, A. Feil , L. Amaral, S. Teixeria, F. Horowitz. "Adjustable hydrophobicity of Al

  9. Developments in Nano-Satellite Structural Subsystem Design at NASA-GSFC

    Science.gov (United States)

    Rossoni, Peter; Panetta, Peter V.

    1999-01-01

    The NASA-GSFC Nano-satellite Technology Development Program will enable flying constellations of tens to hundreds of nano-satellites for future NASA Space and Earth Science missions. Advanced technology components must be developed to make these future spacecraft compact, lightweight, low-power, low-cost, and survivable to a radiation environment over a two-year mission lifetime. This paper describes the efforts underway to develop lightweight, low cost, and multi-functional structures, serviceable designs, and robust mechanisms. As designs shrink, the integration of various subsystems becomes a vital necessity. This paper also addresses structurally integrated electrical power, attitude control, and thermal systems. These innovations bring associated fabrication, integration, and test challenges. Candidate structural materials and processes are examined and the merits of each are discussed. Design and fabrication processes include flat stock composite construction, cast aluminum-beryllium alloy, and an injection molded fiber-reinforced plastic. A viable constellation deployment scenario is described as well as a Phase-A Nano-satellite Pathfinder study.

  10. Universal wetting transition of an evaporating water droplet on hydrophobic micro- and nano-structures.

    Science.gov (United States)

    Bussonnière, Adrien; Bigdeli, Masoud B; Chueh, Di-Yen; Liu, Qingxia; Chen, Peilin; Tsai, Peichun Amy

    2017-02-07

    Water-repellent, rough surfaces have a remarkable and beneficial wetting property: when a water droplet comes in contact with a small fraction of the solid, both liquid-solid adhesion and hydrodynamic drag are reduced. As a prominent example from nature, the lotus leaf-comprised of a wax-like material with micro- and nano-scaled roughness-has recently inspired numerous syntheses of superhydrophobic substrates. Due to the diverse applications of superhydrophobicity, much research has been devoted to the fabrication and investigations of hydrophobic micro-structures using established micro-fabrication techniques. However, wetting transitions remain relatively little explored. During evaporation, a water droplet undergoes a wetting transition from a (low-frictional) partial to (adhesive) complete contact with the solid, destroying the superhydrophobicity and the self-cleaning properties of the slippery surface. Here, we experimentally examine the wetting transition of a drying droplet on hydrophobic nano-structures, a previously unexplored regime. In addition, using a theoretical analysis we found a universal criterion of this wetting transition that is characterized by a critical contact angle. Different from previous results showing different critical droplet sizes, our results show a universal, geometrically-dependent, critical contact angle, which agrees well with various data for both hydrophobic micro- and nano-structures.

  11. High power nano-LiMn2O4 cathode materials with high-rate pulse discharge capability for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Chen Ying-Chao; Xie Kai; Pan Yi; Zheng Chun-Man; Wang Hua-Lin

    2011-01-01

    Nano-LiMn2O4 cathode materials with nano-sized particles are synthesized via a citric acid assisted sol-gel route. The structure, the morphology and the electrochemical properties of the nano-LiMn2O4 are investigated. Compared with the micro-sized LiMn2O4, the nano-LiMn2O4 possesses a high initial capacity (120 mAh/g) at a discharge rate of 0.2 C (29.6 mA/g). The nano-LiMn2O4 also has a good high-rate discharge capability, retaining 91% of its capacity at a discharge rate of 10 C and 73% at a discharge rate of 40 C. In particular, the nano-LiMn2O4 shows an excellent high-rate pulse discharge capability. The cut-off voltage at the end of 50-ms pulse discharge with a discharge rate of 80 C is above 3.40 V, and the voltage returns to over 4.10 V after the pulse discharge. These results show that the prepared nano-LiMn2O4 could be a potential cathode material for the power sources with the capability to deliver very high-rate pulse currents.

  12. Structure and Properties of poly (para phynelyne benzobisoxazole) (PBO) /single wall carbon nano tube composite fibers

    Science.gov (United States)

    Kumar, Satish; Zhang, Xiefei; Bhattacharyya, Arup R.; Min, Byung G.; Dang, T. D.; Arnold, F. E.; Vaia, Richard A.; Ramesh, S.; Willis, P. A.; Hauge, R. H.; Smalley, R. E.

    2002-03-01

    The liquid crystalline compositions are prepared by the in-situ polycondensation of diamines and diacid monomers in the presence of single wall carbon nano tubes (SWNT). Processing of the new compositions into fibers provide hybrid materials with improved mechanical properties. The in-situ polymerizations were carried out in polyphosphoric acid (PPA). Carbon nano tubes as high as 10 wt.polymer weight have been utilized. Fiber spinning has been carried out using dry jet wet spinning using a piston driven spinning system and the fiber coagulated in water and subsequently vacuum dried and heat treated in nitrogen at 400oC. Structure and properties of these fibers have been studied. Tensile strength of the composite fibers increased by about 50morphology of these fibers have been studied using X- ray diffraction and scanning electron microscopy.

  13. Vibrational nano-spectroscopic imaging correlating structure with intermolecular coupling and dynamics.

    Science.gov (United States)

    Pollard, Benjamin; Muller, Eric A; Hinrichs, Karsten; Raschke, Markus B

    2014-04-11

    Molecular self-assembly, the function of biomembranes and the performance of organic solar cells rely on nanoscale molecular interactions. Understanding and control of such materials have been impeded by difficulties in imaging their properties with the desired nanometre spatial resolution, attomolar sensitivity and intermolecular spectroscopic specificity. Here we implement vibrational scattering-scanning near-field optical microscopy with high spectral precision to investigate the structure-function relationship in nano-phase separated block copolymers. A vibrational resonance is used as a sensitive reporter of the local chemical environment and we image, with few nanometre spatial resolution and 0.2 cm(-1) spectral precision, solvatochromic Stark shifts and line broadening correlated with molecular-scale morphologies. We discriminate local variations in electric fields between nano-domains with quantitative agreement with dielectric continuum models. This ability to directly resolve nanoscale morphology and associated intermolecular interactions can form a basis for the systematic control of functionality in multicomponent soft matter systems.

  14. Nano-Textured Fiber Coatings for Energy Absorbing Polymer Matrix Composite Materials

    Science.gov (United States)

    2004-12-01

    NANO-TEXTURED FIBER COATINGS FOR ENERGY ABSORBING POLYMER MATRIX COMPOSITE MATERIALS R. E. Jensen and S. H. McKnight Army Research Laboratory...Textured Fiber Coatings For Energy Absorbing Polymer Matrix Composite Materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  15. Synthesis and structural characterization of coaxial nano tubes intercalated of molybdenum disulfide with carbon; Sintesis y caracterizacion estructural de nanotubos coaxiales intercalados de disulfuro de molibdeno con carbono

    Energy Technology Data Exchange (ETDEWEB)

    Reza San German, C.M

    2005-07-01

    In this work the study of some fundamental aspects in the growth of unidimensional systems of coaxial nano tubes from the mold method is approached. This method is an inclusion technique of a precursor reagent into oxide nano porous alumina film (mold), and later applying some processes of synthesis it is gotten to obtain the wished material. The synthesized structures are identified later because they take place by means of the initial formation of nano tubes of MoS{sub 2}, enclosing to carbon nano tubes by the same method, with propylene flow which generates a graphitization process that 'copy' the mold through as it flows. Binary phase MoS{sub 2} + C nano tubes were synthesized by propylene pyrolysis inside MoS{sub 2} nano tubes prepared by template assisted technique. The large coaxial nano tubes constituted of graphite sheets inserted between the MoS{sub 2} layers forming the outer part, and coaxial multi wall carbon nano tubes (MWCNT) intercalated with MoS{sub 2} inside. High resolution electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), high angle annular dark field (HAADF), gatan image filter (GIF), nano beam electron diffraction patterns (NBEDP), along with molecular dynamics simulation and quantum mechanical calculations were used to characterize the samples. The one-dimensional structures exhibit diverse morphologies such as long straight and twisted nano tubes with several structural irregularities. The inter-planar spacing between MoS{sub 2} layers was found to increase from 6.3 to 7.4 A due to intercalation with carbon. Simulated HREM images revealed the presence of these twisted nano structures, with mechanical stretch into intercalate carbon between MoS{sub 2} layers. Our results open up the possibility of using MoS{sub 2} nano tubes as templates for the synthesis of new one- dimensional binary phase systems. (Author)

  16. The Properties of Nano TiO2-Geopolymer Composite as a Material for Functional Surface Application

    Directory of Open Access Journals (Sweden)

    Syamsidar D.

    2017-01-01

    Full Text Available The aim of this study is to examine the properties of Nano TiO2-geopolymer as a material for functional surface applications such as walls, floors, bench top, arts and decoration materials. Class-C fly ash and metakaolin were used as raw materials to produce geopolymers pastes (binder. Geopolymers were synthesized through alkali activation method cured at 50°C for 2 hours using molar oxide ratios of SiO2/Al2O3 = 3.0, Na2O/SiO2 = 0.2, and H2O/Na2O = 10. Nano TiO2 was added into geopolymers paste at different concentration namely 0 wt%, 5wt%, 10wt% and 15wt % relative the weight of fly ash or metakaolin. The measurements were commenced after the samples aged 7 days. The samples made from fly ash were immersed in 1 M H2SO4 solution for 3 days for acid resistance examination. The self-cleaning properties of the composites were observed by immersing the sample into red clays solution. The X-Ray Diffraction (XRD was performed to examine the structure and phase of the samples before and after acid resistance measurement. Scanning Electron Microscopy (SEM was performed to examine the surface morphology of the resulting composites. The measurements results showed that Nano TiO2–geopolymers composite can be applied as functionally surface materials.

  17. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano-structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-

  18. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-

  19. Building energetic material from novel salix leaf-like CuO and nano-Al through electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yan Jun; Li, Xueming [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

    2016-11-15

    In this study, an energetic material was prepared by depositing nano-Al on CuO arrays via electrophoretic deposition (EPD), which offers a feasible route for nano-Al integration. The morphology and structure of the CuO arrays and Al/CuO composites were characterized by scanning electron microscopy and X-ray diffraction. The CuO arrays were homogenously salix leaf-like structure with a width of ⁓150 to 200 nm. The energy density of Al/CuO composites was approximate to 1454.5 J/g by integrating the differential scanning calorimetry (DSC) plot and the combustion performance was recorded by a high-speed camera. Moreover, the combustion flames were violent and the whole reaction process only lasted 72.2 ms, indicating that the energy of the Al/CuO nanothermite can be released effectively.

  20. Nano-scale spinning detonation in condensed phase energetic materials

    Science.gov (United States)

    Zhakhovsky, Vasily; Budzevich, Mikalai; Landerville, Aaron; White, Carter; Oleynik, Ivan

    2013-06-01

    Single- and multi-headed spinning detonation waves are observed in molecular dynamics simulations of a condensed phase detonation of an energetic material (EM) confined in round tubes of different radii. The EM is modeled using a modified AB Reactive Empirical Bond Order potential. The thermochemistry and reactive equation of state are varied by adjusting the barrier height for the exothermic reaction AB +B --> A +BB. This allows us to study the evolution of the detonation-wave structure as a function of physico-chemical properties of the AB explosive. The detonation wave is found to exhibit a pulsating planar front in a tube of 8 nm radius, which later collapses due to the development of longitudinal perturbations. Upon increase of the tube's radius to 16 nm, the detonation wave structure is stabilized through the development of a single-headed spinning detonation. The spinning detonation displays a four-wave configuration, including incident, oblique, transverse, and contact shock waves. The contact shock generated by a contact discontinuity is observed for the first time in our MD simulations. A multi-headed turbulent-like detonation structure develops within tubes of larger radii, and exhibit features similar to those observed in gases.

  1. Synthesis of Carbon Nano Materials Originated from Waste Cooking Oil Using a Nebulized Spray Pyrolysis

    Science.gov (United States)

    Arie, A. A.; Hadisaputra, L.; Susanti, R. F.; Devianto, H.; Halim, M.; Enggar, R.; Lee, J. K.

    2017-07-01

    Synthesis of nanocarbon on snake fruit-peel’s activated carbon from waste cooking oil palm was conducted by a nebulized spray pyrolysis process (NSP) by varying the processing temperature from 650 to 750 °C. Ferrocene was used as a catalyst with constant concentration of 0.015 g/ml of carbon source. The structure of nanocarbon was studied by using scanning electron microscope (SEM),x-ray diffraction (XRD), surface area analyzer and Raman spectroscopy. SEM results showed that the structures of carbon products was in the the form of carbon nanopsheres (CNS). XRD and Raman analysis confirmed the CNS structure. The carbon producs were then tested as electrode’s materials for lithium ion capacitors (LIC) by cyclic voltammetry (CV) instruments. From the CV results the specific capacitance was estimated as 79.57 F / g at a scan rate of 0.1 mV / s and voltage range from 2.5 - 4 V. This study shows that the nano carbons synthesized from the waste cooking oil can be used as prospective electrode materials for LIC.

  2. Plasma-enhanced Deposition of Nano-Structured Carbon Films

    Institute of Scientific and Technical Information of China (English)

    Yang Qiaoqin (杨巧勤); Xiao Chijin (肖持进); A. Hirose

    2005-01-01

    By pre-treating substrate with different methods and patterning the catalyst, selective and patterned growth of diamond and graphitic nano-structured carbon films have been realized through DC Plasma-Enhanced Hot Filament Chemical Vapor Deposition (PE-HFCVD).Through two-step processing in an HFCVD reactor, novel nano-structured composite diamond films containing a nanocrystalline diamond layer on the top of a nanocone diamond layer have been synthesized. Well-aligned carbon nanotubes, diamond and graphitic carbon nanocones with controllable alignment orientations have been synthesized by using PE-HFCVD. The orientation of the nanostructures can be controlled by adjusting the working pressure. In a Microwave Plasma Enhanced Chemical Vapor Deposition (MW-PECVD) reactor, high-quality diamond films have been synthesized at low temperatures (310 ℃~550 ℃) without adding oxygen or halogen gas in a newly developed processing technique. In this process, carbon source originates from graphite etching, instead of hydrocarbon. The lowest growth temperature for the growth of nanocrystalline diamond films with a reasonable growth rate without addition of oxygen or halogen is 260 ℃.

  3. Structure-­mediated nano-­biophotonics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Villangca, Mark Jayson; Bañas, Andrew Rafael;

    2015-01-01

    The synergy between photonics, nanotechnology and biotechnology is spawning the emerging fields of nano-biotechnology and nano-biophotonics. Photonic innovations already hurdle the diffraction barrier for imaging with nanoscopic resolutions. However, scientific hypothesis testing demands tools...

  4. Applications of nano-composite materials for improving the performance of anode-supported electrolytes of SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Jin; Moon, Hwan; Park, Hae-Gu; Yoon, Dae Il; Hyun, Sang-Hoon [School of Advanced Materials Science and Engineering, Yonsei Univ., Seoul 120-749 (Korea)

    2010-01-15

    In order to improve the performance of the anode-supported electrolyte of solid oxide fuel cells (SOFCs), the anode electrode is modified by inserting an anode functional layer of nano-composite powders between a Ni-YSZ electrode and YSZ electrolyte. The NiO-YSZ nano-composite powders are fabricated by coating nano-sized Ni and YSZ particles on the YSZ core particle by the Pechini process. The reduction of the polarization resistance of a single cell that is applied to the anode functional layer is attributed to the increasing reaction of three-phase boundaries (TPBs) within the layer and the micro-structured uniformity in the electrode. Two methods were used, namely tape-casting/dip-coating and tape-casting/co-firing, for studying the performance. It can be concluded that the cell with an anode functional layer thickness (15-20 {mu}m) and a microstructure of NiO-YSZ nano-composite materials which was fabricated by the tape-casting/dip-coating method improved the output power (to 1.3 W cm{sup -2}) at 800 C using hydrogen as fuel and air as an oxidant. (author)

  5. Realization of High-temperature Superconductivity in Nano-carbon Materials and Its Application

    Science.gov (United States)

    2015-07-13

    hottest topics in condensed matter physics and also for application to zero- emission energy system. In particular, carbon-based superconductors have...nano- carbon materials and its application II 5a. CONTRACT NUMBER FA2386-13-1-4059 5b. GRANT NUMBER Grant 13RSZ067_134059 5c. PROGRAM ELEMENT...for AOARD Grant F A2386-13- l-4059 "Realization of high-temperature superconductivity in nano-carbon materials and its application " Date: 07/13

  6. Bio-Nano ECRIS: an electron cyclotron resonance ion source for new materials production.

    Science.gov (United States)

    Uchida, T; Minezaki, H; Tanaka, K; Muramatsu, M; Asaji, T; Kato, Y; Kitagawa, A; Biri, S; Yoshida, Y

    2010-02-01

    We developed an electron cyclotron resonance ion source (ECRIS) for new materials production on nanoscale. Our main target is the endohedral fullerenes, which have potential in medical care, biotechnology, and nanotechnology. In particular, iron-encapsulated fullerene can be applied as a contrast material for magnetic resonance imaging or microwave heat therapy. Thus, our new ECRIS is named the Bio-Nano ECRIS. In this article, the recent progress of the development of the Bio-Nano ECRIS is reported: (i) iron ion beam production using induction heating oven and (ii) optimization of singly charged C(60) ion beam production.

  7. Application progress of rare earth nano-materials

    Institute of Scientific and Technical Information of China (English)

    Xiao Zhe

    2009-01-01

    @@ Total rare earth consumption exceeded 72,600 tREO domestically in China in 2007, among which over 38,500 tREO were consumed in functional materials like permanent magnetic materials, fluorescent materials, hydrogen storage materials, catalytic materials and polishing powders,representing 53% of total RE consumption. Production and application of RE performance materials have been the main force promoting the development of China rare earth industry.

  8. Structure and Properties of Modified Unsaturated Polyester Resin by Nano-TiO2

    Institute of Scientific and Technical Information of China (English)

    Ying XU; Mingli LI; Yan GUO; Fengji LU

    2003-01-01

    The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the "reaction method", by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP long chain. The performance of the nano-TiO2/UPR was determined by such a new structure. The research results showed that the reactivity of nano-TiO2/UPR is higher than that of UPR. The impact strength and bending strength of nanoTiO2/UPR are greatly enhanced as compared with that of UPR. Thermal resistance and dielectric property of nano-TiO2/UPR are the same as that of UPR.

  9. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  10. Chip-package nano-structured copper and nickel interconnections with metallic and polymeric bonding interfaces

    Science.gov (United States)

    Aggarwal, Ankur

    developed to address the IC packaging requirements beyond the ITRS projections and to introduce innovative design and fabrication concepts that will further advance the performance of the chip, the package, and the system board. The nano-structured interconnect technology simultaneously packages all the ICs intact in wafer form with quantum jump in the number of interconnections with the lowest electrical parasitics. The intrinsic properties of nano materials also enable several orders of magnitude higher interconnect densities with the best mechanical properties for the highest reliability and yet provide higher current and heat transfer densities. Nano-structured interconnects provides the ability to assemble the packaged parts on the system board without the use of underfill materials and to enable advanced analog/digital testing, reliability testing, and burn-in at wafer level. This thesis investigates the electrical and mechanical performance of nanostructured interconnections through modeling and test vehicle fabrication. The analytical models evaluate the performance improvements over solder and compliant interconnections. Test vehicles with nano-interconnections were fabricated using low cost electro-deposition techniques and assembled with various bonding interfaces. Interconnections were fabricated at 200 micron pitch to compare with the existing solder joints and at 50 micron pitch to demonstrate fabrication processes at fine pitches. Experimental and modeling results show that the proposed nano-interconnections could enhance the reliability and potentially meet all the system performance requirements for the emerging micro/nano-systems.

  11. Influence of active nano particle size and material composition on multiple quantum emitter enhancements: Their Enhancement and Jamming Effects

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Ziolkowski, Richard W.

    2014-01-01

    of a gain-impregnated silica nano-core covered with a nano-shell of a specific plasmonic material. Attention is devoted to the influence of the over-all size of these particles and their material composition on the obtained levels of active enhancement or jamming. Silver, gold and copper are employed...... levels are most notable when the nano-shell is gold....

  12. Development of construction materials using nano-silica and aggregates recycled from construction and demolition waste.

    Science.gov (United States)

    Mukharjee, Bibhuti Bhusan; Barai, Sudhirkumar V

    2015-06-01

    The present work addresses the development of novel construction materials utilising commercial grade nano-silica and recycled aggregates retrieved from construction and demolition waste. For this, experimental work has been carried out to examine the influence of nano-silica and recycled aggregates on compressive strength, modulus of elasticity, water absorption, density and volume of voids of concrete. Fully natural and recycled aggregate concrete mixes are designed by replacing cement with three levels (0.75%, 1.5% and 3%) of nano-silica. The results of the present investigation depict that improvement in early days compressive strength is achieved with the incorporation of nano-silica in addition to the restoration of reduction in compressive strength of recycled aggregate concrete mixes caused owing to the replacement of natural aggregates by recycled aggregates. Moreover, the increase in water absorption and volume of voids with a reduction of bulk density was detected with the incorporation of recycled aggregates in place of natural aggregates. However, enhancement in density and reduction in water absorption and volume of voids of recycled aggregate concrete resulted from the addition of nano-silica. In addition, the results of the study reveal that nano-silica has no significant effect on elastic modulus of concrete.

  13. Eu{sup 2+} doped TiO{sub 2} nano structures synthesized by HYSYCVD for thermoluminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Perez A, J. A. [Universidad de Sonora, Departamento de Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Leal C, A. L.; Melendrez A, R.; Barboza F, M., E-mail: alanix89@gmail.com [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico)

    2016-10-15

    Titania (TiO{sub 2}) has attracted interest owing his potential applications as dosimetry material given his excellent optical, electrical and thermal properties and the ability to shape his structure make TiO{sub 2} suitable for research and dosimetry applications. In this work, a systematic study to know the magnitude of processing parameters influence on thermoluminescent properties of undoped (TiO{sub 2}) and doped (TiO{sub 2}:Eu{sup 2+}) nano materials obtained by hybrid precursor systems chemical vapor deposition (HYSYCVD) technique is presented. Synthesis of one dimension nano structures of TiO{sub 2}:Eu{sup 2+} was carried out using K{sub 2}TiF{sub 6} and EuCl{sub 2} as dopant at 0.5, 1, 2.5 and 5 wt %. The nano structures samples were irradiated with β-ray in a doses range of 0.083-3000 Gy. All thermoluminescence (Tl) glow curves showed 3 broad Tl peaks around 373, 473 and 573 K, and a dosimetric linear behavior from 0.083 to 300 Gy. The Tl has a good reproducibility, with deviations of around 5%, making these TiO{sub 2}:Eu{sup 2+} nano materials suitable for dosimetric applications. (Author)

  14. Strength of Materials and Structures

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ All engineering structures designed according to modern principles have to be strong and sufficiently rigid. Scientists and engineers have long recognized the importance of the strength of materials and structures, and dedicated much their efforts to both fundamental and industrial research into the theory for vast engineering materials and various structures. A lot of engineers need to be familiar with the fundamental principles of strength in materials and structures in order to design structures to resist failures. This book is a very good one to provide them with these principles.

  15. Scalable synthesis and energy applications of defect engineeered nano materials

    Science.gov (United States)

    Karakaya, Mehmet

    Nanomaterials and nanotechnologies have attracted a great deal of attention in a few decades due to their novel physical properties such as, high aspect ratio, surface morphology, impurities, etc. which lead to unique chemical, optical and electronic properties. The awareness of importance of nanomaterials has motivated researchers to develop nanomaterial growth techniques to further control nanostructures properties such as, size, surface morphology, etc. that may alter their fundamental behavior. Carbon nanotubes (CNTs) are one of the most promising materials with their rigidity, strength, elasticity and electric conductivity for future applications. Despite their excellent properties explored by the abundant research works, there is big challenge to introduce them into the macroscopic world for practical applications. This thesis first gives a brief overview of the CNTs, it will then go on mechanical and oil absorption properties of macro-scale CNT assemblies, then following CNT energy storage applications and finally fundamental studies of defect introduced graphene systems. Chapter Two focuses on helically coiled carbon nanotube (HCNT) foams in compression. Similarly to other foams, HCNT foams exhibit preconditioning effects in response to cyclic loading; however, their fundamental deformation mechanisms are unique. Bulk HCNT foams exhibit super-compressibility and recover more than 90% of large compressive strains (up to 80%). When subjected to striker impacts, HCNT foams mitigate impact stresses more effectively compared to other CNT foams comprised of non-helical CNTs (~50% improvement). The unique mechanical properties we revealed demonstrate that the HCNT foams are ideally suited for applications in packaging, impact protection, and vibration mitigation. The third chapter describes a simple method for the scalable synthesis of three-dimensional, elastic, and recyclable multi-walled carbon nanotube (MWCNT) based light weight bucky-aerogels (BAGs) that are

  16. Poly(vinyl alcohol) physical hydrogels: noncryogenic stabilization allows nano- and microscale materials design.

    Science.gov (United States)

    Jensen, Bettina E B; Smith, Anton A A; Fejerskov, Betina; Postma, Almar; Senn, Philipp; Reimhult, Erik; Pla-Roca, Mateu; Isa, Lucio; Sutherland, Duncan S; Städler, Brigitte; Zelikin, Alexander N

    2011-08-16

    Physical hydrogels based on poly(vinyl alcohol), PVA, have an excellent safety profile and a successful history of biomedical applications. However, highly inhomogeneous and macroporous internal organization of these hydrogels as well as scant opportunities in bioconjugation with PVA have largely ruled out micro- and nanoscale control and precision in materials design and their use in (nano)biomedicine. To address these shortcomings, herein we report on the assembly of PVA physical hydrogels via "salting-out", a noncryogenic method. To facilitate sample visualization and analysis, we employ surface-adhered structured hydrogels created via microtransfer molding. The developed approach allows us to assemble physical hydrogels with dimensions across the length scales, from ∼100 nm to hundreds of micrometers and centimeter sized structures. We determine the effect of the PVA molecular weight, concentration, and "salting out" times on the hydrogel properties, i.e., stability in PBS, swelling, and Young's modulus using exemplary microstructures. We further report on RAFT-synthesized PVA and the functionalization of polymer terminal groups with RITC, a model fluorescent low molecular weight cargo. This conjugated PVA-RITC was then loaded into the PVA hydrogels and the cargo concentration was successfully varied across at least 3 orders of magnitude. The reported design of PVA physical hydrogels delivers methods of production of functionalized hydrogel materials toward diverse applications, specifically surface mediated drug delivery.

  17. Synthesis and structural characterization of nano-hydroxyapatite biomaterials prepared by microwave processing

    Science.gov (United States)

    Ramli, Rosmamuhamadani; Arawi, Ainaa Zafirah Omar; Talari, Mahesh Kumar; Mahat, Mohd Muzamir; Jais, Umi Sarah

    2012-07-01

    Synthetic hydroxyapatite, (HA, Ca10(PO4)6(OH)2), is an attractive and widely utilized bio-ceramic material for orthopedic and dental implants because of its close resemblance of native tooth and bone crystal structure. Synthetic HA exhibits excellent osteoconductive properties. Osteoconductivity means the ability to provide the appropriate scaffold or template for bone formation. Calcium phosphate biomaterials [(HA), tri-calcium phosphate (TCP) and biphasic calcium phosphate (HA/TCP)] with appropriate three-dimensional geometry are able to bind and concentrate endogenous bone morphogenetic proteins in circulation, and may become osteoinductive and can be effective carriers of bone cell seeds. This HA can be used in bio-implants as well as drug delivery application due to the unique properties of HA. Biomaterials synthesized from the natural species like mussel shells have additional benefits such as high purity, less expensive and high bio compatibility. In this project, HA-nanoparticles of different crystallite size were prepared by microwave synthesis of precursors. High purity CaO was extracted from the natural mussel shells for the synthesis of nano HA. Dried nano HA powders were analyzed using X-Ray Diffraction (XRD) technique for the determination of crystal structure and impurity content. Scanning Electron Microscopic (SEM) investigation was employed for the morphological investigation of nano HA powders. From the results obtained, it was concluded that by altering the irradiation time, nano HA powders of different crystallite sizes and morphologies could be produced. Crystallite sizes calculated from the XRD patterns are found to be in the range of 10-55 nm depending on the irradiation time.

  18. Preparation and structure characteristics of nano-Bi2O3 powders with mixed crystal structure

    Institute of Scientific and Technical Information of China (English)

    LI Wei

    2005-01-01

    The nano-Bi2 O3 powders were prepared by a chemical precipitation method with Bi(NO3)3, H NO3 and NaOH as reactants. The structural characteristics and morphology of nano-Bi2O3 powders were investigated by X-ray diffraction and transmission electron microscopy, respectively. The results show that under the optimum condition that 300 g/L Bi(NO3)3 reacts at 90 ℃ for 2 h, the Bi2O3 powders with 60 nm on the average and 99.5% in purity are obtained. The prepared nano-Bi2 O3 powders contain a mixed crystal structure of monoclinic and triclinic in stead of traditional structure of monoclinic α-Bi2 O3. And the mixed crystal structure is stable in air. The reason for the appearance of the mixed crystal structure may be that the ionic radius ratio of Bi3+ to O2- changes easily during the formation of nano-Bi2 O3 particles by a chemical precipitation method.

  19. Hierarchical periodic micro/nano-structures on nitinol and their influence on oriented endothelialization and anti-thrombosis.

    Science.gov (United States)

    Nozaki, Kosuke; Shinonaga, Togo; Ebe, Noriko; Horiuchi, Naohiro; Nakamura, Miho; Tsutsumi, Yusuke; Hanawa, Takao; Tsukamoto, Masahiro; Yamashita, Kimihiro; Nagai, Akiko

    2015-12-01

    The applications of hierarchical micro/nano-structures, which possess properties of two-scale roughness, have been studied in various fields. In this study, hierarchical periodic micro/nano-structures were fabricated on nitinol, an equiatomic Ni-Ti alloy, using a femtosecond laser for the surface modification of intravascular stents. By controlling the laser fluence, two types of surfaces were developed: periodic nano- and micro/nano-structures. Evaluation of water contact angles indicated that the nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. Endothelial cells aligned along the nano-structures on both surfaces, whereas platelets failed to adhere to the micro/nano-surface. Decorrelation between the responses of the two cell types and the results of water contact angle analysis were a result of the pinning effect. This is the first study to show the applicability of hierarchical periodic micro/nano-structures for surface modification of nitinol.

  20. Nano-Composites: Relationships Between Nano-Structure and Mechanical Properties: Phase II

    Science.gov (United States)

    2006-01-01

    a standard diglycidyl ether of bis-phenol A ( DGEBA ) with an epoxy equivalent weight (EEW) of 185 g/mol, ‘Bakelite EPR 164’ supplied by Bakelite AG...Duisberg, Germany. The nano-particles of silica (SiO2) were obtained at a concentration at 40wt.% in this DGEBA epoxy resin: ‘Nanopox F400’ from...the simple DGEBA epoxy with given amounts of the nano-SiO2 epoxy and CTBN- epoxy adduct, to give the required levels of added nano-SiO2 and CTBN

  1. Microleakage of conventional, resin-modified, and nano-ionomer glass ionomer cement as primary teeth filling material

    Directory of Open Access Journals (Sweden)

    Dita Madyarani

    2014-12-01

    Full Text Available Background: Glass ionomer cements are one of many dental materials that widely used in pediatric dentistry due to their advantage of fluoride release and chemical bond to tooth structure. Adherence of the filling material to the cavity walls is one of the most important characteristic that need to be examined its effect on microleakage. Purpose: This study was conducted to examine the microleakage of nano-ionomer glass ionomer cement compared with the conventional and resin-modified glass ionomer cements. Methods: Standard class V cavities sized 3 mm x 2 mm x 2 mm were made on a total of 21 extracted maxillary primary canine teeth and restored with the conventional, resin-modified, dan nano-ionomer glass ionomer cements. All the teeth were immersed in a 2% methylene blue dye for 4 hours. The depth of dye penetration was assessed using digital microscope after sectioning the teeth labio-palatally. The results were statistically analyzed using Kruskal-Wallis test. Results: All type of glass ionomer material showed microleakage. Conventional glass ionomer cement demonstrated the least microleakage with mean score 1.29. the resin-modified glass ionomer cements (mean score 1.57 and nano-ionomer glass ionomer cement (mean score 2.57. Conclusion: The conventional glassionomer, resin modified glassionomer, and nano-ionomer glassionomer showed micro leakage as filling material in primary teeth cavity. The micro leakage among three types was not significant difference. All three material were comparable in performance and can be used for filling material but still needs a coating material to fill the microleakage.Latar belakang: Semen ionomer kaca adalah salah satu dari banyak bahan gigi yang banyak digunakan dalam praktek kedokteran gigi anak karena bahan tersebut merilis fluoride dan berikatan kimia dengan struktur gigi. Perlekatan bahan tumpatan pada dinding kavitas adalah salah satu karakteristik paling penting yang perlu diteliti efeknya terhadap

  2. Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

    Institute of Scientific and Technical Information of China (English)

    王昱征; 薛向欣; 杨合

    2014-01-01

    Antibacterial activity of boron-doped TiO2 (B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2 (anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti-O-B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans (ATCC10231), Gram-negative Escherichia coli (ATCC25922) and Gram-positive Staphylococcus aureus (ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

  3. Impact of the Excitation Source and Plasmonic Material on Cylindrical Active Coated Nano-Particles

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Liu, Yan; Malureanu, Radu

    2011-01-01

    , as well as to their far-field radiation characteristics, in the presence of an electric or a magnetic line source. A constant frequency canonical gain model is used to account for the gain introduced in the dielectric part of the nano-particle, whereas three different plasmonic materials (silver, gold...

  4. Nano-spectroscopic imaging of intermolecular structure, coupling and dynamics

    CERN Document Server

    Pollard, Benjamin; Hinrichs, Karsten; Raschke, Markus B

    2013-01-01

    Molecular self-assembly, the function of biomembranes, and the performance of organic solar cells rely on molecular interactions on the nanoscale. The understanding and design of such intrinsic or engineered heterogeneous functional soft matter has long been impeded by a lack of spectroscopic tools with sufficient nanometer spatial resolution, attomolar sensitivity, and intermolecular spectroscopic specificity. We implement vibrational scattering-scanning near-field optical microscopy ($s$-SNOM) in a multi-spectral modality with unprecedented spectral precision to investigate the structure-function relationship in nano-phase separated block-copolymers. We use a vibrational resonance as a sensitive reporter of the local chemical environment and resolve, with few nanometer spatial resolution and 0.2 cm$^{-1}$ spectral precision, spectral Stark shifts and line broadening correlated with molecular-scale morphologies. By creating images of solvatochromic vibrational shifts we discriminate local variations in elect...

  5. Hierarchical periodic micro/nano-structures on nitinol and their influence on oriented endothelialization and anti-thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Nozaki, Kosuke [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Shinonaga, Togo [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Ebe, Noriko; Horiuchi, Naohiro; Nakamura, Miho; Tsutsumi, Yusuke; Hanawa, Takao [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Tsukamoto, Masahiro [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Yamashita, Kimihiro [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Nagai, Akiko, E-mail: nag-bcr@tmd.ac.jp [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan)

    2015-12-01

    The applications of hierarchical micro/nano-structures, which possess properties of two-scale roughness, have been studied in various fields. In this study, hierarchical periodic micro/nano-structures were fabricated on nitinol, an equiatomic Ni–Ti alloy, using a femtosecond laser for the surface modification of intravascular stents. By controlling the laser fluence, two types of surfaces were developed: periodic nano- and micro/nano-structures. Evaluation of water contact angles indicated that the nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. Endothelial cells aligned along the nano-structures on both surfaces, whereas platelets failed to adhere to the micro/nano-surface. Decorrelation between the responses of the two cell types and the results of water contact angle analysis were a result of the pinning effect. This is the first study to show the applicability of hierarchical periodic micro/nano-structures for surface modification of nitinol. - Highlights: • Hierarchical micro/nano-structures were created on nitinol using a femtosecond laser. • The nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. • Endothelial cells aligned along the nano-structures • Platelets failed to adhere to the micro/nano-surface.

  6. Processing and applications of carbon based nano-materials

    Science.gov (United States)

    Yu, Aiping

    Carbon-based nanomaterials, including single walled carbon nanotubes (SWNTs) and graphite nanoplatelets (GNPs, multi-layer graphene), possess exceptional electrical, thermal and mechanical properties coupled with high aspect ratio and high temperature stability. These unique properties have attracted increased attention during the past decade. These materials form the basis of the work presented here, which includes research targeting fabrication, processing and applications in new composites and devices. As-prepared SWNTs are typically contaminated with amorphous carbon as well as metal catalyst and graphitic nanoparticles. We have demonstrated an efficient approach for removing most of these impurities by the combination of nitric acid treatment and both low speed (2000 g) and high speed centrifugation (20,000 g). This approach gives rise to the highest-purified arc-discharge SWNTs which are almost free from impurities, and in addition are left in a low state of aggregation. The new purification process offers a convenient way to obtain different grade of SWNTs and allows the study of the effect purity on the thermal conductivity of SWNT epoxy composite. Purified functionalized SWNTs provide a significantly greater enhancement of the thermal conductivity, whereas AP-SWNTs allow the best electrical properties because of their ability to form efficient percolating network. We found that purified SWNTs provide ˜5 times greater enhancement of the thermal conductivity than the impure SWNT fraction demonstrating the significance of SWNTs quality for thermal management. The introduced GNPs have directed the thermal management project to a new avenue due to the significant improvement of the thermal conductivity of the composites in comparison with that of SWNTs. A novel process was demonstrated to achieve a 4-graphene layer structure referred to GNPs with a thickness of ˜2 nm. This material was embedded in an epoxy resin matrix and the measured thermal conductivity of

  7. Nano-Structures for Optics and Photonics: Optical Strategies for Enhancing

    CERN Document Server

    Collins, John; Silvestri, Luciano

    2015-01-01

    The contributions in this volume were presented at a NATO Advanced Study Institute held in Erice, Italy, 4-19 July 2013. Many aspects of important research into nanophotonics, plasmonics, semiconductor materials and devices, instrumentation for bio sensing to name just a few, are covered in depth in this volume.  The growing connection between optics and electronics, due to the increasing important role plaid by semiconductor materials and devices, find their expression in the term photonics, which also reflects the importance of the photon aspect of light in the description of the performance of several optical systems. Nano-structures have unique capabilities that allow the enhanced performance of processes of interest in optical and photonic devices. In particular these structures permit the nanoscale manipulation of photons, electrons and atoms; they represent a very hot topic of research and are relevant to many devices and applications. The various subjects bridge over the disciplines of physics, biolo...

  8. Environmental silicate nano-biocomposites

    CERN Document Server

    Pollet, Eric

    2012-01-01

    Environmental Silicate Nano-Biocomposites focuses on nano-biocomposites, which are obtained by the association of silicates such as bioclays with biopolymers. By highlighting recent developments and findings, green and biodegradable nano-composites from both renewable and biodegradable polymers are explored. This includes coverage of potential markets such as packaging, agricultures, leisure and the fast food industry. The knowledge and experience of more than twenty international experts in diverse fields, from chemical and biochemical engineering to applications, is brought together in four different sections covering: Biodegradable polymers and Silicates, Clay/Polyesters Nano-biocomposites, Clay/Agropolymers Nano-biocomposites, and Applications and biodegradation of Nano-biocomposites. By exploring the relationships between the biopolymer structures, the processes, and the final properties Environmental Silicate Nano-Biocomposites explains how to design nano-materials to develop new, valuable, environmenta...

  9. Thermally modulated nano-trampoline material as smart skin for gas molecular mass detection

    Science.gov (United States)

    Xia, Hua

    2012-06-01

    Conventional multi-component gas analysis is based either on laser spectroscopy, laser and photoacoustic absorption at specific wavelengths, or on gas chromatography by separating the components of a gas mixture primarily due to boiling point (or vapor pressure) differences. This paper will present a new gas molecular mass detection method based on thermally modulated nano-trampoline material as smart skin for gas molecular mass detection by fiber Bragg grating-based gas sensors. Such a nanomaterial and fiber Bragg grating integrated sensing device has been designed to be operated either at high-energy level (highly thermal strained status) or at low-energy level (low thermal strained status). Thermal energy absorption of gas molecular trigs the sensing device transition from high-thermal-energy status to low-thermal- energy status. Experiment has shown that thermal energy variation due to gas molecular thermal energy absorption is dependent upon the gas molecular mass, and can be detected by fiber Bragg resonant wavelength shift with a linear function from 17 kg/kmol to 32 kg/kmol and a sensitivity of 0.025 kg/kmol for a 5 micron-thick nano-trampoline structure and fiber Bragg grating integrated gas sensing device. The laboratory and field validation data have further demonstrated its fast response characteristics and reliability to be online gas analysis instrument for measuring effective gas molecular mass from single-component gas, binary-component gas mixture, and multi-gas mixture. The potential industrial applications include fouling and surge control for gas charge centrifugal compressor ethylene production, gas purity for hydrogen-cooled generator, gasification for syngas production, gasoline/diesel and natural gas fuel quality monitoring for consumer market.

  10. Tribological Properties of the Semi-metallic Friction Material with Nano-SiC

    Institute of Scientific and Technical Information of China (English)

    CHENDong; HUANGPing; ZHUWen-jian

    2004-01-01

    The tribological properties of the semi-metallic friction materials with nano-SiC were studied by the contrast experiments. The experimental result indicates that when the nano-SiC powder substitutes the generalSiC powder, the friction coefficient is not obviously improved. On the contrary, the wear rate increases a little.The friction surfaces and the mixed powder were examined by a scanning electron microscope and the experimental data were analysed. The main reason, which leads to the high wear, is found.

  11. Electromagnetic and thermal properties of three-dimensional printed multilayered nano-carbon/poly(lactic) acid structures

    Science.gov (United States)

    Paddubskaya, A.; Valynets, N.; Kuzhir, P.; Batrakov, K.; Maksimenko, S.; Kotsilkova, R.; Velichkova, H.; Petrova, I.; Biró, I.; Kertész, K.; Márk, G. I.; Horváth, Z. E.; Biró, L. P.

    2016-04-01

    A new type of light-weight material produced by 3D printing consisting of nano-carbon doped polymer layer followed by a dielectric polymer layer is proposed. We performed temperature dependent characterization and measured the electromagnetic (EM) response of the samples in the GHz and THz range. The temperature dependent structural characteristics, crystallization, and melting were observed to be strongly affected by the presence and the number of nano-carbon doped layers in the sandwich structure. The electromagnetic measurements show a great potential of such a type of periodic material for electromagnetic compatibility applications in microwave frequency range. Sandwich structures containing only two nano-carbon layers already become not transparent to the microwaves, giving an electromagnetic interference shielding efficiency at the level of 8-15 dB. A sandwich consisting of one nano-carbon doped and one polymer layer is opaque for THz radiation, because of 80% of absorption. These studies serve as a basis for design and realization of specific optimal geometries of meta-surface type with the 3D printing technique, in order to reach a high level of electromagnetic interference shielding performance for real world EM cloaking and EM ecology applications.

  12. Hypersonic Materials and Structures

    Science.gov (United States)

    Glass, David E.

    2016-01-01

    Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components.

  13. Nano-architecture and material designs for water splitting photoelectrodes.

    Science.gov (United States)

    Chen, Hao Ming; Chen, Chih Kai; Liu, Ru-Shi; Zhang, Lei; Zhang, Jiujun; Wilkinson, David P

    2012-09-07

    This review concerns the efficient conversion of sunlight into chemical fuels through the photoelectrochemical splitting of water, which has the potential to generate sustainable hydrogen fuel. In this review, we discuss various photoelectrode materials and relative design strategies with their associated fabrication for solar water splitting. Factors affecting photoelectrochemical performance of these materials and designs are also described. The most recent progress in the research and development of new materials as well as their corresponding photoelectrodes is also summarized in this review. Finally, the research strategies and future directions for water splitting are discussed with recommendations to facilitate the further exploration of new photoelectrode materials and their associated technologies.

  14. First Helical Structure in the Nano-world

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Although a commonplace structure in nature, the helix remains a mystery to scientific researchers. In biology,the structure is important as DNA is helical and so does the substructure of many proteins. Since its discovery more than 50 years ago, the double helix has offered an important approach to interpret and make use of bio-organic structures. Yet, it is seldom to see a helical structure formed by inorganic crystalstate materials.

  15. Book Review: Nano physics & Nano technology

    Directory of Open Access Journals (Sweden)

    Abdolkhaled Zaree

    2012-12-01

    Full Text Available During last decades, there are a lot of emphases on studying material behavior in atomic scale. In most scientific and engineering fields, one can see the effect of nanotechnology. The aim of nanoscience is to design and fabrication of new and applicable materials. Nowadays, Nano is a popular science which chemists, physicist, doctors, engineers, financial managers and environment's fans for creating a good life via nanoscience have a great cooperation with each others. Materials in nano scale such as nanotubes and nanowires have extraordinary properties which by optimization of these properties in nano scale and then develop these properties to macro scale, they've been challenging issues. For instance, materials in nano scale improve mechanical properties of polymers and metallic materials via nano particles and on the other hand by producing a thin film on surfaces improve surface hardening. Besides, nanotechnology is in hi-tech industries such as magnetic devices, surface coating, and biomaterial, material having sensors, polymers, gels, ceramics and intelligent membrane. Nano-carbon tubes are considered intelligent due to the fact that they couple electrochemical and elastic properties simultaneously, hence have greater activation energy density in comparison with other intelligent materials. Studying nanoscience is important because it causes the life to be better. Future Materials and structures will have a lot of outstanding properties. Intelligent machines can repair, recycle and reconstruct themselves. All these features are only possible in nano zone. Nano in engineering science can provide the possibility of making light missiles for exploring space. The reduced weight can be achieved by replacing traditional materials with hybrid nanocomposites.

  16. Upconversion luminescence of lanthanide-doped mixed CaMoO4-CaWO4 micro-/nano-materials.

    Science.gov (United States)

    Liu, Jing; Kaczmarek, Anna M; Billet, Jonas; Van Driessche, Isabel; Van Deun, Rik

    2016-08-14

    Uniform mixed CaMoO4-CaWO4 micro-/nano-materials have been successfully synthesised by a facile hydrothermal method. The morphology of these upconversion materials could be changed to different shapes and the size could also be decreased from the micro- to nano-scale by varying the type of surfactant used. It was observed that before heat treatment, the materials show relatively weak green light emission under excitation at 975 nm, whereas after heat treatment, the intensity of the upconversion luminescence increases dramatically while the intensity of the red component decreases relatively. By adjusting the molybdate/tungstate ratio, it was found that the samples with a higher molybdate content have stronger luminescence properties. XRD measurements have been done to investigate the structure of the mixed CaMoO4-CaWO4 upconversion materials. The effect of heat treatment at different temperatures on the emission spectra and XRD patterns has also been studied. TG-DTA was used to further confirm the most suitable temperature for heat treatment. The luminescence lifetimes and CIE coordinates for these samples were also determined. Additionally it was found that Gd(3+) co-doping could further increase the upconversion luminescence from these mixed CaMoO4-CaWO4 materials. Finally, monitoring the upconversion luminescence intensity as a function of laser pump power confirmed the upconversion process to be a two-photon absorption mechanism.

  17. Introduction to nano- and biotech-based materials for energy building efficiency

    OpenAIRE

    Torgal,Fernando Pacheco

    2016-01-01

    This chapter starts with an overview of the unsustainable energy consumption which is due to fast population growth and related greenhouse gas emissions. The case of energy efficiency building is introduced. A short analysis of the ambitious European nearly zero-energy building (NZEB) target is presented. Shortcomings of current materials concerning energy building efficiency are reviewed. Examples of promising nano- and biotech-based materials for energy building efficiency are briefly cover...

  18. Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

    Science.gov (United States)

    Almuslem, A. S.; Hanna, A. N.; Yapici, T.; Wehbe, N.; Diallo, E. M.; Kutbee, A. T.; Bahabry, R. R.; Hussain, M. M.

    2017-02-01

    In the recent past, with the advent of transient electronics for mostly implantable and secured electronic applications, the whole field effect transistor structure has been dissolved in a variety of chemicals. Here, we show simple water soluble nano-scale (sub-10 nm) germanium oxide (GeO2) as the dissolvable component to remove the functional structures of metal oxide semiconductor devices and then reuse the expensive germanium substrate again for functional device fabrication. This way, in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured and billions are disposed, which extend the harmful impact to our environment. Therefore, this is a key study to show a pragmatic approach for water soluble high performance electronics for environmentally friendly manufacturing and bioresorbable electronic applications.

  19. Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

    KAUST Repository

    Almuslem, A. S.

    2017-02-14

    In the recent past, with the advent of transient electronics for mostly implantable and secured electronic applications, the whole field effect transistor structure has been dissolved in a variety of chemicals. Here, we show simple water soluble nano-scale (sub-10 nm) germanium oxide (GeO) as the dissolvable component to remove the functional structures of metal oxide semiconductor devices and then reuse the expensive germanium substrate again for functional device fabrication. This way, in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured and billions are disposed, which extend the harmful impact to our environment. Therefore, this is a key study to show a pragmatic approach for water soluble high performance electronics for environmentally friendly manufacturing and bioresorbable electronic applications.

  20. Direct-Write Fabrication of Cellulose Nano-Structures via Focused Electron Beam Induced Nanosynthesis

    Science.gov (United States)

    Ganner, Thomas; Sattelkow, Jürgen; Rumpf, Bernhard; Eibinger, Manuel; Reishofer, David; Winkler, Robert; Nidetzky, Bernd; Spirk, Stefan; Plank, Harald

    2016-09-01

    In many areas of science and technology, patterned films and surfaces play a key role in engineering and development of advanced materials. Here, we introduce a new generic technique for the fabrication of polysaccharide nano-structures via focused electron beam induced conversion (FEBIC). For the proof of principle, organosoluble trimethylsilyl-cellulose (TMSC) thin films have been deposited by spin coating on SiO2 / Si and exposed to a nano-sized electron beam. It turns out that in the exposed areas an electron induced desilylation reaction takes place converting soluble TMSC to rather insoluble cellulose. After removal of the unexposed TMSC areas, structured cellulose patterns remain on the surface with FWHM line widths down to 70 nm. Systematic FEBIC parameter sweeps reveal a generally electron dose dependent behavior with three working regimes: incomplete conversion, ideal doses and over exposure. Direct (FT-IR) and indirect chemical analyses (enzymatic degradation) confirmed the cellulosic character of ideally converted areas. These investigations are complemented by a theoretical model which suggests a two-step reaction process by means of TMSC → cellulose and cellulose → non-cellulose material conversion in excellent agreement with experimental data. The extracted, individual reaction rates allowed the derivation of design rules for FEBIC parameters towards highest conversion efficiencies and highest lateral resolution.

  1. Nanostructured materials for hydrogen storage

    Science.gov (United States)

    Williamson, Andrew J.; Reboredo, Fernando A.

    2007-12-04

    A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

  2. SYNTHESIS OF NANO-ZnO PARTICLES FOR ALUMINUM METALLURGY AS INERT ANODE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    A.A.A. Saleh; Y. Fu; X.J. Zhai; Y.C. Zhai; M.M. Elomella; A.L. Zhang

    2004-01-01

    Nano-ZnO particle was produced by evaporating zinc powders in air at air flow-rate from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evaporated zinc vapor. X-ray diffraction shows the powders to be ZnO with lattice parameters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit time from the source to the collection area. The size of particles was ranged between 81 to 103nm. The average density resulted was 4.865g/cm3.Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as an inert anode material. A certain amount of both oxides were molded subsequently inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior of both oxides. When the sintering temperature increased up to 1300 ℃, the weight loss ratio rose to 5.01%-7.33% and up to 7.67%-10.18% for nano-ZnO and normal ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide were put for long time, the corrosive rate was found to be higher. It was found that the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use inert anode material.

  3. The Tribological Efficiency and the Mechanism of Action of Nano-Porous Composition Base Brake Lining Materials

    Science.gov (United States)

    Kutelia, E. R.; Gventsadze, D. I.; Eristavil, B. G.; Maisuradze, N. I.; Tsurtsumia, O. O.; Gventsadze, L. D.; Olofsson, U.; Wahlström, J.; Olander, L.

    2011-12-01

    Based on the comparative analysis of the experimental values determined for the tribological parameters for the three novel nano-porous composition base and two conventional brake lining materials while friction with the grey cast iron disc, it was shown the considerable high tribological efficiency of the novel nano-porous composition base lining materials in comparison with the conventional (from EU and USA market) brake lining materials. The explanation is given to the action mechanism of nano-porous composition base brake lining material and its tribological efficiency basing on the "triple phase" tribo-pair model.

  4. Synthesis of NiMnO3/C nano-composite electrode materials for electrochemical capacitors.

    Science.gov (United States)

    Kakvand, Pejman; Rahmanifar, Mohammad Safi; El-Kady, Maher F; Pendashteh, Afshin; Kiani, Mohammad Ali; Hashami, Masumeh; Najafi, Mohsen; Abbasi, Ali; Mousavi, Mir F; Kaner, Richard B

    2016-08-05

    Demand for high-performance energy storage materials has motivated research activities to develop nano-engineered composites that benefit from both high-rate and high-capacitance materials. Herein, NiMnO3 (NMO) nanoparticles have been synthesized through a facile co-precipitation method. As-prepared NMO samples are then employed for the synthesis of nano-composites with graphite (Gr) and reduced graphene oxide (RGO). Various samples, including pure NMO, NMO-graphite blend, as well as NMO/Gr and NMO/RGO nano-composites have been electrochemically investigated as active materials in supercapacitors. The NMO/RGO sample exhibited a high specific capacitance of 285 F g(-1) at a current density of 1 A g(-1), much higher than the other samples (237 F g(-1) for NMO/Gr, 170 F g(-1) for NMO-Gr and 70 F g(-1) for NMO). Moreover, the NMO/RGO nano-composite has shown excellent cycle stability with a 93.5% capacitance retention over 1000 cycles at 2 A g(-1) and still delivered around 87% of its initial capacitance after cycling for 4000 cycles. An NMO/RGO composite was assessed in practical applications by assembling NMO/RGO//NMO/RGO symmetric devices, exhibiting high specific energy (27.3 Wh kg(-1)), high specific power (7.5 kW kg(-1)), and good cycle stability over a broad working voltage of 1.5 V. All the obtained results demonstrate the promise of NMO/RGO nano-composite as a high-performance electrode material for supercapacitors.

  5. Metal Ions Removal Using Nano Oxide Pyrolox™ Material

    Science.gov (United States)

    Gładysz-Płaska, A.; Skwarek, E.; Budnyak, T. M.; Kołodyńska, D.

    2017-02-01

    The paper presents the use of Pyrolox™ containing manganese nano oxides used for the removal of Cu(II), Zn(II), Cd(II), and Pb(II) as well as U(VI) ions. Their concentrations were analyzed using the atomic absorption spectrometer SpectrAA 240 FS (Varian) as well as UV-vis method. For this purpose the static kinetic and equilibrium studies were carried out using the batch technique. The effect of solution pH, shaking time, initial metal ion concentrations, sorbent dosage, and temperature was investigated. The equilibrium data were analyzed using the sorption isotherm models proposed by Freundlich, Langmuir-Freundlich, Temkin, and Dubinin-Radushkevich. The kinetic results showed that the pseudo second order kinetic model was found to correlate the experimental data well. The results indicate that adsorption of Cu(II), Zn(II), Cd(II), and Pb(II) as well as U(VI) ions is strongly dependent on pH. The value of pH 4-7 was optimal adsorption. The time to reach the equilibrium was found to be 24 h, and after this time, the sorption percentage reached about 70%. Kinetics of Cu(II), Zn(II), Cd(II), Pb(II), and U(VI) adsorption on the adsorbent can be described by the pseudo second order rate equation. Nitrogen adsorption/desorption, infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) measurements for adsorbent characterization were performed. Characteristic points of the double layer determined for the studied Pyrolox™ sample in 0.001 mol/dm3 NaCl solution are pHPZC = 4 and pHIEP < 2.

  6. Raman Mapping for the Investigation of Nano-phased Materials

    Science.gov (United States)

    Gouadec, G.; Bellot-Gurlet, L.; Baron, D.; Colomban, Ph.

    Nanosized and nanophased materials exhibit special properties. First they offer a good compromise between the high density of chemical bonds by unit volume, needed for good mechanical properties and the homogeneity of amorphous materials that prevents crack initiation. Second, interfaces are in very high concentration and they have a strong influence on many electrical and redox properties. The analysis of nanophased, low crystallinity materials is not straigtforward. The recording of Raman spectra with a geometric resolution close to 0.5 \\upmu {text{ m}^3} and the deep understanding of the Raman signature allow to locate the different nanophases and to predict the properties of the material. Case studies are discussed: advanced polymer fibres, ceramic fibres and composites, textured piezoelectric ceramics and corroded (ancient) steel.

  7. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1997-01-01

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the p......The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete...

  8. Towards easily reproducible nano-structured SERS substrates

    DEFF Research Database (Denmark)

    Schmidt, Michael Stenbæk; Boisen, Anja; Hübner, Jörg

    2009-01-01

    , it is possible to narrowly control the parameters of the fabrication process to create silicon nano-pillars with controlled heights and spacing. The silicon nano-pillars are coated by thin films of silver and/or gold to create surfaces that greatly enhance the Raman effect. Surface enhanced Raman scattering...

  9. Optical materials based on molecular nano/microcrystals and ultrathin films

    Indian Academy of Sciences (India)

    A Patra; K Rajesh; T P Radhakrishnan

    2008-06-01

    Methodologies that we developed recently for the fabrication of molecular crystals with size variation in the nano to micro regime and polyelectrolyte templated mono and multilayer Langmuir–Blodgett films, are reviewed. The electronic absorption and strong fluorescence in the molecular nano/microcrystals are found to be size-dependent. Crystal structure and computational investigations provide a unified model to explain these observations. Role of polyelectrolyte templating in achieving stable and enhanced optical second harmonic generation response from LB films based on a hemicyanine amphiphile is highlighted.

  10. Bioinspired synthesis of hierarchically micro/nano-structured CuI tetrahedron and its potential application as adsorbent for Cd(II) with high removal capacity.

    Science.gov (United States)

    Gao, Shuyan; Yang, Jianmao; Li, Zhengdao; Jia, Xiaoxia; Chen, Yanli

    2012-04-15

    An environment friendly bioinspired strategy for synthesizing hierarchically micro/nano-structured CuI tetrahedron has been developed by combining the stabilization and the reduction performances of l-tryptophan together. A possible growth mechanism of such hierarchical tetrahedron is tentatively proposed. Remarkably, such CuI tetrahedron is found to possess high removal capacity for poisonous Cd(II) ions, 136.3mg/g, and ideal reusability. This is ascribed to the hierarchical micro/nano-structure and chemical adsorption mechanism, which shows great advantages over the traditional nano-scaled adsorbents. These interesting results stand out the promising applications of such hierarchically micro/nano-structured materials in environment. It is also a good example for the organic combination of green chemistry and nanotechnologies for the treatment of contaminated water.

  11. Optimal lattice-structured materials

    Science.gov (United States)

    Messner, Mark C.

    2016-11-01

    This work describes a method for optimizing the mesostructure of lattice-structured materials. These materials are periodic arrays of slender members resembling efficient, lightweight macroscale structures like bridges and frame buildings. Current additive manufacturing technologies can assemble lattice structures with length scales ranging from nanometers to millimeters. Previous work demonstrates that lattice materials have excellent stiffness- and strength-to-weight scaling, outperforming natural materials. However, there are currently no methods for producing optimal mesostructures that consider the full space of possible 3D lattice topologies. The inverse homogenization approach for optimizing the periodic structure of lattice materials requires a parameterized, homogenized material model describing the response of an arbitrary structure. This work develops such a model, starting with a method for describing the long-wavelength, macroscale deformation of an arbitrary lattice. The work combines the homogenized model with a parameterized description of the total design space to generate a parameterized model. Finally, the work describes an optimization method capable of producing optimal mesostructures. Several examples demonstrate the optimization method. One of these examples produces an elastically isotropic, maximally stiff structure, here called the isotruss, that arguably outperforms the anisotropic octet truss topology.

  12. Fabrication and mechanical evaluation of hydroxyapatite/oxide nano-composite materials.

    Science.gov (United States)

    Mohamed, Khaled R; Beherei, Hanan H; El Bassyouni, Gehan T; El Mahallawy, Nahed

    2013-10-01

    In the current study, the semiconducting metal oxides such as nano-ZnO and SiO2 powders were prepared via sol-gel technique and conducted on nano-hydroxyapatite (nHA) which was synthesized by chemical precipitation. The properties of fabricated nano-structured composites containing different ratios of HA, ZnO and SiO2 were examined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The effect of the variation of ratios between the three components on mechanical, microstructure and in-vitro properties was assessed to explore the possibility of enhancing these properties. The results proved that the mechanical properties exhibited an increment with increasing the ZnO content at the extent of HA. In-vitro study proved the formation and nucleation of apatite onto the surface of the fabricated composites after one week of immersion. It is concluded that HA composites containing SiO2 or SiO2/ZnO content had a suitable mechanical properties and ability to form apatite particles onto the composite surface. Based on bioactivity behavior, Si-HA is more bioactive than pure hydroxyapatite and nano-arrangements will provide an interface for better bone formation. Therefore, these nano-composites will be promising as bone substitutes especially in load bearing sites.

  13. Preparation of New Type Ni-P Micro/Nano Metal Material Based on Bacteria Shape

    Institute of Scientific and Technical Information of China (English)

    Xin Liang; Jianhua Liu; Songmei Li

    2009-01-01

    A new type of Ni-P alloy with rod-shape was prepared by electroless deposition method based on the shape of Nocadia, a kind of bacteria. The material was characterized by microbiological method, scanning elec-tron microscope, energy dispersion spectroscopy, transmission electron microscopy, fourier transform infrared spectroscopy, X-ray diffraction and vibrant sample magnetometer. It was found that Ni-P alloy deposited on Nocadia surface was amorphous when pH=8.0. The amount of Ni crystalline increased with pH of plating solution. Ni-P nano-particles deposited on active locations on the surface at the initial stage, and then ho-mogeneous Ni-P film formed with time. Nocadia remained their original rod shape after Ni-P nano-particles deposition. The new type metal material formed of Ni-P alloy with nano-particles was prepared. The mag-netization of the material prepared at pH=9.7 is greater than that prepared at pH=8.0. The magnetic loss of the material prepared at pH=9.7 is less than 0.1. The dielectric loss exceeds 0.3 when frequency is higher than 14 GHz, which is 1.5 at 18 GHz. The new type Ni-P metal material with Nocadia shape has dielectric loss property.

  14. Nano finish grinding of brittle materials using electrolytic in-process dressing (ELID) technique

    Indian Academy of Sciences (India)

    M Rahman; A Senthil Kumar; H S Lim; K Fatima

    2003-10-01

    Recent developments in grinding have opened up new avenues for finishing of hard and brittle materials with nano-surface finish, high tolerance and accuracy. Grinding with superabrasive wheels is an excellent way to produce ultraprecision surface finish. However, superabrasive diamond grits need higher bonding strength while grinding, which metal-bonded grinding wheels can offer. Truing and dressing of the wheels are major problems and they tend to glaze because of wheel loading. When grinding with superabrasive wheels, wheel loading can be avoided by dressing periodically to obtain continuous grinding. Electrolytic inprocess dressing (ELID) is the most suitable process for dressing metal-bonded grinding wheels during the grinding process. Nano-surface finish can be achieved only when chip removal is done at the atomic level. Recent developments of ductile mode machining of hard and brittle materials show that plastically deformed chip removal minimizes the subsurface damage of the workpiece. When chip deformation takes place in the ductile regime, a defect-free nano-surface is possible and it completely eliminates the polishing process. ELID is one of the processes used for atomic level metal removal and nano-surface finish. However, no proper and detailed studies have been carried out to clarify the fundamental characteristics for making this process a robust one. Consequently, an attempt has been made in this study to understand the fundamental characteristics of ELID grinding and their influence on surface finish.

  15. Structural and Optical Study of Chemical Bath Deposited Nano-Structured CdS Thin Films

    Science.gov (United States)

    Kumar, Suresh; Sharma, Dheeraj; Sharma, Pankaj; Sharma, Vineet; Barman, P. B.; Katyal, S. C.

    2011-12-01

    CdS is commonly used as window layer in polycrystalline solar cells. The paper presents a structural and optical study of CdS nano-structured thin films. High quality CdS thin films are grown on commercial glass by means of chemical bath deposition. It involves an alkaline solution of cadmium salt, a complexant, a chalcogen source and a non-ionic surfactant. The films have been prepared under various process parameters. The chemically deposited films are annealed to estimate its effect on the structural and optical properties of films. These films (as -deposited and annealed) have been characterized by means of XRD, SEM and UV-Visible spectrophotometer. XRD of films show the nano-crystalline nature. The energy gap of films is found to be of direct in nature.

  16. Emerging enantiomeric resolution materials with homochiral nano-fabrications

    Science.gov (United States)

    Wang, Huai-Song; Wei, Ji-Ping

    2015-07-01

    The major scientific challenge of enantiomeric separation is to develop simple, rapid, and sensitive routine analytical methods. Generally, enantio-resolution is still based on ``three-point interaction'' theory, which indicates that homochiral sites are needed for enantio-selective interaction. However, in recent years, advanced materials with precise homochiral fabrication at the nanoscale have been synthesized, and have shown great potential in development of high-throughput enantio-resolution methods. This tutorial review summarizes fabrication and applications of homochiral materials for enantio-selective recognition and separation. These materials, which include intrinsic and restructured chiral metal surfaces, plasmonic nanostructures, coordination polymers, organic polymer sensors, and molecularly imprinted polymers, have been applied as sensors or chiral stationary phases (CSPs) for efficient enantio-resolution.

  17. 7th ECCOMAS Thematic Conference on Smart Structures and Materials

    CERN Document Server

    Soares, Carlos

    2017-01-01

    This work was compiled with expanded and reviewed contributions from the 7th ECCOMAS Thematic Conference on Smart Structures and Materials, that was held from 3 to 6 June 2015 at Ponta Delgada, Azores, Portugal. The Conference provided a comprehensive forum for discussing the current state of the art in the field as well as generating inspiration for future ideas specifically on a multidisciplinary level. The scope of the Conference included topics related to the following areas: Fundamentals of smart materials and structures; Modeling/formulation and characterization of smart actuators, sensors and smart material systems; Trends and developments in diverse areas such as material science including composite materials, intelligent hydrogels, interfacial phenomena, phase boundaries and boundary layers of phase boundaries, control, micro- and nano-systems, electronics, etc. to be considered for smart systems; Comparative evaluation of different smart actuators and sensors; Analysis of structural concepts and des...

  18. MATERIALS WITH COMPLEX ELECTRONIC/ATOMIC STRUCTURES

    Energy Technology Data Exchange (ETDEWEB)

    D. M. PARKIN; L. CHEN; ET AL

    2000-09-01

    We explored both experimentally and theoretically the behavior of materials at stresses close to their theoretical strength. This involves the preparation of ultra fine scale structures by a variety of fabrication methods. In the past year work has concentrated on wire drawing of in situ composites such as Cu-Ag and Cu-Nb. Materials were also fabricated by melting alloys in glass and drawing them into filaments at high temperatures by a method known as Taylor wire technique. Cu-Ag microwires have been drawn by this technique to produce wires 10 {micro}m in diameter that consist of nanoscale grains of supersaturated solid solution. Organogels formed from novel organic gelators containing cholesterol tethered to squaraine dyes or trans-stilbene derivatives have been studied from several different perspectives. The two types of molecules are active toward several organic liquids, gelling in some cases at w/w percentages as low as 0.1. While relatively robust, acroscopically dry gels are formed in several cases, studies with a variety of probes indicate that much of the solvent may exist in domains that are essentially liquid-like in terms of their microenvironment. The gels have been imaged by atomic force microscopy and conventional and fluorescence microscopy, monitoring both the gelator fluorescence in the case of the stilbene-cholesterol gels and, the fluorescence of solutes dissolved in the solvent. Remarkably, our findings show that several of the gels are composed of similarly appearing fibrous structures visible at the nano-, micro-, and macroscale.

  19. From Block Copolymers to Nano-porous Materials

    DEFF Research Database (Denmark)

    Vigild, Martin Etchells; Ndoni, Sokol; Berg, Rolf Henrik

    2003-01-01

    Quantitative etching of the polydimethylsiloxane block in a series of polystyrene-polydimethylsiloxane (PS-PDMS) block copolymers is reported. Reacting the block copolymer with anhydrous hydrogen fluoride (HF) renders a nanoporous material with the remaining PS maintaining the original morphology...

  20. Structural Chemistry of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ This innovative research group on structural chemistry of functional materials was approved by NSFC in 2005.Headed by Prof.HONG Maochun, the team consists of several young research scientists from the CAS Fujian Institute of Research on the Structures of Matter, including Profs CAO Rong, LU Canzhong, GUO Guocong, CHEN Zhongning, MAO Jianggao Mao and CHEN Ling.

  1. Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case

    Science.gov (United States)

    Roebben, Gert; Kestens, Vikram; Varga, Zoltan; Charoud-Got, Jean; Ramaye, Yannic; Gollwitzer, Christian; Bartczak, Dorota; Geißler, Daniel; Noble, James; Mazoua, Stéphane; Meeus, Nele; Corbisier, Philippe; Palmai, Marcell; Mihály, Judith; Krumrey, Michael; Davies, Julie; Resch-Genger, Ute; Kumarswami, Neelam; Minelli, Caterina; Sikora, Aneta; Goenaga-Infante, Heidi

    2015-10-01

    This paper describes the production and characteristics of the nanoparticle test materials prepared for common use in the collaborative research project NanoChOp (Chemical and optical characterisation of nanomaterials in biological systems), in casu suspensions of silica nanoparticles and CdSe/CdS/ZnS quantum dots. This paper is the first to illustrate how to assess whether nanoparticle test materials meet the requirements of a 'reference material' (ISO Guide 30:2015) or rather those of the recently defined category of 'representative test material' (ISO TS 16195:2013). The NanoChOp test materials were investigated with small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and centrifugal liquid sedimentation (CLS) to establish whether they complied with the required monomodal particle size distribution. The presence of impurities, aggregates, agglomerates and viable microorganisms in the suspensions was investigated with DLS, CLS, optical and electron microscopy and via plating on nutrient agar. Suitability of surface functionalization was investigated with attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR) and via the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. Between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper shows that only based on the outcome of a detailed characterization process one can raise the status of a test material to representative test material or reference material, and how this status depends on its intended use.

  2. Structure-mechanical function relations at nano-scale in heat-affected human dental tissue.

    Science.gov (United States)

    Sui, Tan; Sandholzer, Michael A; Le Bourhis, Eric; Baimpas, Nikolaos; Landini, Gabriel; Korsunsky, Alexander M

    2014-04-01

    The knowledge of the mechanical properties of dental materials related to their hierarchical structure is essential for understanding and predicting the effect of microstructural alterations on the performance of dental tissues in the context of forensic and archaeological investigation as well as laser irradiation treatment of caries. So far, few studies have focused on the nano-scale structure-mechanical function relations of human teeth altered by chemical or thermal treatment. The response of dental tissues to thermal treatment is thought to be strongly affected by the mineral crystallite size, their spatial arrangement and preferred orientation. In this study, synchrotron-based small and wide angle X-ray scattering (SAXS/WAXS) techniques were used to investigate the micro-structural alterations (mean crystalline thickness, crystal perfection and degree of alignment) of heat-affected dentine and enamel in human dental teeth. Additionally, nanoindentation mapping was applied to detect the spatial and temperature-dependent nano-mechanical properties variation. The SAXS/WAXS results revealed that the mean crystalline thickness distribution in dentine was more uniform compared with that in enamel. Although in general the mean crystalline thickness increased both in dentine and enamel as the temperature increased, the local structural variations gradually reduced. Meanwhile, the hardness and reduced modulus in enamel decreased as the temperature increased, while for dentine, the tendency reversed at high temperature. The analysis of the correlation between the ultrastructure and mechanical properties coupled with the effect of temperature demonstrates the effect of mean thickness and orientation on the local variation of mechanical property. This structural-mechanical property alteration is likely to be due to changes of HAp crystallites, thus dentine and enamel exhibit different responses at different temperatures. Our results enable an improved understanding of

  3. Hydrothermal synthesis, structure and photocatalytic property of nano-TiO2-MnO2

    Institute of Scientific and Technical Information of China (English)

    DING; Shiwen(丁士文); WANG; Liyong(王利勇); ZHANG; Shaoyan(张绍岩); ZHOU; Qiuxiang(周秋香); DING; Yu(丁宇); LIU; Shujuan(刘淑娟); LIU; Yanchao(刘燕朝); KANG; Quanying(康全影)

    2003-01-01

    TiCl4 and MnSO4·H2O as raw materials are hydrolyzed stiochiometrically, following the intermediate of oxide hydrating reacts at 150℃, 0.5 Mpa in high-pressure reactor, after filtering, washing and drying, nanometric TiO2-MnO2 (Ti1-xMnxO2) is prepared. The effects of the reaction temperature and time on nanometric TiO2-MnO2 are also discussed. XRD shows that the product is TiO2-MnO2 with amorphous phase. After being sintered at above 780℃, it transfers into Ti1-xMnxO2 with a rutile structure. TEM shows that TiO2-MnO2 is the spherical particle. And the average diameter of the particles is 20 nm. The optical absorbance was determined by UV-265 spectrophotometer after dispersing the sample in the mixture of water and glycerol with the ratio of 1︰1 equably. It is found that the nano-material possesses the advantages of both nano-TiO2 and nano-MnO2, and it has strong absorption in the UV and visible region. Photodegradation of dyes in an aqueous solution is investigated using nanometricTiO2-MnO2 as a photocatalyst. The results show that after 60 min illumination, the decolorization rate of the acidic red B and acidic black 234 dye can be as high as 100%.

  4. 具有微纳复合结构的超疏水材料的制备%A Method to Prepare Superhydrophobic Materials with Hierarchical Micro-and Nano-Structures

    Institute of Scientific and Technical Information of China (English)

    郭永梅

    2015-01-01

    In recent years,the self-cleaning lotus leaf surface with hierarchical micro-and nanostructures was simulated using chemical or physical methods,which has become a research hostpot in the scientific community.Currently,there are many reports that the coating with hierarchical micro- and nanostructures was prepared using layer-by-layer assembly technology .It is time-consuming and complicated using the layer-by-layer assembly to prepared micro-membranes. Poly⁃electrolyte-polyelectrolyte complexes is a kind of aggregates which were formed by the polycation and polyanion compounds in solution. The driving force for polyelectrolyte-polyelectrolyte complexes formation is mainly electrostatic interactions ,hy⁃drogen bonding,coordination bond,guest-hostinteraction and synergetic interaction of the above force,etc. However,by far,less attention has been paid to use polyelectrolyte-polyelectrolyte complexes for layer-by-layer assembled multilayer fabrication.In this paper,we demonstrated that the polyelectrolyte-polyelectrolyte complexes PAH-PAA can be used as building blocks for layer-by-layer film fabrication.In the study,we found that the ratio of PAH to PAA,containing NaCl in PSS,thermally cross-linked and the no-drying process for layer-by-layer assembing PSS/PAH-PAA film fabrication are critical to rapidly fabricate superhydrophobic coatings with hierarchical micro-and nano-structures.%近年来,利用化学或物理的方法模拟荷叶的表面制备具有超疏水自清洁功能的微纳米复合结构的表面成为了科学界的一大研究热点。目前,利用层状组装技术制备具有微纳复合结构涂层的研究已有不少报道,然而层状组装技术在制备微米厚度的组装膜时非常耗时、制备过程也较为繁琐。以聚阳离子与聚阴离子在溶液中复合所形成的聚电解质复合物是一类基于静电、氢键、配位键、主客体相互作用等弱相互作用力而形成的聚集体。到目前为止,

  5. Virus-resembling nano-structures for near infrared fluorescence imaging of ovarian cancer HER2 receptors

    Science.gov (United States)

    Guerrero, Yadir A.; Bahmani, Baharak; Singh, Sheela P.; Vullev, Valentine I.; Kundra, Vikas; Anvari, Bahman

    2015-10-01

    Ovarian cancer remains the dominant cause of death due to malignancies of the female reproductive system. The capability to identify and remove all tumors during intraoperative procedures may ultimately reduce cancer recurrence, and lead to increased patient survival. The objective of this study is to investigate the effectiveness of an optical nano-structured system for targeted near infrared (NIR) imaging of ovarian cancer cells that over-express the human epidermal growth factor receptor 2 (HER2), an important biomarker associated with ovarian cancer. The nano-structured system is comprised of genome-depleted plant-infecting brome mosaic virus doped with NIR chromophore, indocyanine green, and functionalized at the surface by covalent attachment of monoclonal antibodies against the HER2 receptor. We use absorption and fluorescence spectroscopy, and dynamic light scattering to characterize the physical properties of the constructs. Using fluorescence imaging and flow cytometry, we demonstrate the effectiveness of these nano-structures for targeted NIR imaging of HER2 receptors in vitro. These functionalized nano-materials may provide a platform for NIR imaging of ovarian cancer.

  6. Recent patents on nano-enhanced materials for use in thermal energy storage (TES).

    Science.gov (United States)

    Cabeza, Luisa F; Ferrer, Gerard; Barreneche, Camila; Solé, Aran; Juliá, José Enrique

    2016-10-27

    Thermal energy storage (TES) systems using phase change materials (PCM) have been lately studied and are presented as one of the key solutions for the implementation of renewable energies. These systems take advantage of the latent heat of phase change of PCM during their melting/solidification processes to store or release heat depending on the needs and availability. Low thermal conductivity and latent heat are the main disadvantages of organic PCM, while corrosion, subcooling and thermal stability are the prime problems that inorganic PCM present. Nanotechnology can be used to overcome these drawbacks. Nano-enhanced PCM are obtained by the dispersion of nanoparticles in the base material and thermal properties such as thermal conductivity, viscosity and specific heat capacity, within others, can be enhanced. This paper presents a review of the patents regarding the obtaining of nano-enhanced materials for thermal energy storage (TES) in order to realize the development nanotechnologies have gained in the TES field. Patents regarding the synthesis methods to obtain nano-enhanced phase materials (NEPCM) and TES systems using NEPCM have been found and are presented in the paper. The few existing number of patents found is a clear indicator of the recent and thus low development nanotechnology has in the TES field so far. Nevertheless, the results obtained with the reviewed inventions already show the big potential that nanotechnology has in TES and denote a more than probable expansion of its use in the next years.

  7. Microwave irradiation on carbon black: Studies on the transformation of particles into nano-balls, nano-sticks and nano-onion like structures

    Science.gov (United States)

    Asokan, Vijayshankar; Venkatachalapathy, Vishnukanthan; Rajavel, Krishnamoorthy; Madsen, Dorte Nørgaard

    2016-12-01

    The solid-state transformation behavior of carbon black (CB) nanoparticles after irradiated with microwave energy was studied with and without influence of a metal catalyst. The CB sample was exposed to microwave radiation at power of 900 W from the oven and collected after 15 min and after 30 min and 45 min of irradiation. The samples were characterized using X-ray diffraction measurements, Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM) and thermogravimetric analysis. Characterization of the samples prepared without catalyst shows that microwave irradiation can transform CB nanoparticles into nano-balls and nano-stick like structures. While nanoballs of almost 300-500 nm diameter are visible in all the samples irrespective of microwave irradiation time, amorphous nano-stick like structure are present only in the sample collected after 30 min of microwave irradiation. CB irradiated together with a metal catalyst resulted in metal-encapsulated onion like structures with perfectly arranged graphene layers.

  8. Structural and optical properties of SnO{sub 2} nano films by spin-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Uysal, Bengü Özuğur, E-mail: bozugur@khas.edu.tr [Department of Energy Systems Engineering, Faculty of Engineering and Natural Sciences, Kadir Has University, Fatih, Istanbul, 34083 (Turkey); Arıer, Ümit Özlem Akkaya [Department of Physics, Faculty of Science and Letters, Mimar Sinan Fine Arts University, Beşiktaş, Istanbul 34349 (Turkey)

    2015-09-30

    Highlights: • SnO{sub 2} nano films were deposited on glass substrates by spin-coating method. • The structural and optical properties of SnO{sub 2} nano films were characterized. • The properties of SnO{sub 2} nano films were controlled by changing the SnCl{sub 2}:water ratio. • The activation energy and the band gap energy values of the films were determined. - Abstract: In this work, tin oxide (SnO{sub 2}) nano films were deposited on glass substrates with different water content using the sol–gel spin-coating method. SnO{sub 2} is a wide band gap semiconductor and it belongs to the class of transparent conductive oxides (TCO). The influence of the water content and the heat treatment temperature on the structural and optical properties of the thin films is characterized by X-ray diffractometer (XRD), scanning electron microscope, atomic force microscope, ultraviolet–visible spectrophotometer, and spectrophotometer. Crystallite size of nano SnO{sub 2} films was controlled by SnCl{sub 2}:water ratios. The most significant characteristic of nano materials is the increase in surface area as particle size decreases. XRD studies showed that the formation of tetragonal rutil phase was initiated at an annealing temperature close to 450 °C. The activation energy of nano SnO{sub 2} films for particle growth was calculated. The film has an activation energy of 42.8 kJ/mol, and the optical band gap of 3.02-3.35 eV is proportional to the SnCl{sub 2}:water ratio. The quantum size effect of nano particles was confirmed by the band gap energy shift, using ultraviolet–visible spectroscopy (UV–vis). SnO{sub 2} films have been considered as one of the most promising functional materials due to their wide direct band-gap, and excellent electrical and optical properties. Those properties of SnO{sub 2} films allow them to be used in electronic and optoelectronic devices like gas sensors, solar cells and lithium batteries etc.

  9. Investigation the Al–Fe–Cr–Ti nano composites structures with using XRD and AFM techniques

    Indian Academy of Sciences (India)

    Ali Bahari; Aref Sadeghi Nik; Mandana Roodbari; Nordin Mirnia

    2012-12-01

    The performance of multilayers has been widely investigated in metal/metal systems. Shrinking this system down to less than 10 nm dislocation blocking occurs. We should thus try to find a way to get a structure with less dislocation, and/or strain because low diffusivity ultra high vacuum chamber is the basic requirements for growing ultra thin films and nano scale materials. We used William–Hall relation based on Scherr equation in X-ray powder spectrum and drawn the stress–strain diagrams. It shows that Al–Fe–Cr–Ti composites have very low diffusivity and equilibrium solubility in Al (0.05 at.% Fe, >0.02 at.% Cr, and >0.3 at.% Ti). Al–Ti– Fe–Cr composite powders have also been prepared from sol–gel method starting from elemental powders at both ambient and elevated temperatures. The obtained results from XRD (X-ray Diffraction), AFM (Atomic Force Microscopy) and X-ray powder techniques indicate that nano-grains with 0.03 at %Cr can cause a reduction of leakage current through the SS chamber due to its amorphous structure.

  10. Calcium-phosphorus interactions at a nano-structured silicate surface.

    Science.gov (United States)

    Southam, Daniel C; Lewis, Trevor W; McFarlane, Andrew J; Borrmann, T; Johnston, Jim H

    2008-03-15

    Nano-structured calcium silicate (NCS), a highly porous material synthesized by controlled precipitation from geothermal fluids or sodium silicate solution, was developed as filler for use in paper manufacture. NCS has been shown to chemisorb orthophosphate from an aqueous solution probably obeying a Freundlich isotherm with high selectivity compared to other common environmental anions. Microanalysis of the products of chemisorption indicated there was significant change from the porous and nano-structured morphology of pristine NCS to fibrous and crystalline morphologies and non-porous detritus. X-ray diffraction analysis of the crystalline products showed it to be brushite, CaHPO42H2O, while the largely X-ray amorphous component was a mixture of calcium phosphates. A two-step mechanism was proposed for the chemisorption of phosphate from an aqueous solution by NCS. The first step, which was highly dependent on pH, was thought to be desorption of hydroxide ions from the NCS surface. This was kinetically favoured at lower initial pH, where the predominant form of phosphate present was H2PO(-)4, and led to decreased phosphorus uptake with increasing pH. The second step was thought to be a continuing chemisorption process after stabilization of the pH-value. The formation of brushite as the primary chemisorption product was found to be consistent with the proposed mechanism.

  11. Gaussian process based intelligent sampling for measuring nano-structure surfaces

    Science.gov (United States)

    Sun, L. J.; Ren, M. J.; Yin, Y. H.

    2016-09-01

    Nanotechnology is the science and engineering that manipulate matters at nano scale, which can be used to create many new materials and devices with a vast range of applications. As the nanotech product increasingly enters the commercial marketplace, nanometrology becomes a stringent and enabling technology for the manipulation and the quality control of the nanotechnology. However, many measuring instruments, for instance scanning probe microscopy, are limited to relatively small area of hundreds of micrometers with very low efficiency. Therefore some intelligent sampling strategies should be required to improve the scanning efficiency for measuring large area. This paper presents a Gaussian process based intelligent sampling method to address this problem. The method makes use of Gaussian process based Bayesian regression as a mathematical foundation to represent the surface geometry, and the posterior estimation of Gaussian process is computed by combining the prior probability distribution with the maximum likelihood function. Then each sampling point is adaptively selected by determining the position which is the most likely outside of the required tolerance zone among the candidates and then inserted to update the model iteratively. Both simulationson the nominal surface and manufactured surface have been conducted on nano-structure surfaces to verify the validity of the proposed method. The results imply that the proposed method significantly improves the measurement efficiency in measuring large area structured surfaces.

  12. Preparation of nano-sized hydrophilic aluminum fins coating materials for air conditioner

    Institute of Scientific and Technical Information of China (English)

    陈志明; 韩峰; 邵利

    2002-01-01

    Semicontinuous seeded emulsion copolymerization of acrylic acid, acrylamide and divinylbenzene was carried out at 80℃ with ammonium persulphate as the initiator and the polyether with comb configuration as the emulsifier to prepare approximately mono-dispersed nano-sized polymer particles with average diameter 90nm. The particles were used to combine with special polyether and de-ionized water was added to obtain nano-sized hydrophilic aluminum fins coating materials with solid content of 10%. The aluminum fins were coated with the materials to get the film showing self-assembly properties in some degree. The obtained hydrophilic fins have contact angles <5° with de-ionized water, minimum value 0°, after 4 cycles of wet and dry, contact angles <10° with de-ionized water.

  13. Differential autophagic responses to nano-sized materials.

    Science.gov (United States)

    Popp, Lauren; Segatori, Laura

    2015-12-01

    Autophagy is a complex catabolic pathway that mediates degradation of excess or unwanted cytoplasmic components through the lysosome. Activated by environmental factors, such as nutrient depletion, and intracellular stimuli, such as proteotoxic stress, it provides a highly dynamic quality control mechanism to recycle cellular components, eliminate aberrant materials, and, ultimately, maintain cellular homeostasis. A growing body of evidence suggests that autophagy is also activated upon internalization of engineered nanomaterials, most likely as a protective response to what is perceived as foreign or toxic. This review describes the mechanisms of autophagy activation in response to naturally occurring and engineered nanomaterials. We provide a comprehensive analysis of the impact of nanomaterials on the lysosome-autophagy system, with particular emphasis on cellular markers associated with biocompatible and bioadverse outcomes of autophagy activation, such as clearance of toxic material and autophagy-associated cell death. Potential applications of the next-generation nanomaterials designed to interface with cellular clearance mechanisms with precisely tunable properties are also discussed.

  14. Micro to Nano Scale Heat Conduction in Thermoelectric Materials

    Science.gov (United States)

    Maldovan, Martin

    2011-03-01

    Understanding and controlling heat transfer in solids is very important for increasing the efficiency of thermoelectric materials such as skutterudites, clatharates, superlattices, nanowires, and quantum dots. Although the mechanisms governing the thermal conductivity have been understood for years, a comprehensive theoretical method to calculate heat transfer, particularly at small scales, has not been available. This is mainly due to the complexity of anharmonic processes and phonon boundary scattering. We present a comprehensive theoretical model to calculate the thermal conductivity of thermoelectric materials at small length scales. The approach involves an exact calculation of the reduction of the phonon mean free paths due to boundary scattering and removes the need to solve the Boltzmann equation or to use adjustable terms as in the Callaway or Holland models. The analysis is based on the kinetic theory of transport processes and considers general expressions for dispersion relations, phonon mean free paths, and surface specularity parameters. The results show an excellent agreement with experiments for thin films, nanowires, and superlattices over a wide range of temperature and across multiple length scales. The theoretical approach can further be applied to a wide variety of problems involving the conduction of heat in micro/nanostructured thermoelectrics. This research was funded by the MIT Energy Initiative.

  15. Application of nano material for shielding power-frequency electromagnetic field

    Science.gov (United States)

    Li, Hualiang; Li, Li; Liu, Jiawen

    2015-07-01

    Only limited data are available on shielding electromagnetic field exposure in professional work. In our paper, we studied the electromagnetic field intensity in 500 kV substations, and explored influence of nanomaterial in high voltage laboratory simulation. Moreover, the results of nano-fabrics material for shielding power frequency electromagnetic field indicated that, both shielding fabrics can almost completely shield the electric field, but have weak shielding effectiveness against magnetic field.

  16. Special Issue: 14th International Symposium on Novel and Nano Materials

    Science.gov (United States)

    Kim, Woo-Byoung; Choa, Yong-Ho; Ahn, Hyo-Jin; Park, Il-Kyu

    2017-09-01

    This Special Issue of Applied Surface Science is intended to provide a collection of peer-reviewed contributions presented at the 14th International Symposium on Novel Nano Materials (ISNNM) held in Budapest, Hungary as one of the most beautiful cities in Europe from July 3 to July 8, 2016. All selected papers underwent the regular peer review process as set by the journal of Applied Surface Science and its publisher (Elsevier).

  17. A Unified Guide to Two Opposite Size Effects in Nano Elastic Materials

    Institute of Scientific and Technical Information of China (English)

    TANG Yi-Zhe; ZHENG Zhi-Jun; XIA Meng-Fen; BAI Yi-Long

    2009-01-01

    The microstructural variation near surface of nano elastic materials is analyzed based on different potentials.The atomic/molecular mechanism underlying the variation and its effect on elastic modulus are such that the nature of long-range interactions(attractive or repulsive)in the atomic/molecular potentials essentially governs the variation near surface(looser or tighter)and results in two opposite size effects(decreasing or increasing modulus)with decreasing size.

  18. Hydrodynamics of Macromolecular and Nano-Composite Materials

    Science.gov (United States)

    2005-08-05

    profiles in plane Couette and Poiseuille flows . The results are published in International Journal of Engineering Science and Physics of Fluids. Ref...H. Zhou, R. Zhou, "Scaling Structure scaling properties of confined nematic polymers in plane Couette cells: the weak flow limit," J. Rheology, 48(1... Couette and Poisuille flows ," Physics of Fluids, in press 2004. 18. M. G. Forest, R. Zhou, and Q. Wang, "Chaotic boundaries of nematic polymers in

  19. Novel nano materials for high performance logic and memory devices

    Science.gov (United States)

    Das, Saptarshi

    After decades of relentless progress, the silicon CMOS industry is approaching a stall in device performance for both logic and memory devices due to fundamental scaling limitations. In order to reinforce the accelerating pace, novel materials with unique properties are being proposed on an urgent basis. This list includes one dimensional nanotubes, quasi one dimensional nanowires, two dimensional atomistically thin layered materials like graphene, hexagonal boron nitride and the more recently the rich family of transition metal di-chalcogenides comprising of MoS2, WSe2, WS2 and many more for logic applications and organic and inorganic ferroelectrics, phase change materials and magnetic materials for memory applications. Only time will tell who will win, but exploring these novel materials allow us to revisit the fundamentals and strengthen our understanding which will ultimately be beneficial for high performance device design. While there has been growing interest in two-dimensional (2D) crystals other than graphene, evaluating their potential usefulness for electronic applications is still in its infancies due to the lack of a complete picture of their performance potential. The fact that the 2-D layered semiconducting di-chalcogenides need to be connected to the "outside" world in order to capitalize on their ultimate potential immediately emphasizes the importance of a thorough understanding of the contacts. This thesis demonstrate that through a proper understanding and design of source/drain contacts and the right choice of number of MoS2 layers the excellent intrinsic properties of this 2D material can be harvested. A comprehensive experimental study on the dependence of carrier mobility on the layer thickness of back gated multilayer MoS 2 field effect transistors is also provided. A resistor network model that comprises of Thomas-Fermi charge screening and interlayer coupling is used to explain the non-monotonic trend in the extracted field effect

  20. Synthesis and structural characterization of two-dimensional hierarchical covellite nano-structures

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Nirupam, E-mail: n.banerjee@utwente.nl [Materials Research Center, Indian Institute of Science, Bangalore 560012 (India); MESA Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Krupanidhi, S.B., E-mail: sbk@mrc.iisc.ernet.in [Materials Research Center, Indian Institute of Science, Bangalore 560012 (India)

    2012-12-14

    We report a simple, template free and low-temperature hydrothermal reaction pathway using Cu(II) - thiourea complex (prepared in situ from copper (II) chloride and thiourea as precursors) and citric acid as complexing agent to synthesize two-dimensional hierarchical nano-structures of covellite (CuS). The product was characterized with the help of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray spectroscopy (EDAX) and X-ray photoelectron spectroscopy (XPS). The concentration of citric acid in the hydrothermal precursor solution was seen to have a profound effect on the nanostructure of the product generated. Based on the outcoming product nano-architecture at different concentration of the ionic surfactant in the hydrothermal precursor solution a possible mechanism suited for reaction and further nucleation is also discussed. -- Highlights: Black-Right-Pointing-Pointer A novel reaction scheme is proposed for synthesizing covellite 2D nano-structures. Black-Right-Pointing-Pointer The nanostructures were thoroughly characterized, both structurally and chemically. Black-Right-Pointing-Pointer Through variation of synthetic parameters a general growth mechanism is proposed.

  1. In situ thermomechanical testing methods for micro/nano-scale materials.

    Science.gov (United States)

    Kang, Wonmo; Merrill, Marriner; Wheeler, Jeffrey M

    2017-02-23

    The advance of micro/nanotechnology in energy-harvesting, micropower, electronic devices, and transducers for automobile and aerospace applications has led to the need for accurate thermomechanical characterization of micro/nano-scale materials to ensure their reliability and performance. This persistent need has driven various efforts to develop innovative experimental techniques that overcome the critical challenges associated with precise mechanical and thermal control of micro/nano-scale specimens during material characterization. Here we review recent progress in the development of thermomechanical testing methods from miniaturized versions of conventional macroscopic test systems to the current state of the art of in situ uniaxial testing capabilities in electron microscopes utilizing either indentation-based microcompression or integrated microsystems. We discuss the major advantages/disadvantages of these methods with respect to specimen size, range of temperature control, ease of experimentation and resolution of the measurements. We also identify key challenges in each method. Finally, we summarize some of the important discoveries that have been made using in situ thermomechanical testing and the exciting research opportunities still to come in micro/nano-scale materials.

  2. The influence of nano-ceramic modifier on the structure and properties of polyolefin composites

    Science.gov (United States)

    Sudnik, L.; Dubkova, V.; Galinovsky, A.; Osipkov, A.

    2016-10-01

    It has been shown, that the nano-ceramic modifier boehmite, with specific surface area of up to 400 m2/g and dispersion degree of less than100 nm, is a structurally active filler of an ultra-high-molecular-weight polyethylene. The boehmite influences the polymer crystalline and supra-molecular structure, during crystallization of the polymer from the melt under uniaxial plastic deformation conditions. It results in the production of nano-composites with an improved complex of properties.

  3. Nano-structural and Nano-chemical analysis of dissimilar metal weld interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung Joon; Shin, Sang Hoon; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2012-05-15

    Dissimilar Metal Welds (DMWs) is generally applied to nuclear power plants for manufacturing and machining in structural components such as reactor pressure vessels and pressurizer nozzles. Alloy 152 is used frequently as filler metal in the manufacture of the DMW in light water reactors to join the low alloy steel pressure vessel nozzles and steam generator nozzles to nickel-based wrought alloy or austenitic stainless steel components. However, in recent years cracking phenomena has been observed in the welded joints. Concerns have been raised to the integrity and reliability in the joint transition zone due to the high susceptibility of the heat affected zone (HAZ) and the fusion boundary (FB) to stress corrosion cracking in combination with thermal aging. Since the material microstructure and chemical composition are key parameters affecting the stress corrosion cracking, improving the understanding of stress corrosion cracking at the FB region requires fundamental understanding of the unique microstructure of the FB region in DMW. Despite the potential degradation and consequent risk in the DMW, there is still a lack of the fundamental understanding of microstructure in the FB region, in particular the region containing unidentified band structures near the FB. The scale of the microstructure in modern metallic materials is becoming increasingly smaller. The 3-dimensional atom probe tomography (3D APT) has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multi-component metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. The 3D APT is a microscope that allows the reconstruction of 3D 'atom maps'. These reconstructions can be interrogated and interpreted to determine the nanoscale chemistry of the material. Therefore, the current study is aiming at the establishment of detail procedure

  4. Development of nano structured diamond windows for application in synchrotron beamlines

    Energy Technology Data Exchange (ETDEWEB)

    Campos, R.A.; Trava-Airoldi, V.J.; Corat, E.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Bagnato, O.R. [Laboratorio Nacional de Luz Sincroton (LNLS), Campinas, SP (Brazil); Moro, J.R. [Instituto Federal de Educacao, Ciencia e Tecnologia de Sao Paulo (IFSP), SP (Brazil)

    2011-07-01

    Full text. Synchrotron light sources are important tools in the scientific field. In essence, they are rather like enormous super-microscopes capable of studying biological, chemical and material samples at very high resolution, down to the atomic and molecular level, by using synchrotron light. The intense synchrotron light is electromagnetic radiation produced by high-energy electrons in a particle accelerator. The configuration of the beamlines uses windows of material transparent to radiation. Beryllium (Be) is the standard material. In general, these windows serve both, as filters to absorb the photons of low energy and, as insulating barrier between the storage ring and the environment. The justification for the use of beryllium windows at synchrotron beamlines is that elements with low atomic number - (4) transmit more electromagnetic radiation. Besides all the qualities, beryllium has some drawbacks such as deterioration of spatial coherence due to surface roughness and defects. Another problem observed is the appearance of Fresnel diffraction due to manufacturing defects of the windows. In this paper, we propose the use of windows made of nano structured diamond with average roughness of 20nm, without the need to polish, with maximum thickness of around 3 {mu}m. Diamond also has a low atomic number - (6). Another quality of nano structured diamond films is its mechanical properties. It needs only 5-6% of the thickness of beryllium to withstand the same pressure gradient. The film morphology was characterized with the help of Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM-FEG). Diamond's quality was determined by Raman Spectroscopy

  5. Spatio-temporal behaviour of atomic-scale tribo-ceramic films in adaptive surface engineered nano-materials.

    Science.gov (United States)

    Fox-Rabinovich, G; Kovalev, A; Veldhuis, S; Yamamoto, K; Endrino, J L; Gershman, I S; Rashkovskiy, A; Aguirre, M H; Wainstein, D L

    2015-03-05

    Atomic-scale, tribo-ceramic films associated with dissipative structures formation are discovered under extreme frictional conditions which trigger self-organization. For the first time, we present an actual image of meta-stable protective tribo-ceramics within thicknesses of a few atomic layers. A mullite and sapphire structure predominates in these phases. They act as thermal barriers with an amazing energy soaking/dissipating capacity. Less protective tribo-films cannot sustain in these severe conditions and rapidly wear out. Therefore, a functional hierarchy is established. The created tribo-films act in synergy, striving to better adapt themselves to external stimuli. Under a highly complex structure and non-equilibrium state, the upcoming generation of adaptive surface engineered nano-multilayer materials behaves like intelligent systems - capable of generating, with unprecedented efficiency, the necessary tribo-films to endure an increasingly severe environment.

  6. D. C. plasma-sprayed coatings of nano-structured alumina-titania-silica

    CERN Document Server

    Jiang Xian Liang

    2002-01-01

    nano-crystalline powders of omega(Al sub 2 O sub 3) = 95%, omega(TiO sub 2) = 3%, and omega(SiO sub 2) = 2%, were reprocessed into agglomerated particles for plasma spraying, by using consecutive steps of ball milling, slurry forming, spray drying, and heat treatment. D.C. plasma was used to spray the agglomerated nano-crystalline powders, and resultant coatings were deposited on the substrate of stainless steel. Scanning electron microscopy (SEM) was used to examine the morphology of the agglomerated powders and the cross section of the alumina-titania-silica coatings. Experimental results show that the agglomerated nano-crystalline particles are spherical, with a size from (10-90) mu m. The flow ability of the nano-crystalline powders is greatly improved after the reprocessing. The coatings deposited by the plasma spraying are mainly of nano-structure. Unlike conventional plasma-sprayed coatings, no laminar layer could be found in the nano-structured coatings. Although the nano-structured coatings have a lo...

  7. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those

  8. Polarization of modified titanium and titanium–zirconium creates nano-structures while hydride formation is modulated

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Matthias J.; Walter, Martin S. [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway); Institute of Medical and Polymer Engineering, Chair of Medical Engineering, Technische Universität München, Boltzmannstrasse 15, D-85748 Garching (Germany); Bucko, Miroslaw M. [Department of Ceramics and Refractory Materials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al Mickiewicza 30, 30-059 Krakow (Poland); Pamula, Elzbieta [Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al Mickiewicza 30, 30-059 Krakow (Poland); Lyngstadaas, S. Petter [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway); Haugen, Håvard J., E-mail: h.j.haugen@odont.uio.no [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway)

    2013-10-01

    The majority of titanium based bone-level dental implants available on the market today feature a sand-blasted and acid-etched (SBAE) surface that contains comparably high hydrogen levels. Cathodic polarization of titanium in acidic solutions is known to further increase titanium hydride on the surface. The aim of this study was to explore the effect of cathodic reduction on titanium (Ti) and titanium–zirconium (TiZr) with a SBAE surface in order to investigate the potential of such a process for further improving surfaces for bone anchored dental implants. Samples of both materials were cathodically polarized in acidic solution at different current densities and for different process times. Chemical analysis of the hydrogen levels by SIMS showed that cathodic reduction re-arranged the hydride already present on the surfaces from the etching process but could not significantly increase hydride levels. The hydrogen layer created by the preceding hot acid etching appeared to modulate further hydride creation. Analysis of the surface topography by SEM showed changes to the nano-topography of both materials after polarization. TiZr showed homogeneously distributed nano-spheres as they were already observed for TiZr SBAE at increased size of 80–100 nm on the whole surface. By contrast, polarization of Ti created nano-nodules and nano-spheres of 150–200 nm on the surface. These spheres were interconnected to form flower-like structures along the ridges and peaks of the surface. Moreover the flanks were covered by a rippled structure of isotropically distributed small-diameter (10–20 nm) nano-nodules.

  9. Molecular dynamics simulation of atomic-scale frictional behavior of corrugated nano-structured surfaces.

    Science.gov (United States)

    Kim, Hyun-Joon; Kim, Dae-Eun

    2012-07-01

    Surface morphology is one of the critical parameters that affect the frictional behavior of two contacting bodies in relative motion. It is important because the real contact area as well as the contact stiffness is dictated by the micro- and nano-scale geometry of the surface. In this regard, the frictional behavior may be controlled by varying the surface morphology through nano-structuring. In this study, molecular dynamics simulations were conducted to investigate the effects of contact area and structural stiffness of corrugated nano-structures on the fundamental frictional behavior at the atomic-scale. The nano-structured surface was modeled as an array of corrugated carbon atoms with a given periodicity. It was found that the friction coefficient of the nano-structured surface was lower than that of a smooth surface under specific contact conditions. The effect of applied load on the friction coefficient was dependent on the size of the corrugation. Furthermore, stiffness of the nano-structure was identified to be an important variable in dictating the frictional behavior.

  10. Nano-spatial parameters from 3D to 2D lattice dimensionality by organic variant in [ZnCl4]- [R]+ hybrid materials: Structure, architecture-lattice dimensionality, microscopy, optical Eg and PL correlations

    Science.gov (United States)

    Kumar, Ajit; Verma, Sanjay K.; Alvi, P. A.; Jasrotia, Dinesh

    2016-04-01

    The nanospatial morphological features of [ZnCl]- [C5H4NCH3]+ hybrid derivative depicts 28 nm granular size and 3D spreader shape packing pattern as analyzed by FESEM and single crystal XRD structural studies. The organic moiety connect the inorganic components through N-H+…Cl- hydrogen bond to form a hybrid composite, the replacement of organic derivatives from 2-methylpyridine to 2-Amino-5-choloropyridine results the increase in granular size from 28nm to 60nm and unit cell packing pattern from 3D-2D lattice dimensionality along ac plane. The change in optical energy direct band gap value from 3.01eV for [ZnCl]- [C5H4NCH3]+ (HM1) to 3.42eV for [ZnCl]- [C5H5ClN2]+ (HM2) indicates the role of organic moiety in optical properties of hybrid materials. The photoluminescence emission spectra is observed in the wavelength range of 370 to 600 nm with maximum peak intensity of 9.66a.u. at 438 nm for (HM1) and 370 to 600 nm with max peak intensity of 9.91 a.u. at 442 nm for (HM2), indicating that the emission spectra lies in visible range. PL excitation spectra depicts the maximum excitation intensity [9.8] at 245.5 nm for (HM1) and its value of 9.9 a.u. at 294 nm, specify the excitation spectra lies in UV range. Photoluminescence excitation spectra is observed in the wavelength range of 280 to 350 nm with maximum peak intensity of 9.4 a.u. at 285.5 nm and 9.9 a.u. at 294 and 297 nm, indicating excitation in the UV spectrum. Single crystal growth process and detailed physiochemical characterization such as XRD, FESEM image analysis photoluminescence property reveals the structure stability with non-covalent interactions, lattice dimensionality (3D-2D) correlations interweaving into the design of inorganic-organic hybrid materials.

  11. Controlling Light-Matter Interaction in Semiconductors with Hybrid Nano-Structures

    Science.gov (United States)

    Gehl, Michael R.

    Nano-structures, such as photonic crystal cavities and metallic antennas, allow one to focus and store optical energy into very small volumes, greatly increasing light-matter interactions. These structures produce resonances which are typically characterized by how well they confine energy both temporally (quality factor -- Q) and spatially (mode volume -- V). In order to observe non-linear effects, modified spontaneous emission (e.g. Purcell enhancement), or quantum effects (e.g. vacuum Rabi splitting), one needs to maximize the ratio of Q/V while also maximizing the coupling between the resonance and the active medium. In this dissertation I will discuss several projects related by the goal of controlling light-matter interactions using such nano-structures. In the first portion of this dissertation I will discuss the deterministic placement of self-assembled InAs quantum dots, which would allow one to precisely position an optically-active material, for maximum interaction, inside of a photonic crystal cavity. Additionally, I will discuss the use of atomic layer deposition to tune and improve both the resonance wavelength and quality factor of silicon based photonic crystal cavities. Moving from dielectric materials to metals allows one to achieve mode-volumes well below the diffraction limit. The quality factor of these resonators is severely limited by Ohmic loss in the metal; however, the small mode-volume still allows for greatly enhanced light-matter interaction. In the second portion of this dissertation I will investigate the coupling between an array of metallic resonators (antennas) and a nearby semiconductor quantum well. Using time-resolved pump-probe measurements I study the properties of the coupled system and compare the results to a model which allows one to quantitatively compare various antenna geometries.

  12. Preparation of nano-compounded polyolefin materials through in situ polymerization technique: status quo and future prospects

    Institute of Scientific and Technical Information of China (English)

    QIN YaWei; DONG JinYong

    2009-01-01

    Nano-compounding of polyolefins,an economical yet very effective route to high-performance poly-olefin materials,has considerable attention in recent years.Unlike most of the other polymers,polyolefins are chemically inert,which dictates that nano-compounding of polyolefins has to be con-ducted via in situ polymerization.In this review,a technological progress of the nano-compounding of polyolefins via in situ polymerization technique was summarized thoroughly,with emphasis laid on the current research status of polyolefin/montmorillonite (MMT) nanocomposites.A clear perspective for future researches on this specific family of materials was envisaged.

  13. Application of Carbon Based Nano-Materials to Aeronautics and Space Lubrication

    Science.gov (United States)

    Street, Kenneth W., Jr.; Miyoshi, Kazuhisa; Wal, Randy L. Vander

    2007-01-01

    The tribology program at NASA Glenn Research Center in Cleveland, Ohio, is investigating carbon based nano-particles for their potential in advanced concept lubrication products. Service conditions range from high temperature atmospheric to low temperature vacuum. Some of the lubricants and surface coatings of tribological significance that we have evaluated include neat nano-particles, both grown in-situ and as bulk material deposited on the substrate, and nano-particles dispersed in oils which are all highly substrate interactive. We discuss results of testing these systems in a spiral orbit tribometer (SOT) and a unidirectional pin-on-disc (PoD) tribometer. A nano-onions/Krytox mixture evaluated as a lubricant for angular contact bearings in air caused a marked lowering of the coefficient of friction (CoF) (0.04 to 0.05) for the mixture with an eight-fold improvement in lifetime over that of the Krytox alone. In vacuum, no effect was observed from the nano-onions. Multi-walled nanotubes (MWNT) and graphitized MWNT were tested under sliding friction in both air and vacuum. The MWNT which were grown in-situ oriented normal to the sliding surface exhibited low CoF (0.04) and long wear lives. Bulk MWNT also generate low CoF (0.01 to 0.04, vacuum; and 0.06, air) and long wear life (>1 million orbits, vacuum; and >3.5 million, air). Dispersed graphitized MWNT were superior to MWNT and both were superior to aligned MWNT indicating that orientation is not an issue for solid lubrication. Single-walled nanotubes (SWNT) were modified by cutting into shorter segments and by fluorination. All SWNTs exhibited low CoF in air, with good wear lives. The SWNT with slight fluorination yielded an ultra-low CoF of 0.002 although the best wear life was attributed to the nascent SWNT.

  14. Lighting up the Christmas tree: high-intensity laser interactions with a nano-structured target

    CERN Document Server

    Gonoskov, A; Ilderton, A; Mackenroth, F; Marklund, M

    2014-01-01

    We perform a numerical study of the interaction of a high-intensity laser pulse with a nano-structured target. In particular, we study a target where the nano-structuring increases the absorption rate as compared to the flat target case. The transport of electrons within the target, and in particular in the nano-structure, is analysed. It is shown that it is indeed possible, using a terawatt class laser, to light up a nano-scale Christmas tree. Due to the form of the tree we achieve very strong edge fields, in particular at the top where the star is located. Such edge fields, as here located at ion rich spots, makes strong acceleration gradients possible. It also results in a nice, warm glow suitable for the holiday season.

  15. Improving electronic structure methods to predict nano-optoelectronics and nano-catalyst functions.

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Ida Marie B.; Marzari, Nicola (Massachusetts Institute of Technology); Shelnutt, John Allen; Kulik, Heather J. (Massachusetts Institute of Technology); Medforth, Craig John (University of New Mexico, Albuquerque, NM); Leung, Kevin

    2009-10-01

    This report focuses on quantum chemistry and ab initio molecular dynamics (AIMD) calculations applied to elucidate the mechanism of the multi-step, 2-electron, electrochemical reduction of the green house gas molecule carbon dioxide (CO{sub 2}) to carbon monoxide (CO) in aqueous media. When combined with H{sub 2} gas to form synthesis ('syn') gas, CO becomes a key precursor to methane, methanol, and other useful hydrocarbon products. To elucidate the mechanism of this reaction, we apply computational electrochemistry which is a fledgling, important area of basic science critical to energy storage. This report highlights several approaches, including the calculation of redox potentials, the explicit depiction of liquid water environments using AIMD, and free energy methods. While costly, these pioneering calculations reveal the key role of hydration- and protonation-stabilization of reaction intermediates, and may inform the design of CO{sub 2}-capture materials as well as its electrochemical reduction. In the course of this work, we have also dealt with the challenges of identifying and applying electronic structure methods which are sufficiently accurate to deal with transition metal ion complex-based catalyst. Such electronic structure methods are also pertinent to the accurate modeling of actinide materials and therefore to nuclear energy research. Our multi-pronged effort towards achieving this titular goal of the LDRD is discussed.

  16. Synthesis of nano-carbon (nanotubes, nanofibres, graphene) materials

    Indian Academy of Sciences (India)

    Kalpana Awasthi; Rajesh Kumar; Himanshu Raghubanshi; Seema Awasthi; Ratnesh Pandey; Devinder Singh; T P Yadav; O N Srivastava

    2011-07-01

    In the present study, we report the synthesis of carbon nanotubes (CNTs) using a new natural precursor: castor oil. The CNTs were synthesized by spray pyrolysis of castor oil–ferrocene solution at 850°C under an Ar atmosphere. We also report the synthesis of carbon nitrogen (C–N) nanotubes using castor oil–ferrocene–ammonia precursor. The as-grown CNTs and C–N nanotubes were characterized through scanning and transmission electron microscopic techniques. Graphitic nanofibres (GNFs) were synthesized by thermal decomposition of acetylene (C2H2) gas using Ni catalyst at 600°C. As-grown GNFs reveal both planar and helical morphology. We have investigated the structural and electrical properties of multi-walled CNTs (MWNTs)–polymer (polyacrylamide (PAM)) composites. The MWNTs–PAM composites were prepared using as purified, with ball milling and functionalized MWNTs by solution cast technique and characterized through SEM. A comparative study has been made on the electrical property of these MWNTs–PAM composites with different MWNTs loadings. It is shown that the ball milling and functionalization of MWNTs improves the dispersion of MWNTs into the polymer matrix. Enhanced electrical conductivity was observed for the MWNTs–PAM composites. Graphene samples were prepared by thermal exfoliation of graphite oxide. XRD analysis confirms the formation of graphene.

  17. A nano-Si/FeSi2Ti hetero-structure with structural stability for highly reversible lithium storage

    Science.gov (United States)

    Jo, Mi Ru; Heo, Yoon-Uk; Lee, Yoon Cheol; Kang, Yong-Mook

    2013-12-01

    A nano-Si/FeSi2Ti hetero-structure has been synthesized for highly reversible Li-ion batteries by using a simple melt-spinning method. We demonstrate that this composite has a very peculiar core/shell structure in which the FeSi2Ti alloy plays various pivotal roles as a mechanically supporting backbone and as an electronic pathway for the active Si attached to its surface, and is responsible for the altered electrochemical reactions with relatively small volume expansion routes. The FeSi2Ti matrix significantly contributes to not only the stabilization of cyclic retention, but also the enhancement of conductivity, as well as a high rate capability unprecedented in research on Si-based anodes. This achievement demonstrates the potency of this novel hybrid design for electrode materials for energy storage.A nano-Si/FeSi2Ti hetero-structure has been synthesized for highly reversible Li-ion batteries by using a simple melt-spinning method. We demonstrate that this composite has a very peculiar core/shell structure in which the FeSi2Ti alloy plays various pivotal roles as a mechanically supporting backbone and as an electronic pathway for the active Si attached to its surface, and is responsible for the altered electrochemical reactions with relatively small volume expansion routes. The FeSi2Ti matrix significantly contributes to not only the stabilization of cyclic retention, but also the enhancement of conductivity, as well as a high rate capability unprecedented in research on Si-based anodes. This achievement demonstrates the potency of this novel hybrid design for electrode materials for energy storage. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr04954j

  18. Nano-sized carboxylates as anode materials for rechargeable lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Wu; Jie Ma; Yong-Sheng Hu; Hong Li; Liquan Chen

    2014-01-01

    Nano-sized carboxylates Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries. Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs. Li+/Li, potentially improving the safety of the batteries. In addition, good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.

  19. Adsorption of phenol from aqueous solution by a hierarchical micro-nano porous carbon material

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    A hierarchical micro-nano porous carbon material (MNC) was prepared using expanded graphite (EG), sucrose, and phosphoric acid as raw materials, followed by sucrose-phosphoric acid solution impregnation, solidification, carbonization and activation. Nitrogen adsorption and mercury porosimetry show that mixed nanopores and micropores coexist in MNC with a high specific surface area of 1978 m2·g-1 and a total pore volume of 0.99 cm3·g-1. In addition, the MNC is found to consist of EG and activated carbon with...

  20. Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing.

    Science.gov (United States)

    Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

    2014-02-07

    The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

  1. Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

    Science.gov (United States)

    Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

    2014-02-01

    The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

  2. Nano-light-emitting-diodes based on InGaN mesoscopic structures for energy saving optoelectronics

    Science.gov (United States)

    Mikulics, M.; Winden, A.; Marso, M.; Moonshiram, A.; Lüth, H.; Grützmacher, D.; Hardtdegen, H.

    2016-07-01

    Vertically integrated III-nitride based nano-LEDs (light emitting diodes) were designed and fabricated for operation in the telecommunication wavelength range in the (p-GaN/InGaN/n-GaN/sapphire) material system. The band edge luminescence energy of the nano-LEDs could be engineered by tuning the composition and size of the InGaN mesoscopic structures. Narrow band edge photoluminescence and electroluminescence were observed. Our mesoscopic InGaN structures (depending on diameter) feature a very low power consumption in the range between 2 nW and 30 nW. The suitability of the technological process for the long-term operation of LEDs is demonstrated by reliability measurements. The optical and electrical characterization presented show strong potential for future low energy consumption optoelectronics.

  3. Cadmium Chalcogenide Nano-Heteroplatelets: Creating Advanced Nanostructured Materials by Shell Growth, Substitution, and Attachment.

    Science.gov (United States)

    Kormilina, Tatiana K; Cherevkov, Sergei A; Fedorov, Anatoly V; Baranov, Alexander V

    2017-09-12

    The current direction in the evolution of 2D semiconductor nanocrystals involves the combination of metal and semiconductor components to form new nanoengineered materials called nano-heteroplatelets. This Review covers different heterostructure architectures that can be applied to cadmium chalcogenide nanoplatelets, including variously shaped shell, metal nanoparticle decoration, and doped and alloy systems. Here, for the first time a complete classification of nano-heteroplatelet types is provided with recommended notations and a systematization of the existing knowledge and experience concerning heterostructure formation techniques, addressing the morphology, optoelectronic and magnetic properties, and novel features of different heterostructures. This Review is also devoted to possible applications of these heterostructures and of one-component nanoplatelets in multiple fields, including light-emitting devices and biological imaging. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Characterization and modelling of the elastic properties of nano-structured W/Cu multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Castelnau, O. [LPMTM-CNRS, av. J.B. Clement, Universite Paris-Nord, 93430 Villetaneuse (France)], E-mail: olivier.castelnau@lpmtm.univ-paris13.fr; Geandier, G.; Renault, P.-O.; Goudeau, Ph.; Le Bourhis, E. [LMP, UMR 6630 CNRS, Universite de Poitiers, B. P. 30179, 86962 Futuroscope (France)

    2007-12-03

    Understanding the mechanical behavior of nano-structured thin films in relation to their microstructure, in particular to the grain size, is of utmost importance for the development of technological applications. Model nanometric W/Cu multilayers exhibiting different microstructures and supported by a (thin) polyimide substrate are elaborated. The films mechanical response is characterized experimentally by tensile tests carried out in-situ in an X-ray diffractometer installed at a synchrotron beam line. The orientation dependence of elastic strains and stresses is determined by an appropriate micromechanical model accounting for the material microstructure, and based on homogenization schemes. While a good agreement is globally found, the model better reproduces the experimental results of the W component than those of Cu, due probably to the elastic anisotropy of Cu grains.

  5. Preparation of biomimetic nano-structured films with multi-scale roughness

    Science.gov (United States)

    Shelemin, A.; Nikitin, D.; Choukourov, A.; Kylián, O.; Kousal, J.; Khalakhan, I.; Melnichuk, I.; Slavínská, D.; Biederman, H.

    2016-06-01

    Biomimetic nano-structured films are valuable materials in various applications. In this study we introduce a fully vacuum-based approach for fabrication of such films. The method combines deposition of nanoparticles (NPs) by gas aggregation source and deposition of overcoat thin film that fixes the nanoparticles on a surface. This leads to the formation of nanorough surfaces which, depending on the chemical nature of the overcoat, may range from superhydrophilic to superhydrophobic. In addition, it is shown that by proper adjustment of the amount of NPs it is possible to tailor adhesive force on superhydrophobic surfaces. Finally, the possibility to produce NPs in a wide range of their size (45-240 nm in this study) makes it possible to produce surfaces not only with single scale roughness, but also with bi-modal or even multi-modal character. Such surfaces were found to be superhydrophobic with negligible water contact angle hysteresis and hence truly slippery.

  6. Analysis of the Carbon Nano-Structures Formation in Liquid Arcing

    Institute of Scientific and Technical Information of China (English)

    XING Gang; JIA Shen-li; XING Jian; SHI Zong-qian

    2007-01-01

    Graphite electrodes were used for the direct current (DC) arc discharge in water.And high-resolution transmission electron microscopy (HRTEM) was used to investigate the products.Based on the experimental phenomena and nano-structure products,arc plasma characteristics in water were analyzed theoretically.Two growth regions and relevant growth modes were proposed to interpret the formation mechanisms of nano-struetures by are discharge in water.Furthermore,liquid nitrogen and cross magnetic field was applied to change the arcing state respectively,and new carbon nano-struetures were obtained.Their formation mechanisms were also analyzed correspondingly.

  7. Construction of Binary Cooperative Nano-scale Interfacial Materials with Special Wettability (Superhydrophobicity/Superhydrophilicity)

    Institute of Scientific and Technical Information of China (English)

    JIANG Lei; ZHAI Jin; SONG Yanlin; LI Yuliang; ZHU Daoben

    2007-01-01

    @@ This project was started by learning the biological surface structures with special wettabilities in nature at first, and selects some typical ones to reveal the mechanism about the special wettabilities on their surface. Via scrutinizing the micro-structure on the surface of a lotus leaf, the project's scientists discover that the coordinated role exerted by the leaf surface's micro-/nano- composite structure and the wax-like secretion is the key point that gives rise to the self-clearance of the leaf.

  8. Understanding supercapacitors based on nano-hybrid materials with interfacial conjugation

    Institute of Scientific and Technical Information of China (English)

    George Z. Chen

    2013-01-01

    The recent fast development of supercapacitors, also known scientifically as electrochemical capacitors, has benefited significantly from synthesis, characterisations and electrochemistry of nanoma-terials. Herein, the principle of supercapacitors is explained in terms of performance characteristics and charge storage mechanisms, i.e. double layer (or interfacial) capacitance and pseudo-capacitance. The semiconductor band model is applied to qualitatively account for the pseudo-capacitance in association with rectangular cyclic voltammograms (CVs) and linear galvanostatic charging and discharging plots (GCDs), aiming to differentiate supercapacitors from rechargeable batteries. The invalidity of using peak shaped CVs and non-linear GCDs for capacitance measurement is highlighted. A selective review is given to the nano-hybrid materials between carbon nanotubes and redox active materials such as electronically conducting polymers and transition metal oxides. A new concept,“interfacial conjugation”, is introduced to reflect the capacitance enhancement resulting from π-π stacking interactions at the interface between two materials with highly conjugated chemical bonds. The prospects of carbon nanotubes and graphenes for supercapacitor applications are briefly compared and discussed. Hopefully, this article can help readers to understand supercapacitors and nano-hybrid materials so that further developments in materials design and synthesis, and device engineering can be more efficient and objective.

  9. Fabrication of Anti-reflecting Si Nano-structures with Low Asp ect Ratio by Nano-sphere Litho-graphy Technique

    Institute of Scientific and Technical Information of China (English)

    Shenghua Sun; Peng Lu; Jun Xu; Ling Xu; Kunji Chen; Qimin Wang; Yuhua Zuo

    2013-01-01

    Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devices, such as Si-based solar cells and light emitting diodes. Here, we report the fabrication of periodically nano-patterned Si structures by using polystyrene nano-sphere lithography technique. By changing the diameter of nano-spheres and the dry etching parameters, such as etching time and etching power, the morphologies of formed Si nano-structures can be well controlled as revealed by atomic force microscopy. A good broadband antireflection property has been achieved for the formed periodically nano-patterned Si structures though they have the low aspect ratio (<0.53). The reflection can be significantly reduced compared with that of flat Si substrate in a wavelength range from 400 nm to 1200 nm. The weighted mean reflection under the AM1.5 solar spectrum irradiation can be as low as 3.92% and the corresponding optical absorption is significantly improved, which indicates that the present Si periodic nano-structures can be used in Si-based thin film solar cells.

  10. On hydrophilicity improvement of the porous anodic alumina film by hybrid nano/micro structuring

    Science.gov (United States)

    Wang, Weichao; Zhao, Wei; Wang, Kaige; Wang, Lei; Wang, Xuewen; Wang, Shuang; Zhang, Chen; Bai, Jintao

    2017-09-01

    In both, laboratory and industry, tremendous attention is paid to discover an effective technique to produce uniform, controllable and (super) hydrophilic surfaces over large areas that are useful in a wide range of applications. In this investigation, by combing porous anodic alumina (PAA) film with nano-structures and microarray of aluminum, the hydrophilicity of hybrid nano-micro structure has been significantly improved. It is found some factors can affect the hydrophilicity of film, such as the size and aspect ratio of microarray, the thickness of nano-PAA film etc. Comparing with pure nano-PAA films and microarray, the hybrid nano-micro structure can provide uniform surface with significantly better hydrophilicity. The improvement can be up to 84%. Also, this technique exhibits good stability and repeatability for industrial production. By optimizing the thickness of nano-PAA film and aspect ratio of micro-structures, super-hydrophilicity can be reached. This study has obvious prospect in the fields of chemical industry, biomedical engineering and lab-on-a-chip applications.

  11. On the shear strength of tungsten nano-structures with embedded helium

    Science.gov (United States)

    Smirnov, R. D.; Krasheninnikov, S. I.

    2013-08-01

    Modification of plastic properties of tungsten nano-structures under shear stress load due to embedded helium atoms is studied using molecular dynamics modelling. The modelling demonstrates that the yield strength of tungsten nano-structures reduces significantly with increasing embedded helium concentration. At high helium concentrations (>10 at%), the yield strength decreases to values characteristic to the pressure in helium nano-bubbles, which are formed in tungsten under such conditions and thought to be responsible for the formation of nano-fuzz on tungsten surfaces irradiated with helium plasma. It is also shown that tungsten plastic flow strongly facilitates coagulation of helium clusters to larger bubbles. The temperature dependencies of the yield strength are obtained.

  12. Fabrication of Micro/Nano Structures on Metals by Femtosecond Laser Micromachining

    Directory of Open Access Journals (Sweden)

    K. M. Tanvir Ahmmed

    2014-11-01

    Full Text Available Femtosecond laser micromachining has emerged in recent years as a new technique for micro/nano structure fabrication because of its applicability to virtually all kinds of materials in an easy one-step process that is scalable. In the past, much research on femtosecond laser micromachining was carried out to understand the complex ablation mechanism, whereas recent works are mostly concerned with the fabrication of surface structures because of their numerous possible applications. The state-of-the-art knowledge on the fabrication of these structures on metals with direct femtosecond laser micromachining is reviewed in this article. The effect of various parameters, such as fluence, number of pulses, laser beam polarization, wavelength, incident angle, scan velocity, number of scans, and environment, on the formation of different structures is discussed in detail wherever possible. Furthermore, a guideline for surface structures optimization is provided. The authors’ experimental work on laser-inscribed regular pattern fabrication is presented to give a complete picture of micromachining processes. Finally, possible applications of laser-machined surface structures in different fields are briefly reviewed.

  13. Radiation damage of structural materials

    CERN Document Server

    Koutsky, Jaroslav

    1994-01-01

    Maintaining the integrity of nuclear power plants is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for RPV and Zr-Nb alloys for fuel element cladding. The book is divided into 7 main chapters, with the exception of the opening one and the chapter providing a phenomenological background for the subject of radiation damage. Ch

  14. Synthesis of Carbon nano structures by plasma discharge; Sintesis de nanoestructuras de carbono por descarga de plasmaa

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez L, M.L

    2007-07-01

    Due to the great quantity of applications of the carbon nano structures (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, it has seen the necessity to generate new processes of synthesis of this materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither sludges. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arch discharge, in a gas mixture of He-CH{sub 4} with 34% at. Ni/10.32% at.Y like catalyst; at a frequency of 42 kHz and low power (300 W). This method benefits the amass of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the NEC type obtained and by X-ray diffraction analysis and Raman spectroscopy for determining the purity of the samples. The NFC is relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of plasma using the Swan band for determining the temperature. (Author)

  15. Manipulating the bioactivity of hydroxyapatite nano-rods structured networks: effects on mineral coating morphology and growth kinetic.

    Science.gov (United States)

    D'Elía, Noelia L; Gravina, A Noel; Ruso, Juan M; Laiuppa, Juan A; Santillán, Graciela E; Messina, Paula V

    2013-11-01

    Nano-hydroxyapatite particles have better bioactivity than the coarse crystals. So, they can be utilized for engineered tissue implants with improved efficiency over other materials. The development of materials with specific bioactive characteristics is still under investigation. The surface properties of four hydroxyapatite materials templated by different micelle-polymer structured network are studied. The synergistic interaction of each block copolymer in contact with CTAB rod-like micelles results in crystalline HAp nano-rods of 25-50nm length organized in hierarchical structures with different micro-rough characteristics. It was observed that the material in vitro bioactivity strongly depends on the surface structure while in a minor extent on their Ca/P ratio. So, MIII and MIV materials with Skewness parameter Rsk>2.62 favored the formation on their surfaces of net-like phase with a high growth kinetic constant; while MI and MII (Rsk≤2.62) induced the appearance of spherulitic-like structures and a growth rate 1.75 times inferior. Material biocompatibility was confirmed by interaction with rat calvarial osteoblasts. The different structures growth is attributed to a dissimilar matching of crystal planes in the material and the apatite layer formed. In specific synthesis conditions, a biocompatible material with a Ca/P ratio close to that for the trabecular bone and a morphology that are considered essential for bone-bonding was obtained. The creation of implantable devices with a specific bioactive characteristic may be useful to manipulate the attachment of cells on mineral coating directly affecting the stability and life of the implant. © 2013.

  16. Fabrication and analysis of nano-structured thermal spraying feeds

    Institute of Scientific and Technical Information of China (English)

    YE Xiong-lin; MA Shi-ning; LI Chang-qing

    2004-01-01

    A kind of thermal spray nanostructured Al2O3 and TiO2 feeds fabricating technology was investigated.Agglomerated nanogranules prepared by spray drying were heat treated in order to be dense, and there were two sintering technologies used, i.e. high temperature electric furnace sintering and high velocity flame sintering, respectively. The results indicate feeds phase components using high temperature electric furnace sintering at 1 200 ℃,1 300 ℃ and 1 400 ℃ do not change, and grain sizes of nano-Al2O3 and TiO2 grow little at 1 200 ℃ and 1 300 ℃,while grain sizes of nano-Al2O3 and TiO2 grow obviously, and the grain size of nano-TiO2 is larger than 100 nm at 1400 ℃. Phase components of the feeds using high velocity flame sintering change, where α-Al2O3 changes to γ-Al2O3 and rutile TiO2 changes to brookite TiO2, though grain size of nano-Al2O3 does not grow and is less than 100 nm because cooling velocity is too quick. Compared with these two heat treatment technology, the technology using electric furnace to treat nanostructured Al2O3 and TiO2 feeds is more suitable.

  17. Comparison of 3 methods on fabricating micro- /nano- structured surface on 3D mold cavity

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2015-01-01

    The methods to manufacture micro- or nano- structures on surfaces have been an area of intense investigation. Demands are shown for technologies for surface structuring on real 3D parts in many fields. However, most technologies for the fabrication of micro-structured functional surfaces are stil...

  18. Long time and distance self-propelling of a PVC sphere on a water surface with an embedded ZnO micro-/nano-structured hollow sphere.

    Science.gov (United States)

    Wang, Lei; Yu, Lujia; Yi, Liting; Yuan, Bin; Hou, Yongping; Meng, Xiangfu; Liu, Jing

    2017-02-16

    In this research, a zinc oxide micro-/nano-structured hollow sphere (MNHS) with a large specific surface area is applied as energy storage material to encapsulate poly(vinyl chloride) solution and control the fuel release. The sustained release effect of MNHS not only makes the motion more controllable, but enhances the motion time and distance.

  19. Bio-inspired micro-nano structured surface with structural color and anisotropic wettability on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130022 (China); Li, Shuyi; Niu, Shichao [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Cao, Xiaowen [Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Han, Zhiwu, E-mail: zwhan@jlu.edu.cn [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Ren, Luquan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China)

    2016-08-30

    Highlights: • We have prepared a biomimetic hydrophobic surface on copper substrate by one-step femtosecond laser technique. • The hydrophobicity mechanism relies on morphology and chemical component on surface. • The hydrophobic surfaces exhibit different structural colors and a anisotropic wettability. - Abstract: Inspired by the unique creatures in the nature, the femtosecond laser technology has been usually used to fabricate the periodic microstructures due to its advantages of rapidness, simplicity, ease of large-area fabrication, and simultaneously offering dual micro/nano-scale structures simply via one-step process for a wide variety of materials. By changing the experimental conditions, multi-functional surfaces which possess superhydrophobicity and structural colors could be achieved on copper substrate. In addition, the apparent contact angle can reach 144.3° without any further modification, which also exhibits the anisotropic wettability. Moreover, it can be inferred that higher laser fluence can lead to a larger CA within a certain range. At the same time, due to the change of laser processing parameters, the obtained surfaces present different structural colors. This study may expand the applications of bio-inspired functional materials because multiple colors and hydrophobicity are both important features in the real life and industrial applications, such as display, decoration, and anti-counterfeiting technology etc.

  20. Preparation and characterization of Zn/Ce/SO{sub 4}{sup 2−}-doped titania nano-materials with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuzheng; Xue, Xiangxin; Yang, He, E-mail: yangh@smm.neu.edu.cn; Luan, Che

    2014-02-15

    SO{sub 4}{sup 2−}-doped Zn/Ce/TiO{sub 2} nano-materials (Zn/Ce/SO{sub 4}{sup 2−}/TiO{sub 2}) were prepared by a sol–gel method. The structures of Zn/Ce/SO{sub 4}{sup 2−}/TiO{sub 2} nano-materials were characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), X-ray photoelectron spectroscopy (XPS), X-ray photoelectron (PL) spectroscopy and Fourier transform infrared spectroscopy (FT-IR). Gram-negative Escherichia coli (ATCC25922) and Gram-positive Staphylococcus aureus (ATCC6538) as model organisms, antibacterial activities of nano-materials were tested using inhibition zone method and shaking flask method under visible light irradiation and in the dark. The results show that the materials crystal structure and elemental composition are changed after SO{sub 4}{sup 2−} doped. Zn/Ce/SO{sub 4}{sup 2−}/TiO{sub 2} exhibit predominant antibacterial activity in the dark and visible light irradiation. The action mechanism of Zn/Ce/SO{sub 4}{sup 2−}/TiO{sub 2} is discussed.

  1. Fabrication of polyimide micro/nano-structures based on contact-transfer and mask-embedded lithography

    Science.gov (United States)

    Chiu, Cheng-Yu; Lee, Yung-Chun

    2009-10-01

    Polyimide materials are well known for their excellent mechanical and chemical stability which, as an adverse consequence, makes their fabrication processes much more difficult, especially in micro- and nano-scales. In this paper, we demonstrate an innovative and powerful method for fabricating micro/nano-structures on polyimides. The proposed method first adopts an imprinting approach to transfer a patterned metal film from a mold to a polymer layer coated on a polyimide layer. The patterned double polymer layers are then dry etched using the transferred metal pattern as an etching mask. Finally, polyimide structures are obtained by lifting off the top polymer layer and the metal film through wet etching. Experiments have been carried out and important parameters to achieve high pattern-transformation fidelity are determined. Fine structures of polyimides with a feature size of 500 nm and a total patterned area of 8 × 8 mm2 are demonstrated. Advantages of the proposed method include low-temperature, low contact pressure, small feature size, high throughput and ease of in implementation. Most importantly, it is applicable for a large number of tough polymers which are difficult to deal with by other methods in terms of micro/nano-fabrication.

  2. From Molecular Meccano to Nano-Functional Materials for Molecular Electronics Applications

    Science.gov (United States)

    Sue, Chi-Hau

    resulting MOF-1001 and MOF-1002, which adopt the primitive cubic structure, are capable of docking paraquat cation guests within the crown ethers inside in a stereoelectronically controlled fashion, a behavior similar to enzymes binding incoming substrates. And MOF-1030, which is synthesized from an exceptionally long [2]catenane organic strut, is a three-dimensional MOF structure with vast openness, allowing MIMs-based prototypical molecular switches to be anchored at precise locations and with uniform relative orientations throughout the framework as a whole. These studies not only represent efficient approaches to the preparation of MOFs with complex functionalities, but also set the stage for the development of next-generation nano-functional materials for molecular electronics applications.

  3. Synthesis and Characterization of Storage Energy Materials Prepared from Nano-crystalline Cellulose/Polyethylene Glycol

    Institute of Scientific and Technical Information of China (English)

    Xiao Ping YUAN; En Yong DING

    2006-01-01

    This paper gives a brief report of the synthesis of a new kind of solid-solid phase change materials (SSPCMs), nano-crystalline cellulose/polyethylene glycol (NCC/PEG). These PCMs have very high ability for energy storage, and their enthalpies reach 103.8 J/g. They are composed of two parts, PEG as functional branches for energy storage, and NCC as skeleton. The flexible polymer PEG was grafted onto the surface of rigid powder of NCC by covalent bonds. The results of DSC, FT-IR were briefly introduced, and some comments were also given.

  4. Removal of lead ions using hydroxyapatite nano-material prepared from phosphogypsum waste

    OpenAIRE

    Mousa, S.M.; N.S. Ammar; H.A. Ibrahim

    2016-01-01

    Nano-material of calcium hydroxyapatite (n-CaHAP), with particle size ranging from 50 to 57 nm which was prepared from phosphogypsum waste (PG), was used for the removal of lead ions (Pb (II)) from aqueous solutions. It was investigated in a batch reactor under different experimental conditions. Effects of process parameters such as pH, initial Pb ion concentration and adsorbent dose were studied. Also, various types of kinetic modeling have been studied where the lead uptake was quantitative...

  5. Drag reduction in ultrahydrophobic channels with micro-nano structured surfaces

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A series of experiments have been performed to demonstrate the significant drag reduction of the laminar flow in the ultrahydrophobic channels with dual-scale micro-nano structured surfaces.However,in previous experiments,the ultrahydrophobic surfaces were fabricated with micro-structures or nano-structures and the channels were on the microscale.For the drag reduction in macro-scale channels few reports are available.Here a new method was developed to fabricate ultrahydrophobic surfaces with micro-nano hierarchical structures made from carbon nanotubes.The drag reductions up to 36.3% were observed in the macro-channels with ultrahydrophobic surfaces.The micro-PIV was used to measure the flow velocity in channels.Compared with the traditional no-slip theory at walls,a significant slip velocity was observed on the ultrahydrophobic surfaces.

  6. Using neural networks to predict the functionality of reconfigurable nano-material networks

    NARCIS (Netherlands)

    Greff, Klaus; Damme, van Ruud; Koutnik, Jan; Broersma, Hajo; Mikhal, Julia; Lawrence, Celestine; Wiel, van der Wilfred; Schmidhuber, Jürgen

    2017-01-01

    This paper demonstrates how neural networks can be applied to model and predict the functional behaviour of disordered nano-particle and nano-tube networks. In recently published experimental work, nano-particle and nano-tube networks show promising functionality for future reconfigurable devices, w

  7. Nanorobotic System iTRo for Controllable 1D Micro/nano Material Twisting Test.

    Science.gov (United States)

    Lu, Haojian; Shang, Wanfeng; Wei, Xueyong; Yang, Zhan; Fukuda, Toshio; Shen, Yajing

    2017-06-08

    In-situ micro/nano characterization is an indispensable methodology for material research. However, the precise in-situ SEM twisting of 1D material with large range is still challenge for current techniques, mainly due to the testing device's large size and the misalignment between specimen and the rotation axis. Herein, we propose an in-situ twist test robot (iTRo) to address the above challenges and realize the precise in-situ SEM twisting test for the first time. Firstly, we developed the iTRo and designed a series of control strategies, including assembly error initialization, triple-image alignment (TIA) method for rotation axis alignment, deformation-based contact detection (DCD) method for sample assembly, and switch control for robots cooperation. After that, we chose three typical 1D material, i.e., magnetic microwire Fe74B13Si11C2, glass fiber, and human hair, for twisting test and characterized their properties. The results showed that our approach is able to align the sample to the twisting axis accurately, and it can provide large twisting range, heavy load and high controllability. This work fills the blank of current in-situ mechanical characterization methodologies, which is expected to give significant impact in the fundamental nanomaterial research and practical micro/nano characterization.

  8. Nano-magnetic particles used in biomedicine: core and coating materials.

    Science.gov (United States)

    Karimi, Z; Karimi, L; Shokrollahi, H

    2013-07-01

    Magnetic nanoparticles for medical applications have been developed by many researchers. Separation, immunoassay, drug delivery, magnetic resonance imaging and hyperthermia are enhanced by the use of suitable magnetic nanoparticles and coating materials in the form of ferrofluids. Due to their low biocompatibility and low dispersion in water solutions, nanoparticles that are used for biomedical applications require surface treatment. Various kinds of coating materials including organic materials (polymers), inorganic metals (gold, platinum) or metal oxides (aluminum oxide, cobalt oxide) have been attracted during the last few years. Based on the recent advances and the importance of nanomedicine in human life, this paper attempts to give a brief summary on the different ferrite nano-magnetic particles and coatings used in nanomedicine.

  9. Hyper-elastic modeling and mechanical behavior investigation of porous poly-D-L-lactide/nano-hydroxyapatite scaffold material.

    Science.gov (United States)

    Han, Quan Feng; Wang, Ze Wu; Tang, Chak Yin; Chen, Ling; Tsui, Chi Pong; Law, Wing Cheung

    2017-07-01

    Poly-D-L-lactide/nano-hydroxyapatite (PDLLA/nano-HA) can be used as the biological scaffold material in bone tissue engineering as it can be readily made into a porous composite material with excellent performance. However, constitutive modeling for the mechanical response of porous PDLLA/nano-HA under various stress conditions has been very limited so far. In this work, four types of fundamental compressible hyper-elastic constitutive models were introduced for constitutive modeling and investigation of mechanical behaviors of porous PDLLA/nano-HA. Moreover, the unitary expressions of Cauchy stress tensor have been derived for the PDLLA/nano-HA under uniaxial compression (or stretch), biaxial compression (or stretch), pure shear and simple shear load by using the theory of continuum mechanics. The theoretical results determined from the approach based on the Ogden compressible hyper-elastic constitutive model were in good agreement with the experimental data from the uniaxial compression tests. Furthermore, this approach can also be used to predict the mechanical behaviors of the porous PDLLA/nano-HA material under the biaxial compression (or stretch), pure shear and simple shear. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Synthesis, structural, dielectric and magnetic properties of polyol assisted copper ferrite nano particles

    Science.gov (United States)

    Pavithradevi, S.; Suriyanarayanan, N.; Boobalan, T.

    2017-03-01

    Nanocrystalline copper ferrite CuFe2O4 is synthesized by co-precipitation method in ethylene glycol as chelating agent, using sodium Hydroxide as precipitator at pH 8. The as synthesized CuFe2O4 is annealed at temperatures of 350 °C, 700 °C, and 1050 °C for 2 h respectively. The thermal analysis of the synthesized sample is done by TG technique. It is shown that at 260 °C ethylene glycol has evaporated completely and after 715 °C, spinel ferrite is formed with a cubic structure. The calculated lattice parameters are in agreement with the reported values. FTIR spectra of CuFe2O4 nano particles are as synthesized and annealed at 1050 °C and recorded between 400 cm-1 and 4000 cm-1. It shows that when the temperature increases ethylene glycol gradually evaporates. Finally, nano crystalline single phase spinel ferrite is obtained. X-ray diffraction (XRD) and electron diffraction (EDS) studies show that the sample is indexed as the face centered cubic spinel structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the particles are flaky and spherical with the crystallite size in the range of 25-34 nm. From the dielectric studies, the dielectric constant decreases as the frequency increases. Low value of dielectric loss at higher frequencies suggests that the material is suitable for high frequency applications. AC conductivity increases with frequency. The magnetic properties of the samples are measured using a vibrating sample magnetometer (VSM) at room temperature, which shows that the sample exhibited a typical super paramagnetic behavior at low temperature. The saturation magnetization, remanant magnetism, and coercivity increases with applied field.

  11. A nano-structured ZnO film as diagnostic X-ray sensor

    Energy Technology Data Exchange (ETDEWEB)

    Valenca, Claudia Patricia Varela; Liborio da Silveira, Matheus Augusto; Macedo, Marcelo Andrade; Pereira dos Santos, Luiz Antonio [CNEN/CRCN-NE Av. Prof. Luiz Freire, 1 Cidade Universitaria RECIFE-PE CEP 50740-540 (Brazil)

    2015-07-01

    Currently some international organizations such as WHO and IAEA have shown concerns about the quality of diagnostic services in clinics and hospitals that use ionizing radiation. In fact, the IAEA recommend that the characteristics of the X-ray beam must be adjusted to obtain the highest quality of the radiographic image with the minimum exposure to the patient. Several types of detectors may be used for monitoring X-ray beams, such as: ionization chamber, photodiode, phototransistor, among others. Recently nano-structured films made of various types of metal oxide materials have been used for various technological applications. Accordingly, the purpose of this paper is to present a sort of device based on a nano-structured zinc oxide (ZnO) to operate as a diagnostic X-ray sensor. By depositing a thin film on the glass substrate some ZnO semiconductor samples were built by sputtering techniques and then mounted in a BNC type connector to perform the electrical characterization. To test the device, we choose a standard X-Ray beam, the RQR9 radiation quality, which is normally used as the tool and condition for calibrating diagnostic X-Ray instruments in the energy range of computed tomography, in accordance with the stated requirements of IEC 61267. A 6430 sub-femto-ammeter, Keithley, was used as electrometer to perform the output readings and simultaneously bias the ZnO sensor. Analysis of the angular dependence and the dose rate were performed to evaluate how the device responds under the RQR9 radiation spectra. Although the results have shown that the ZnO film presents a certain angular dependence, if an angle of incidence of photons is selected, the device displays reproducibility as X-ray sensor and has the feature of radiation hardness unlike other types of semiconductor electronic devices typically used as an X-ray detector. (authors)

  12. Bio-inspired micro-nano structured surface with structural color and anisotropic wettability on Cu substrate

    Science.gov (United States)

    Liu, Yan; Li, Shuyi; Niu, Shichao; Cao, Xiaowen; Han, Zhiwu; Ren, Luquan

    2016-08-01

    Inspired by the unique creatures in the nature, the femtosecond laser technology has been usually used to fabricate the periodic microstructures due to its advantages of rapidness, simplicity, ease of large-area fabrication, and simultaneously offering dual micro/nano-scale structures simply via one-step process for a wide variety of materials. By changing the experimental conditions, multi-functional surfaces which possess superhydrophobicity and structural colors could be achieved on copper substrate. In addition, the apparent contact angle can reach 144.3° without any further modification, which also exhibits the anisotropic wettability. Moreover, it can be inferred that higher laser fluence can lead to a larger CA within a certain range. At the same time, due to the change of laser processing parameters, the obtained surfaces present different structural colors. This study may expand the applications of bio-inspired functional materials because multiple colors and hydrophobicity are both important features in the real life and industrial applications, such as display, decoration, and anti-counterfeiting technology etc.

  13. Electroless Deposition and Nanolithography Can Control the Formation of Materials at the Nano-Scale for Plasmonic Applications

    Directory of Open Access Journals (Sweden)

    Maria Laura Coluccio

    2014-03-01

    Full Text Available The new revolution in materials science is being driven by our ability to manipulate matter at the molecular level to create structures with novel functions and properties. The aim of this paper is to explore new strategies to obtain plasmonic metal nanostructures through the combination of a top down method, that is electron beam lithography, and a bottom up technique, that is the chemical electroless deposition. This technique allows a tight control over the shape and size of bi- and three-dimensional metal patterns at the nano scale. The resulting nanostructures can be used as constituents of Surface Enhanced Raman Spectroscopy (SERS substrates, where the electromagnetic field is strongly amplified. Our results indicate that, in electroless growth, high quality metal nanostructures with sizes below 50 nm may be easily obtained. These findings were explained within the framework of a diffusion limited aggregation (DLA model, that is a simulation model that makes it possible to decipher, at an atomic level, the rules governing the evolution of the growth front; moreover, we give a description of the physical mechanisms of growth at a basic level. In the discussion, we show how these findings can be utilized to fabricate dimers of silver nanospheres where the size and shape of those spheres is controlled with extreme precision and can be used for very large area SERS substrates and nano-optics, for single molecule detection.

  14. Electroless deposition and nanolithography can control the formation of materials at the nano-scale for plasmonic applications.

    Science.gov (United States)

    Coluccio, Maria Laura; Gentile, Francesco; Francardi, Marco; Perozziello, Gerardo; Malara, Natalia; Candeloro, Patrizio; Di Fabrizio, Enzo

    2014-03-27

    The new revolution in materials science is being driven by our ability to manipulate matter at the molecular level to create structures with novel functions and properties. The aim of this paper is to explore new strategies to obtain plasmonic metal nanostructures through the combination of a top down method, that is electron beam lithography, and a bottom up technique, that is the chemical electroless deposition. This technique allows a tight control over the shape and size of bi- and three-dimensional metal patterns at the nano scale. The resulting nanostructures can be used as constituents of Surface Enhanced Raman Spectroscopy (SERS) substrates, where the electromagnetic field is strongly amplified. Our results indicate that, in electroless growth, high quality metal nanostructures with sizes below 50 nm may be easily obtained. These findings were explained within the framework of a diffusion limited aggregation (DLA) model, that is a simulation model that makes it possible to decipher, at an atomic level, the rules governing the evolution of the growth front; moreover, we give a description of the physical mechanisms of growth at a basic level. In the discussion, we show how these findings can be utilized to fabricate dimers of silver nanospheres where the size and shape of those spheres is controlled with extreme precision and can be used for very large area SERS substrates and nano-optics, for single molecule detection.

  15. Electroless deposition and nanolithography can control the formation of materials at the nano-scale for plasmonic applications

    KAUST Repository

    Coluccio, Maria Laura

    2014-03-27

    The new revolution in materials science is being driven by our ability to manipulate matter at the molecular level to create structures with novel functions and properties. The aim of this paper is to explore new strategies to obtain plasmonic metal nanostructures through the combination of a top down method, that is electron beam lithography, and a bottom up technique, that is the chemical electroless deposition. This technique allows a tight control over the shape and size of bi- and three-dimensional metal patterns at the nano scale. The resulting nanostructures can be used as constituents of Surface Enhanced Raman Spectroscopy (SERS) substrates, where the electromagnetic field is strongly amplified. Our results indicate that, in electroless growth, high quality metal nanostructures with sizes below 50 nm may be easily obtained. These findings were explained within the framework of a diffusion limited aggregation (DLA) model, that is a simulation model that makes it possible to decipher, at an atomic level, the rules governing the evolution of the growth front; moreover, we give a description of the physical echanisms of growth at a basic level. In the discussion, we show how these findings can be utilized to fabricate dimers of silver nanospheres where the size and shape of those spheres is controlled with extreme precision and can be used for very large area SERS substrates and nano-optics, for single molecule detection. 2014 by the authors; licensee MDPI, Basel, Switzerland.

  16. Integrated Surface and Mechanical Characterization of Freestanding Biological and Other Nano-Structures Using Atomic Force Microscopy

    Science.gov (United States)

    Wang, Xin

    This dissertation is focused on surface and mechanical characterization of freestanding biological and other nano-structures using atomic force microscopy including two parts: cell mechanics and nano-structure mechanics. The main purpose of this work is to investigate how the nano- / micro-scale mechanical properties affect macro-scale function. In cancer cells, efficacy of drug delivery is oftentimes declined due to the thick dendritic network of oligosaccharide mucin chains on the cell surface. AFM is used to measure the force needed to pierce the mucin layer to reach the cell surface. A pool of ovarian, pancreatic, lung, colorectal and breast cancer cells are characterized. The studies offer additional support for the development of clinical and pharmaceutical approaches to combat mucin over-expression in tumors during cancer chemotherapy. Macroscopic adhesion-aggregation and subsequent transportation of microorganisms in porous medium are closely related to the microscopic deformation and adhesion mechanical properties. The classical Tabor's parameter is modified. Multiple bacterial strains are characterized in terms of aggregates size, aggregation index and transportation kinetics. AFM is employed to obtain the microscopic coupled adhesion-deformation properties. The strong correlation between Tabor's parameter and aggregation-deposition-transportation suggests the AFM characterization is capable of making reliable predication of macroscopic behavior. A novel "nano-cheese-cutter" is fabricated on tipless AFM cantilever to measure elastic modulus and interfacial adhesion of a 1-D freestanding nano-structure. A single electrospun fiber is attached to the free end of AFM cantilever, while another fiber is similarly prepared on a mica substrate in an orthogonal direction. An external load is applied to deform the two fibers into complementary V-shapes. This work is extended to investigate the interfacial adhesion energy between dissimilar materials. SWCNT thin

  17. The diametral tensile strength and hydrostability of polymer-ceramic nano-composite (pcnc) material prototypes

    Science.gov (United States)

    Yepez, Johanna

    Statement of the problem: There is a weak connection between the filler and the resin matrix of dental composites caused primarily by hydrolysis of silane coupling agent, therefore, jeopardizing the mechanical properties of the dental restorations. Purpose: The purpose of this study was to compare the diametral tensile strength (DTS) of a nano-mechanically bonded polymer ceramic nano composite (pcnc) versus the chemically bonding prototype polymer ceramic nano composite (pcnc) fabricated by using hydrolytically stable interphase. Materials and Methods: Composites were made with 60wt % filler, 38% triethyleneglycol dimethacrylate (TEDGMA), 1% camphorquinone (CQ) and 1% 2-(dimethylamino) ethyl methacrylate (DMAEMA). Tests for DTS were performed using a universal testing machine. The disk-shaped specimens were loaded in compression between two supporting plates at a crosshead speed of 0.5 mm/min until fracture. The samples, measuring 3 mm in height and 6 mm in diameter, were produced in a round stainless steel (SS) mold. A total of 144 samples were created. Groups of 48 samples were made for each of three different fillers. Specimens were soaked in artificial saliva at 37° for four time periods, dry(t=0), 1 day, 7 days, 28 days). At the end of each soaking time DTS tests were performed. Results: There where statistically significant differences in the DTS between the filler groups and the soaking times (p=composition and bonding interphase of resin base composites promise improvements of mechanical properties, decreasing the incidence of clinical failure of posterior composite restorations, hence resulting in a more ideal restorative material for use in posterior segment. The results of this investigation showed that the deficiency of hydrostability in dental composites is a detrimental factor in the mechanical behavior. The silanation of the filler particles have a positive influence on the mechanical properties of dental composites but the hydrolysis of the silane

  18. Focused ion beam nano-structuring of $Al_2O_3$ dielectric layers for photonic applications

    NARCIS (Netherlands)

    Ay, Feridun; Bradley, Jonathan D.B.; Hopman, Wico C.L.; Gadgil, Vishwas J.; Ridder, de René M.; Wörhoff, Kerstin; Pollnau, Markus

    2007-01-01

    In order to enable full integration of active integrated optical components based on Si-technology, high quality micro- and nano-structuring processes aiming at the development of on-chip resonator structures are to be achieved. By optimizing focused ion beam milling parameters such as ion current,

  19. Key Techniques on Preparing High Aspect Ratio Micro and Nano Structures

    DEFF Research Database (Denmark)

    Jian, Zhao; Lianhe, Dong; Xiaoli, Zhu

    2016-01-01

    effectively. The mechanism of action between NaCl and HSQ was analyzed. The collapse and adhesion of resist structure due to the effect of gas-liquid interfacial capillary surface tension were suppressed by the CO2 supercritical drying method. Large-area dense nano-structures with the aspect ratio of 12...

  20. Fabrication of nano-Fe3O4 3D structure on carbon fibers as a microwave absorber and EMI shielding composite by modified EPD method

    Science.gov (United States)

    Gholampoor, Mahdi; Movassagh-Alanagh, Farid; Salimkhani, Hamed

    2017-02-01

    Recently, electromagnetic interference (EMI) shielding materials have absorbed a lot of attention due to a growing need for application in the area of electronic and wireless devices. In this study, a carbon-based EMI shielding composite was fabricated by electrophoretic deposition of Fe3O4 nano-particles on carbon fibers (CFs) as a 3D structure incorporated with an epoxy resin. Co-precipitation method was employed to synthesize Fe3O4 nano-particles. This as-synthesized Fe3O4 nano-powder was then successfully deposited on CFs using a modified multi-step electrophoretic deposition (EPD) method. The results of structural studies showed that the Fe3O4 nano-particles (25 nm) were successfully and uniformly deposited on CFs. The measured magnetic properties of as-synthesized Fe3O4 nano-powder and nano-Fe3O4/CFs composite showed that the saturation magnetization of bare Fe3O4 was decreased from Ms = 72.3 emu/g to Ms = 33.1 emu/g for nano-Fe3O4/CFs composite and also corecivity of Fe3O4 was increased from Hc = 4.9 Oe to Hc = 168 Oe for composite. The results of microwave absorption tests revealed that the reflection loss (RL) of an epoxy-based nano-Fe3O4/CFs composite are significantly influenced by layer thickness. The maximum RL value of -10.21 dB at 10.12 GHz with an effective absorption bandwidth about 2 GHz was obtained for the sample with the thickness of 2 mm. It also exhibited an EMI shielding performance of -23 dB for whole the frequency range of 8.2-12.4 GHz.

  1. Fabrication and characterization of micro- /nano structures for nanophotonic applications

    Science.gov (United States)

    Jee, Hongsub

    The objective of this thesis is finding and developing fabrication methods to provide background techniques for potential applications with nanomaterials. The inclined UV lithography has announced to make three-dimensional fabrication process. With a movable stage, complex structures were achieved but difference of the refractive index, design of the final structures were limited. Refractive index matching medium between the substrate and the light source could reduce the refractive indices between the polymer and the substrate successfully. Nanoporous structures fabricated by multibeam interference lithography shows limitation of the usage since its periodicity. By insertion of the lift off resist layer between the patterned layer and the substrate, final photonic crystal structures could be partially removed for its own purpose and it provide potential application in the future. Two-step processing, combining with reactive ion etching system, nanoporous structures were on various substrates such as silicon and Polydimethylsiloxane. Photonic crystal template anodic aluminum oxide process has been described too. Large optical activity at visible wavelengths are of great attention in photonics. Dramatic enhancement of the optical activity of chiral poly(fluorene-alt-benzothiadiazole) with photoresist was demonstrated and successive photo patterning of chiral polymer shows the potential usage of this material for the photonics applications. Two photon lithography also used to pattern a photoresist-chiral polymer mixture into planar shapes and enhanced chirality can be realized by tuning the wavelength-dependent chiral response at both the molecular and geometric level. Near infrared light induced photopolymerization in-situ was demonstrated which can be applied everywhere where ultraviolet-polymerization is employed such as dentistry, coating industry. Use of the ultraviolet upconverting nanoparticles doped into the polymer, we show that expensive femtosecond pulsed

  2. Basic reactions of osteoblasts on structured material surfaces

    Directory of Open Access Journals (Sweden)

    B�chter A.

    2005-04-01

    Full Text Available In order to assess how bone substitute materials determine bone formation in vivo it is useful to understand the mechanisms of the material surface/tissue interaction on a cellular level. Artificial materials are used in two applications, as biomaterials alone or as a scaffold for osteoblasts in a tissue engineering approach. Recently, many efforts have been undertaken to improve bone regeneration by the use of structured material surfaces. In vitro studies of bone cell responses to artificial materials are the basic tool to determine these interactions. Surface properties of materials surfaces as well as biophysical constraints at the biomaterial surface are of major importance since these features will direct the cell responses. Studies on osteoblastlike cell reactivity towards materials will have to focus on the different steps of protein and cell reactions towards defined surface properties. The introduction of new techniques allows nowadays the fabrication of materials with ordered surface structures. This paper gives a review of present knowledge on the various stages of osteoblast reactions on material surfaces, focused on basic cell events under in vitro conditions. Special emphasis is given to cellular reactions towards ordered nano-sized topographies.

  3. Synthesis and electrochemical performance of nano-metastructured LiFePO4/C cathode material.

    Science.gov (United States)

    Zhi, Xiaoke; Liang, Guangchuan; Wang, Li; Cui, Junyan; Yang, Limei

    2010-11-01

    The nano-metastructured LiFePO4/C composites were synthesized by carbothermal reduction method using starch gel as carbon source and dispersing media to obtain high tap density LiFePO4 with excellent electrochemical performance. The raw materials were coated by starch gel as compact precursors, which was sintered at 750 degrees C for 8 h to obtain high-density LiFePO4/C composite aggregated with nano-sized particles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that the primary particles had an average size of about 50-80 nm and the aggregates had a homogeneous particle size distribution of about 400 nm. The asprepared samples had a shortened lithium-ion diffusion length but with higher tap density, thus leading to the excellent electrochemical performance of the cathode materials. Electrochemical results showed that the samples delivered high discharge capacities of 155.6 and 120.7 mAh/g at 0.2C and 5C rates, respectively, with excellent cycling performance.

  4. Surface constructions of nano TiO_2 as the environmental and energy materials

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis applications.In this presentation,we summarize some progress in surface constructions of nano TiO_2 and its characterizations of physicochemistry and properties. (1)Superhydrophobic nanostructure TiO_2 films Superhydrophobic nanotube,nanopore and sponge-like structure TiO_2 films are fabricated ...

  5. X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhenhai; Wang, Qinglin; Ma, Yanzhang; Wang, Lin

    2017-01-17

    Nanoscale materials exhibit properties that are quite distinct from those of bulk materials because of their size restricted nature. Here, we investigated the high-pressure structural stability of cubic (C-type) nano-Eu2O3 using in situ synchrotron X-ray diffraction (XRD), Raman and luminescence spectroscopy, and impedance spectra techniques. Our high-pressure XRD experimental results revealed a pressure-induced structural phase transition in nano-Eu2O3 from the C-type phase (space group: Ia-3) to a hexagonal phase (A-type, space group: P-3m1). Our reported transition pressure (9.3 GPa) in nano-Eu2O3 is higher than that of the corresponding bulk-Eu2O3 (5.0 GPa), which is contrary to the preceding reported experimental result. After pressure release, the A-type phase of Eu2O3 transforms into a new monoclinic phase (B-type, space group: C2/m). Compared with bulk-Eu2O3, C-type and A-type nano-Eu2O3 exhibits a larger bulk modulus. Our Raman and luminescence findings and XRD data provide consistent evidence of a pressure-induced structural phase transition in nano-Eu2O3. To our knowledge, we have performed the first high-pressure impedance spectra investigation on nano-Eu2O3 to examine the effect of the structural phase transition on its transport properties. We propose that the resistance inflection exhibited at ~12 GPa results from the phase boundary between the C-type and A-type phases. Besides, we summarized and discussed the structural evolution process by the phase diagram of lanthanide sesquioxides (Ln2O3) under high pressure.

  6. Stability of magnetic nano-structures with respect to shape modifications

    Science.gov (United States)

    Blachowicz, T.; Ehrmann, A.

    2016-08-01

    Magnetic nano-structures can be used for various applications. Examinations of nano-structured systems often aim at decreasing pattern sizes due to their possible utilization in data storage media, in order to enhance the possible information density in a given area. This scaling process, however, is limited by the resolution of the lithography process which is used to produce the nano-particles. Thus the influence of shape modifications on the magnetic properties is important to be examined, especially the correlation between small form changes and magnetization reversal processes or coercive fields. In a recent project, square nanoparticles from permalloy were simulated using Magpar. Simulations were performed for the ideal geometric shape used in the lithography process, for the realistic shape of the produced nano-particles as obtained by SEM, and for intermediate steps between these extreme shapes. This study allows for estimation of the reliability of magnetic properties of nano-structures with respect to shape modifications in the lithography process.

  7. Co-Assembled Supported Catalysts: Synthesis of Nano-Structured Supported Catalysts with Hierarchic Pores through Combined Flow and Radiation Induced Co-Assembled Nano-Reactors

    OpenAIRE

    Galip Akay

    2016-01-01

    A novel generic method of silica supported catalyst system generation from a fluid state is presented. The technique is based on the combined flow and radiation (such as microwave, thermal or UV) induced co-assembly of the support and catalyst precursors forming nano-reactors, followed by catalyst precursor decomposition. The transformation from the precursor to supported catalyst oxide state can be controlled from a few seconds to several minutes. The resulting nano-structured micro-porous s...

  8. Nano-bio-sensing

    CERN Document Server

    Carrara, Sandro

    2011-01-01

    This book examines state-of-the-art applications of nano-bio-sensing. It brings together researchers from nano-electronics and bio-technology, providing multidisciplinary content from nano-structures fabrication to bio-sensing applications.

  9. Overview of the Characteristics of Micro- and Nano-Structured Surface Plasmon Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Byoungho Lee

    2011-01-01

    Full Text Available The performance of bio-chemical sensing devices has been greatly improved by the development of surface plasmon resonance (SPR based sensors. Advancements in micro- and nano-fabrication technologies have led to a variety of structures in SPR sensing systems being proposed. In this review, SPR sensors (from typical Kretschmann prism configurations to fiber sensor schemes with micro- or nano-structures for local light field enhancement, extraordinary optical transmission, interference of surface plasmon waves, plasmonic cavities, etc. are discussed. We summarize and compare their performances and present guidelines for the design of SPR sensors.

  10. Relationship between nano-scale deformation of coal structure and metamorphic-deformed environments

    Institute of Scientific and Technical Information of China (English)

    JU Yiwen; JIANG Bo; HOU Quanlin; WANG Guiliang

    2005-01-01

    There is a more consanguineous relation between nano-scale deformation of coal structure and metamorphic-deformed environment. In different metamorphic-deformed environments, deformation in the coal structure can occur not only at micro-scale, but also at nano-scale, and even leads to the change of molecular structure and nano-scale pore (<100 nm) structure. The latter is the main space absorbing coalbed methane. Through X-ray diffraction (XRD) and liquid-nitrogen absorption methods, the characteristics of macromolecular and nano-scale pore structures of coals in different metamorphic-deformed environments and deformational series of coals have been studied. By combining with high-resolution transmission electron microcopy (HRTEM), the macromolecular and nano-scale pore structures are also directly observed. These results demonstrate that the stacking Lc of the macromolecular BSU in tectonic coals increases quickly from the metamorphic-deformed environment of low rank coals to that of high rank coals. For different deformed tectonic coals, in the same metamorphic-deformed environment, the difference of Lc is obvious. These changes reflect chiefly the difference of different temperature and stress effect of nano-scale deformation in tectonic coals. The factor of temperature plays a greater role in the increase of macromolecular structure parameters Lc, the influence of stress factor is also important. With the stress strengthening, Lc shows an increasing trend, and La /Lc shows a decreasing trend. Therefore, Lc and La /Lc can be used as the indicator of nano-scale deformation degree of tectonic coals. With increasing temperature and pressure, especially oriented stress, the orientation of molecular structure becomes stronger, and ordering degree of C-nets and the arrangement of BSU are obviously enhanced. For the deformation of nano-scale pore structure, in the same metamorphic-deformed environment, along with the strengthening of stress, the ratio of mesopores to

  11. Few layered vanadyl phosphate nano sheets-MWCNT hybrid as an electrode material for supercapacitor application

    Science.gov (United States)

    Dutta, Shibsankar; De, Sukanta

    2016-05-01

    It have been already seen that 2-dimensional nano materials are the suitable choice for the supercapacitor application due to their large specific surface area, electrochemical active sites, micromechanical flexibility, expedite ion migration channel properties. Free standing hybrid films of functionalized MWCNT (- COOH group) and α-Vanadyl phosphates (VOPO42H2O) are prepared by vacuum filtering. The surface morphology and microstructure of the samples are studied by transmission electron microscope, field emission scanning electron microscope, XRD, Electrochemical properties of hybrid films have been investigated systematically in 1M Na2SO4 aqueous electrolyte. The hybrid material exhibits a high specific capacitance 236 F/g with high energy density of 65.6 Wh/Kg and a power density of 1476 W/Kg.

  12. Enhancement in biological response of Ag-nano composite polymer membranes using plasma treatment for fabrication of efficient bio materials

    Science.gov (United States)

    Agrawal, Narendra Kumar; Sharma, Tamanna Kumari; Chauhan, Manish; Agarwal, Ravi; Vijay, Y. K.; Swami, K. C.

    2016-05-01

    Biomaterials are nonviable material used in medical devices, intended to interact with biological systems, which are becoming necessary for the development of artificial material for biological systems such as artificial skin diaphragm, valves for heart and kidney, lenses for eye etc. Polymers having novel properties like antibacterial, antimicrobial, high adhesion, blood compatibility and wettability are most suitable for synthesis of biomaterial, but all of these properties does not exist in any natural or artificial polymeric material. Nano particles and plasma treatment can offer these properties to the polymers. Hence a new nano-biomaterial has been developed by modifying the surface and chemical properties of Ag nanocomposite polymer membranes (NCPM) by Argon ion plasma treatment. These membranes were characterized using different techniques for surface and chemical modifications occurred. Bacterial adhesion and wettability were also tested for these membranes, to show direct use of this new class of nano-biomaterial for biomedical applications.

  13. Nano-scale Interfacial Friction Behavior between Two Kinds of Materials in MEMS Based on Molecular Dynamics Simulations

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; LIAO Linbo; DING Jianning; YANG Jichang; LI Changsheng; FAN Zen; LIN Zhiyong

    2006-01-01

    The aim of this article was to provide a systematic method to perform molecular dynamics simulation or evaluation for nano-scale interfacial friction behavior between two kinds of materials in MEMS design. Friction is an important factor affecting the performance and reliability of MEMS. The model of the nano-scale interfacial friction behavior between two kinds of materials was presented based on the Newton's equations of motion. The Morse potential function was selected for the model. The improved Verlet algorithm was employed to resolve the model, the atom trajectories and the law of the interfacial friction behavior. Comparisons with experimental data in other paper confirm the validity of the model. Using the model it is possible to simulate or evaluate the importance of different factors for designing of the nano-scale interfacial friction behavior between two kinds of materials in MEMS.

  14. Structural and corrosion protection properties of electrochemically deposited nano-sized Zn–Ni alloy coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tozar, A., E-mail: tozarali@gmail.com; Karahan, İ.H.

    2014-11-01

    Highlights: • Nano-sized, compact and bright deposits were obtained galvanostatically. • Deposition of zinc–nickel alloys has been materialized in domination of zinc-rich ∂-(Ni{sub 3}Zn{sub 22}) and γ-(Ni{sub 5}Zn{sub 22}) phases. • Sodium citrate (Na{sub 3}C{sub 6}H{sub 5}O{sub 7}) has been used together with boric acid (H{sub 3}BO{sub 3}) for inhibition of instantaneous deposition of zinc and accordingly increasing the relative amount of nickel. • Corrosion protection performances of the deposits were increased with increasing deposition current density and nickel amount. • Crystal defects have been increased with decreasing crystallite size. - Abstract: Zn–Ni alloy coatings were fabricated galvanostatically by applying varied current densities from 10 to 30 mA cm{sup −2}. Surface morphology of the coatings was examined with SEM. Crystal structure of the coatings was studied with X-ray diffraction spectroscopy (XRD). Compositions of the coatings were determined by atomic absorption spectroscopy (AAS). Corrosion protection properties studied using open circuit potential (OCP) measurements, potentiodynamic polarization measurements (Tafel), electrochemical impedance spectroscopy (EIS). Deposited alloy coatings were compact and nano-sized. Crystallite sizes of the coatings were varying from 26 nm to 36 nm. Nickel content of the samples were increased by increasing current densities and varied from 6.7 to 18.9 wt.%. Best corrosion protection performance was seen on the sample obtained at 30 mA cm{sup −2}. Our results are considerably encouraging for protection of mild steel against corrosion by obtained Zn–Ni alloys.

  15. The application of quasi-one dimensional nano-materials in nanoelectronic devices

    Science.gov (United States)

    Zhang, Li

    As the scaling of silicon based electronic devices is approaching limitations set by the physical and materials properties, several nano-sized materials have gained much interest as possible substitutions of silicon for future electronics. This thesis focuses on carbon nanotubes (CNTs), graphene nanoribbons (GNRs) and germanium nanowires (GeNWs) due to their unique properties. Single walled carbon nanotubes are molecular quantum wires (diameter ˜1nm) which are highly chemically stable and exhibit outstanding electrical conductivity. However, typical synthesis of SWNTs yields a mixture of both metallic and semiconducting varieties with a range of diameters. Several methods have been reported to separate SWNTs and anion exchange (IEC) chromatography has shown the most promise for electronic type separation. In the first part of the dissertation, I will discuss the characterization of IEC separation efficiency by combining spectroscopy and electrical measurements. In the early experiment, the SWNTs were separated according to diameter and electronic types and the separation efficiency decreased with increasing tube diameter. The separation efficiency was much improved by using the new DNA sequence to suspend the SWNTs and single-chirality-enrichment was achieved. Graphene is single layer graphite, which is predicted to exhibit bandgaps useful for room temperature transistor operations with excellent switching speed and high mobilities when made into narrow ribbons (sub-10 nm). The all-semiconducting nature of sub-10 nm GNRs could bypass the problem of extreme chirality dependence of metal or semiconductor carbon nanotubes (CNTs) for future electronics. Currently, making GNRs remains challenging by lithographic, chemical or sonochemical methods. It is difficult to obtain GNRs with smooth edges and controllable width at high yields. In the second part of the thesis, I will show an interesting approach to making GNRs by unzipping multiwalled carbon nanotubes (MWNTs) by

  16. Broadband light-trapping in ultra-thin nano-structured solar cells

    Science.gov (United States)

    Colin, Clément; Massiot, Inès.; Cattoni, Andrea; Vandamme, Nicolas; Dupuis, Christophe; Bardou, Nathalie; Gerard, Isabelle; Naghavi, Negar; Guillemoles, Jean-François; Pelouard, Jean-Luc; Collin, Stéphane

    2013-03-01

    Conventional light trapping techniques are inefficient at the sub-wavelength scale. This is the main limitation for the thickness reduction of thin-film solar cells below 500nm. We propose a novel architecture for broadband light absorption in ultra-thin active layers based on plasmonic nano-cavities and multi-resonant mechanism. Strong light enhancement will be shown numerically for photovoltaic materials such as CIGSe and GaAs. First experiments on ultrathin nano-patterned CIGSe solar cells will be presented.

  17. Synthesis, optical properties and growth mechanism of MnO nano structures

    Science.gov (United States)

    Pandey, B. K.; Shahi, A. K.; Gopal, R.

    2013-10-01

    Manganese oxide (MnO) colloidal nanoparticles have been successfully synthesized by pulse laser ablation in double distilled water. Nd: YAG laser with focused output operating at different pulse energies (20, 30, 40, 50 mJ/pulse) was used for ablation. Synthesized MnO nano crystal phase and structure were confirmed by X-ray diffraction and SAED pattern. Optical properties of as synthesized MnO nano colloidal solution were studied by UV-vis absorption spectroscopy. Optical particle size and band gap of as synthesized MnO colloidal nanoparticles were calculated. Particle shape and size were determined by TEM/SEM image. It is observed that MnO nano colloidal particles assembled to make different structures after aging in the liquid media. Aspect ratio has been calculated from SEM picture. MnO nanoparticles show weak antiferromagnetic behavior at room temperature as measured by VSM. A typical mechanism has been proposed for the formation of different nanostructures.

  18. Synthesis, optical properties and growth mechanism of MnO nano structures

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.K., E-mail: bishnu.pandey750@gmail.com; Shahi, A.K.; Gopal, R., E-mail: profrgopal@gmail.com

    2013-10-15

    Manganese oxide (MnO) colloidal nanoparticles have been successfully synthesized by pulse laser ablation in double distilled water. Nd: YAG laser with focused output operating at different pulse energies (20, 30, 40, 50 mJ/pulse) was used for ablation. Synthesized MnO nano crystal phase and structure were confirmed by X-ray diffraction and SAED pattern. Optical properties of as synthesized MnO nano colloidal solution were studied by UV–vis absorption spectroscopy. Optical particle size and band gap of as synthesized MnO colloidal nanoparticles were calculated. Particle shape and size were determined by TEM/SEM image. It is observed that MnO nano colloidal particles assembled to make different structures after aging in the liquid media. Aspect ratio has been calculated from SEM picture. MnO nanoparticles show weak antiferromagnetic behavior at room temperature as measured by VSM. A typical mechanism has been proposed for the formation of different nanostructures.

  19. Characterizing the nano-structure and defect structure of nano-scaled non-ferrous structural alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ghamarian, Iman, E-mail: imanghamarian@yahoo.com [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States); Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Samimi, Peyman; Liu, Yue [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States); Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Center for Advanced Non-Ferrous Structural Alloys, an NSF-I/UCRC between the University of North Texas (Denton, TX, 76203) and the Colorado School of Mines (Golden, CO, 80401) (United States); Poorganji, Behrang; Vasudevan, Vijay K. [Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221 (United States); Collins, Peter C. [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States); Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Center for Advanced Non-Ferrous Structural Alloys, an NSF-I/UCRC between the University of North Texas (Denton, TX, 76203) and the Colorado School of Mines (Golden, CO, 80401) (United States)

    2016-03-15

    The presence and interaction of nanotwins, geometrically necessary dislocations, and grain boundaries play a key role in the mechanical properties of nanostructured crystalline materials. Therefore, it is vital to determine the orientation, width and distance of nanotwins, the angle and axis of grain boundary misorientations as well as the type and the distributions of dislocations in an automatic and statistically meaningful fashion in a relatively large area. In this paper, such details are provided using a transmission electron microscope-based orientation microscopy technique called ASTAR™/precession electron diffraction. The remarkable spatial resolution of this technique (~ 2 nm) enables highly detailed characterization of nanotwins, grain boundaries and the configuration of dislocations. This orientation microscopy technique provides the raw data required for the determination of these parameters. The procedures to post-process the ASTAR™/PED datasets in order to obtain the important (and currently largely hidden) details of nanotwins as well as quantifications of dislocation density distributions are described in this study. - Highlights: • EBSD cannot characterize defects such as dislocations, grain boundaries and nanotwins in severely deformed metals. • TEM based orientation microscopy technique called ASTAR™/PED was used to resolve the problem. • Locations and orientations of nanotwins, dislocation density distribution and grain boundary characters can be resolved. • This work provides the bases for further studies on the interactions between dislocations, grain boundaries and nanotwins. • The computation part is explained sufficiently which helps the readers to post process their own data.

  20. Nano CMOS

    Directory of Open Access Journals (Sweden)

    Malay Ranjan Tripathy

    2009-05-01

    Full Text Available Complementary metal-oxide-semiconductor (CMOS has become major challenge to scaling and integration. However, innovation in transistor structures and integration of novel materials are needed to sustain this performance trend. CMOS variability in the scaling technology becoming very important concern because of limitation of process control over statistical variability related to the fundamental discreteness of charge and matter. Different aspects responsible for device variability are discussed in this article. The challenges and opportunities of nano CMOS technology are outlined here.

  1. 3D printing of nano- and micro-structures

    Science.gov (United States)

    Ramasamy, Mouli; Varadan, Vijay K.

    2016-04-01

    Additive manufacturing or 3D printing techniques are being vigorously investigated as a replacement to the traditional and conventional methods in fabrication to bring forth cost and time effective approaches. Introduction of 3D printing has led to printing micro and nanoscale structures including tissues and organelles, bioelectric sensors and devices, artificial bones and transplants, microfluidic devices, batteries and various other biomaterials. Various microfabrication processes have been developed to fabricate micro components and assemblies at lab scale. 3D Fabrication processes that can accommodate the functional and geometrical requirements to realize complicated structures are becoming feasible through advances in additive manufacturing. This advancement could lead to simpler development mechanisms of novel components and devices exhibiting complex features. For instance, development of microstructure electrodes that can penetrate the epidermis of the skin to collect the bio potential signal may prove very effective than the electrodes that measure signal from the skin's surface. The micro and nanostructures will have to possess extraordinary material and mechanical properties for its dexterity in the applications. A substantial amount of research being pursued on stretchable and flexible devices based on PDMA, textiles, and organic electronics. Despite the numerous advantages these substrates and techniques could solely offer, 3D printing enables a multi-dimensional approach towards finer and complex applications. This review emphasizes the use of 3D printing to fabricate micro and nanostructures for that can be applied for human healthcare.

  2. Characterization and antimicrobial performance of nano silver coatings on leather materials.

    Science.gov (United States)

    Lkhagvajav, N; Koizhaiganova, M; Yasa, I; Çelik, E; Sari, Ö

    2015-03-01

    In this study, the characterization and the antimicrobial properties of nano silver (nAg) coating on leather were investigated. For this purpose, turbidity, viscosity and pH of nAg solutions prepared by the sol-gel method were measured. The formation of films from these solutions was characterized according to temperature by Differential Thermal Analysis-Thermogravimetry (DTA-TG) equipment. The surface morphology of treated leathers was observed using Scanning Electron Microscopy (SEM). The antimicrobial performance of nAg coatings on leather materials to the test microorganisms as Escherichia coli , Staphylococcus aureus , Candida albicans and Aspergillius niger was evaluated by the application of qualitative (Agar overlay method) and quantitative (percentage of microbial reduction) tests. According to qualitative test results it was found that 20 μg/cm (2) and higher concentrations of nAg on the leather samples were effective against all microorganisms tested. Moreover, quantitative test results showed that leather samples treated with 20 μg/cm (2) of nAg demonstrated the highest antibacterial activity against E. coli with 99.25% bacterium removal, whereas a 10 μg/cm (2) concentration of nAg on leather was enough to exhibit the excellent percentage reduction against S. aureus of 99.91%. The results are promising for the use of colloidal nano silver solution on lining leather as antimicrobial coating.

  3. Characterization and antimicrobial performance of nano silver coatings on leather materials

    Directory of Open Access Journals (Sweden)

    N. Lkhagvajav

    2015-03-01

    Full Text Available In this study, the characterization and the antimicrobial properties of nano silver (nAg coating on leather were investigated. For this purpose, turbidity, viscosity and pH of nAg solutions prepared by the sol-gel method were measured. The formation of films from these solutions was characterized according to temperature by Differential Thermal Analysis-Thermogravimetry (DTA-TG equipment. The surface morphology of treated leathers was observed using Scanning Electron Microscopy (SEM. The antimicrobial performance of nAg coatings on leather materials to the test microorganisms as Escherichia coli, Staphylococcus aureus, Candida albicans and Aspergillius niger was evaluated by the application of qualitative (Agar overlay method and quantitative (percentage of microbial reduction tests. According to qualitative test results it was found that 20 μg/cm2 and higher concentrations of nAg on the leather samples were effective against all microorganisms tested. Moreover, quantitative test results showed that leather samples treated with 20 μg/cm2 of nAg demonstrated the highest antibacterial activity against E. coli with 99.25% bacterium removal, whereas a 10 μg/cm2 concentration of nAg on leather was enough to exhibit the excellent percentage reduction against S. aureus of 99.91%. The results are promising for the use of colloidal nano silver solution on lining leather as antimicrobial coating.

  4. Fe catalysts for methane decomposition to produce hydrogen and carbon nano materials

    KAUST Repository

    Zhou, Lu

    2017-02-21

    Conducting catalytic methane decomposition over Fe catalysts is a green and economic route to produce H2 without CO/CO2 contamination. Fused 65wt% and impregnated 20wt% Fe catalysts were synthesized with different additives to investigate their activity, whereas showing Fe-Al2O3 combination as the best catalyst. Al2O3 is speculated to expose more Fe00 for the selective deposition of carbon nano tubes (CNTs). A fused Fe (65wt%)-Al2O3 sample was further investigated by means of H2-TPR, in-situ XRD, HRTEM and XAS to conclude 750°C is the optimized temperature for H2 pre-reduction and reaction to obtain a high activity. Based on density functional theory (DFT) study, a reaction mechanism over Fe catalysts was proposed to explain the formation of graphite from unstable supersaturated iron carbides decomposition. A carbon deposition model was further proposed which explains the formation of different carbon nano materials.

  5. Preparation, bioactivity and mechanism of nano-hydroxyapatite/sodium alginate/chitosan bone repair material.

    Science.gov (United States)

    Liao, Jianguo; Li, Yanqun; Li, Haiyan; Liu, Jingxian; Xie, Yufen; Wang, Jianping; Zhang, Yongxiang

    2017-08-11

    As the major inorganic component of natural bone, nano-hydroxyapatite (n-HA) on its own is limited in its use in bone repair, due to its brittleness. Chitosan (CS) and sodium alginate (SAL) are used to reduce its brittleness and tendency to degradation. However, the compressive strength of the composite is still low, and its biological performance needs further study. Nano-hydroxyapatite/sodium alginate/chitosan (n-HA/SAL/CS) composite was prepared via an in situ synthesis method. Further, we prepared the n-HA/SAL/CS self-setting bone repair material by mixing n-HA/SAL/CS powder with a curing liquid (20 wt.% citric acid). In addition, the in vitro bioactivity and cell cytotoxicity were also explored. Transmission electron microscopy photos revealed that the n-HA crystals were uniformly distributed throughout the polymer matrix. Infrared IR spectroscopy indicated that the HA interacted with the COO- of SAL and NH2- of CS. The compressive strength of the n-HA/SAL/CS bone cement was 34.3 MPa and matched the demands of weight-bearing bones. Soaking in vitro in simulated body fluid demonstrated that the composite material had reasonably good bioactivity, while cytotoxicity tests indicated that the n-HA/SAL/CS cement could promote cell proliferation and was biocompatible. Compressive strength of n-HA/SAL/CS can satisfy the needs of cancellous bone, and in vitro bioactivity and cytotoxicity tests results indicated that the n-HA/SAL/CS composite could act as an optimal bone repair material.

  6. Influence of nano-inclusions' grain boundaries on crack propagation modes in materials

    Energy Technology Data Exchange (ETDEWEB)

    Karakasidis, T.E., E-mail: thkarak@uth.gr [Department of Civil Engineering, University of Thessaly, Pedion Areos, 38834 Volos (Greece); Charitidis, C.A. [National Technical University of Athens, School of Chemical Engineering, 9 Heroon Polytechniou st., Zografos, 157 80 Athens (Greece)

    2011-04-15

    The effect of nano-inclusions on materials' strength and toughness has attracted great interest in recent years. It has been shown that tuning the morphological and microstructural features of materials can tailor their fracture modes. The existence of a characteristic size of inclusions that favours the fracture mode (i.e. transgranular or intergranular) has been experimentally observed but also predicted by a 2D model based on energetic arguments which relates the crack propagation mode to the ratio of the interface area between the crystalline inclusion and the matrix with the area of the crystallite inclusion in a previous work. In the present work, a 3D model is proposed in order to extend the 2D model and take into account the influence of the size of grain boundary zone on the toughening/hardening behavior of the material as it was observed experimentally in the literature. The model relates crack propagation mode to the ratio of the volume of the grain boundary zone between the crystalline inclusion and the matrix with the volume of the nano-inclusion. For a ratio below a critical value, transgranular propagation is favoured while for larger values, intergranular propagation is favoured. We also demonstrate that the extent of the grain boundary region also can significantly affect this critical value. The results of the model are in agreement with the literature experimental observations related to the toughening/hardening behavior as a function of the size of crystalline inclusions as well as the width of the grain boundary regions.

  7. Nano-based sensor for assessment of weaponry structural degradation

    Science.gov (United States)

    Brantley, Christina L.; Edwards, Eugene; Ruffin, Paul B.; Kranz, Michael

    2016-04-01

    Missiles and weaponry-based systems are composed of metal structures that can degrade after prolonged exposure to environmental elements. A particular concern is accumulation of corrosion that generally results from prolonged environmental exposure. Corrosion, defined as the unintended destruction or deterioration of a material due to its interaction with the environment, can negatively affect both equipment and infrastructure. System readiness and safety can be reduced if corrosion is not detected, prevented and managed. The current corrosion recognition methods (Visual, Radiography, Ultrasonics, Eddy Current, and Thermography) are expensive and potentially unreliable. Visual perception is the most commonly used method for determining corrosion in metal. Utilization of an inductance-based sensor system is being proposed as part of the authors' research. Results from this research will provide a more efficient, economical, and non-destructive sensing approach. Preliminary results demonstrate a highly linear degradation within a corrosive environment due to the increased surface area available on the sensor coupon. The inductance of the devices, which represents a volume property of the coupon, demonstrated sensitivity to corrosion levels. The proposed approach allows a direct mass-loss measurement based on the change in the inductance of the coupon when placed in an alternating magnetic field. Prototype devices have demonstrated highly predictable corrosion rates that are easily measured using low-power small electronic circuits and energy harvesting methods to interrogate the sensor. Preliminary testing demonstrates that the device concept is acceptable and future opportunities for use in low power embedded applications are achievable. Key results in this paper include the assessment of typical Army corrosion cost, degradation patterns of varying metal materials, and application of wireless sensors elements.

  8. Lift-Off Free Fabrication Approach for Periodic Structures with Tunable Nano Gaps for Interdigitated Electrode Arrays.

    Science.gov (United States)

    Partel, Stefan; Dincer, Can; Kasemann, Stephan; Kieninger, Jochen; Edlinger, Johannes; Urban, Gerald

    2016-01-26

    We report a simple, low-cost and lift-off free fabrication approach for periodic structures with adjustable nanometer gaps for interdigitated electrode arrays (IDAs). It combines an initial structure and two deposition process steps; first a dielectric layer is deposited, followed by a metal evaporation. The initial structure can be realized by lithography or any other structuring technique (e.g., nano imprint, hot embossing or injection molding). This method allows the fabrication of nanometer sized gaps and completely eliminates the need for a lift-off process. Different substrate materials like silicon, Pyrex or polymers can be used. The electrode gap is controlled primarily by sputter deposition of the initial structure, and thus, adjustable gaps in the nanometer range can be realized independently of the mask or stamp pattern. Electrochemical characterizations using redox cycling in ferrocenemethanol (FcMeOH) demonstrate signal amplification factors of more than 110 together with collection factors higher than 99%. Furthermore, the correlation between the gap width and the amplification factor was studied to obtain an electrochemical performance assessment of the nano gap electrodes. The results demonstrate an exponential relationship between amplification factor and gap width.

  9. Experiment and prediction on thermal conductivity of Al2O3/ZnO nano thin film interface structure

    Indian Academy of Sciences (India)

    Ping Yang; Liqiang Zhang; Haiying Yang; Dongjing Liu; Xialong Li

    2014-05-01

    We predict that there is a critical value of Al2O3/ZnO nano thin interface thickness based on two assumptions according to an interesting phenomenon, which the thermal conductivity (TC) trend of Al2O3/ZnO nano thin interface is consistent with that of relevant single nano thin interface when the nano thin interface thickness is > 300 nm; however, TC of Al2O3/ZnO nano thin interface is higher than that of relevant single nano thin interface when the thin films thickness is < 10 nm. This prediction may build a basis for the understanding of interface between two different oxide materials. It implies an idea for new generation of semiconductor devices manufacturing.

  10. Unified nano-mechanics based probabilistic theory of quasibrittle and brittle structures: I. Strength, static crack growth, lifetime and scaling

    Science.gov (United States)

    Le, Jia-Liang; Bažant, Zdeněk P.; Bazant, Martin Z.

    2011-07-01

    Engineering structures must be designed for an extremely low failure probability such as 10 -6, which is beyond the means of direct verification by histogram testing. This is not a problem for brittle or ductile materials because the type of probability distribution of structural strength is fixed and known, making it possible to predict the tail probabilities from the mean and variance. It is a problem, though, for quasibrittle materials for which the type of strength distribution transitions from Gaussian to Weibullian as the structure size increases. These are heterogeneous materials with brittle constituents, characterized by material inhomogeneities that are not negligible compared to the structure size. Examples include concrete, fiber composites, coarse-grained or toughened ceramics, rocks, sea ice, rigid foams and bone, as well as many materials used in nano- and microscale devices. This study presents a unified theory of strength and lifetime for such materials, based on activation energy controlled random jumps of the nano-crack front, and on the nano-macro multiscale transition of tail probabilities. Part I of this study deals with the case of monotonic and sustained (or creep) loading, and Part II with fatigue (or cyclic) loading. On the scale of the representative volume element of material, the probability distribution of strength has a Gaussian core onto which a remote Weibull tail is grafted at failure probability of the order of 10 -3. With increasing structure size, the Weibull tail penetrates into the Gaussian core. The probability distribution of static (creep) lifetime is related to the strength distribution by the power law for the static crack growth rate, for which a physical justification is given. The present theory yields a simple relation between the exponent of this law and the Weibull moduli for strength and lifetime. The benefit is that the lifetime distribution can be predicted from short-time tests of the mean size effect on

  11. Influence of contamination on resin bond strength to nano-structured alumina-coated zirconia ceramic.

    Science.gov (United States)

    Zhang, Shanchuan; Kocjan, Andraz; Lehmann, Frank; Kosmac, Tomaz; Kern, Matthias

    2010-08-01

    The purpose of this study was to evaluate the influence of contamination and subsequent cleaning on the bond strength and durability of an adhesive resin to nano-structured alumina-coated zirconia ceramic. Zirconia ceramic disks were coated with nano-structured alumina, utilizing the hydrolysis of aluminum nitride powder. After immersion in saliva or the use of a silicone disclosing agent, specimens were cleaned with phosphoric acid etching or with tap water rinsing only. Uncontaminated specimens served as controls. Plexiglas tubes filled with composite resin were bonded with a phosphate monomer [10-methacryloxydecyl-dihydrogenphosphate (MDP)]-containing resin (Panavia 21). Subgroups of eight specimens each were stored in distilled water at 37 degrees C, either for 3 d without thermal cycling (TC) or for 150 d with 37,500 thermal cycles from 5 to 55 degrees C. The tensile bond strength (TBS) was determined using a universal testing machine at a crosshead speed of 2 mm min(-1). The topography of the debonded surface was scrutinized for fractographic features, utilizing both optical and scanning electron microscopy. The TBS to uncontaminated nano-structured alumina-coated zirconia ceramic was durable, while contamination significantly reduced the TBS. Phosphoric acid cleaning was effective in removal of saliva contamination from the coated bonding surface but was not effective in removal of the silicone disclosing agent. Nano-structured alumina coating improves resin bonding to zirconia ceramic and eliminates the need for air-abrasion before bonding.

  12. Focused ion beam nano-structuring of Bragg gratings in $Al_2O_3$ channel waveguides

    NARCIS (Netherlands)

    Ay, Feridun; Uranga, Amaia; Bradley, Jonathan D.B.; Wörhoff, Kerstin; Ridder, de René M.; Pollnau, Markus; Ridder, de R.M.; Ay, F.; Kauppinen, L.J.

    2008-01-01

    We report our recent results on an optimization study of focused ion beam (FIB) nano-structuring of Bragg gratings in $Al_2O_3$ channel waveguides. By optimizing FIB milling parameters such as ion current, dwell time, loop repetitions, scanning strategy, and applying a top metal layer for reducing c

  13. Towards the understanding of structure formation and dynamics in bio-nano systems

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2008-01-01

    This paper gives an overview of a number of key structure formation processes involving the well known biomolecular and nano objects such as fullerenes, nanotubes, polypeptides, proteins and DNA molecules. We formulate the problems, describe the main experimental observations and theoretical adva...

  14. Review of the Multi-scale Nano-structure Approach to the Development of High Efficiency Solar Cells

    Directory of Open Access Journals (Sweden)

    Seung Hwan Ko

    2014-05-01

    Full Text Available The energy crisis is one of the most urgent problem we face today. Among all the different and reliable clean energy sources, solar energy has been getting much attention as a possible solution. However, the use of the solar cell is still limited by two major challenges, conversion efficiency and cost. In this review, recent promising progress in hierarchical nanostructures such as branched nanoforest and nanoporous structures to develop high efficiency solar cells are discussed. One of the major trends in the research into high efficiency solar cells is a focus on new material development. However, smart nano-structuring that enhances the surface area with 2D and 3D hierarchical nanostructures and improved carrier mobility, using the same materials, can further boost cell efficiency.

  15. Fabrication of micro/nano hierarchical structures with analysis on the surface mechanics

    Science.gov (United States)

    Jheng, Yu-Sheng; Lee, Yeeu-Chang

    2016-10-01

    Biomimicry refers to the imitation of mechanisms and features found in living creatures using artificial methods. This study used optical lithography, colloidal lithography, and dry etching to mimic the micro/nano hierarchical structures covering the soles of gecko feet. We measured the static contact angle and contact angle hysteresis to reveal the behavior of liquid drops on the hierarchical structures. Pulling tests were also performed to measure the resistance of movement between the hierarchical structures and a testing plate. Our results reveal that hierarchical structures at the micro-/nano-scale are considerably hydrophobic, they provide good flow characteristics, and they generate more contact force than do surfaces with micro-scale cylindrical structures.

  16. Characterizing the nano and micro structure of concrete to improve its durability

    KAUST Repository

    Monteiro, P.J.M.

    2009-09-01

    New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper. © 2009 Elsevier Ltd. All rights reserved.

  17. Self-assembled dual-sided hemispherical nano-dimple-structured broadband antireflection coatings

    Science.gov (United States)

    Lin, Cheng-Yen; Lin, Kun-Yi; Tsai, Hui-Ping; He, Yi-Xuan; Yang, Hongta

    2016-11-01

    A non-lithography-based approach is developed in this study for assembling monolayer close-packed hemispherical nano-dimple arrays on both sides of a PET film by a scalable Langmuir-Blodgett technology. The resulting gratings greatly suppress specular reflection and therefore enhance specular transmission for a broad range of visible wavelengths, resulting from a gradual change in the effective refractive index at air/PET interface. The experimental results reveal that the antireflection properties of the as-fabricated coatings are affected by the size of the nano-dimples. Moreover, both optical performances of single-sided and dual-sided nano-dimple-structured coatings have been investigated in this study.

  18. Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Li Yubao; Zhou Gang; Wu Lan; Mu Yuanhua; Yang Zheng

    2007-01-01

    Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca(OH)2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, bum-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.

  19. The electrical conductivity characteristics of Fe/Cu nano-scale multilayer materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A mathematical model for describing the relationship betweenelectrical conductivity and the thickness of bilayer, ratio of sublayer thickness of a nano-scale multilayer material (MLM) is presented. Fe/Cu MLM was synthesized by electron beam physical vapor deposition (EB-PVD) technique, and the dependence of electrical conductivity of Fe/Cu MLM on the bilayer thickness and ratio of sublayer thickness were investigated. It is shown that the electrical conductivity of Fe/Cu MLM with fixed ratio of sublayer thickness decreases sharply when the thickness of bilayer becomes thinner than 30 nm. When the bilayer thickness is kept constant, the electrical conductivity linearly decreases with the increasing ratio of sublayer thickness. The values of parameters in the model were obtained by fitting the measured results of electrical conductivity of Fe/Cu MLM with fixed ratio of sublayer thickness. It is found that the calculated values agree well with measured ones.

  20. Removal of lead ions using hydroxyapatite nano-material prepared from phosphogypsum waste

    Directory of Open Access Journals (Sweden)

    S.M. Mousa

    2016-05-01

    Full Text Available Nano-material of calcium hydroxyapatite (n-CaHAP, with particle size ranging from 50 to 57 nm which was prepared from phosphogypsum waste (PG, was used for the removal of lead ions (Pb (II from aqueous solutions. It was investigated in a batch reactor under different experimental conditions. Effects of process parameters such as pH, initial Pb ion concentration and adsorbent dose were studied. Also, various types of kinetic modeling have been studied where the lead uptake was quantitatively evaluated using the Langmuir, Freundlich and Dubinin–Kaganer–Radushkevich (DKR model. The Pb ions adsorption onto n-CaHAP could best fit the Langmuir isotherm model. The maximum adsorption capacity (qmax for Pb ions was 769.23 mg/g onto n-CaHAP particles.

  1. Emission Mössbauer spectroscopy of advanced materials for opto- and nano-electronics

    CERN Multimedia

    Olafsson, S; Weyer, G O P; Masenda, H; Dlamini, W B

    Mössbauer Spectroscopy (MS) is a versatile solid state method giving information about probe atom interactions with its nearest neighbours. Simultaneously, information on the probe valence state, site symmetry, and electric and magnetic hyperfine interactions is obtained. MS can be applied in many different contexts in material science and solid state physics. MS using radioactive isotopes, applied for decades at the ISOLDE facilities, has the particular merit of very high sensitivity. This opens up many new possibilities compared to traditional (absorption) Mössbauer spectroscopy. Among them is the possibility of working with very low concentrations (10$^{-4}$ at. ~\\%), where the probe atoms are true dilute impurities. Here we propose four main themes in our Mössbauer investigations for the coming years: \\\\(1) Para-magnetic relaxations in compound semiconductors. \\\\(2) Vacancy diffusion in group IV semiconductors. \\\\(3) Doping of Si-nano-particles. \\\\(4) Investigation of phase change mechanisms in chalcog...

  2. Condensation and Wetting Dynamics on Micro/Nano-Structured Surfaces

    Science.gov (United States)

    Olceroglu, Emre

    Because of their adjustable wetting characteristics, micro/nanostructured surfaces are attractive for the enhancement of phase-change heat transfer where liquid-solid-vapor interactions are important. Condensation, evaporation, and boiling processes are traditionally used in a variety of applications including water harvesting, desalination, industrial power generation, HVAC, and thermal management systems. Although they have been studied by numerous researchers, there is currently a lack of understanding of the underlying mechanisms by which structured surfaces improve heat transfer during phase-change. This PhD dissertation focuses on condensation onto engineered surfaces including fabrication aspect, the physics of phase-change, and the operational limitations of engineered surfaces. While superhydrophobic condensation has been shown to produce high heat transfer rates, several critical issues remain in the field. These include surface manufacturability, heat transfer coefficient measurement limitations at low heat fluxes, failure due to surface flooding at high supersaturations, insufficient modeling of droplet growth rates, and the inherent issues associated with maintenance of non-wetted surface structures. Each of these issues is investigated in this thesis, leading to several contributions to the field of condensation on engineered surfaces. A variety of engineered surfaces have been fabricated and characterized, including nanostructured and hierarchically-structured superhydrophobic surfaces. The Tobacco mosaic virus (TMV) is used here as a biological template for the fabrication of nickel nanostructures, which are subsequently functionalized to achieve superhydrophobicity. This technique is simple and sustainable, and requires no applied heat or external power, thus making it easily extendable to a variety of common heat transfer materials and complex geometries. To measure heat transfer rates during superhydrophobic condensation in the presence of non

  3. Structure and magnetic properties of Co and Ni nano-ferrites prepared by a two step direct microemulsions synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Pulišová, P., E-mail: pulisovap@yahoo.com [Faculty of Metallurgy, Technical University of Košice, Park Komenského 3, 04200 Košice (Slovakia); Institute of Inorganic Chemistry of the AS CR, v.v.i., Husinec-Řež 1001, 25068 Řež (Czech Republic); Kováč, J. [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice (Slovakia); Voigt, A. [Process Systems Engineering, Otto-von-Guericke Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg (Germany); Raschman, P. [Faculty of Metallurgy, Technical University of Košice, Park Komenského 3, 04200 Košice (Slovakia)

    2013-09-15

    Nano-particles of CoFe{sub 2}O{sub 4}, NiFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} were synthesized by a two step microemulsion precipitation where inverse micelles of water in hexanol were stabilized using cetyltrimethylammonium bromide. Powder X-ray diffraction analysis and Transmission electron microscopy measurements provided data to clarify the crystal structure and size of the produced nano-particles. Different measurements of magnetic properties at low temperatures of 2 K revealed that nano-particles of NiFe{sub 2}O{sub 4} represent magnetically soft ferrite with a coercivity ∼40 kA/m, whereas nano-particles of CoFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} were magnetically harder with a coercivity of 815 and 947 kA/m, respectively. Additionally zero field cooling and field cooling measurements provided data for estimating the blocking temperature of the materials produced. For NiFe{sub 2}O{sub 4} this temperature is lower, 23 K. The blocking temperature of CoFe{sub 2}O{sub 4} of 238 K and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} of 268 K are higher in comparison with NiFe{sub 2}O{sub 4}. - Highlights: • Nano-scale ferrites prepared by precipitation in microemulsions show magnetic behavior. • XRD and TEM found that particle size of prepared magnetic nano-ferrites is in range from 5 to 10 nm. • Prepared CoFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} ferrites are magnetically harder than NiFe{sub 2}O{sub 4} ferrite. • Precipitation in microemulsions offers preparation at low temperature as cost effective method.

  4. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures.

    Science.gov (United States)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano-structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-wire array center gradually formed micro-flower like structure evolved in this solvo-chemical route. This novel synthesis happened under cationic surfactant CTAB in the solution helps to form hierarchical structures of ZnO. The length of nano-wire is around 2.0 µm, which formed micro-flower diameter 5.0 µm. Micro-flowers were scratched out from ITO substrate thin film and annealed at 650 °C in electric oven for 1 hour, eventually this micro-flower transformed to novel nano-rose structure confirmed by electron microscopic study. Synthesized nano-rose diameter was around 730 nm. Moreover, we found a drastic change of dielectric behavior and DC conductivity of ZnO nanostructures depending on geometry regulated by the duration of preparation. Interestingly enough, optical and electrical properties also changed due to different crystalline structure formation. The dielectric constant is higher at 7.5 also high threshold voltages at 4 V, corresponds to nano-wires array with micro-flower system. A detail dielectric analysis of one step behavior of broad single relaxation peak was obtained only shows the normal dispersion in this system from 1000 kHz to 10 MHz. While less dielectric constant 1.7 and low threshold voltage 1 V, investigated nano-wires with micro-flower, then nano-rose transition appeared in two step behaviors of double relaxations phenomenon appeared one at low frequency and other at higher frequency region. Besides, I~V response characteristics is new idea about different breakdown voltages and bi-stable DC switching capability. Our work demonstrates the possibility of a fast novel synthesis route using a Solvo-chemical process for this type of nanomaterials

  5. Deposition by liquid epitaxy and study of the properties of nano-heteroepitaxial structures with quantum dots for high efficient solar cells

    Science.gov (United States)

    Maronchuk, I. I.; Maronchuk, I. E.; Sankovitch, D. D.; Lovchinov, K.; Dimova-Malinovska, D.

    2014-12-01

    The paper presents experimental results showing the possibility of liquid-phase epitaxy with a pulse-cooled substrate nano-heteroepitaxial structures with Ge quantum dots and GaP matrix for production of single-junction solar cells working under sun light concentration. The preparation of the surface of Si wafers suitable for growing of these structures is described. The optimal technological conditions for growing of the of GaP buffer layer on the Si wafer from supersaturated solutions of melts Sn are applied. Structures with Ge quantum dots are grown at different conditions and study of their structural and optical properties is performed. The surface morphology of the grown materials is studied by AFM microscopy. The photoluminescence spectra of nano-heteroepitaxial structures with Ge quantum dots are presented and analyzed.

  6. The Influence of Nano-Materials in Presence of Vinyl Acetate Copolymer ( Beva 371 for Consolidation of an Egyptian Coptic Fresco Painting

    Directory of Open Access Journals (Sweden)

    Mona F. Ali

    2016-05-01

    Full Text Available Nano-lime dispersed in propanol was extensively used for consolidation of mural paintings. Current result pointed out the effect of using different nano-dispersed materials (nano silica, nano calcium hydroxide and carbonate with Beva 37 soluble in toluene/ethanol to consolidate models of an Egyptian Coptic fresco. Scanning electron microscope (SEM, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and spectrophotometer were used to determine the visual properties, morphological and physical properties of the treated models. The influence of treatment on various mechanical characteristics of consolidated models were also, tested in detail by means of tests on specimens of the treated models. The treatment was carried out in presence of the nano-materials with or without the polymeric material. The mechanical characteristics of the treated models were improved. This can be attributed to nano-calcium hydroxide was turned into calcium carbonate and both of nano- silica and nano-calcium carbonate appeared as filler. The high impact of nano-materials remind even in presence of polymeric material (Beva 371.

  7. Surface nano-patterning in realizing large-scale ordered arrays of metallic nanoshells with controllable structures and properties

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shikuan; Xu, Feng; Winkler, Nina; Zhao, Huaping; Lei, Yong [Institute of Materials Physics, University of Muenster (Germany); Center for Nanotechnology (Germany)

    2011-07-01

    Surface patterns of metallic nanostructure arrays play an important role in many application areas such as surface-enhanced Raman scattering sensors, lithium-ion batteries, solar cells, and optical devices. Here we present an innovative surface nano-patterning technique in our group for realizing large-scale ordered arrays of metallic spherical nanoshells with well-defined structures. Silver nanoshell arrays are synthesized using polystyrene sphere templates by an electrophoretic process. The fabricated Ag nanoshell arrays have a high controllability of the structural parameters, including the diameter, the surface roughness, and the inter-shell spacing. And the properties of the synthesized nanoshell arrays can be controlled based on the adjustment of the structural parameters. As an example, tunable surface-enhanced Raman scattering and localized surface plasmon resonance of the nanoshell arrays are demonstrated by controlling the structural parameters. The presented surface nano-patterning technique is a general fabrication process in achieving not only metallic nanoshell arrays, but also nanoshell arrays of other materials, such as semiconductors and metallic oxides.

  8. Sensing characteristics of plasmonic structure based on transferring process of polystyrene nano-beads

    Science.gov (United States)

    Kim, Doo Gun; Hwang, Jeongwoo; Kim, Seon Hoon; Ki, Hyun Chul; Kim, Tae Un; Shin, Jae Cheol; Jeong, Dae-Cheol; Jeon, Seungwon; Kim, Hong-Seung; Choi, Young-Wan

    2016-04-01

    We analyzed and demonstrated the double layered metallic nano-structures using polystyrene lift-off process on the conventional surface plasmon resonance (SPR) sensor to enhance the sensitivity of an SPR surface. The double layered plasmonic structures are optimized using the three-dimensional finite-difference time-domain method for the width, thickness, and period of the polystyrene beads. The thickness of the metal film and the metallic nano-hole is 20 and 20 nm in the 305 nm wide nano-hole size, respectively. The double layered metallic nano-structures are fabricated with monolayer polystyrene beads of chloromethyl latex 4% w/v 0.4 μm. The sensitivities of the conventional SPR sensor and the double layered plasmonic sensor are obtained to 42.2 and 60 degree/RIU, respectively. The SPR devices are also applied to the lead ion sensor. The resonance shifts of SPR sensors with and without a poly(vinyl chloride) membrane are 1328 RU and 788 RU from 10-5 M to 10-2 M concentration, respectively.

  9. Radiation effects on structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Ghoniem, N.M.

    1991-06-28

    This report discusses the following topics on the effect radiation has on thermonuclear reactor materials: Atomic Displacements; Microstructure Evolution; Materials Engineering, Mechanics, and Design; Research on Low-Activation Steels; and Research Motivated by Grant Support.

  10. Nano-Material and Structural Engineering for Thermal Highways

    Science.gov (United States)

    2013-06-14

    growing interests arising from this effort. It will likely extend its impact beyond thermal management into basic sciences for years to come...carbon nanotube microfin architectures used as a heat sink device [1,2]. While incorporating macroscale thermal management concepts on a micro and...ultrasmooth and ultraconductive Bi films would generate great interests and impact on the thermoelectric research field that has suffered from its lack

  11. Materials research at Stanford University. [composite materials, crystal structure, acoustics

    Science.gov (United States)

    1975-01-01

    Research activity related to the science of materials is described. The following areas are included: elastic and thermal properties of composite materials, acoustic waves and devices, amorphous materials, crystal structure, synthesis of metal-metal bonds, interactions of solids with solutions, electrochemistry, fatigue damage, superconductivity and molecular physics and phase transition kinetics.

  12. Investigation into the effects of high-Z nano materials in proton therapy

    Science.gov (United States)

    Ahmad, R.; Royle, G.; Lourenço, A.; Schwarz, M.; Fracchiolla, F.; Ricketts, K.

    2016-06-01

    High-Z nano materials have been previously shown to increase the amount of dose deposition within the tumour due to an increase in secondary electrons. This study evaluates the effects of high-Z nano materials in combination with protons, and the impact of proton energy, nanoparticle material and concentration. These effects were studied in silico through Monte Carlo simulation and experimentally through a phantom study, with particular attention to macroscale changes to the Bragg peak in the presence of nanoparticles. Three nanoparticle materials were simulated (gold, silver and platinum) at three concentrations (0.01, 0.1 and 6.5 mg ml-1) at two clinical proton energies (60 and 226 MeV). Simulations were verified experimentally using Gafchromic film measurements of gold nanoparticles suspended in water at two available high concentrations (5.5 mg ml-1 and 1.1 mg ml-1). A significant change to Bragg peak features was evident, where at 226 MeV and 6.5 mg ml-1, simulations of gold showed a 4.7 mm longitudinal shift of the distal edge and experimentally at 5.5 mg ml-1, a shift of 2.2 mm. Simulations showed this effect to be material dependent, where platinum having the highest physical density caused the greatest shift with increasing concentration. A dose enhancement of 6%  ±  0.05 and 5%  ±  0.15 (60 MeV and 226 MeV, respectively) was evident with gold at 6.5 mg ml-1 to water alone, compared to the 21%  ±  0.53 observed experimentally as dose to film with 5.5 mg ml-1 of gold nanoparticles suspended in water at 226 MeV. The introduction of nanoparticles has strong potential to enhance dose in proton therapy, however the changes to the Bragg peak distribution that occur with high concentrations need to be accounted for to ensure tumour coverage.

  13. Nano-coatings Used in Building Materials%建筑纳米涂料崭露头角

    Institute of Scientific and Technical Information of China (English)

    杨忠敏

    2012-01-01

    To introduce the definition,application,status quo,properties,and market prospect of nano-coatings used in building materials.%介绍建筑纳米涂料定义,应用现状,性能优势和市场前景。

  14. Nano- and micro-structured silicon for hybrid near-infrared photodetectors

    Science.gov (United States)

    Äńerek, V.; Głowacki, E. D.; Bednorz, M.; Demchyshyn, S.; Sariciftci, N. S.; Ivanda, M.

    2016-05-01

    Structuring surface and bulk of crystalline silicon on different length scales can significantly alter its properties and possibly improve the performance of opto-electronic devices and sensors based on silicon. Different dominant feature scales are responsible for modification of some of electronic and optical properties of silicon. Several easily reproducible chemical methods for facile structuring of silicon on nano and micro-scales, based on both electroless and anodic etching of silicon in hydrofluoric acid based etchants, and chemical anisotropic etching of silicon in basic environments, are presented. We show how successive micro and nano structuring creates hierarchical silicon surfaces, which can be used to simultaneously exploit the advantages of both structuring feature length scales. Finally, we demonstrate a large increase in photocurrent obtained from a hybrid structured silicon/organic near-infrared photodetector. Improved silicon/6,6'-dibromoindigo hybrid photodiodes were prepared by nano- and micro-structuring the silicon part of the heterojunction by wet chemical etching methods. Photocurrent and spectral responsivity were improved in comparison to planar diodes by up to two orders of magnitude by optimization of the silicon structuring process. We show that the improvement in photocurrent is not due to the increase in surface area or light trapping.

  15. NASICON-Structured Materials for Energy Storage.

    Science.gov (United States)

    Jian, Zelang; Hu, Yong-Sheng; Ji, Xiulei; Chen, Wen

    2017-05-01

    The demand for electrical energy storage (EES) is ever increasing, which calls for better batteries. NASICON-structured materials represent a family of important electrodes due to its superior ionic conductivity and stable structures. A wide range of materials have been considered, where both vanadium-based and titanium-based materials are recommended as being of great interest. NASICON-structured materials are suitable for both the cathode and the anode, where the operation potential can be easily tuned by the choice of transition metal and/or polyanion group in the structure. NASICON-structured materials also represent a class of solid electrolytes, which are widely employed in all-solid-state ion batteries, all-solid-state air batteries, and hybrid batteries. NASICON-structured materials are reviewed with a focus on both electrode materials and solid-state electrolytes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Bio-inspired variable structural color materials.

    Science.gov (United States)

    Zhao, Yuanjin; Xie, Zhuoying; Gu, Hongcheng; Zhu, Cun; Gu, Zhongze

    2012-04-21

    Natural structural color materials, especially those that can undergo reversible changes, are attracting increasing interest in a wide variety of research fields. Inspired by the natural creatures, many elaborately nanostructured photonic materials with variable structural colors were developed. These materials have found important applications in switches, display devices, sensors, and so on. In this critical review, we will provide up-to-date research concerning the natural and bio-inspired photonic materials with variable structural colors. After introducing the variable structural colors in natural creatures, we will focus on the studies of artificial variable structural color photonic materials, including their bio-inspired designs, fabrications and applications. The prospects for the future development of these fantastic variable structural color materials will also be presented. We believe this review will promote the communications among biology, bionics, chemistry, optical physics, and material science (196 references).

  17. Simulation and Measurement of Neuroelectrodes' Characteristics with Integrated High Aspect Ratio Nano Structures

    Directory of Open Access Journals (Sweden)

    Christoph Nick

    2015-07-01

    Full Text Available Improving the interface between electrodes and neurons has been the focus of research for the last decade. Neuroelectrodes should show small geometrical surface area and low impedance for measuring and high charge injection capacities for stimulation. Increasing the electrochemically active surface area by using nanoporous electrode material or by integrating nanostructures onto planar electrodes is a common approach to improve this interface. In this paper a simulation approach for neuro electrodes' characteristics with integrated high aspect ratio nano structures based on a point-contact-model is presented. The results are compared with experimental findings conducted with real nanostructured microelectrodes. In particular, effects of carbon nanotubes and gold nanowires integrated onto microelectrodes are described. Simulated and measured impedance properties are presented and its effects onto the transfer function between the neural membrane potential and the amplifier output signal are studied based on the point-contact-model. Simulations show, in good agreement with experimental results, that electrode impedances can be dramatically reduced by the integration of high aspect ratio nanostructures such as gold nanowires and carbon nanotubes. This lowers thermal noise and improves the signal-to-noise ratio for measuring electrodes. It also may increase the adhesion of cells to the substrate and thus increase measurable signal amplitudes.

  18. Modelling the Size Effects on the Mechanical Properties of Micro/Nano Structures

    Science.gov (United States)

    Abazari, Amir Musa; Safavi, Seyed Mohsen; Rezazadeh, Ghader; Villanueva, Luis Guillermo

    2015-01-01

    Experiments on micro- and nano-mechanical systems (M/NEMS) have shown that their behavior under bending loads departs in many cases from the classical predictions using Euler-Bernoulli theory and Hooke’s law. This anomalous response has usually been seen as a dependence of the material properties on the size of the structure, in particular thickness. A theoretical model that allows for quantitative understanding and prediction of this size effect is important for the design of M/NEMS. In this paper, we summarize and analyze the five theories that can be found in the literature: Grain Boundary Theory (GBT), Surface Stress Theory (SST), Residual Stress Theory (RST), Couple Stress Theory (CST) and Surface Elasticity Theory (SET). By comparing these theories with experimental data we propose a simplified model combination of CST and SET that properly fits all considered cases, therefore delivering a simple (two parameters) model that can be used to predict the mechanical properties at the nanoscale. PMID:26569256

  19. Ab initio calculation and spectral properties of nano- and bulk materials

    Energy Technology Data Exchange (ETDEWEB)

    Kulagin, N. A., E-mail: nkulagin@bestnet.kharkov.ua [Kharkov National University for Radioelectronics (Ukraine)

    2013-01-15

    This paper presents the development of ab initio calculation of the electronic structure of either clusters, nano-crystals, doped and unperfected bulk crystals. In addition, analysis of selected experimental data for {gamma}- or plasma irradiated pure and doped wide-band gap oxides such as sapphire, {alpha}-Al{sub 2}O{sub 3}, garnet, Y{sub 3}Al{sub 5}O{sub 12}, Gd{sub 3}Sc{sub 2}Al{sub 3}O{sub 12} and perovskites YAlO{sub 3}, SrTiO{sub 3} is presented. Change in the crystals surface morphology and spectroscopic properties of sapphire, perovskites, garnets as well as ion oxidation state in pure and doped {gamma}- and plasma irradiated crystals are discussed in detail using the optical and X ray spectroscopy experimental results.

  20. Nano-structural and Nano-chemical analysis of dissimilar metal weld interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung Joon; Shin, Shang Hoon; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2011-10-15

    Dissimilar metal weld is generally applied to nuclear power plant for manufacturing and machining in structural components such as RPV and Pressurizer nozzles. Alloy 152 is used frequently as filler metal in the manufacture of dissimilar metal welds (DMWs) in light water reactors (LWR) to join the low alloy steel (LAS) pressure vessel nozzles and steam generator nozzles to nickel-based wrought alloy or austenitic stainless steel components. The thermal expansion coefficient of the alloy lies between those of ferrite steel and austenitic stainless steel, and it also significantly retards the carbon diffusion from the ferrite base metal to the weld metal. However, in recent years cracking phenomena have been observed in the welded joints. A concern has been raised about the integrity and reliability in the joint transition zone due to the high susceptibility of heat affected zone (HAZ) and fusion zone (FZ) to stress corrosion cracking (SCC). The dissimilar metal joints which were welded between Inconel 690, Ni-based alloy and A533B, low alloy steel with Inconel 152, filler metal were investigated. This study shows microstructural and chemical analysis between Inconel 152 and A533B by using optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), secondary ion mass spectrometry (SIMS) and 3 dimension atom probe (3D AP). In the root region, OM and SEM analysis show the microstructure which contains the interface of Inconel 152 and A533B near the rooter region. And it shows unidentified band structure which is formed along weld interface. AP and TEM/EDS analyses show the chemical gradient containing higher Fe but lower Mn, Ni and Cr than Inconel 152 and the unidentified band

  1. Carbon-based catalysts:Opening new scenario to develop next-generation nano-engineered catalytic materials

    Institute of Scientific and Technical Information of China (English)

    Claudio Ampelli; Siglinda Perathoner; Gabriele Centi

    2014-01-01

    This essay analyses some of the recent development in nanocarbons (carbon materials having a defined and controlled nano-scale dimension and functional properties which strongly depend on their nano-scale features and architecture), with reference to their use as advanced catalytic materials. It is remarked how their features open new possibilities for catalysis and that they represent a new class of catalytic materials. Although carbon is used from long time in catalysis as support and electrocatalytic applications, nanocarbons offer unconventional ways for their utilization and to address some of the new challenges deriving from moving to a more sustainable future. This essay comments how nanocarbons are a key element to develop next-generation catalytic materials, but remarking that this goal requires overcoming some of the actual limits in current research. Some aspects are discussed to give a glimpse on new directions and needs for R&D to progress in this direction.

  2. Efficient gas sensitivity in mixed bismuth ferrite micro (cubes) and nano (plates) structures

    Energy Technology Data Exchange (ETDEWEB)

    Waghmare, Shivaji D.; Jadhav, Vijaykumar V.; Gore, Shaym K. [Center for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, Maharashtra (India); Yoon, Seog-Joon; Ambade, Swapnil B. [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-1791 (Korea, Republic of); Lokhande, B.J. [Department of Physics, Solapur University, Solapur (India); Mane, Rajaram S., E-mail: rsmane_2000@yahoo.com [Center for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, Maharashtra (India); Han, Sung-Hwan, E-mail: shhan@hanyang.ac.kr [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-1791 (Korea, Republic of)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Micro (cubes) structure embedded in nano (plates) of bismuth ferrite was prepared by a chemical method. ► These structures were characterized by XRD and SEM. ► LPG, CO{sub 2} and NH{sub 4} gases were exposed. ► Properties related to gas sensors were measured and reported. -- Abstract: Mixed micro (cubes) and nano (plates) structures of bismuth ferrite (BFO) have been synthesized by a simple and cost-effective wet-chemical method. Structural, morphological and phase confirmation characteristics are measured using X-ray diffraction, field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis techniques. The digital FE-SEM photo-images of BFO sample confirmed an incubation of discrete micro-cubes into thin and regularly placed large number of nano-plates. The bismuth ferrite, with mixed structures, films show considerable performance when used in liquefied petroleum (LPG), carbon dioxide (CO{sub 2}) and ammonium (NH{sub 3}) gas sensors application. Different chemical entities in LPG have made it more efficient with higher sensitivity, recovery and response times compared to CO{sub 2} and NH{sub 3} gases. Furthermore, effect of palladium surface treatment on the gas sensitivity and the charge transfer resistances of BFO mixed structures is investigated and reported.

  3. Structural Materials for Innovative Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yvon, Pascal [Commissariat a l' energie atomique - CEA (France)

    2011-07-01

    This series of slides deal with: the goals for advanced fission reactor systems; the requirements for structural materials; a focus on two important types of materials: ODS and CMC; a focus on materials under irradiation (multiscale modelling, experimental simulation, 'smart' experiments in materials testing reactors); some concluding remarks.

  4. Special section on Nano-Catalysis

    CSIR Research Space (South Africa)

    Makgwane, PR

    2013-01-01

    Full Text Available This special issue on nano-catalysis was devoted to the development and application of nanosized structured catalysts materials in various fields such as chemical transformation, environmental cleaning and energy generation supply as a concept tool...

  5. Investigation of nano-talc as a filling material and a reinforcing agent in high density polyethylene (HDPE)

    Institute of Scientific and Technical Information of China (English)

    CHEN Nanchun; MA Lei; ZHANG Tao

    2006-01-01

    An experiment of producing high density polyethylene (HDPE) nano-composite filled with 4wt.% talc was presented. Acting as filler and a reinforcing agent in the HDPE, talc powder, sized at around 5 μm, was surface-treated with aluminum diethylene glycol dinitrate coupling agent before adding to the HDPE. Analyses of the reinforced HDPE nano-composite show significant improvement in its mechanical properties including, tensile strength (>26 MPa), break elongation (<1.1%), flexural strength (>22 MPa), and friction coefficients<0.11. The results demonstrate that, after surface-treated, talc can be used as a promising filling material and a reinforcing agent in making HDPE nano-composite.

  6. Synthesis of Hierarchical CoO Nano/Microstructures as Anode Materials for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Dan Qin

    2014-01-01

    Full Text Available Hierarchical CoO nano/microstructures are synthesized via a hydrothermal method and a subsequent annealed process. When evaluated for use in lithium-ion batteries, hierarchical CoO nano/microstructures show a high initial discharge capacity of 1370 mAh/g and a high reversible capacity of 1148 mAh/g over 20 cycles at a current density of 100 mA/g. Superior rate performance with coulombic efficiency of about 100% upon galvanostatic cycling is also revealed. The excellent electrochemical properties of hierarchical CoO nano/microstructures make it a promising alternative anode material for high power lithium-ion batteries applications.

  7. Designing of Hybrid Structured Glass Laminated Transparent Nano Composites through Vacuum infusion Technique

    Science.gov (United States)

    Mukherji, A.; Tarapure, N. D.; Wakure, G. N.

    2017-05-01

    Glass is the most commonly used transparent material. However, glass is not suitable in applications where low weight, high strength is required. The present invention comprises a method of making a Transparent Glass Laminated Nano composite product. The product contains a Bidirectionally oriented E-Glass Fabric an essentially bidirectional yarn woven fabrics is stretched Bidirectionally by specially fabricated steel frame associated with both co and counter rotating device. These fibers include glass fibrics/cloths or mixtures of any of these. The synthetic fiber may be any synthetic silica based oven waived bi-directional or Uni-directional fabrics. Engaged gear provided in the device develops uniform tension on fabric, in both direction. Nano particle dispersed resin to be used is formulated with their respective curing agents and extenders. The formulated resin contains 0.1-0.5% of Nano additives and the product composed from 5-10 % of Glass fabric, between 10 to 20 % of ordinary glass, and between 60-80 % of the product is the Nano particles dispersed formulated resin, all measured by volume.

  8. Evaluation of the Nano-TiO2 as a Novel Deswelling Material.

    Science.gov (United States)

    Chu, Ming; Hou, Yue-Long; Xu, Lan; Chu, Zheng-Yun; Zhang, Ming-Bo; Wang, Yue-Dan

    2016-01-04

    Nano-TiO2 is widely applied in the automobile exhaust hose reels as a catalyst to reduce oxynitride emissions, including nitric oxide (NO). In the biomedicine field, NO plays an important role in vasodilation and edema formation in human bodies. However, the deswelling activity of nano-TiO2 has not been reported. Here, we demonstrated that nano-TiO2 can significantly degrade the production of NO in LPS-induced RAW264.7 mouse macrophages. Further study indicated that nano-TiO2 exhibited an effect on vascular permeability inhibition, and prevented carrageenan-induced footpad edema. Therefore, we prepared a nano-TiO2 ointment and observed similar deswelling effects. In conclusion, nano-TiO2 might act as a novel deswelling agent related with its degradation of NO, which will aid in our ability to design effective interventions for edema involved diseases.

  9. Evaluation of the Nano-TiO2 as a Novel Deswelling Material

    Directory of Open Access Journals (Sweden)

    Ming Chu

    2016-01-01

    Full Text Available Nano-TiO2 is widely applied in the automobile exhaust hose reels as a catalyst to reduce oxynitride emissions, including nitric oxide (NO. In the biomedicine field, NO plays an important role in vasodilation and edema formation in human bodies. However, the deswelling activity of nano-TiO2 has not been reported. Here, we demonstrated that nano-TiO2 can significantly degrade the production of NO in LPS-induced RAW264.7 mouse macrophages. Further study indicated that nano-TiO2 exhibited an effect on vascular permeability inhibition, and prevented carrageenan-induced footpad edema. Therefore, we prepared a nano-TiO2 ointment and observed similar deswelling effects. In conclusion, nano-TiO2 might act as a novel deswelling agent related with its degradation of NO, which will aid in our ability to design effective interventions for edema involved diseases.

  10. Building Investigation: Material or Structural Performance

    Directory of Open Access Journals (Sweden)

    Yusof M.Z.

    2014-03-01

    Full Text Available Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  11. Spatial solitons in periodic semiconductor-dielectric nano-structures

    CERN Document Server

    Gorbach, A V

    2009-01-01

    A detailed analysis of the existence and stability of TE and TM nonlinear guided modes in one-dimensional sub-wavelength periodic semiconductor-dielectric structures is done using the full vector nonlinear Maxwell equations. Linear spectra for both light polarizations gradually transform towards those of a quasi-homogeneous medium with decreasing structure period. The properties of TE solitons change accordingly, so that for small enough periods, TE solitons stop feeling the presence of the structure. However TM sotitons are demonstrated to sustain inhomogeneous field distribution for any small period of the structure, developing strong intensity peaks inside dielectric slots. Qualitative transfomation in the structure of TM solitons occurs as the structure period is decreased, and is accompained by the change in their stability properties. This is linked to the corresponding qualitative changes in the linear modes structure, related to the Brewster condition.

  12. A study of angle dependent surface plasmon polaritons in nano-hole array structures

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Shankar [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Lawson Health Research Institute, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Najiminaini, Mohamadreza; Carson, Jeffrey J. L. [Lawson Health Research Institute, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2016-07-21

    We report that the light-matter interaction in metallic nano-hole array structures possess a subwavelength hole radius and periodicity. The transmission coefficient for nano-hole array structures was measured for different angles of incidence of light. Each measured transmission spectrum had several peaks due to surface plasmon polaritons. A theory of the transmission coefficient was developed based on the quantum density matrix method. It was found that the location of the surface plasmon polariton and the heights of the spectral peaks were dependent on the angle of incidence of light. Good agreement was observed between the experimental and theoretical results. This property of these structures has opened up new possibilities for sensing applications.

  13. Composite Materials for Structural Design.

    Science.gov (United States)

    1982-03-01

    Introduction to Composite Materials , Technomic, Westport, Connecticut, 1980, pp. 19-20, 388-401. 8. W.D. Bascom, J.L. Bitner, R.J. Moulton, and A.R. Siebert...34 Introduction to Composite Materials ", Technomic Publishing Co., pp. 8-18,(1980). [6] Beckwith, S. W., "Viscoelastic Characterization of a Nonlinear Glass

  14. Research report of FY 1997 on the industrial science and technology development. Technology development of super-metal (technology development of nano-amorphous structural control materials); 1997 nendo sangyo kagaku gijutsu kenkyu kaihatsu Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku seika hokokusho. Super metal no gijutsu kaihatsu (nano-amorphous kozo seigyo zairyo no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Research and development of the innovative metals have been conducted, by which the weight reduction of members can be done by drastically improving the strength compared with conventional metals. For the high-rate cluster deposition and super plastic forming technologies, research and development of aluminum-based light-weight materials have been conducted, which provides excellent strength, toughness, and super plastic formability at room temperature. For the high-density energy utilization and control technology (amorphous-A), super-metals have been investigated as high dew point and corrosion resistance materials used for waste incinerators operated under the very severe conditions. These are expected to be applied to the apparatuses and equipment due to their excellent properties. For the controlled cooling technology (amorphous-B), super-metals with excellent soft magnetic characteristics and degree of shape freedom have been investigated for high performance and high efficiency devices including electric/electronic/communication devices, power transmission devices, and various industrial devices and parts. These are expected to contribute to the creation of new markets and the improvement of international competitive force. 123 refs., 160 figs., 33 tabs.

  15. Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees

    Energy Technology Data Exchange (ETDEWEB)

    Leon, V

    2006-07-15

    Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)

  16. Direct writing of large-area micro/nano-structural arrays on single crystalline germanium substrates using femtosecond lasers

    Science.gov (United States)

    Li, Lin; Wang, Jun

    2017-06-01

    A direct writing technique for fabricating micro/nano-structural arrays without using a multi-scanning process, multi-beam interference, or any assisted microlens arrays is reported. Various sub-wavelength micro/nano-structural arrays have been directly written on single crystalline germanium substrate surfaces using femtosecond laser pulses. The evolution of the multiscale surface morphology from periodic micro/nano-structures to V-shaped microgrooves has been achieved, and the relationship between array characteristics and laser polarization directions has been discussed. The self-organization model agrees well with the experimental results in this study.

  17. New smart materials to address issues of structural health monitoring.

    Energy Technology Data Exchange (ETDEWEB)

    Chaplya, Pavel Mikhail

    2004-12-01

    technologies to mature enough to make self-sensing materials a reality. Nevertheless, recent advances in the field of nanotechnology demonstrate that nanotubes, nanorods, and nanoparticles of carbon, boron and other materials have remarkable mechanical and electrical properties. This would provide. for a plethora of potential applications including self-sensing materials. Record strength-to-weight ratios, ballistic conductivity, and sensing capabilities (i.e., piezo- resistance and piezoelectricity) have been reported for carbon nanotubes. The first transistors, sensors, and actuators have been made from the carbon nanotubes and other nanomaterials. However, nanomaterials are notoriously difficult to manipulate into useful geometries. Nano-manufacturing processes often produce bundles or random networks of nanostructured materials. Samples of the material are then manipulated with advanced microscopy tools to measure properties or to create a single device. This is a laborious and time consuming process. An often overlooked property of the manufactured nanotube bundles is their similarity to the dendritic structure of neural networks with a great quantity of interconnects that may serve as initiation sites for artificial neurons in a self-sensing material nervous system. To accelerate the development of self-sensing materials, future research should concentrate on naturally occurring dendritic nano-structures. While self-sensing materials with subgrain size sensors (scale of micrometers) remain in the realm of basic research, meso-scale (millimeters to centimeters) sensors and their networks are in the state of mature research and have begun to find their way into commercial applications. Macro-scale (centimeters to decimeters) sensors and their networks are commercially available from various sources. The majority of applications that employ sensor networks are driven by the needs of the Department of Defense. Widespread adaptation of sensor networks has been limited by, on

  18. A review on graphite and hybrid nano-materials as lubricant additives

    Science.gov (United States)

    Anand, Gautam; Saxena, Prateek

    2016-09-01

    The paper presents a review on use of nano-particles as lubricant additives. Nanoparticles have a strong potential to improve the lubrication property of grease when they are used as additives. Nano-grease has several advantages such as improved frictional behaviour, high load bearing capacity and reduced wear, as compared to base oil grease. Current advancements, limitations and challenges in use of nano-grease as a lubricant are discussed. Although, nanogrease has shown outstanding results, more research is required in this field for the commercialization of technology related to nano-grease.

  19. Development of Standards for NanoSIMS Analyses of Biological Materials

    Energy Technology Data Exchange (ETDEWEB)

    Davission, M L; Weber, P K; Pett-Ridge, J; Singer, S

    2008-07-31

    NanoSIMS is a powerful analytical technique for investigating element distributions at the nanometer scale, but quantifying elemental abundances requires appropriate standards, which are not readily available for biological materials. Standards for trace element analyses have been extensively developed for secondary ion mass spectrometry (SIMS) in the semiconductor industry and in the geological sciences. The three primary approaches for generating standards for SIMS are: (1) ion implantation (2) using previously characterized natural materials, and (3) preparing synthetic substances. Ion implantation is a reliable method for generating trace element standards, but it is expensive, which limits investigation of the analytical issues discussed above. It also requires low background levels of the elements of interest. Finding or making standard materials has the potential to provide more flexibility than ion implantation, but realizing homogeneity at the nano-scale is in itself a significant challenge. In this study, we experiment with all three approaches, but with an emphasis toward synthetic organic polymers in order to reduce costs, increase flexibility, and achieve a wide dynamic concentration range. This emphasis serves to meet the major challenge for biological samples of identifying matrix matched, homogeneous material. Biological samples themselves are typically heterogeneous at the scale of microns to 100s of microns, and therefore they are poor SIMS standards. Therefore, we focused on identifying 'biological-like' materials--either natural or synthetic--that can be used for standards. The primary criterion is that the material be as compositionally similar to biological samples as possible (primarily C, H, O, and N). For natural material we adsorbed organic colloids consisting of peptidoglycan (i.e., amino sugars), activated charcoal, and humic acids. Experiments conducted with Si on peptidoglycan showed low affinity as SiO{sub 2}, yet its

  20. Micro-Nano Materials for Tumor Microwave Hyperthermia: Design, Preparation, and Application.

    Science.gov (United States)

    Chen, Xue; Meng, Xianwei; Tan, Longfei; Liu, Tianlong

    2016-01-07

    Nowadays, cancer hyperthermia is attracting much attention in basic science and clinics. Among the hyperthermia techniques, microwave (MW) heating is most commonly used for cancer treatment. It offers highly competitive advantages: faster heat generation from microwave radiation, less susceptibility to heat up local tissues, maneuverability, and depth of penetration in tissues and capability of killing tumor cells. Although the encouraging clinical results are being collected, MW hyperthermia has its own challenges, such as inaccurate targeting, low selectivity, which leads to damage to surrounding vital organs and tissues. To address these issues, micro-nano materials have emerged as a promising agent as the receiver of the electromagnetic wave, which should be beneficial for improving the efficacy of MW hyperthermia. Here, we review the most recent literature on micro/nanomaterials-based MW heating strategies for treatment of cancer, with the aim to give the reader an overview of the state-of-the-art of MW hyperthermia therapy. The future of MW responsive materials will also be discussed, including combination of imaging probes and targeting moieties.

  1. Structural, Morphological and Antibacterial Investigation of Ag-Impregnated Sol-Gel-Derived 45S5 NanoBioglass Systems.

    Science.gov (United States)

    Durgalakshmi, D; Balakumar, S; Raja, C Ashok; George, Rani P; Mudali, U Kamachi

    2015-06-01

    An increasing percentage of ageing population requires 30-year survivability of orthopedic devices that is not possible with the current bioinert materials, having a maximum of 15-year survivability. To satisfy this growing need, a shift is needed from replacement of tissues to regeneration of tissues. This is highly possible through the use of silica-bioactive glasses. However, a failure of implant can occur due to infections even by using such materials. Advances in using silver for antibacterial applications have been commercialized. However, higher concentrations of silver also lead to toxic effects. In this study, nanoBioglass 45S5 (NBG) and Ag-NBG were synthesized by using sol-gel method followed by solution-phase method, respectively. The bioactive crystals such as Na2Ca2Si3O9, CaCO3, and AgPO3, very much needed in the field of bone tissue engineering and in antibacterial strategies, were obtained in the NBG Matrix. The morphological investigation of NBG with 1 mM Ag+ concentrations shows the nanospikes arrangement of size 30-40 nm with spherical porous structure of size 10-20 nm, which supports the formation of collagen molecular fibrils on the surface of NBG matrices and enhances osseointegration. Both gram-positive and gram-negative strains show higher antibacterial activity for nanoBioglass with 1 mM Ag+ concentration.

  2. Self-assembled germanium nano-structures by laser-assisted oxidation

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Liu Shi-Rong

    2006-01-01

    The investigation on the oxidation behaviour of Si1-xGex; alloys (x=0.05, 0.15, and 0.25) is carried out. It is found for the first time that on the oxide film a germanium nano-cap with a thickness of 1.8ranging from 5.5 nm to 10 nm are formed by the low-temperature laser-assisted dry oxidation of Si1-xGex substrate. A new scanning method on the decline cross-section of the multiple-layer sample is adopted to measure the layer thickness and the composition. Some new peaks in photoluminescence (PL) spectra are discovered, which could be related to the nano-cap and the nano-particles of germanium. A suitable model and several new calculating formulae with the unrestricted Hartree-Fock-Roothaan (UHFR) method and quantum confinement analysis are proposed to interpret the PL spectra and the nano-structure mechanism in the oxide.

  3. Experiences in supporting the structured collection of cancer nanotechnology data using caNanoLab

    Directory of Open Access Journals (Sweden)

    Stephanie A. Morris

    2015-07-01

    Full Text Available The cancer Nanotechnology Laboratory (caNanoLab data portal is an online nanomaterial database that allows users to submit and retrieve information on well-characterized nanomaterials, including composition, in vitro and in vivo experimental characterizations, experimental protocols, and related publications. Initiated in 2006, caNanoLab serves as an established resource with an infrastructure supporting the structured collection of nanotechnology data to address the needs of the cancer biomedical and nanotechnology communities. The portal contains over 1,000 curated nanomaterial data records that are publicly accessible for review, comparison, and re-use, with the ultimate goal of accelerating the translation of nanotechnology-based cancer therapeutics, diagnostics, and imaging agents to the clinic. In this paper, we will discuss challenges associated with developing a nanomaterial database and recognized needs for nanotechnology data curation and sharing in the biomedical research community. We will also describe the latest version of caNanoLab, caNanoLab 2.0, which includes enhancements and new features to improve usability such as personalized views of data and enhanced search and navigation.

  4. Experiences in supporting the structured collection of cancer nanotechnology data using caNanoLab.

    Science.gov (United States)

    Morris, Stephanie A; Gaheen, Sharon; Lijowski, Michal; Heiskanen, Mervi; Klemm, Juli

    2015-01-01

    The cancer Nanotechnology Laboratory (caNanoLab) data portal is an online nanomaterial database that allows users to submit and retrieve information on well-characterized nanomaterials, including composition, in vitro and in vivo experimental characterizations, experimental protocols, and related publications. Initiated in 2006, caNanoLab serves as an established resource with an infrastructure supporting the structured collection of nanotechnology data to address the needs of the cancer biomedical and nanotechnology communities. The portal contains over 1,000 curated nanomaterial data records that are publicly accessible for review, comparison, and re-use, with the ultimate goal of accelerating the translation of nanotechnology-based cancer therapeutics, diagnostics, and imaging agents to the clinic. In this paper, we will discuss challenges associated with developing a nanomaterial database and recognized needs for nanotechnology data curation and sharing in the biomedical research community. We will also describe the latest version of caNanoLab, caNanoLab 2.0, which includes enhancements and new features to improve usability such as personalized views of data and enhanced search and navigation.

  5. Numerical analysis of melting of nano-enhanced phase change material in latent heat thermal energy storage system

    Directory of Open Access Journals (Sweden)

    Kashani Sina

    2014-01-01

    Full Text Available The heat transfer enhancement in the latent heat thermal energy storage system through dispersion of nanoparticle is reported. The resulting nanoparticle-enhanced phase change materials exhibit enhanced thermal conductivity in comparison to the base material. Calculation is performed for nanoparticle volume fraction from 0 to 0.08. In this study rectangular and cylindrical containers are modeled numerically and the effect of containers dimensions and nano particle volume fraction are studied. It has been found that the rectangular container requires half of the melting time as for the cylindrical container of the same volume and the same heat transfer area and also, higher nano particle volume fraction result in a larger solid fraction. The increase of the heat release rate of the nanoparticle-enhanced phase change materials shows its great potential for diverse thermal energy storage application.

  6. Optimization of thermoelectric properties for rough nano-ridge GaAs/AlAs superlattice structure

    Science.gov (United States)

    Wu, Chao-Wei; Wu, Yuh-Renn

    2016-11-01

    In this paper, optimizations of thermoelectric(TE) properties for the rough surface of the nano-ridge GaAs/AlAs superlattice(SL) structure are investigated. The nano-ridge featured with rough surface at both sides of the SL structure is introduced, where the modification of the phonon spatial confinement and phonon surface roughness scattering are taken into account. The elastic continuum model is employed to calculate the phonon dispersion relation and the related phonon group velocity. Reported experimental results with SL structures were used for verification of our model. The lattice thermal conductivity, electrical conductivity, Seebeck coefficient, and electronic thermal conductivity are calculated by Boltzmann transport equations and relaxation time approximation. Simulation results show that the nano-ridge SL structure with certain periodicity and phonon surface roughness scattering have strong influences on the TE properties. Highest ZT in our calculation is 1.285 at 300K and the ZT value of 3.04 is obtained at 1000K.

  7. Fabrication of Nano-Micro Hybrid Structures by Replication and Surface Treatment of Nanowires

    Directory of Open Access Journals (Sweden)

    Yeonho Jeong

    2017-07-01

    Full Text Available Nanowire structures have attracted attention in various fields, since new characteristics could be acquired in minute regions. Especially, Anodic Aluminum Oxide (AAO is widely used in the fabrication of nanostructures, which has many nanosized pores and well-organized nano pattern. Using AAO as a template for replication, nanowires with a very high aspect ratio can be fabricated. Herein, we propose a facile method to fabricate a nano-micro hybrid structure using nanowires replicated from AAO, and surface treatment. A polymer resin was coated between Polyethylene terephthalate (PET and the AAO filter, roller pressed, and UV-cured. After the removal of aluminum by using NaOH solution, the nanowires aggregated to form a micropattern. The resulting structure was subjected to various surface treatments to investigate the surface behavior and wettability. As opposed to reported data, UV-ozone treatment can enhance surface hydrophobicity because the UV energy affects the nanowire surface, thus altering the shape of the aggregated nanowires. The hydrophobicity of the surface could be further improved by octadecyltrichlorosilane (OTS coating immediately after UV-ozone treatment. We thus demonstrated that the nano-micro hybrid structure could be formed in the middle of nanowire replication, and then, the shape and surface characteristics could be controlled by surface treatment.

  8. Aged nano-structured platinum based catalyst: effect of chemical treatment on adsorption and catalytic activity.

    Science.gov (United States)

    Shim, Wang Geun; Nahm, Seung Won; Park, Hyuk Ryeol; Yun, Hyung Sun; Seo, Seong Gyu; Kim, Sang Chai

    2011-02-01

    To examine the effect of chemical treatment on the adsorption and catalytic activity of nanostructured platinum based catalyst, the aged commercial Pt/AC catalyst was pretreated with sulfuric acid (H2SO4) and a cleaning agent (Hexane). Several reliable methods such as nitrogen adsorption, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and inductively coupled plasma (ICP) were employed to characterize the aged Pt/AC catalyst and its chemically pretreated Pt/AC catalysts. The catalytic and adsorption activities of nano-structured heterogeneous Pt/AC catalyst were investigated on the basis of toluene oxidation and adsorption isotherm data. In addition, the adsorption isotherms of toluene were used to calculate the adsorption energy distribution functions for the parent catalyst and its pre-treated nano-structured Pt/AC catalysts. It was found that sulfuric acid aqueous treatment can enhance the catalytic performance of aged Pt/AC catalyst toward catalytic oxidation of toluene. It was also shown that a comparative analysis of the energy distribution functions for nano-structured Pt/AC catalysts as well as the pore size distribution provides valuable information about their structural and energetic heterogeneity.

  9. Computational Nano-materials Design for Spinodal Nanotechnology as a New Class of Bottom-up Nanotechnology

    Science.gov (United States)

    Katayama-Yoshida, Hiroshi; Fukushima, Tetsuya; Sato, Kazunori

    Based on the spinodal nano-decomposition (SND) of dilute magnetic semiconductors (DMS), we generalized the SND to the application of catalysis and photovoltaic solar-cells, where nano-scale particle formation in catalysis and and nano-scale separation of electrons and holes are essential in order to enhance the efficiency. First, we summarize the shape control (Konbu- & Dairiseki-Phases) and dimensionality dependence of crystal growth condition on SND in DMS. Second, we discuss the application of SND for the formation of nano-particles and the self-regeneration in three-way catalysis for automotive emission control by Perovskite La(Fe,Pd or Rh)O3. Third, we propose (i) self-regeneration mechanism and (ii) self-organized nano-structures by SND in chalcopyrite Cu(In,Ga)Se2, Kesterite Cu2ZnSnSe4, and Perovskite CsSnI3 for the low-cost, environment-friendly and high-efficiency photovoltaic solar cells using first-principles calculations.

  10. 3-D eigenmode calculation of metallic nano-structures

    Directory of Open Access Journals (Sweden)

    B. Bandlow

    2009-05-01

    Full Text Available In the calculation of eigenfrequencies of 3-D metallic nanostructures occurs the challenge that the material parameters depend on the desired eigenfrequency. We propose a formulation where this leads to a polynomial eigenvalue problem which can be tackled by different solving strategies. A comparison between a Newton-type method and a Jacobi-Davidson algorithm is given.

  11. Evaluation of rheological behavior of 10W40 lubricant containing hybrid nano-material by measuring dynamic viscosity

    Science.gov (United States)

    Ahmadi Nadooshan, Afshin; Hemmat Esfe, Mohammad; Afrand, Masoud

    2017-08-01

    In the present paper, the dynamic viscosity of 10W40 lubricant containing hybrid nano-materials has been examined. Hybrid nano-materials were composed of 90% of silica (SiO2) with 20-30 nm mean particle size and 10% of multi-walled carbon nanotubes (MWCNTs) with inner diameter of 2-6 nm and outer diameter of 5-20 nm. Nano-lubricant samples were prepared by two-step method with solid volume fractions of 0.05%, 0.1%, 0.25%, 0.5%, 0.75% and 1%. Dynamic viscosity of the samples was measured at temperatures between 5 and 55 °C and at shear rates of 666.5 s-1 up to 11,997 s-1. Experimental results indicated that the nano-lubricant had non-Newtonian behavior at all temperatures, while 10w40 oil was non-Newtonian only at high temperatures. With the use of the curve fitting technique of experimental data, power law and consistency indexes were obtained; furthermore, these coefficients were assessed by shear stress and viscosity diagram.

  12. Seeing with the nano-eye: accessing structure, function, and dynamics of matter on its natural length and time scales

    Science.gov (United States)

    Raschke, Markus

    2015-03-01

    To understand and ultimately control the properties of most functional materials, from molecular soft-matter to quantum materials, requires access to the structure, coupling, and dynamics on the elementary time and length scales that define the microscopic interactions in these materials. To gain the desired nanometer spatial resolution with simultaneous spectroscopic specificity we combine scanning probe microscopy with different optical, including coherent, nonlinear, and ultrafast spectroscopies. The underlying near-field interaction mediated by the atomic-force or scanning tunneling microscope tip provides the desired deep-sub wavelength nano-focusing enabling few-nm spatial resolution. I will introduce our generalization of the approach in terms of the near-field impedance matching to a quantum system based on special optical antenna-tip designs. The resulting enhanced and qualitatively new forms of light-matter interaction enable measurements of quantum dynamics in an interacting environment or to image the electromagnetic local density of states of thermal radiation. Other applications include the inter-molecular coupling and dynamics in soft-matter hetero-structures, surface plasmon interferometry as a probe of electronic structure and dynamics in graphene, and quantum phase transitions in correlated electron materials. These examples highlight the general applicability of the new near-field microscopy approach, complementing emergent X-ray and electron imaging tools, aiming towards the ultimate goal of probing matter on its most elementary spatio-temporal level.

  13. Fabrication of various micro/nano structures by modified near-field electrospinning

    Directory of Open Access Journals (Sweden)

    T. P. Lei

    2015-04-01

    Full Text Available The modified near-field electrospinning (NFES and the conventional NFES have been compared to demonstrate the viability of direct-writing micro/nano structures from PVDF solution systems. The modified NFES shows good capability in writing various orderly micro/nano patterns, such as straight and continuous lines, parallel lines, arc lines, and beads-on-string structures, whereas the conventional NFES is difficult to give a continuous writing process. Besides, the modified NFES also allows a lower electric field due to the jet initiated in a mechanical way. By finely tuning the key parameters during the modified NFES process, such as the solution property, speed of the movable collector, and the distance between the spinneret and the collector, it is likely to construct complex patterns as required on rigid or flexible substrates for a myriad of applications.

  14. Nano-scale structure in membranes in relation to enzyme action - computer simulation vs. experiment

    DEFF Research Database (Denmark)

    Høyrup, P.; Jørgensen, Kent; Mouritsen, O.G.

    2002-01-01

    lengths are in the nano-meter range. The nano-scale structure is believed to be important for controlling the activity of enzymes, specifically phospholipases, which act at bilayer membranes. We propose here a lattice-gas statistical mechanical model with appropriate dynamics to account for the non......There is increasing theoretical and experimental evidence indicating that small-scale domain structure and dynamical heterogeneity develop in lipid membranes as a consequence of the the underlying phase transitions and the associated density and composition fluctuations. The relevant coherence......-equilibrium action of the enzyme phospholipase A(2) which hydrolyses lipid-bilayer substrates. The resulting product molecules are assumed to induce local variations in the membrane interfacial pressure. Monte Carlo simulations of the non-equilibrium properties of the model for one-component as well as binary lipid...

  15. Ni(OH){sub 2} and NiO nano structures: Synthesis, characterization and electrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Saghatforoush, Lotf Ali; Sanati, Soheila; Mehdizadeh, Robabeh [Payam Noor Univ., Tehran (Iran, Islamic Republic of); Hasanzadeh, Mohammad [Tabriz Univ. of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2012-04-15

    Hydrothermal route have been used in different conditions for preparation of Ni(OH){sub 2} nano structures. The NiO nanoparticles were obtained by calcining the Ni(OH){sub 2} precursor at 450 .deg. C for 2 h. The effect of sodium dodecyl sulfonate (SDS) as surfactant on the morphology and size of Ni(OH){sub 2} nanoparticles were discussed in detail. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize the products. The growth mechanism of the as-synthesized nano structures was also discussed in detail based on the experimental results. Coming up, the NiO nanoparticle modified carbon paste electrode was applied to the determination of captopril in aqueous solution.

  16. Avoided Crossing Patterns and Spectral Gaps of Surface Plasmon Modes in Gold Nano-Structures

    CERN Document Server

    Kolomenskii, Alexandre; Hembd, Jeshurun; Kolomenski, Andrei; Noel, John; Teizer, Winfried; Schuessler, Hans

    2010-01-01

    The transmission of ultrashort (7 fs) broadband laser pulses through periodic gold nano-structures is studied. The distribution of the transmitted light intensity over wavelength and angle shows an efficient coupling of the incident p-polarized light to two counter-propagating surface plasmon (SP) modes. As a result of the mode interaction, the avoided crossing patterns exhibit energy and momentum gaps, which depend on the configuration of the nano-structure and the wavelength. Variations of the widths of the SP resonances and an abrupt change of the mode interaction in the vicinity of the avoided crossing region are observed. These features are explained by the model of two coupled modes and a coupling change due to switching from the high frequency dark mode to the low frequency bright mode for increasing wavelength of the excitation light. PACS numbers: 73.20.Mf, 42.70.Qs, 42.25.-p,

  17. Preparation and Characterization of Nano-Structured SiO2 Thin Films on Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Dong Zhou YAN; Gang WEI

    2003-01-01

    Nano-structured SiO2 thin films were prepared on the surface of carbon steel for the first time by LPD. The compositions of the films were analyzed by XPS, and the surface morphology of the thin films were observed by AFM. The thin films were constituted by compact particles of SiO2, and there was no Fe in the films. In the process of film forming, the SiO2 colloid particles were deposited or absorbed directly onto the surface of carbon steel substrates that were activated by acid solution containing inhibitor, and corrosion of the substrates was avoided. The nano-structured SiO2 thin films that were prepared had excellent protective efficiency to the carbon steel.

  18. Electron emission degradation of nano-structured sp2-bonded amorphous carbon films

    Institute of Scientific and Technical Information of China (English)

    Lu Zhan-Ling; Wang Chang-Qing; Jia Yu; Zhang Bing-Lin; Yao Ning

    2007-01-01

    The initial field electron emission degradation behaviour of original nano-structured sp2-bonded amorphous carbon films has been observed.which can be attributed to the increase of the work function of the film in the field emission process analysed using a Fowler-Nordheim plot.The possible re.on for the change of work function is suggested to be the desorption of hydrogen from the original hydrogen termination film surface due to field emission current-induced local heating.For the explanation of the emission degradation behaviour of the nano-structured sp2-bonded amorphous carbon film,a cluster model with a series of graphite(0001) basal surfaces has been presented,and the theoretical calculations have been performed to investigate work functions of graphite(0001) surfaces with different hydrogen atom and ion chemisorption sites by using first principles method based on density functional theory-local density approximation.

  19. Multi-Beam Interference Advances and Applications: Nano-Electronics, Photonic Crystals, Metamaterials, Subwavelength Structures, Optical Trapping, and Biomedical Structures

    OpenAIRE

    Thomas K. Gaylord; Guy M. Burrow

    2011-01-01

    Research in recent years has greatly advanced the understanding and capabilities of multi-beam interference (MBI). With this technology it is now possible to generate a wide range of one-, two-, and three-dimensional periodic optical-intensity distributions at the micro- and nano-scale over a large length/area/volume. These patterns may be used directly or recorded in photo-sensitive materials using multi-beam interference lithography (MBIL) to accomplish subwavelength patterning. Advances in...

  20. Direct Electron Transfer of Glucose Oxidase and Glucose Biosensor Based on Nano-structural Attapulgite Clay Matrix

    Institute of Scientific and Technical Information of China (English)

    XU, Jiming; HAN, Wenxia; YIN, Qifan; SONG, Jie; ZHONG, Hui

    2009-01-01

    The direct electrochemistry of glucose oxidase (GOD) was achieved based on the immobilization of GOD on a natural nano-structural attapulgite (ATP) clay film modified glassy carbon (GC) electrode. The immobilized GOD displayed a pair of well-defined quasi-reversible redox peaks with a formal potential (E~0) of -457.5 mV (vs. SCE) in 0.1 mol·L~(-1) pH 7.0 phosphate buffer solution. The peak current was linearly dependent on the scan rate, indicating that the direct electrochemistry of GOD in that case was a surface-controlled process. The immobilized glucose oxidase could retain bioactivity and catalyze the oxidation of glucose in the presence of ferrocene monocarboxylic acid (FMCA) as a mediator with the apparent Michaclis-Menten constant K_m~(app) of 1.16 mmol·L~(-1) The electrocatalytic response showed a linear dependence on the glucose concentration ranging widely from 5.0×10~(-6) to 6.05×10~(-4) mol·L~(-1) (with correlation coefficient of 0.9960). This work demonstrated that the nano-structural attapulgite clay was a good candidate material for the direct electrochemistry of the redox-active enzyme and the construction of the related enzyme biosensors. The proposed biosensors were applied to determine the glucose in blood and urine samples with satisfactory results.