WorldWideScience

Sample records for nanostructured materials application

  1. Nanotechnologies. Properties and applications of nanostructured materials

    International Nuclear Information System (INIS)

    Rempel, A A

    2007-01-01

    The review summarises the main methods for the preparation of nanostructured metals, alloys, semiconductors and ceramics. The formation mechanisms of nanostructures based on two different principles, viz. the assembly principle (bottom-up) and the disintegration principle (top-down), are analysed. Isolated nanoparticles, nanopowders and compact nanomaterials produced by these methods possess different properties. The scope of application of various classes of nanostructured materials is considered and the topicality of the development of nanoindustry is emphasised.

  2. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Directory of Open Access Journals (Sweden)

    Zheng eRen

    2013-11-01

    Full Text Available This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  3. Silk fibroin nanostructured materials for biomedical applications

    Science.gov (United States)

    Mitropoulos, Alexander N.

    Nanostructured biopolymers have proven to be promising to develop novel biomedical applications where forming structures at the nanoscale normally occurs by self-assembly. However, synthesizing these structures can also occur by inducing materials to transition into other forms by adding chemical cross-linkers, changing pH, or changing ionic composition. Understanding the generation of nanostructures in fluid environments, such as liquid organic solvents or supercritical fluids, has not been thoroughly examined, particularly those that are based on protein-based block-copolymers. Here, we examine the transformation of reconstituted silk fibroin, which has emerged as a promising biopolymer due to its biocompatibility, biodegradability, and ease of functionalization, into submicron spheres and gel networks which offer applications in tissue engineering and advanced sensors. Two types of gel networks, hydrogels and aerogels, have small pores and large surface areas that are defined by their structure. We design and analyze silk nanoparticle formation using a microfluidic device while offering an application for drug delivery. Additionally, we provide a model and characterize hydrogel formation from micelles to nanoparticles, while investigating cellular response to the hydrogel in an in vitro cell culture model. Lastly, we provide a second model of nanofiber formation during near-critical and supercritical drying and characterize the silk fibroin properties at different drying pressures which, when acting as a stabilizing matrix, shows to improve the activity of entrapped enzymes dried at different pressures. This work has created new nanostructured silk fibroin forms to benefit biomedical applications that could be applied to other fibrous proteins.

  4. Nanostructured Electrode Materials for Electrochemical Capacitor Applications.

    Science.gov (United States)

    Choi, Hojin; Yoon, Hyeonseok

    2015-06-02

    The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013). Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  5. Nanostructured materials, production and application in construction

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2014-12-01

    Full Text Available The paper considers characteristics of water-soluble high module silicate systems: based on polysilicates of alkali element called liquid glasses and the chains of their transformations from the lowest oligomers into the highest ones with further formation colloid solutions – silica sol. The authors describe the potentialities of the use of such systems as binders or modifying additives to produce different nanostructured silicate polymer concretes. There are examples of prospective application of liquid glass and water solutions of high module silicates in industrial areas and construction. Quantum-chemical calculations of the structure and properties of tetraphenylarsonium are given and heterogeneity of its functional groups is shown.

  6. Application of Nanostructures in Electrochromic Materials and Devices: Recent Progress

    Directory of Open Access Journals (Sweden)

    Jin Min Wang

    2010-11-01

    Full Text Available The recent progress in application of nanostructures in electrochromic materials and devices is reviewed. ZnO nanowire array modified by viologen and WO3, crystalline WO3 nanoparticles and nanorods, mesoporous WO3 and TiO2, poly(3,4-ethylenedioxythiophene nanotubes, Prussian blue nanoinks and nanostructures in switchable mirrors are reviewed. The electrochromic properties were significantly enhanced by applying nanostructures, resulting in faster switching responses, higher stability and higher optical contrast. A perspective on the development trends in electrochromic materials and devices is also proposed.

  7. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hojin Choi

    2015-06-01

    Full Text Available The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013. Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  8. Nanostructure materials for biosensing and bioimaging applications

    Science.gov (United States)

    Law, Wing Cheung

    not fully understand, three possible factors are concluded after systematic researches: (i) an increase of the absolute mass in each binding event, (ii) an increase in the bulk refractive index of the analyte, and (iii) coupling between the localized surface plasmon resonance (LSPR) of metallic nanoparticles and surface plasmon resonance (SPR) of the sensing film. Indeed, the role of plasmonic coupling in sensitivity enhancement is still an open question. In order to obtain a better understanding of this phenomenon, at the end of part I, extended studies were performed to investigate how the LSPR properties of metallic nanoparticle labels correlate with the enhancement factor. For this purpose, gold nanorods (Au-NRs) were chosen as the amplification labels because of the easy tunability of LSPR peak of Au-NR. After reading the "Result and Discussion" section, the readers will have better understanding of "plasmonic coupling" between the sensing film and the metallic labels with suitable operating laser source. In the second part of the thesis, the bioimaging part, the application of nanostructure materials in live cancer cell imaging and small animal imaging were demonstrated. There are different types of imaging technique available in laboratories and clinics: optical imaging, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), thermography and ultrasound imaging. Although such imaging techniques have been well developed and used over a decade, improving the sensitivity, enhancing the contrast, decreasing the acquisition time and reducing the toxicity of the contrast agent are highly desirable. For optical imaging, the scientists discovered that the use of near infrared fluorescence materials can assist the surgeon to locate the tumor, the nerve and the lymph node more accurately. For CT scan, the use of Au-NR as the contrast agent can improve the sensitivity. Iron oxide nanoparticle or gadolinium ion containing

  9. Potential applications of nanostructured materials in nuclear waste management.

    Energy Technology Data Exchange (ETDEWEB)

    Braterman, Paul S. (The University of North Texas, Denton, TX); Phol, Phillip Isabio; Xu, Zhi-Ping (The University of North Texas, Denton, TX); Brinker, C. Jeffrey; Yang, Yi (University of New Mexico, Albuquerque, NM); Bryan, Charles R.; Yu, Kui; Xu, Huifang (University of New Mexico, Albuquerque, NM); Wang, Yifeng; Gao, Huizhen

    2003-09-01

    This report summarizes the results obtained from a Laboratory Directed Research & Development (LDRD) project entitled 'Investigation of Potential Applications of Self-Assembled Nanostructured Materials in Nuclear Waste Management'. The objectives of this project are to (1) provide a mechanistic understanding of the control of nanometer-scale structures on the ion sorption capability of materials and (2) develop appropriate engineering approaches to improving material properties based on such an understanding.

  10. Characterization of novel nanostructured materials for applications

    International Nuclear Information System (INIS)

    Klauser, F.

    2009-01-01

    This thesis presents a characterization of bulk- and surface properties of various (nanoscale) materials with respect to their possible use in applications. The main part of this work is dedicated to nanocrystalline Diamond films (NCD). Other materials include silicon nanoparticle films, gallium-, tungsten-, niobium- and hafnium-oxides as well as commercially available piercing materials. Diamond films of different surface terminations and morphologies were prepared and characterized, in order to realize surfaces with optimized properties for biological and medical applications. It was shown that properly terminated NCD Materials can be used as defined substrates for cell culture and cell-adhesion studies. In view of the use of NCD as coating for medical implants also in-vivo studies on the tissue attachment to differently terminated NCD surfaces were performed. NCD from chemical vapour deposition is a composite material which - in addition to diamond - also contains carbon species in grain boundaries. Thus - besides characterization of bulk properties (as hydrogen- and sp2 content or diamond grain size) - investigation of grain-boundary properties is important for the NCD-based applications presented within this thesis, including an electrochemical sensor, a thin-film acoustic resonator and a surface-plasmon- resonance based sensor. Thin films of silicon nanoparticles were studied by means of XPS-sputter depth profiling with respect to their behaviour under various oxidation conditions, such as exposure to ambient air or to oxygen plasma as well as upon electron irradiation under high-vacuum conditions. The investigation of gallium and tungsten oxides aims at their potential use as model catalysts. Besides a structural characterization, their oxidation and reduction behaviour was studied. Furthermore, a dendritic mixed-oxide system with an enhanced interface area could be prepared. Niobium and hafnium oxides are often used as dielectrics. It was the aim of the

  11. Metal Oxide Nanostructured Materials for Optical and Energy Applications

    OpenAIRE

    Moore, Michael Christopher

    2013-01-01

    With a rapidly growing population, dwindling resources, and increasing environmental pressures, the need for sustainable technological solutions becomes more urgent. Metal oxides make up much of the earth's crust and are typically inexpensive materials, but poor electrical and optical properties prevent them from being useful for most semiconductor applications. Recent breakthroughs in chemistry and materials science allow for the growth of high-quality materials with nanometer-scale features...

  12. Nanostructured composite reinforced material

    Science.gov (United States)

    Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  13. Nanostructured Materials for Magnetoelectronics

    CERN Document Server

    Mikailzade, Faik

    2013-01-01

    This book provides an up-to-date review of nanometer-scale magnetism and focuses on the investigation of the basic properties of magnetic nanostructures. It describes a wide range of physical aspects together with theoretical and experimental methods. A broad overview of the latest developments in this emerging and fascinating field of nanostructured materials is given with emphasis on the practical understanding and operation of submicron devices based on nanostructured magnetic materials.

  14. 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.

  15. Fabrication and application of nanostructured materials for sulfite biosensing

    OpenAIRE

    Hussain, Shahid

    2017-01-01

    A biosensor as an integrated miniaturized device, exploits the modern microelectronics with specific sensing probe through signal transduction. The challenge for new generation biosensors is to achieve specific analyte detection at very low concentrations, which is possible by tailoring the materials used for fabrication of these devices based on nanoscience and nanotechnology. The new approach is explored in this thesis for fabrication of novel nanobiosensors for ultrasensitive detection of ...

  16. Nanostructured layers of thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffrey J.; Lynch, Jared; Coates, Nelson; Forster, Jason; Sahu, Ayaskanta; Chabinyc, Michael; Russ, Boris

    2018-01-30

    This disclosure provides systems, methods, and apparatus related to thermoelectric materials. In one aspect, a method includes providing a plurality of nanostructures. The plurality of nanostructures comprise a thermoelectric material, with each nanostructure of the plurality of nanostructures having first ligands disposed on a surface of the nanostructure. The plurality of nanostructures is mixed with a solution containing second ligands and a ligand exchange process occurs in which the first ligands disposed on the plurality of nanostructures are replaced with the second ligands. The plurality of nanostructures is deposited on a substrate to form a layer. The layer is thermally annealed.

  17. Synthesis and study of nano-structured cellulose acetate based materials for energy applications

    International Nuclear Information System (INIS)

    Fischer, F.

    2006-12-01

    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 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 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 -3 together with a meso-porous volume of 3,40 cm 3 .g -1 was elaborated. Once in granular shape, this material has a thermal conductivity of 0,029 W.m -1 .K -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)

  18. 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.

  19. Recent advances in MoS2 nanostructured materials for energy and environmental applications - A review

    Science.gov (United States)

    Theerthagiri, J.; Senthil, R. A.; Senthilkumar, B.; Reddy Polu, Anji; Madhavan, J.; Ashokkumar, Muthupandian

    2017-08-01

    Molybdenum disulfide (MoS2), a layered transition metal dichalcogenide with an analogous structure to graphene, has attracted enormous attention worldwide owing to its use in a variety of applications such as energy storage, energy conversion, environmental remediation and sensors. MoS2 and graphene have almost similar functional properties such as high charge carrier transport, high wear resistance and good mechanical strength and friction. However, MoS2 is advantageous over graphene due to its low-cost, abundancy, tailorable morphologies and tuneable band gap with good visible light absorption properties. In this review, we have focussed mainly on recent advances in MoS2 nanostructured materials for the applications in the broad area of energy and environment. Special attention has been paid to their applications in dye-sensitized solar cells, supercapacitor, Li-ion battery, hydrogen evolution reaction, photocatalysis for the degradation of organic pollutants, chemical/bio sensors and gas sensors. Finally, the challenges to design MoS2 nanostructures suitable for energy and environmental applications are also highlighted.

  20. Application of 2D Non-Graphene Materials and 2D Oxide Nanostructures for Biosensing Technology

    Directory of Open Access Journals (Sweden)

    Kateryna Shavanova

    2016-02-01

    Full Text Available The discovery of graphene and its unique properties has inspired researchers to try to invent other two-dimensional (2D materials. After considerable research effort, a distinct “beyond graphene” domain has been established, comprising the library of non-graphene 2D materials. It is significant that some 2D non-graphene materials possess solid advantages over their predecessor, such as having a direct band gap, and therefore are highly promising for a number of applications. These applications are not limited to nano- and opto-electronics, but have a strong potential in biosensing technologies, as one example. However, since most of the 2D non-graphene materials have been newly discovered, most of the research efforts are concentrated on material synthesis and the investigation of the properties of the material. Applications of 2D non-graphene materials are still at the embryonic stage, and the integration of 2D non-graphene materials into devices is scarcely reported. However, in recent years, numerous reports have blossomed about 2D material-based biosensors, evidencing the growing potential of 2D non-graphene materials for biosensing applications. This review highlights the recent progress in research on the potential of using 2D non-graphene materials and similar oxide nanostructures for different types of biosensors (optical and electrochemical. A wide range of biological targets, such as glucose, dopamine, cortisol, DNA, IgG, bisphenol, ascorbic acid, cytochrome and estradiol, has been reported to be successfully detected by biosensors with transducers made of 2D non-graphene materials.

  1. Nanostructured materials for water desalination

    Energy Technology Data Exchange (ETDEWEB)

    Humplik, T; Lee, J; O' Hern, S C; Fellman, B A; Karnik, R; Wang, E N [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge (United States); Baig, M A; Hassan, S F; Atieh, M A; Rahman, F; Laoui, T, E-mail: tlaoui@kfupm.edu.sa, E-mail: karnik@mit.edu, E-mail: enwang@mit.edu [Departments of Mechanical Engineering and Chemical Engineering and Research Institute, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2011-07-22

    Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity. (topical review)

  2. Nanostructured materials for water desalination

    International Nuclear Information System (INIS)

    Humplik, T; Lee, J; O'Hern, S C; Fellman, B A; Karnik, R; Wang, E N; Baig, M A; Hassan, S F; Atieh, M A; Rahman, F; Laoui, T

    2011-01-01

    Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity. (topical review)

  3. Nanostructured materials for water desalination

    Science.gov (United States)

    Humplik, T.; Lee, J.; O'Hern, S. C.; Fellman, B. A.; Baig, M. A.; Hassan, S. F.; Atieh, M. A.; Rahman, F.; Laoui, T.; Karnik, R.; Wang, E. N.

    2011-07-01

    Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.

  4. A Short Overview on the Biomedical Applications of Silica, Alumina and Calcium Phosphate-based Nanostructured Materials.

    Science.gov (United States)

    Ellahioui, Younes; Prashar, Sanjiv; Gómez-Ruiz, Santiago

    2016-01-01

    This article reviews the use of silica, alumina and calcium phosphate-based nanostructured materials with biomedical applications. A short introduction on the use of the materials in Science, Nanotechnology and Health is included followed by a revision of each of the selected materials. A description of the principal synthetic methods used in the preparation of the materials in nanostructured form is included. The most widely used applications in biomedicine are reviewed including, for example drug-delivery, bone regeneration, imaging, sensoring amongst others. Finally, a short description of the toxicity and cytotoxicity associated with each of the materials of this revision is presented. This short literature revision serves to demonstrate the very promising future ahead of nanosystems based on silica, alumina and calcium phosphate for biological and biomedical applications.

  5. Towards the Industrial Application of Spark Ablation for Nanostructured Functional Materials

    NARCIS (Netherlands)

    Pfeiffer, T.V.

    2014-01-01

    Nanostructuring of functional materials is an essential part in the design of energy related devices – but the industrial tools we have to make these materials are lacking. This dissertation explores the green, flexible, and scalable spark discharge process for the fabrication of complex

  6. Synthesis of polymeric micro- and nanostructural materials for application in non-linear optics

    International Nuclear Information System (INIS)

    Kravets, Lyubov; Palistrant, Natalia; Bivol, Valerii; Robu, Stepan; Barba, Nikolai; Orelovitch, Oleg

    2007-01-01

    The present paper describes a new approach developed for the preparation of micro- and nanostructural materials on the basis of polymeric compositions used as a matrix in non-linear optics. This approach consists in filling the pores of poly(ethylene terephthalate) track membranes (PET TM) from polymeric compositions using an impregnation method. It is shown that depending on the concentration of polymeric compositions in the solution it is possible to form a variety of micro- and nanostructural materials (tubules and wires as well as composite membranes) with a wide spectrum of characteristics. The developed method of producing micro- and nanostructural materials provides a possible way for creating polymeric objects with non-linear optic properties which can be used to design electronic micro- and nanodevices and to obtain chemical and optical sensors

  7. Synthesis of nano-structured materials by laser-ablation and their application to sensors

    International Nuclear Information System (INIS)

    Okada, T.; Suehiro, J.

    2007-01-01

    We describe the synthesis of nano-structured materials of ZnO and Pd by laser ablation and their applications to sensors. The synthesis of ZnO nano-wires was performed by nano-particle assisted deposition (NPAD) where nano-crystals were grown with nano-particles generated by laser-ablating a ZnO sintered target in an Ar background gas. The synthesized ZnO nano-wires were characterized with a scanning electron microscopy and the photoluminescent characteristics were examined under an excitation with the third harmonics of a Nd:YAG laser. The nano-wires with a diameter in the range from 50 to 150 nm and a length of up to 5 μm were taken out of the substrate by laser blow-off technique and/or sonication. It was confirmed that the nano-wires showed the stimulated emission under optical pumping, indicating a high quality of the crystalinity. Pd nano-particles were generated by laser-ablating a Pd plate in pure water. The transmission electron microscope observation revealed that Pd nano-particles with a diameter in the range from 3 nm to several tens of nanometers were produced. Using these nano-structured materials, we successfully fabricated sensors by the dielectrophoresis techniques. In the case of the ultraviolet photosensor, a detection sensitivity of 10 nW/cm 2 was achieved and in the case of hydrogen sensing, the response time of less than 10 s has been demonstrated with Pd nano-particles

  8. Sonochemical synthesis of nanostructured nickel hydroxide as an electrode material for improved electrochemical energy storage application

    Directory of Open Access Journals (Sweden)

    Arshid Numan

    2017-08-01

    Full Text Available A facile and fast approach for the synthesis of a nanostructured nickel hydroxide (Ni(OH2 via sonochemical technique is reported in the present study. The X-ray diffraction results confirmed that the synthesized Ni(OH2 was oriented in β-phase of hexagonal brucite structure. The nanostructured Ni(OH2 electrode exhibited the maximum specific capacitance of 1256 F/g at a current density of 200 mA/g in 1 M KOH(aq. Ni(OH2 electrodes exhibited the pseudocapacitive behavior due to the presence of redox reaction. It also exhibited long-term cyclic stability of 85% after 2000 cycles, suggesting that the nanostructured Ni(OH2 electrode will play a promising role for high performance supercapacitor application.

  9. Quantitative Characterization of Nanostructured Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Frank (Bud) Bridges, University of California-Santa Cruz

    2010-08-05

    The two-and-a-half day symposium on the "Quantitative Characterization of Nanostructured Materials" will be the first comprehensive meeting on this topic held under the auspices of a major U.S. professional society. Spring MRS Meetings provide a natural venue for this symposium as they attract a broad audience of researchers that represents a cross-section of the state-of-the-art regarding synthesis, structure-property relations, and applications of nanostructured materials. Close interactions among the experts in local structure measurements and materials researchers will help both to identify measurement needs pertinent to real-world materials problems and to familiarize the materials research community with the state-of-the-art local structure measurement techniques. We have chosen invited speakers that reflect the multidisciplinary and international nature of this topic and the need to continually nurture productive interfaces among university, government and industrial laboratories. The intent of the symposium is to provide an interdisciplinary forum for discussion and exchange of ideas on the recent progress in quantitative characterization of structural order in nanomaterials using different experimental techniques and theory. The symposium is expected to facilitate discussions on optimal approaches for determining atomic structure at the nanoscale using combined inputs from multiple measurement techniques.

  10. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    Energy Technology Data Exchange (ETDEWEB)

    Bordia, Rajendra [Univ. of Washington, Seattle, WA (United States); Tomar, Vikas [Purdue Univ., West Lafayette, IN (United States); Henager, Chuck [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-08

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  11. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    International Nuclear Information System (INIS)

    Bordia, Rajendra; Tomar, Vikas; Henager, Chuck

    2015-01-01

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  12. Application of Nanostructured Materials and Multi-junction Structure in Polymer Solar Cells

    KAUST Repository

    Gao, Yangqin

    2015-12-09

    With power conversion efficiency surpassing the 10% milestone for commercialization, photovoltaic technology based on solution-processable polymer solar cells (PSCs) provides a promising route towards a cost-efficient strategy to address the ever-increasing worldwide energy demands. However, to make PSCs successful, challenges such as insufficient light absorption, high maintenance costs, and relatively high production costs must be addressed. As solutions to some of these problems, the unique properties of nanostructured materials and complimentary light absorption in multi-junction device structure could prove to be highly beneficial. As a starting point, integrating nanostructure-based transparent self-cleaning surfaces in PSCs was investigated first. By controlling the length of the hydrothermally grown ZnO nanorods and covering their surface with a thin layer of chemical vapor-deposited SiO2, a highly transparent and UV-resistant superhydrophobic surface was constructed. Integrating the transparent superhydrophobic surface in a PSC shows minimal impact on the figure of merit of the PSC. To address the low mechanical durability of the transparent superhydrophobic surface based on SiO2-coated ZnO nanorods, a novel method inspired by the water condensation process was developed. This method involved directly growing hollow silica half-nanospheres on the substrate through the condensation of water in the presence of a silica precursor. Benefit from the decreased back scattering efficiency and increased light transport mean free path arise from the hollow nature, a transparent superhydrophobic surface was realized using submicrometer sized silica half-nanospheres. The decent mechanical property of silica and the “direct-grown” protocol are expected to impart improved mechanical durability to the transparent superhydrophobic surface. Regarding the application of multi-junction device structure in PSCs, homo multi-junction PSCs were constructed from an identical

  13. Leafy nanostructure PANI for material of supercapacitors

    OpenAIRE

    XI Dong; CHEN Xinman

    2013-01-01

    Nanostructure conducting polyaniline(PANI) has great potential applications in supercapacitor electrode materials.In this paper,we report a template-free approach to synthesize PANI by a galvanostatic current procedure with a three-electrode configuration directly on indium-doped tin-oxide substrates (ITO).The morphology of product was characterized by Hitachi S-4800 field emission scanning electron microscope (FE-SEM).Due to the nanostructure,the specific capacitance of PANI film with the th...

  14. Application of nanostructural materials in electro optical measuring sets of big powers based on usage of optical effects

    Science.gov (United States)

    Salihov, Aidar I.; Tljavlin, Anfar Z.; Kusimov, Salavat M.

    2005-06-01

    Optically transparent nanostructural materials show to themselves a heightened interest owing to display in them the new physic mechanical properties. Variation of structure of the materials received by methods of intensive plastic deformation, results in variation of many fundamental parameters. Among them special interest was caused with variations of fundamental magnetic characteristics. One of them is the magnetization of saturation, which is usually structurally tolerant, but reflects changes in an atomic-crystal structure of solids. Even in the first probing of the transparent nanostructures, received by intensive deformation by torsion of samples, was found that the magnetization of saturation was revealed at room temperature in comparison with coarse-grained samples. High-power measuring devices are based on Faraday effect, representing itself rotation of a plane of polarization of linearly polarized light in optical active substances under action of a magnetic field. Application of nanostructural materials in the optical insulator, which is the main part of the measuring device, allows improving the measuring characteristics of instruments qualitatively. Brought losses in Faraday cell make 0,35 -0,89 dB instead of 0,7 - I,2 dB, and value of the backward losses makes not less than 62 dB instead of 55 dB. Undoubtedly, improvement of the given parameters allows making the measuring operations with the greater accuracy, reducing both absolute, and relative errors.

  15. Metal Nanoparticles and Carbon-Based Nanostructures as Advanced Materials for Cathode Application in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Pietro Calandra

    2010-01-01

    Full Text Available We review the most advanced methods for the fabrication of cathodes for dye-sensitized solar cells employing nanostructured materials. The attention is focused on metal nanoparticles and nanostructured carbon, among which nanotubes and graphene, whose good catalytic properties make them ideal for the development of counter electrode substrates, transparent conducting oxide, and advanced catalyst materials.

  16. Nanostructured materials for multifunctional applications under NSF-CREST research at Norfolk State University

    Science.gov (United States)

    Pradhan, A. K.; Mundle, R.; Zhang, K.; Holloway, T.; Amponsah, O.; Biswal, D.; Konda, R.; White, C.; Dondapati, H.; Santiago, K.; Birdsong, T.; Arslan, M.; Peeples, B.; Shaw, D.; Smak, J.; Samataray, C.; Bahoura, M.

    2012-04-01

    Magnetic nanoparticles of CoFe2O4 have been synthesized under an applied magnetic field through a co-precipitation method followed by thermal treatments at different temperatures, producing nanoparticles of varying size. The magnetic behavior of these nanoparticles of varying size was investigated. As-grown nanoparticles demonstrate superparamagnetism above the blocking temperature, which is dependent on the particle size. The anomalous magnetic behavior is attributed to the preferred Co ions and vacancies arrangements when the CoFe2O4 nanoparticles were synthesized under applied magnetic field. Furthermore, this magnetic property is strongly dependent on the high temperature heat treatments, which produce Co ions and vacancies disorder. We performed the fabrication of condensed and mesoporous silica coated CoFe2O4 magnetic nanocomposites. The CoFe2O4 magnetic nanoparticles were encapsulated with well-defined silica layer. The mesopores in the shell were fabricated as a consequence of removal of organic group of the precursor through annealing. The NiO nanoparticles were loaded into the mesoporous silica. The mesoporous silica coated magnetic nanostructure loaded with NiO as a final product may have potential use in the field of biomedical applications. Growth mechanism of ZnO nanorod arrays on ZnO seed layer investigated by electric and Kelvin probe force microscopy. Both electric and Kelvin force probe microscopy was used to investigate the surface potentials on the ZnO seed layer, which shows a remarkable dependence on the annealing temperature. The optimum temperature for the growth of nanorod arrays normal to the surface was found to be at 600 °C, which is in the range of right surface potentials and energy measured between 500 °C and 700 °C. We demonstrated from both EFM and Kelvin force probe microscopy studies that surface potential controls the growth of ZnO nanorods. This study will provide important understanding of growth of other nanostructures. Zn

  17. Nanostructured conductive polymeric materials

    Science.gov (United States)

    Al-Saleh, Mohammed H.

    Conductive polymer composites (CPCs) are a suitable alternative to metals in many applications due to their light-weight, corrosion resistance, low cost, ease of processing and design flexibility. CPCs have been formulated using different types of conductive fillers. In this PhD thesis, the focus is on CPCs for electrostatic discharge (ESD) protection and electromagnetic interference (EMI) attenuation. Despite the versatility of conductive fillers, carbon black (CB) has been the dominant filler to make CPCs for ESD protection applications because CB/polymer composites have a cost advantage over all other CPCs. For EMI shielding, stainless steel fibres and metal coated fibers are the preferred fillers, however CPCs made of those fibers are not the dominant EMI shielding materials. Metal coated and polymer plated polymers are the most widely used EMI shielding options. The limited use of CPCs in the EMI shielding market is because the high filler loading required to formulate a composite with an adequate level of shielding remarkably increases the composite price. In order to increase the competitiveness of CPCs, percolation threshold should be minimized as much as possible and composites with high EMI shielding capabilities at low filler loading should be formulated because all conductive fillers are expensive compared to polymers. In this thesis, two different methodologies to reduce percolation threshold in CPCs have been successfully developed and a CPC with exceptional EMI shielding capability has been formulated using copper nanowires as conductive filler. The first percolation threshold reduction technique is based on the selective localization of CB at the interface of immiscible polymer blend. The technique requires adding a copolymer that prefers the blend's interface and for which CB nanoparticles has the highest affinity. The second method is based on producing a CPC powder and then using this powder as a conductive filler to produce composite by dry

  18. Ferroelectric mesocrystals of bismuth sodium titanate: formation mechanism, nanostructure, and application to piezoelectric materials.

    Science.gov (United States)

    Hu, Dengwei; Kong, Xingang; Mori, Kotaro; Tanaka, Yasuhiro; Shinagawa, Kazunari; Feng, Qi

    2013-09-16

    Ferroelectric mesocrystals of Bi0.5Na0.5TiO3 (BNT) with [100]-crystal-axis orientation were successfully prepared using a topotactic structural transformation process from a layered titanate H1.07Ti1.73O4·nH2O (HTO). The formation reactions of BNT mesocrystals in HTO-Bi2O3-Na2CO3 and HTO-TiO2-Bi2O3-Na2CO3 reaction systems and their nanostructures were studied by XRD, FE-SEM, TEM, SAED, and EDS, and the reaction mechanisms were given. The BNT mesocrystals are formed by a topotactic structural transformation mechanism in the HTO-Bi2O3-Na2CO3 reaction system and by a combination mechanism of the topotactic structural transformation and epitaxial crystal growth in the HTO-TiO2-Bi2O3-Na2CO3 reaction system, respectively. The BNT mesocrystals prepared by these methods are constructed from [100]-oriented BNT nanocrystals. Furthermore, these reaction systems were successfully applied to the fabrication of [100]-oriented BNT ferroelectric ceramic materials. A BNT ceramic material with a high degree of orientation, high relative density, and small grain size was achieved.

  19. Solution plasma applications for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers

    Science.gov (United States)

    Watthanaphanit, Anyarat; Saito, Nagahiro

    2018-01-01

    Reducing the use of toxic chemicals, production steps, and time consumption are important concerns for researchers and process engineers to contribute in the quest for an efficient process in any production. If an equipment setup is simple, the process additionally becomes more profitable. Combination of the mentioned requirements has opened up various applications of the solution plasma process (SPP) — a physical means of generating plasma through an electrical discharge in a liquid medium at atmospheric pressure and room temperature. This review shows the progress of scientific research on the applications of the SPP for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers. Development achieved in each application is demonstrated.

  20. Nanostructured Materials for Li-Ion Batteries and Beyond

    Directory of Open Access Journals (Sweden)

    Xifei Li

    2016-04-01

    Full Text Available This Special Issue “Nanostructured Materials for Li-Ion Batteries and Beyond” of Nanomaterials is focused on advancements in the synthesis, optimization, and characterization of nanostructured materials, with an emphasis on the application of nanomaterials for building high performance Li-ion batteries (LIBs and future systems.[...

  1. Composite materials formed with anchored nanostructures

    Science.gov (United States)

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

    2015-03-10

    A method of forming nano-structure composite materials that have a binder material and a nanostructure fiber material is described. A precursor material may be formed using a mixture of at least one metal powder and anchored nanostructure materials. The metal powder mixture may be (a) Ni powder and (b) NiAl powder. The anchored nanostructure materials may comprise (i) NiAl powder as a support material and (ii) carbon nanotubes attached to nanoparticles adjacent to a surface of the support material. The process of forming nano-structure composite materials typically involves sintering the mixture under vacuum in a die. When Ni and NiAl are used in the metal powder mixture Ni.sub.3Al may form as the binder material after sintering. The mixture is sintered until it consolidates to form the nano-structure composite material.

  2. Superconducting nanostructured materials

    International Nuclear Information System (INIS)

    Metlushko, V.

    1998-01-01

    Within the last year it has been realized that the remarkable properties of superconducting thin films containing a periodic array of defects (such as sub-micron sized holes) offer a new route for developing a novel superconducting materials based on precise control of microstructure by modern photolithography. A superconductor is a material which, when cooled below a certain temperature, loses all resistance to electricity. This means that superconducting materials can carry large electrical currents without any energy loss--but there are limits to how much current can flow before superconductivity is destroyed. The current at which superconductivity breaks down is called the critical current. The value of the critical current is determined by the balance of Lorentz forces and pinning forces acting on the flux lines in the superconductor. Lorentz forces proportional to the current flow tend to drive the flux lines into motion, which dissipates energy and destroys zero resistance. Pinning forces created by isolated defects in the microstructure oppose flux line motion and increase the critical current. Many kinds of artificial pinning centers have been proposed and developed to increase critical current performance, ranging from dispersal of small non-superconducting second phases to creation of defects by proton, neutron or heavy ion irradiation. In all of these methods, the pinning centers are randomly distributed over the superconducting material, causing them to operate well below their maximum efficiency. We are overcome this drawback by creating pinning centers in aperiodic lattice (see Fig 1) so that each pin site interacts strongly with only one or a few flux lines

  3. An overview on cellulose-based material in tailoring bio-hybrid nanostructured photocatalysts for water treatment and renewable energy applications.

    Science.gov (United States)

    Mohamed, Mohamad Azuwa; Abd Mutalib, Muhazri; Mohd Hir, Zul Adlan; M Zain, M F; Mohamad, Abu Bakar; Jeffery Minggu, Lorna; Awang, Nor Asikin; W Salleh, W N

    2017-10-01

    A combination between the nanostructured photocatalyst and cellulose-based materials promotes a new functionality of cellulose towards the development of new bio-hybrid materials for various applications especially in water treatment and renewable energy. The excellent compatibility and association between nanostructured photocatalyst and cellulose-based materials was induced by bio-combability and high hydrophilicity of the cellulose components. The electron rich hydroxyl group of celluloses helps to promote superior interaction with photocatalyst. The formation of bio-hybrid nanostructured are attaining huge interest nowadays due to the synergistic properties of individual cellulose-based material and photocatalyst nanoparticles. Therefore, in this review we introduce some cellulose-based material and discusses its compatibility with nanostructured photocatalyst in terms of physical and chemical properties. In addition, we gather information and evidence on the fabrication techniques of cellulose-based hybrid nanostructured photocatalyst and its recent application in the field of water treatment and renewable energy. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Nanostructured Diclofenac Sodium Releasing Material

    Science.gov (United States)

    Nikkola, L.; Vapalahti, K.; Harlin, A.; Seppälä, J.; Ashammakhi, N.

    2008-02-01

    Various techniques have been developed to produce second generation biomaterials for tissue repair. These include extrusion, molding, salt leaching, spinning etc, but success in regenerating tissues has been limited. It is important to develop porous material, yet with a fibrous structure for it to be biomimetic. To mimic biological tissues, the extra-cellular matrix usually contains fibers in nano scale. To produce nanostructures, self-assembly or electrospinning can be used. Adding a drug release function to such a material may advance applications further for use in controlled tissue repair. This turns the resulting device into a multifunctional porous, fibrous structure to support cells and drug releasing properties in order to control tissue reactions. A bioabsorbable poly(ɛ-caprolactone-co-D,L lactide) 95/5 (PCL) was made into diluted solution using a solvent, to which was added 2w-% of diclofenac sodium (DS). Nano-fibers were made by electrospinning onto substrate. Microstructure of the resulting nanomat was studied using SEM and drug release profiles with UV/VIS spectroscopy. Thickness of the electrospun nanomat was about 2 mm. SEM analysis showed that polymeric nano-fibers containing drug particles form a highly interconnected porous nano structure. Average diameter of the nano-fibers was 130 nm. There was a high burst peak in drug release, which decreased to low levels after one day. The used polymer has slow a degradation rate and though the nanomat was highly porous with a large surface area, drug release rate is slow. It is feasible to develop a nano-fibrous porous structure of bioabsorbable polymer, which is loaded with test drug. Drug release is targeted at improving the properties of biomaterial for use in controlled tissue repair and regeneration.

  5. Electron microscopy of nanostructured semiconductor materials

    International Nuclear Information System (INIS)

    Neumann, Wolfgang

    2003-01-01

    For various material systems of low dimensions, including multilayers, islands, and quantum dots, the potential applicability of transmission electron microscopy (TEM) is demonstrated. Conventional TEM is applied to elucidate size, shape, and arrangement of nanostructures, whereas high-resolution imaging is used for visualizing their atomic structure. In addition, microchemical peculiarities of the nanoscopic objects are investigated by analytical TEM techniques (energy-filtered TEM, energy-dispersive X-ray spectroscopy)

  6. Electrodeposited manganese dioxide nanostructures on electro-etched carbon fibers: High performance materials for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, Sayed Habib, E-mail: habibkazemi@iasbs.ac.ir [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Center for Research in Climate Change and Global Warming (CRCC), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Maghami, Mostafa Ghaem [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Kiani, Mohammad Ali [Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran (Iran, Islamic Republic of)

    2014-12-15

    Highlights: • We report a facile method for fabrication of MnO{sub 2} nanostructures on electro-etched carbon fiber. • MnO{sub 2}-ECF electrode shows outstanding supercapacitive behavior even at high discharge rates. • Exceptional cycle stability was achieved for MnO{sub 2}-ECF electrode. • The coulombic efficiency of MnO{sub 2}-ECF electrode is nearly 100%. - Abstract: In this article we introduce a facile, low cost and additive/template free method to fabricate high-rate electrochemical capacitors. Manganese oxide nanostructures were electrodeposited on electro-etched carbon fiber substrate by applying a constant anodic current. Nanostructured MnO{sub 2} on electro-etched carbon fiber was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis. The electrochemical behavior of MnO{sub 2} electro-etched carbon fiber electrode was investigated by electrochemical techniques including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. A maximum specific capacitance of 728.5 F g{sup −1} was achieved at a scan rate of 5 mV s{sup −1} for MnO{sub 2} electro-etched carbon fiber electrode. Also, this electrode showed exceptional cycle stability, suggesting that it can be considered as a good candidate for supercapacitor electrodes.

  7. Electrodeposited manganese dioxide nanostructures on electro-etched carbon fibers: High performance materials for supercapacitor applications

    International Nuclear Information System (INIS)

    Kazemi, Sayed Habib; Maghami, Mostafa Ghaem; Kiani, Mohammad Ali

    2014-01-01

    Highlights: • We report a facile method for fabrication of MnO 2 nanostructures on electro-etched carbon fiber. • MnO 2 -ECF electrode shows outstanding supercapacitive behavior even at high discharge rates. • Exceptional cycle stability was achieved for MnO 2 -ECF electrode. • The coulombic efficiency of MnO 2 -ECF electrode is nearly 100%. - Abstract: In this article we introduce a facile, low cost and additive/template free method to fabricate high-rate electrochemical capacitors. Manganese oxide nanostructures were electrodeposited on electro-etched carbon fiber substrate by applying a constant anodic current. Nanostructured MnO 2 on electro-etched carbon fiber was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis. The electrochemical behavior of MnO 2 electro-etched carbon fiber electrode was investigated by electrochemical techniques including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. A maximum specific capacitance of 728.5 F g −1 was achieved at a scan rate of 5 mV s −1 for MnO 2 electro-etched carbon fiber electrode. Also, this electrode showed exceptional cycle stability, suggesting that it can be considered as a good candidate for supercapacitor electrodes

  8. 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)

  9. Hybrid nanostructured materials for high-performance electrochemical capacitors

    KAUST Repository

    Yu, Guihua; Xie, Xing; Pan, Lijia; Bao, Zhenan; Cui, Yi

    2013-01-01

    The exciting development of advanced nanostructured materials has driven the rapid growth of research in the field of electrochemical energy storage (EES) systems which are critical to a variety of applications ranging from portable consumer

  10. Inorganic nanostructured materials for high performance electrochemical supercapacitors

    Science.gov (United States)

    Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

    2014-01-01

    Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

  11. Simple synthesis of amorphous NiWO4 nanostructure and its application as a novel cathode material for asymmetric supercapacitors.

    Science.gov (United States)

    Niu, Lengyuan; Li, Zhangpeng; Xu, Ye; Sun, Jinfeng; Hong, Wei; Liu, Xiaohong; Wang, Jinqing; Yang, Shengrong

    2013-08-28

    This study reports a simple synthesis of amorphous nickel tungstate (NiWO4) nanostructure and its application as a novel cathode material for supercapacitors. The effect of reaction temperature on the electrochemical properties of the NiWO4 electrode was studied, and results demonstrate that the material synthesized at 70 °C (NiW-70) has shown the highest specific capacitance of 586.2 F g(-1) at 0.5 A g(-1) in a three-electrode system. To achieve a high energy density, a NiW-70//activated carbon asymmetric supercapacitor is successfully assembled by use of NiW-70 and activated carbon as the cathode and anode, respectively, and then, its electrochemical performance is characterized by cyclic voltammetry and galvanostatic charge-discharge measurements. The results show that the assembled asymmetric supercapacitor can be cycled reversibly between 0 and 1.6 V with a high specific capacitance of 71.1 F g(-1) at 0.25 A g(-1), which can deliver a maximum energy density of 25.3 Wh kg(-1) at a power density of 200 W kg(-1). Furthermore, this asymmetric supercapacitor also presented an excellent, long cycle life along with 91.4% specific capacitance being retained after 5000 consecutive times of cycling.

  12. Leafy nanostructure PANI for material of supercapacitors

    Directory of Open Access Journals (Sweden)

    XI Dong

    2013-06-01

    Full Text Available Nanostructure conducting polyaniline(PANI has great potential applications in supercapacitor electrode materials.In this paper,we report a template-free approach to synthesize PANI by a galvanostatic current procedure with a three-electrode configuration directly on indium-doped tin-oxide substrates (ITO.The morphology of product was characterized by Hitachi S-4800 field emission scanning electron microscope (FE-SEM.Due to the nanostructure,the specific capacitance of PANI film with the thickness of 100nm were measured as high as 829 F/g and 667 F/g at a charge-discharge current density of 1 A/g and 10 A/g respectively.After 500 cycle charge-discharge test employed at the current density of 20 A/g the PANI film still had a 95.1% capacitance retention.

  13. Nanostructured manganese oxide thin films as electrode material for supercapacitors

    Science.gov (United States)

    Xia, Hui; Lai, Man On; Lu, Li

    2011-01-01

    Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.

  14. 6. international conference on Nano-technology in Carbon: from synthesis to applications of nano-structured carbon and related materials

    International Nuclear Information System (INIS)

    2004-01-01

    This is the sixth international conference sponsored this year by the French Carbon Group (GFEC), the European Research Group on Nano-tubes GDRE 'Nano-E', in collaboration with the British Carbon Group and the 'Institut des Materiaux Jean Rouxel' (local organizer). The aim of this conference is to promote carbon science in the nano-scale as, for example, nano-structured carbons, nano-tubes, nano-wires, fullerenes, etc. This conference is designed to introduce those with an interest in materials to current research in nano-technology and to bring together research scientists working in various disciplines in the broad area of nano-structured carbons, nano-tubes and fullerene-related nano-structures. Elemental carbon is the simplest exemplar of this nano-technology based on covalent bonding, however other systems (for example containing hetero-atoms) are becoming important from a research point of view, and provide alternative nano-materials with unique properties opening a broad field of applications. Nano-technology requires an understanding of these materials on a structural and textural point of view and this will be the central theme. This year the conference will feature sessions on: S1. Control and synthesis of nano-materials 1.1 Nano-structured carbons: pyrolysis of polymers, activation, templates,... 1.2 Nano-tubes: Catalytic method, HiPCO, graphite vaporization, electrolysis,... 1.3 Fullerenes S2. Chemistry of carbon nano-materials 2.1 Purification of carbon nano-tubes 2.2 Functionalization - Self-assembling S3. Structural characterization S4. Theory and modelling S5. Relationship between structure and properties S6. Applications Water and air purification, Gas and energy storage, Composite materials, Field emission, Nano-electronics, Biotechnology,... S7. Environmental impact. Only one paper concerning carbon under irradiation has been added to the INIS database. (authors)

  15. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    International Nuclear Information System (INIS)

    Prosviryakov, A.S.; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-01

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al 3 Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al 3 Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al 3 Zr crystals were completely dissolved in Al after 20 h. •Cubic Al 3 Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  16. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Prosviryakov, A.S., E-mail: pro.alex@mail.ru; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-15

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al{sub 3}Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al{sub 3}Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al{sub 3}Zr crystals were completely dissolved in Al after 20 h. •Cubic Al{sub 3}Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  17. Nanostructured Materials for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-11-01

    This factsheet describes a research project whose overall objective is to advance the fundamental understanding of novel photoelectronic organic device structures integrated with inorganic nanostructures, while also expanding the general field of nanomaterials for renewable energy devices and systems.

  18. Carbon and oxide nanostructures. Synthesis, characterisation and applications

    Energy Technology Data Exchange (ETDEWEB)

    Yahya, Noorhana [Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia). Dept. of Fundamental and Applied Sciences

    2010-07-01

    This volume covers all aspects of carbon and oxide based nanostructured materials. The topics include synthesis, characterization and application of carbon-based namely carbon nanotubes, carbon nanofibres, fullerenes, carbon filled composites etc. In addition, metal oxides namely, ZnO, TiO2, Fe2O3, ferrites, garnets etc., for various applications like sensors, solar cells, transformers, antennas, catalysts, batteries, lubricants, are presented. The book also includes the modeling of oxide and carbon based nanomaterials. The book covers the topics: - Synthesis, characterization and application of carbon nanotubes, carbon nanofibres, fullerenes - Synthesis, characterization and application of oxide based nanomaterials. - Nanostructured magnetic and electric materials and their applications. - Nanostructured materials for petro-chemical industry. - Oxide and carbon based thin films for electronics and sustainable energy. - Theory, calculations and modeling of nanostructured materials. (orig.)

  19. Synthesis and processing of nanostructured materials

    International Nuclear Information System (INIS)

    Siegel, R.W.

    1992-12-01

    Significant and growing interest is being exhibited in the novel and enhanced properties of nanostructured materials. These materials, with their constituent phase or grain structures modulated on a length scale less than 100 nm, are artificially synthesized by a wide variety of physical, chemical, and mechanical methods. In this NATO Advanced Study Institute, where mechanical behavior is emphasized, nanostructured materials with modulation dimensionalities from one (multilayers) to three (nanophase materials) are mainly considered. No attempt is made in this review to cover in detail all of the diverse methods available for the synthesis of nanostructured materials. Rather, the basic principles involved in their synthesis are discussed in terms of the special properties sought using examples of particular synthesis and processing methodologies. Some examples of the property changes that can result from one of these methods, cluster assembly of nanophase materials, are presented

  20. Modeling of space environment impact on nanostructured materials. General principles

    Science.gov (United States)

    Voronina, Ekaterina; Novikov, Lev

    2016-07-01

    In accordance with the resolution of ISO TC20/SC14 WG4/WG6 joint meeting, Technical Specification (TS) 'Modeling of space environment impact on nanostructured materials. General principles' which describes computer simulation methods of space environment impact on nanostructured materials is being prepared. Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. Most such standards are related to production and characterization of nanostructures, however there is no ISO documents concerning nanomaterials behavior in different environmental conditions, including the space environment. The given TS deals with the peculiarities of the space environment impact on nanostructured materials (i.e. materials with structured objects which size in at least one dimension lies within 1-100 nm). The basic purpose of the document is the general description of the methodology of applying computer simulation methods which relate to different space and time scale to modeling processes occurring in nanostructured materials under the space environment impact. This document will emphasize the necessity of applying multiscale simulation approach and present the recommendations for the choice of the most appropriate methods (or a group of methods) for computer modeling of various processes that can occur in nanostructured materials under the influence of different space environment components. In addition, TS includes the description of possible

  1. Raman Spectroscopy and its Application in Nanostructures

    CERN Document Server

    Zhang, Shu-Lin

    2012-01-01

    Raman Spectroscopy and its Application in Nanostructures is an original and timely contribution to a very active area of physics and materials science research. This book presents the theoretical and experimental phenomena of Raman spectroscopy, with specialized discussions on the physical fundamentals, new developments and main features in low-dimensional systems of Raman spectroscopy. In recent years physicists, materials scientists and chemists have devoted increasing attention to low-dimensional systems and as Raman spectroscopy can be used to study and analyse such materials as carbon nan

  2. Hydrogen storage in nanostructured materials

    Energy Technology Data Exchange (ETDEWEB)

    Assfour, Bassem

    2011-02-28

    Hydrogen is an appealing energy carrier for clean energy use. However, storage of hydrogen is still the main bottleneck for the realization of an energy economy based on hydrogen. Many materials with outstanding properties have been synthesized with the aim to store enough amount of hydrogen under ambient conditions. Such efforts need guidance from material science, which includes predictive theoretical tools. Carbon nanotubes were considered as promising candidates for hydrogen storage applications, but later on it was found to be unable to store enough amounts of hydrogen under ambient conditions. New arrangements of carbon nanotubes were constructed and hydrogen sorption properties were investigated using state-of-the-art simulation methods. The simulations indicate outstanding total hydrogen uptake (up to 19.0 wt.% at 77 K and 5.52wt.% at 300 K), which makes these materials excellent candidates for storage applications. This reopens the carbon route to superior materials for a hydrogen-based economy. Zeolite imidazolate frameworks are subclass of MOFs with an exceptional chemical and thermal stability. The hydrogen adsorption in ZIFs was investigated as a function of network geometry and organic linker exchange. Ab initio calculations performed at the MP2 level to obtain correct interaction energies between hydrogen molecules and the ZIF framework. Subsequently, GCMC simulations are carried out to obtain the hydrogen uptake of ZIFs at different thermodynamic conditions. The best of these materials (ZIF-8) is found to be able to store up to 5 wt.% at 77 K and high pressure. We expected possible improvement of hydrogen capacity of ZIFs by substituting the metal atom (Zn{sup 2+}) in the structure by lighter elements such as B or Li. Therefore, we investigated the energy landscape of LiB(IM)4 polymorphs in detail and analyzed their hydrogen storage capacities. The structure with the fau topology was shown to be one of the best materials for hydrogen storage. Its

  3. Potential of AlN nanostructures as hydrogen storage materials.

    Science.gov (United States)

    Wang, Qian; Sun, Qiang; Jena, Puru; Kawazoe, Yoshiyuki

    2009-03-24

    The capability of AlN nanostructures (nanocages, nanocones, nanotubes, and nanowires) to store hydrogen has been studied using gradient-corrected density functional theory. In contrast to bulk AlN, which has the wurtzite structure and four-fold coordination, the Al sites in AlN nanostructures are unsaturated and have two- and three-fold coordination. Each Al atom is capable of binding one H(2) molecule in quasi-molecular form, leading to 4.7 wt % hydrogen, irrespective of the topology of the nanostructures. With the exception of AlN nanotubes, energetics does not support the adsorption of additional hydrogen. The binding energies of hydrogen to these unsaturated metal sites lie in the range of 0.1-0.2 eV/H(2) and are ideal for applications under ambient thermodynamic conditions. Furthermore, these materials do not suffer from the clustering problem that often plagues metal-coated carbon nanostructures.

  4. Nanostructured hybrid materials from aqueous polymer dispersions.

    Science.gov (United States)

    Castelvetro, Valter; De Vita, Cinzia

    2004-05-20

    Organic-inorganic (O-I) hybrids with well-defined morphology and structure controlled at the nanometric scale represent a very interesting class of materials both for their use as biomimetic composites and because of their potential use in a wide range of technologically advanced as well as more conventional application fields. Their unique features can be exploited or their role envisaged as components of electronic and optoelectronic devices, in controlled release and bioencapsulation, as active substrates for chromatographic separation and catalysis, as nanofillers for composite films in packaging and coating, in nanowriting and nanolithography, etc. A synergistic combination or totally new properties with respect to the two components of the hybrid can arise from nanostructuration, achieved by surface modification of nanostructures, self-assembling or simply heterophase dispersion. In fact, owing to the extremely large total surface area associated with the resulting morphologies, the interfacial interactions can deeply modify the bulk properties of each component. A wide range of starting materials and of production processes have been studied in recent years for the controlled synthesis and characterization of hybrid nanostructures, from nanoparticle or lamellar dispersions to mesoporous materials obtained from templating nanoparticle dispersions in a continuous, e.g. ceramic precursor, matrix. This review is aimed at giving some basic definitions of what is intended as a hybrid (O-I) material and what are the main synthetic routes available. The various methods for preparing hybrid nanostructures and, among them, inorganic-organic or O-I core-shell nanoparticles, are critically analyzed and classified based on the reaction medium (aqueous, non-aqueous), and on the role it plays in directing the final morphology. Particular attention is devoted to aqueous systems and water-borne dispersions which, in addition to being environmentally more acceptable or even a

  5. Multifunctional Carbon Nanostructures for Advanced Energy Storage Applications

    Directory of Open Access Journals (Sweden)

    Yiran Wang

    2015-05-01

    Full Text Available Carbon nanostructures—including graphene, fullerenes, etc.—have found applications in a number of areas synergistically with a number of other materials. These multifunctional carbon nanostructures have recently attracted tremendous interest for energy storage applications due to their large aspect ratios, specific surface areas, and electrical conductivity. This succinct review aims to report on the recent advances in energy storage applications involving these multifunctional carbon nanostructures. The advanced design and testing of multifunctional carbon nanostructures for energy storage applications—specifically, electrochemical capacitors, lithium ion batteries, and fuel cells—are emphasized with comprehensive examples.

  6. Nanostructured metal foams: synthesis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Luther, Erik P [Los Alamos National Laboratory; Tappan, Bryce [Los Alamos National Laboratory; Mueller, Alex [Los Alamos National Laboratory; Mihaila, Bogdan [Los Alamos National Laboratory; Volz, Heather [Los Alamos National Laboratory; Cardenas, Andreas [Los Alamos National Laboratory; Papin, Pallas [Los Alamos National Laboratory; Veauthier, Jackie [Los Alamos National Laboratory; Stan, Marius [Los Alamos National Laboratory

    2009-01-01

    Fabrication of monolithic metallic nanoporous materials is difficult using conventional methodology. Here they report a relatively simple method of synthesizing monolithic, ultralow density, nanostructured metal foams utilizing self-propagating combustion synthesis of novel metal complexes containing high nitrogen energetic ligands. Nanostructured metal foams are formed in a post flame-front dynamic assembly with densities as low as 0.011 g/cc and surface areas as high as 270 m{sup 2}/g. They have produced metal foams via this method of titanium, iron, cobalt, nickel, zirconium, copper, palladium, silver, hafnium, platinum and gold. Microstructural features vary as a function of composition and process parameters. Applications for the metal foams are discussed including hydrogen absorption in palladium foams. A model for the sorption kinetics of hydrogen in the foams is presented.

  7. Hybrid nanostructured materials for high-performance electrochemical capacitors

    KAUST Repository

    Yu, Guihua

    2013-03-01

    The exciting development of advanced nanostructured materials has driven the rapid growth of research in the field of electrochemical energy storage (EES) systems which are critical to a variety of applications ranging from portable consumer electronics, hybrid electric vehicles, to large industrial scale power and energy management. Owing to their capability to deliver high power performance and extremely long cycle life, electrochemical capacitors (ECs), one of the key EES systems, have attracted increasing attention in the recent years since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review article describes the most recent progress in the development of nanostructured electrode materials for EC technology, with a particular focus on hybrid nanostructured materials that combine carbon based materials with pseudocapacitive metal oxides or conducting polymers for achieving high-performance ECs. This review starts with an overview of EES technologies and the comparison between various EES systems, followed by a brief description of energy storage mechanisms for different types of EC materials. This review emphasizes the exciting development of both hybrid nanomaterials and novel support structures for effective electrochemical utilization and high mass loading of active electrode materials, both of which have brought the energy density of ECs closer to that of batteries while still maintaining their characteristic high power density. Last, future research directions and the remaining challenges toward the rational design and synthesis of hybrid nanostructured electrode materials for next-generation ECs are discussed. © 2012 Elsevier Ltd.

  8. Storage of hydrogen in nanostructured carbon materials

    OpenAIRE

    Yürüm, Yuda; Yurum, Yuda; Taralp, Alpay; Veziroğlu, T. Nejat; Veziroglu, T. Nejat

    2009-01-01

    Recent developments focusing on novel hydrogen storage media have helped to benchmark nanostructured carbon materials as one of the ongoing strategic research areas in science and technology. In particular, certain microporous carbon powders, carbon nanomaterials, and specifically carbon nanotubes stand to deliver unparalleled performance as the next generation of base materials for storing hydrogen. Accordingly, the main goal of this report is to overview the challenges, distinguishing trait...

  9. Metal chalcogenide nanostructures for renewable energy applications

    CERN Document Server

    Qurashi, Ahsanulhaq

    2014-01-01

    This first ever reference book that focuses on metal chalcogenide semiconductor nanostructures for renewable energy applications encapsulates the state-of-the-art in multidisciplinary research on the metal chalcogenide semiconductor nanostructures (nanocrystals, nanoparticles, nanorods, nanowires,  nanobelts, nanoflowers, nanoribbons and more).  The properties and synthesis of a class of nanomaterials is essential to renewable energy manufacturing and this book focuses on the synthesis of metal chalcogendie nanostructures, their growth mechanism, optical, electrical, and other important prop

  10. Nanostructured electronic and magnetic materials

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    and magnetic materials are provided. Advantages of nanocrystalline magnetic mate- rials in the context of ... 2.2 Phosphors for high definition TV. Better resolution of television screens could be ..... materials and that of preparing nanoparticles. This will remain a challenge for the future if nanomaterials are to be competitive.

  11. Hydrogen Storage In Nanostructured Materials

    OpenAIRE

    Assfour, Bassem

    2011-01-01

    Hydrogen is an appealing energy carrier for clean energy use. However, storage of hydrogen is still the main bottleneck for the realization of an energy economy based on hydrogen. Many materials with outstanding properties have been synthesized with the aim to store enough amount of hydrogen under ambient conditions. Such efforts need guidance from material science, which includes predictive theoretical tools. Carbon nanotubes were considered as promising candidates for hydrogen storag...

  12. Nanostructured Mo-based electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

    2015-04-21

    The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

  13. Improved antireflection based on biomimetic nanostructures at material interface

    Science.gov (United States)

    Zhang, Lingyu; Song, Gang

    2018-02-01

    Reducing light reflections on the surface of materials has important applications in many fields, such as solar cells, photodetectors, and optical sensors, etc. An effective method of decreasing reflection is using the anti-reflective coating with a gradient refractive index. In this study, we designed a nanostructure composed of optimized cone arrays on the flat thin film surface. The tapered nanostructure forms an anti-reflection layer. The effective refractive index of the anti-reflection layer changes smoothly with the depth so that the surface can efficiently reduce the reflection in a wide visible light range. Moreover, the reflection can also be modulated by adjusting the height and the period of the nanocones. Furthermore, there is an optimal wavelength at which the highest anti-reflection efficiency is achieved. The results here provide a theoretical guidance for the practical design of broadband anti-reflection nanostructures at the device surface.

  14. Complex Hollow Nanostructures: Synthesis and Energy-Related Applications.

    Science.gov (United States)

    Yu, Le; Hu, Han; Wu, Hao Bin; Lou, Xiong Wen David

    2017-04-01

    Hollow nanostructures offer promising potential for advanced energy storage and conversion applications. In the past decade, considerable research efforts have been devoted to the design and synthesis of hollow nanostructures with high complexity by manipulating their geometric morphology, chemical composition, and building block and interior architecture to boost their electrochemical performance, fulfilling the increasing global demand for renewable and sustainable energy sources. In this Review, we present a comprehensive overview of the synthesis and energy-related applications of complex hollow nanostructures. After a brief classification, the design and synthesis of complex hollow nanostructures are described in detail, which include hierarchical hollow spheres, hierarchical tubular structures, hollow polyhedra, and multi-shelled hollow structures, as well as their hybrids with nanocarbon materials. Thereafter, we discuss their niche applications as electrode materials for lithium-ion batteries and hybrid supercapacitors, sulfur hosts for lithium-sulfur batteries, and electrocatalysts for oxygen- and hydrogen-involving energy conversion reactions. The potential superiorities of complex hollow nanostructures for these applications are particularly highlighted. Finally, we conclude this Review with urgent challenges and further research directions of complex hollow nanostructures for energy-related applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Silicon-germanium (Sige) nanostructures production, properties and applications in electronics

    CERN Document Server

    Usami, N

    2011-01-01

    Nanostructured silicon-germanium (SiGe) provides the prospect of novel and enhanced electronic device performance. This book reviews the materials science and technology of SiGe nanostructures, including crystal growth, fabrication of nanostructures, material properties and applications in electronics.$bNanostructured silicon-germanium (SiGe) opens up the prospects of novel and enhanced electronic device performance, especially for semiconductor devices. Silicon-germanium (SiGe) nanostructures reviews the materials science of nanostructures and their properties and applications in different electronic devices. The introductory part one covers the structural properties of SiGe nanostructures, with a further chapter discussing electronic band structures of SiGe alloys. Part two concentrates on the formation of SiGe nanostructures, with chapters on different methods of crystal growth such as molecular beam epitaxy and chemical vapour deposition. This part also includes chapters covering strain engineering and mo...

  16. Tubular nanostructured materials for bioapplications

    Science.gov (United States)

    Xie, Jining; Chen, Linfeng; Srivatsan, Malathi; Varadan, Vijay K.

    2009-03-01

    Tubular nanomaterials possess hollow structures as well as high aspect ratios. In addition to their unique physical and chemical properties induced by their nanoscale dimensions, their inner voids and outer surfaces make them ideal candidates for a number of biomedical applications. In this work, three types of tubular nanomaterials including carbon nanotubes, hematite nanotubes, and maghemite nanotubes, were synthesized by different chemical techniques. Their structural and crystalline properties were characterized. For potential bioapplications of tubular nanomaterials, experimental investigations were carried out to demonstrate the feasibility of using carbon nanotubes, hematite nanotubes, and maghemite nanotubes in glucose sensing, neuronal growth, and drug delivery, respectively. Preliminary results show the promise of tubular nanomaterials in future biomedical applications.

  17. Plant-derived nanostructures: types and applications

    Science.gov (United States)

    Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...

  18. Hollow Micro-/Nanostructures: Synthesis and Applications

    KAUST Repository

    Lou, Xiong Wen (David); Archer, Lynden A.; Yang, Zichao

    2008-01-01

    for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic

  19. Nanostructured core-shell electrode materials for electrochemical capacitors

    Science.gov (United States)

    Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

    2016-11-01

    Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

  20. Engineering of Highly Susceptible Paramagnetic Nanostructures of Gd2S3:Eu3+: Potentially an Efficient Material for Room Temperature Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Muhammed M. Radhi

    2010-11-01

    Full Text Available This research papers throws light into the compositional, morphological and structural properties of novel nanoparticles of Gd2S3:Eu3+ synthesized by a simple co-precipitation technique. Furthermore, we also prognosticate that this material could be useful for gas sensing applications at room temperature. Nanostructures formulation by this method resulted in the formation of orthorhombic crystal structure with primitive lattice having space group Pnma. The material characterizations are performed using X-ray diffraction (XRD, energy dispersive X-ray analysis (EDX, thermo-gravimetric analysis/differential thermal analysis (TGA/DTA and transmission electron microscope (TEM. The calculated crystallite sizes are ~ 2-5 nm and are in well accordance with the HRTEM results. EDX result confirms the presence and homogeneous distribution of Gd and Eu throughout the nanoparticle. The prepared nanoparticles exhibit strong paramagnetic nature with paramagnetic term, susceptibility c = 8.2 ´ 10-5 emg/g Gauss. TGA/DTA analysis shows 27 % weight loss with rise in temperature. The gas sensing capability of the prepared Gd2S3:Eu3+ magnetic nanoparticles are investigated using the amperometric method. These nanoparticles show good I-V characteristics with ideal semiconducting nature at room temperature with and without ammonia dose. The observed room temperature sensitivity with increasing dose of ammonia indicates applicability of Gd2S3 nanoparticles as room temperature ammonia sensors.

  1. Evolving application of biomimetic nanostructured hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Norberto Roveri

    2010-11-01

    Full Text Available Norberto Roveri, Michele IafiscoLaboratory of Environmental and Biological Structural Chemistry (LEBSC, Dipartimento di Chimica ‘G. Ciamician’, Alma Mater Studiorum, Università di Bologna, Bologna, ItalyAbstract: By mimicking Nature, we can design and synthesize inorganic smart materials that are reactive to biological tissues. These smart materials can be utilized to design innovative third-generation biomaterials, which are able to not only optimize their interaction with biological tissues and environment, but also mimic biogenic materials in their functionalities. The biomedical applications involve increasing the biomimetic levels from chemical composition, structural organization, morphology, mechanical behavior, nanostructure, and bulk and surface chemical–physical properties until the surface becomes bioreactive and stimulates cellular materials. The chemical–physical characteristics of biogenic hydroxyapatites from bone and tooth have been described, in order to point out the elective sides, which are important to reproduce the design of a new biomimetic synthetic hydroxyapatite. This review outlines the evolving applications of biomimetic synthetic calcium phosphates, details the main characteristics of bone and tooth, where the calcium phosphates are present, and discusses the chemical–physical characteristics of biomimetic calcium phosphates, methods of synthesizing them, and some of their biomedical applications.Keywords: hydroxyapatite, nanocrystals, biomimetism, biomaterials, drug delivery, remineralization

  2. Infrared hyperbolic metasurface based on nanostructured van der Waals materials

    Science.gov (United States)

    Li, Peining; Dolado, Irene; Alfaro-Mozaz, Francisco Javier; Casanova, Fèlix; Hueso, Luis E.; Liu, Song; Edgar, James H.; Nikitin, Alexey Y.; Vélez, Saül; Hillenbrand, Rainer

    2018-02-01

    Metasurfaces with strongly anisotropic optical properties can support deep subwavelength-scale confined electromagnetic waves (polaritons), which promise opportunities for controlling light in photonic and optoelectronic applications. We developed a mid-infrared hyperbolic metasurface by nanostructuring a thin layer of hexagonal boron nitride that supports deep subwavelength-scale phonon polaritons that propagate with in-plane hyperbolic dispersion. By applying an infrared nanoimaging technique, we visualize the concave (anomalous) wavefronts of a diverging polariton beam, which represent a landmark feature of hyperbolic polaritons. The results illustrate how near-field microscopy can be applied to reveal the exotic wavefronts of polaritons in anisotropic materials and demonstrate that nanostructured van der Waals materials can form a highly variable and compact platform for hyperbolic infrared metasurface devices and circuits.

  3. Mechanical properties of nanostructure of biological materials

    Science.gov (United States)

    Ji, Baohua; Gao, Huajian

    2004-09-01

    Natural biological materials such as bone, teeth and nacre are nanocomposites of protein and mineral with superior strength. It is quite a marvel that nature produces hard and tough materials out of protein as soft as human skin and mineral as brittle as classroom chalk. What are the secrets of nature? Can we learn from this to produce bio-inspired materials in the laboratory? These questions have motivated us to investigate the mechanics of protein-mineral nanocomposite structure. Large aspect ratios and a staggered alignment of mineral platelets are found to be the key factors contributing to the large stiffness of biomaterials. A tension-shear chain (TSC) model of biological nanostructure reveals that the strength of biomaterials hinges upon optimizing the tensile strength of the mineral crystals. As the size of the mineral crystals is reduced to nanoscale, they become insensitive to flaws with strength approaching the theoretical strength of atomic bonds. The optimized tensile strength of mineral crystals thus allows a large amount of fracture energy to be dissipated in protein via shear deformation and consequently enhances the fracture toughness of biocomposites. We derive viscoelastic properties of the protein-mineral nanostructure and show that the toughness of biocomposite can be further enhanced by the viscoelastic properties of protein.

  4. Atomic layer deposition of nanostructured materials

    CERN Document Server

    Pinna, Nicola

    2012-01-01

    Atomic layer deposition, formerly called atomic layer epitaxy, was developed in the 1970s to meet the needs of producing high-quality, large-area fl at displays with perfect structure and process controllability. Nowadays, creating nanomaterials and producing nanostructures with structural perfection is an important goal for many applications in nanotechnology. As ALD is one of the important techniques which offers good control over the surface structures created, it is more and more in the focus of scientists. The book is structured in such a way to fi t both the need of the expert reader (du

  5. Achievement report for fiscal 1998. Research and development of nano-structural materials for ceramic bearing application (the second year); 1998 nendo seika hokokusho. Ceramic bearing yo nano seigyo zairyo no kenkyu kaihatsu (dai 2 nendo)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Development is made on ceramic bearing using high-performance and low-cost nano-structural materials, and its application is performed to high-quality bearings suitable for energy conservation in automobiles and industrial machines, and bearings for office automation devices, electronics, and aeronautic and maritime development. To achieve these goals, raw material synthesizing technologies, forming technologies, structural control technologies, processing technologies and mass production technologies shall be established. Fiscal 1998 had the following achievements: establishment of nano-structure controlled ceramic material powder synthesizing technology (nano-lamination type composite powder made by using the beads mill co-precipitation method, nano-lamination type composite powder made by using the New Mymill co-precipitation method, nano-lamination type composite powder made by using the controlled liquid phase method, composite nano-structured gel, and nano-powder synthesis); near net forming technology for spherical ceramics; high-speed processing technology for ultra smooth surface; evaluation of rolling fatigue properties of ceramic bearings; and analysis and evaluation of nano-structured materials. Since this alumina-based ceramic bearing can be produced at reduced cost with performance comparable to silicon nitride based bearing, investigations and discussions are being given on the application thereof. (NEDO)

  6. METALLIC AND HYBRID NANOSTRUCTURES: FUNDAMENTALS AND APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Murph, S.

    2012-05-02

    This book chapter presents an overview of research conducted in our laboratory on preparation, optical and physico-chemical properties of metallic and nanohybrid materials. Metallic nanoparticles, particularly gold, silver, platinum or a combination of those are the main focus of this review manuscript. These metallic nanoparticles were further functionalized and used as templates for creation of complex and ordered nanomaterials with tailored and tunable structural, optical, catalytic and surface properties. Controlling the surface chemistry on/off metallic nanoparticles allows production of advanced nanoarchitectures. This includes coupled or encapsulated core-shell geometries, nano-peapods, solid or hollow, monometallic/bimetallic, hybrid nanoparticles. Rational assemblies of these nanostructures into one-, two- and tridimensional nano-architectures is described and analyzed. Their sensing, environmental and energy related applications are reviewed.

  7. Monocrystalline halide perovskite nanostructures for optoelectronic applications

    NARCIS (Netherlands)

    Khoram, P.

    2018-01-01

    Halide perovskites are a promising class of materials for incorporation in optoelectronics with higher efficiency and lower cost. The solution processability of these materials provides unique opportunities for simple nanostructure fabrication. In the first half of the thesis (chapter 2 and 3) we

  8. Plasmonic Nanostructures for Biosensor Applications

    Science.gov (United States)

    Gadde, Akshitha

    Improving the sensitivity of existing biosensors is an active research topic that cuts across several disciplines, including engineering and biology. Optical biosensors are the one of the most diverse class of biosensors which can be broadly categorized into two types based on the detection scheme: label-based and label-free detection. In label-based detection, the target bio-molecules are labeled with dyes or tags that fluoresce upon excitation, indicating the presence of target molecules. Label-based detection is highly-sensitive, capable of single molecule detection depending on the detector type used. One method of improving the sensitivity of label-based fluorescence detection is by enhancement of the emission of the labels by coupling them with metal nanostructures. This approach is referred as plasmon-enhanced fluorescence (PEF). PEF is achieved by increasing the electric field around the nano metal structures through plasmonics. This increased electric field improves the enhancement from the fluorophores which in turn improves the photon emission from the fluorophores which, in turn, improves the limit of detection. Biosensors taking advantage of the plasmonic properties of metal films and nanostructures have emerged an alternative, low-cost, high sensitivity method for detecting labeled DNA. Localized surface plasmon resonance (LSPR) sensors employing noble metal nanostructures have recently attracted considerable attention as a new class of plasmonic nanosensors. In this work, the design, fabrication and characterization of plasmonic nanostructures is carried out. Finite difference time domain (FDTD) simulations were performed using software from Lumerical Inc. to design a novel LSPR structure that exhibit resonance overlapping with the absorption and emission wavelengths of quantum dots (QD). Simulations of a composite Au/SiO2 nanopillars on silicon substrate were performed using FDTD software to show peak plasmonic enhancement at QD emission wavelength

  9. Gold nanostructure materials in diabetes management

    International Nuclear Information System (INIS)

    Si, Satyabrata; Mohanta, Jagdeep; Satapathy, Smith Sagar; Pal, Arttatrana

    2017-01-01

    Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia, and is now one of the most non-communicable diseases globally and can be lethal if not properly controlled. Prolonged exposure to chronic hyperglycemia, without proper management, can lead to various vascular complications and represents the main cause of morbidity and mortality in diabetes patients. Studies have indicated that major long-term complications of diabetes arise from persistent oxidative-nitrosative stress and dysregulation in multiple metabolic pathways. Presently, the main focus for diabetes management is to optimize the available techniques to ensure adequate blood sugar level, blood pressure and lipid profile, thereby minimizing the diabetes complications. In this regard, nanomedicine utilizing gold nanostructures has great potential and seems to be a promising option. The present review highlights the basic concepts and up-to-date literature survey of gold nanostructure materials in management of diabetes in several ways, which include sensing, imaging, drug delivery and therapy. The work can be of interest to various researchers working on basic and applied sciences including nanosciences. (paper)

  10. Nanostructured metals. Fundamentals to applications

    International Nuclear Information System (INIS)

    Grivel, J.-C.; Hansen, N.; Huang, X.; Juul Jensen, D.; Mishin, O.V.; Nielsen, S.F.; Pantleon, W.; Toftegaard, H.; Winther, G.; Yu, T.

    2009-01-01

    In the today's world, materials science and engineering must as other technical fields focus on sustainability. Raw materials and energy have to be conserved and metals with improved or new structural and functional properties must be invented, developed and brought to application. In this endeavour a very promising route is to reduce the structural scale of metallic materials, thereby bridging industrial metals of today with emerging nanometals of tomorrow, i.e. structural scales ranging from a few micrometres to the nanometre regime. While taking a focus on metals with structures in this scale regime the symposium spans from fundamental aspects towards applications, uniting materials scientists and technologists. A holistic approach characterizes the themes of the symposium encompassing synthesis, characterization, modelling and performance where in each area significant progress has been made in recent years. Synthesis now covers top-down processes, e.g. plastic deformation, and bottom-up processes, e.g. chemical and physical synthesis. In the area of structural and mechanical characterization advanced techniques are now widely applied and in-situ techniques for structural characterization under mechanical or thermal loading are under rapid development in both 2D and 3D. Progress in characterization techniques has led to a precise description of different boundaries (grain, dislocation, twin, phase), and of how they form and evolve, also including theoretical modelling and simulations of structures, properties and performance. (au)

  11. 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......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...

  12. Anticancer Applications of Nanostructured Silica-Based Materials Functionalized with Titanocene Derivatives: Induction of Cell Death Mechanism through TNFR1 Modulation

    Directory of Open Access Journals (Sweden)

    Santiago Gómez-Ruiz

    2018-01-01

    Full Text Available A series of cytotoxic titanocene derivatives have been immobilized onto nanostructured silica-based materials using two different synthetic routes, namely, (i a simple grafting protocol via protonolysis of the Ti–Cl bond; and (ii a tethering method by elimination of ethanol using triethoxysilyl moieties of thiolato ligands attached to titanium. The resulting nanostructured systems have been characterized by different techniques such as XRD, XRF, DR-UV, BET, SEM, and TEM, observing the incorporation of the titanocene derivatives onto the nanostructured silica and slight changes in the textural features of the materials after functionalization with the metallodrugs. A complete biological study has been carried out using the synthesized materials exhibiting moderate cytotoxicity in vitro against three human hepatic carcinoma (HepG2, SK-Hep-1, Hep3B and three human colon carcinomas (DLD-1, HT-29, COLO320 and very low cytotoxicity against normal cell lines. In addition, the cells’ metabolic activity was modified by a 24-h exposure in a dose-dependent manner. Despite not having a significant effect on TNFα or the proinflammatory interleukin 1α secretion, the materials strongly modulated tumor necrosis factor (TNF signaling, even at sub-cytotoxic concentrations. This is achieved mainly by upregulation of the TNFR1 receptor production, something which has not previously been observed for these systems.

  13. Surface modification of microfibrous materials with nanostructured carbon

    Energy Technology Data Exchange (ETDEWEB)

    Krasnikova, Irina V., E-mail: tokareva@catalysis.ru [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Mishakov, Ilya V.; Vedyagin, Aleksey A. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Bauman, Yury I. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); Korneev, Denis V. [State Research Center of Virology and Biotechnology VECTOR, Koltsovo, Novosibirsk Region 630559 (Russian Federation)

    2017-01-15

    The surface of fiberglass cloth, carbon and basalt microfibers was modified with carbon nanostructured coating via catalytic chemical vapor deposition (CCVD) of 1,2-dichloroethane. Incipient wetness impregnation and solution combustion synthesis (SCS) methods were used to deposit nickel catalyst on the surface of microfibrous support. Prepared NiO/support samples were characterized by X-ray diffraction analysis and temperature-programmed reduction. The samples of resulted hybrid materials were studied by means of scanning and transmission electron microscopies as well as by low-temperature nitrogen adsorption. The nature of the support was found to have considerable effect on the CCVD process peculiarities. High yield of nanostructured carbon with largest average diameter of nanofibers within the studied series was observed when carbon microfibers were used as a support. This sample characterized with moderate surface area (about 80 m{sup 2}/g after 2 h of CCVD) shows the best anchorage effect. Among the mineral supports, fiberglass tissue was found to provide highest carbon yield (up to 3.07 g/g{sub FG}) and surface area (up to 344 m{sup 2}/g) due to applicability of SCS method for Ni deposition. - Highlights: • The microfibers of different nature were coated with nanostructured carbon layer. • Features of CNF growth and characteristics of hybrid materials were studied. • Appropriate anchorage of CNF layer on microfiber’s surface was demonstrated.

  14. Precisely Tailored DNA Nanostructures and their Theranostic Applications.

    Science.gov (United States)

    Zhu, Bing; Wang, Lihua; Li, Jiang; Fan, Chunhai

    2017-12-01

    A critical challenge in nanotechnology is the limited precision and controllability of the structural parameters, which brings about concerns in uniformity, reproducibility and performance. Self-assembled DNA nanostructures, as a newly emerged type of nano-biomaterials, possess low-nanometer precision, excellent programmability and addressability. They can precisely arrange various molecules and materials to form spatially ordered complex, resulting in unambiguous physical or chemical properties. Because of these, DNA nanostructures have shown great promise in numerous biomedical theranostic applications. In this account, we briefly review the history and advances on construction of DNA nanoarchitectures and superstructures with accurate structural parameters. We focus on recent progress in exploiting these DNA nanostructures as platforms for quantitative biosensing, intracellular diagnosis, imaging, and smart drug delivery. We also discuss key challenges in practical applications. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Fibrin nanostructures for biomedical applications

    Czech Academy of Sciences Publication Activity Database

    Riedelová-Reicheltová, Zuzana; Brynda, Eduard; Riedel, Tomáš

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S263-S272 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LQ1604 Institutional support: RVO:61389013 Keywords : fibrinogen * fibrin-bound thrombin * nanostructures Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S263.pdf

  16. Mechanical Properties of Nanostructured Materials Determined Through Molecular Modeling Techniques

    Science.gov (United States)

    Clancy, Thomas C.; Gates, Thomas S.

    2005-01-01

    The potential for gains in material properties over conventional materials has motivated an effort to develop novel nanostructured materials for aerospace applications. These novel materials typically consist of a polymer matrix reinforced with particles on the nanometer length scale. In this study, molecular modeling is used to construct fully atomistic models of a carbon nanotube embedded in an epoxy polymer matrix. Functionalization of the nanotube which consists of the introduction of direct chemical bonding between the polymer matrix and the nanotube, hence providing a load transfer mechanism, is systematically varied. The relative effectiveness of functionalization in a nanostructured material may depend on a variety of factors related to the details of the chemical bonding and the polymer structure at the nanotube-polymer interface. The objective of this modeling is to determine what influence the details of functionalization of the carbon nanotube with the polymer matrix has on the resulting mechanical properties. By considering a range of degree of functionalization, the structure-property relationships of these materials is examined and mechanical properties of these models are calculated using standard techniques.

  17. Debye screening length effects of nanostructured materials

    CERN Document Server

    Ghatak, Kamakhya Prasad

    2014-01-01

    This monograph solely investigates the Debye Screening Length (DSL) in semiconductors and their nano-structures. The materials considered are quantized structures of non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V and Bismuth Telluride respectively. The DSL in opto-electronic materials and their quantum confined counterparts is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestions for the experimental determination of 2D and 3D DSL and the importance of measurement of band gap in optoelectronic materials under intense built-in electric field in nano devices and strong external photo excitation (for measuring photon induced physical properties) have also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the DSL and the DSL in heavily doped ...

  18. Advanced nanostructured materials as media for hydrogen storage

    International Nuclear Information System (INIS)

    David, E.; Niculescu, V.; Armeanu, A.; Sandru, C.; Constantinescu, M.; Sisu, C.

    2005-01-01

    Full text: In a future sustainable energy system based on renewable energy, environmentally harmless energy carriers like hydrogen, will be of crucial importance. One of the major impediments for the transition to a hydrogen based energy system is the lack of satisfactory hydrogen storage alternatives. Hydrogen storage in nanostructured materials has been proposed as a solution for adequate hydrogen storage for a number of applications, in particular for transportation. This paper is a preliminary study with the focus on possibilities for hydrogen storage in zeolites, alumina and nanostructured carbon materials. The adsorption properties of these materials were evaluated in correlation with their internal structure. From N 2 physisorption data the BET surface area (S BET ) , total pore volume (PV), micropore volume (MPV) and total surface area (S t ) were derived. H 2 physisorption measurements were performed at 77 K and a pressure value of 1 bar. From these data the adsorption capacities of sorbent materials were determined. Apparently the microporous adsorbents, e.g activated carbons, display appreciable sorption capacities. Based on their micropore volume, carbon-based sorbents have the largest adsorption capacity for H 2 , over 230 cm 3 (STP)/g, at the previous conditions. By increasing the micropore volume (∼ 1 cm 3 /g) of sorbents and optimizing the adsorption conditions it is expected to obtain an adsorption capacity of ∼ 560 cm 3 (STP)/g, close to targets set for mobile applications. (authors)

  19. Preparation and characterization of nanostructured MWCNT-TiO2 composite materials for photocatalytic water treatment applications

    International Nuclear Information System (INIS)

    Wang Wendong; Serp, Philippe; Kalck, Philippe; Silva, Claudia Gomes; Faria, Joaquim Luis

    2008-01-01

    Nanoscale composite materials containing multi-walled carbon nanotubes (MWCNT) and titania were prepared by using a modified sol-gel method. The composites were comprehensively characterized by thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectroscopy. The analysis revealed the presence of titania crystallites of about 7.5 nm aggregated together with MWCNT in particles of 15-20 nm of diameter. The photoactivity of the prepared materials, under UV or visible irradiation, was tested using the conversion of phenol from model aqueous solutions as probe reaction. A synergy effect on the photocatalytic activities observed for the composite catalysts was discussed in terms of a strong interphase interaction between carbon and TiO 2 phases by comparing the different roles of MWCNT in the composite materials

  20. In-situ TEM studies of nanostructured thermoelectric materials: An application to Mg-doped Zn4Sb3 alloy

    DEFF Research Database (Denmark)

    Ngo, Duc-The; Le, Hung Thanh; Ngo, Nong Van

    2018-01-01

    material have been dynamically captured as a function of temperature from 300 K to 573 K. On heating, we have observed clearly precipitation and growth of a Zn-rich secondary phase as nanoinclusions in the matrix of primary Zn4Sb3 phase. Elemental mapping by STEM-EDX spectroscopy reveals enrichment of Zn...

  1. Micro-/nanostructured multicomponent molecular materials: design, assembly, and functionality.

    Science.gov (United States)

    Yan, Dongpeng

    2015-03-23

    Molecule-based micro-/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro-sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro-/nanomaterials. Unlike single-component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro-/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro-/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low-dimensional multicomponent micro-/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro-/nanomaterials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Titanium nanostructures for biomedical applications

    International Nuclear Information System (INIS)

    Kulkarni, M; Gongadze, E; Perutkova, Š; A Iglič; Mazare, A; Schmuki, P; Kralj-Iglič, V; Milošev, I; Mozetič, M

    2015-01-01

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO 2 ) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO 2 nanotubes in cell interactions is based on the fact that TiO 2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO 2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties. (topical review)

  3. Titanium nanostructures for biomedical applications

    Science.gov (United States)

    Kulkarni, M.; Mazare, A.; Gongadze, E.; Perutkova, Š.; Kralj-Iglič, V.; Milošev, I.; Schmuki, P.; Iglič, A.; Mozetič, M.

    2015-02-01

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

  4. Engineered Metallic Nanostructures: Fabrication, Characterization, and Applications

    Science.gov (United States)

    Bohloul, Arash

    Metallic nanostructures have garnered a great deal of attention due to their fascinating optical properties, which differ from the bulk metal. They have been proven to exceed expectations in wide variety of applications including chemical and biological sensing. Nevertheless, high-throughput and low cost nanofabrication techniques are required to implant metallic nanostructures in widespread applications. With that vision, this thesis presents a versatile and reliable method for scalable fabrication of gold nanostructures. In this approach, a plasma-treated ordered array of polystyrene nanospheres acts as an initial mask. The key step in this process is the vapor-deposition of nickel as a sacrificial mask. Thereby, gold nanostructures are directly formed on the substrate through the nickel mask. This is an easy, powerful, and straightforward method that offers several degrees of freedom to precisely control the shape and size of nanostructures. We made a library of nanostructures including gold nanocrescents, double crescents, nanorings, and nanodisks with the ability to tune the size in the range of 150 to 650 nm. The fabricated nanostructures are highly packed and uniformly cover the centimeter scale substrate. The optical properties of metallic nanostructures were extensively studied by a combination of UV-Vis-NIR and Fourier transform infrared (FTIR) spectroscopies, and correlation between optical response and geometrical parameters were investigated. In the next part of this thesis, highly sensitive surface enhanced infrared absorption (SEIRA) analysis was demonstrated on gold nanocrescent arrays. Theoretical modeling was confirmed that these substrates provide highly dense and strong hot-spots over the substrate, which is required for surface enhanced spectroscopic studies. Gold nanocrescent arrays exhibit highly tunable plasmon resonance to cover desired molecular vibrational bands. These substrates experimentally illustrated 3 orders of magnitude

  5. Magnetic Cluster States in Nanostructured Materials

    International Nuclear Information System (INIS)

    Leslie-Pelecky, Diandra

    2008-01-01

    The goal of this work is to fabricate model nanomaterials with different types of disorder and use atomic-scale characterization and macroscopic magnetization measurements to understand better how specific types of disorder affects macroscopic magnetic behavior. This information can be used to produce magnetic nanomaterials with specific properties for applications such as permanent magnets, soft magnetic material for motors and biomedical applications.

  6. Semiconductive Nanostructures - Materials for Spinelectronics: New Data Bank Requirement

    Directory of Open Access Journals (Sweden)

    Paata J Kervalishvili

    2007-12-01

    Full Text Available Nanoscience, the interdisciplinary science that draws on physics, chemistry, biology, and computational mathematics, is still in its infancy. Control and manipulation on a nanometric scale allow the fabrication of nanostructures, the properties of which are mainly determined by quantum mechanics and differ considerably from that of the common crystalline state. Nanostructures constructed from inorganic solids such as semiconductors have new electronic and optical properties because of their size and quantization effects [1, 2]. The quantization effects reflect the fundamental characteristics of structures as soon as their size falls below a certain limit. An example of the simplest nanostructure is the quantum dot formed from the energy well of certain semiconductor materials with 5-10nm thickness sandwiched between other semiconductors with normal properties. Quantum dots, for example, have led to important novel technology for lasers, optical sensors, and other electronic devices. The application of nanolayers to data storage, switching, lighting, and other devices can lead to substantially new hardware, for example, energy cells, and eventually to the quantum-based internet. Nanoscience and nanotechnology encompass the development of nano-spinelectronics, spinelectronics materials production, and nano-spinelectronic measuring devices and technologies. Nano-spinelectronics, based on usage of magnetic semiconductors, represents a new and emerging area of science and engineering of the 21st century. It is a primary example of the creation and enhancement of new materials and devices for information technologies, operating with charge and spin degrees of freedom of carriers, free from present-day limitations. This new multi-disciplinary direction of science and technology is very much in need of support from new data banks, which will function as a source of new ideas and approaches.

  7. Cavitational synthesis of nanostructured inorganic materials for enhanced heterogeneous catalysis

    Science.gov (United States)

    Krausz, Ivo Michael

    The synthesis of nanostructured inorganic materials by hydrodynamic cavitation processing was investigated. The goal of this work was to develop a general synthesis technique for nanostructured materials with a control over crystallite size in the 1--20 nm range. Materials with crystallite sizes in this range have shown enhanced catalytic activity compared to materials with larger crystallite sizes. Several supported and unsupported inorganic materials were studied to understand the effects of cavitation on crystallite size. Cavitation processing of calcium fluoride resulted in more spherical particles, attached to one another by melted necks. This work produced the first evidence of shock wave heating of nanostructured materials by hydrodynamic cavitation processing. Hydrodynamic cavitation synthesis of various catalytic support materials indicated that their phase composition and purity could be controlled by adjustment of the processing parameters. Zirconia/alumina supports synthesized using hydro-dynamic cavitation and calcined to 1368 K retained a high purity cubic zirconia phase, whereas classically prepared samples showed a phase transformation to monoclinic zirconia. Similarly, the synthesis of alumina resulted in materials with varying Bohmite and Bayerite contents as a function of the process parameters. High temperature calcination resulted in stable alumina supports with varying amounts of delta-, and theta-alumina. Synthesis studies of palladium and silver showed modest variations in crystallite size as a function of cavitation process parameters. Calcination resulted in larger grain materials, indicating a disappearance of intergrain boundaries. Based on these results, a new synthesis method was studied involving controlled agglomeration of small silver crystallites by hydrodynamic cavitation processing, followed by deposition on alumina. The optimal pH, concentration, and processing time for controlling the silver crystallite size in the cavitation

  8. Polar order in nanostructured organic materials

    Science.gov (United States)

    Sayar, M.; Olvera de la Cruz, M.; Stupp, S. I.

    2003-02-01

    Achiral multi-block liquid crystals are not expected to form polar domains. Recently, however, films of nanoaggregates formed by multi-block rodcoil molecules were identified as the first example of achiral single-component materials with macroscopic polar properties. By solving an Ising-like model with dipolar and asymmetric short-range interactions, we show here that polar domains are stable in films composed of aggregates as opposed to isolated molecules. Unlike classical molecular systems, these nanoaggregates have large intralayer spacings (a approx 8 nm), leading to a reduction in the repulsive dipolar interactions which oppose polar order within layers. In finite-thickness films of nanostructures, this effect enables the formation of polar domains. We compute exactly the energies of the possible structures consistent with the experiments as a function of film thickness at zero temperature (T). We also provide Monte Carlo simulations at non-zero T for a disordered hexagonal lattice that resembles the smectic-like packing in these nanofilms.

  9. Hybrid nanostructured materials with tunable magnetic characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Martínez, Nubia E.; Garza-Navarro, M. A., E-mail: marco.garzanr@uanl.edu.mx; García-Gutiérrez, Domingo; González-González, Virgilio A.; Torres-Castro, Alejandro; Ortiz-Méndez, U. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica (Mexico)

    2014-12-15

    We report on the development of hybrid nanostructured materials (HNM) based on spinel-metal-oxide nanoparticles (SMON) stabilized in carboxymethyl-cellulose (CMC)/cetyltrimethyl-ammonium-bromide (CTAB) templates, with tunable magnetic characteristics. These HNM were synthesized using a one-pot chemical approach to obtain CMC/CTAB templates with controllable size and morphology, where the SMON could be densely arranged. The synthesized HNM were characterized by transmission electron microscopy and its related techniques, such as bright field (BF) and Z-contrast (HAADF-STEM) imaging, and selected area electron diffraction, as well as static magnetic measuring. Experimental evidence suggests that the morphology and size of the CMC/CTAB templates are highly dependent on the weight ratio of CTAB:SMON, as well as the hydration days of the CMC that is used for the synthesis of the HNM. Controlling these parameters allows modifying the density of the SMON arrangement in the CMC/CTAB templates. Moreover, magnetic features such as remanence, coercivity, and blocking/de-blocking processes of the particles’ magnetic moments are highly dependent on the interactions among the SMON assembled in the templates. Hence, the magnetic characteristics of HNM can be modulated or tuned by controlling the manner the SMON are arranged within the CMC/CTAB templates.

  10. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Science.gov (United States)

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  11. Thermal Characterization of Nanostructures and Advanced Engineered Materials

    Science.gov (United States)

    Goyal, Vivek Kumar

    Continuous downscaling of Si complementary metal-oxide semiconductor (CMOS) technology and progress in high-power electronics demand more efficient heat removal techniques to handle the increasing power density and rising temperature of hot spots. For this reason, it is important to investigate thermal properties of materials at nanometer scale and identify materials with the extremely large or extremely low thermal conductivity for applications as heat spreaders or heat insulators in the next generation of integrated circuits. The thin films used in microelectronic and photonic devices need to have high thermal conductivity in order to transfer the dissipated power to heat sinks more effectively. On the other hand, thermoelectric devices call for materials or structures with low thermal conductivity because the performance of thermoelectric devices is determined by the figure of merit Z=S2sigma/K, where S is the Seebeck coefficient, K and sigma are the thermal and electrical conductivity, respectively. Nanostructured superlattices can have drastically reduced thermal conductivity as compared to their bulk counterparts making them promising candidates for high-efficiency thermoelectric materials. Other applications calling for thin films with low thermal conductivity value are high-temperature coatings for engines. Thus, materials with both high thermal conductivity and low thermal conductivity are technologically important. The increasing temperature of the hot spots in state-of-the-art chips stimulates the search for innovative methods for heat removal. One promising approach is to incorporate materials, which have high thermal conductivity into the chip design. Two suitable candidates for such applications are diamond and graphene. Another approach is to integrate the high-efficiency thermoelectric elements for on-spot cooling. In addition, there is strong motivation for improved thermal interface materials (TIMs) for heat transfer from the heat-generating chip

  12. Nanostructuring superconductors by ion beams: A path towards materials engineering

    Energy Technology Data Exchange (ETDEWEB)

    Gerbaldo, Roberto; Ghigo, Gianluca; Gozzelino, Laura; Laviano, Francesco [Department of Applied Science and Technology, Politecnico di Torino c.so Duca degli Abruzzi 24, 10129 Torino, Italy and INFN Sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Amato, Antonino; Rovelli, Alberto [INFN Laboratori Nazionali del Sud, via S. Sofia 62, 95125 Catania (Italy); Cherubini, Roberto [INFN Laboratori Nazionali di Legnaro, viale dell' Universita 2, 35020 Legnaro (Italy)

    2013-07-18

    The paper deals with nanostructuring of superconducting materials by means of swift heavy ion beams. The aim is to modify their structural, optical and electromagnetic properties in a controlled way, to provide possibility of making them functional for specific applications. Results are presented concerning flux pinning effects (implantation of columnar defects with nanosize cross section to enhance critical currents and irreversibility fields), confined flux-flow and vortex guidance, design of devices by locally tailoring the superconducting material properties, analysis of disorder-induced effects in multi-band superconductors. These studies were carried out on different kinds of superconducting samples, from single crystals to thin films, from superconducting oxides to magnesium diboride, to recently discovered iron-based superconductors.

  13. AMINO ACIDS APPLICATION TO CREATE OF NANOSTRUCTURES

    Directory of Open Access Journals (Sweden)

    I. S. Chekman

    2014-12-01

    Full Text Available Review is devoted to the amino acids that could be used for nanostructures creation. The investigation of corresponding properties of amino acids is essential for their role definition in creation of nanomedicines. However, amino acid studying as components of nanostructures is insufficient. Study of nanoparticles for medicines creation was initiated by the development of nanotechnology. Amino acids in complexes with the nanoparticles of organic and inorganic nature play an important role for medicines targeting in pathological process. They could reduce toxicity of the nanomaterials used in nanomedicine and are used for creation of biosensors, lab-on-chip and therefore they are a promising material for synthesis of new nanodrugs and diagnostic tools.

  14. Engineering Metal Nanostructure for SERS Application

    Directory of Open Access Journals (Sweden)

    Yanqin Cao

    2013-01-01

    Full Text Available Surface-enhanced Raman scattering (SERS has attracted great attention due to its remarkable enhancement and excellent selectivity in the detection of various molecules. Noble metal nanomaterials have usually been employed for producing substrates that can be used in SERS because of their unique local plasma resonance. As the SERS enhancement of signals depends on parameters such as size, shape, morphology, arrangement, and dielectric environment of the nanostructure, there have been a number of studies on tunable nanofabrication and synthesis of noble metals. In this work, we will illustrate progress in engineering metallic nanostructures with various morphologies using versatile methods. We also discuss their SERS applications in different fields and the challenges.

  15. Synthesis and applications of MOF-derived porous nanostructures

    Directory of Open Access Journals (Sweden)

    Min Hui Yap

    2017-07-01

    Full Text Available Metal organic frameworks (MOFs represent a class of porous material which is formed by strong bonds between metal ions and organic linkers. By careful selection of constituents, MOFs can exhibit very high surface area, large pore volume, and excellent chemical stability. Research on synthesis, structures and properties of various MOFs has shown that they are promising materials for many applications, such as energy storage, gas storage, heterogeneous catalysis and sensing. Apart from direct use, MOFs have also been used as support substrates for nanomaterials or as sacrificial templates/precursors for preparation of various functional nanostructures. In this review, we aim to present the most recent development of MOFs as precursors for the preparation of various nanostructures and their potential applications in energy-related devices and processes. Specifically, this present survey intends to push the boundaries and covers the literatures from the year 2013 to early 2017, on supercapacitors, lithium ion batteries, electrocatalysts, photocatalyst, gas sensing, water treatment, solar cells, and carbon dioxide capture. Finally, an outlook in terms of future challenges and potential prospects towards industrial applications are also discussed. Keywords: Metal organic frameworks, Porous nanostructures, Supercapacitors, Lithium ion batteries, Heterogeneous catalyst

  16. X-ray characterisation of nanostructured materials

    DEFF Research Database (Denmark)

    Oddershede, Jette

    X-ray powder di®raction (XRPD) is an excellent tool for characterising the bulk structure of crystalline materials. Along with the growing interest in exploiting materials with decreasing particle sizes and increasing number of defects, factors that complicate the traditional interpretation...... of the experi- mental XRPD patterns, the need for new interpretation methods has arisen. The method described in the present thesis is by no means new, in fact it was developed by Debye in 1915. However, the Debye method it is rather computationally heavy, so in practise it is only applicable to the X-ray char...

  17. Applications of oligomers for nanostructured conducting polymers.

    Science.gov (United States)

    Wang, Yue; Tran, Henry D; Kaner, Richard B

    2011-01-03

    This Feature Article provides an overview of the distinctive nanostructures that aniline oligomers form and the applications of these oligomers for shaping the nanoscale morphologies and chirality of conducting polymers. We focus on the synthetic methods for achieving such goals and highlight the underlying mechanisms. The clear advantages of each method and their possible drawbacks are discussed. Assembly and applications of these novel organic (semi)conducting nanomaterials are also outlined. We conclude this article with our perspective on the main challenges, new opportunities, and future directions for this nascent yet vibrant field of research. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Water-evaporation-induced electricity with nanostructured carbon materials.

    Science.gov (United States)

    Xue, Guobin; Xu, Ying; Ding, Tianpeng; Li, Jia; Yin, Jun; Fei, Wenwen; Cao, Yuanzhi; Yu, Jin; Yuan, Longyan; Gong, Li; Chen, Jian; Deng, Shaozhi; Zhou, Jun; Guo, Wanlin

    2017-05-01

    Water evaporation is a ubiquitous natural process that harvests thermal energy from the ambient environment. It has previously been utilized in a number of applications including the synthesis of nanostructures and the creation of energy-harvesting devices. Here, we show that water evaporation from the surface of a variety of nanostructured carbon materials can be used to generate electricity. We find that evaporation from centimetre-sized carbon black sheets can reliably generate sustained voltages of up to 1 V under ambient conditions. The interaction between the water molecules and the carbon layers and moreover evaporation-induced water flow within the porous carbon sheets are thought to be key to the voltage generation. This approach to electricity generation is related to the traditional streaming potential, which relies on driving ionic solutions through narrow gaps, and the recently reported method of moving ionic solutions across graphene surfaces, but as it exploits the natural process of evaporation and uses cheap carbon black it could offer advantages in the development of practical devices.

  19. Self-formation of polymer nanostructures in plasma etching: mechanisms and applications

    Science.gov (United States)

    Du, Ke; Jiang, Youhua; Huang, Po-Shun; Ding, Junjun; Gao, Tongchuan; Choi, Chang-Hwan

    2018-01-01

    In recent years, plasma-induced self-formation of polymer nanostructures has emerged as a simple, scalable and rapid nanomanufacturing technique to pattern sub-100 nm nanostructures. High-aspect-ratio nanostructures (>20:1) are fabricated on a variety of polymer surfaces such as poly(methylmethacrylate) (PMMA), polystyrene (PS), polydimethylsiloxane (PDMS), and fluorinated ethylene propylene (FEP). Sub-100 nm nanostructures (i.e. diameter  ⩽  50 nm) are fabricated in this one-step process without relying on slow and expensive nanolithography techniques. This review starts with discussion of the self-formation mechanisms including surface modulation, random masks, and materials impurities. Emphasis is put on the applications of polymer nanostructures in the fields of hierarchical nanostructures, liquid repellence, adhesion, lab-on-a-chip, surface enhanced Raman scattering (SERS), organic light emitting diode (OLED), and energy harvesting. The unique advantages of this nanomanufacturing technique are illustrated, followed by prospects.

  20. Quantum Simulations of Materials and Nanostructures (Q-SIMAN). Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Galli, Giulia [Univ. of California, Davis, CA (United States); Bai, Zhaojun [Univ. of California, Davis, CA (United States); Ceperley, David [Univ. of Illinois, Urbana, IL (United States); Cai, Wei [Stanford Univ., CA (United States); Gygi, Francois [Univ. of California, Davis, CA (United States); Marzari, Nicola [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pickett, Warren [Univ. of California, Davis, CA (United States); Spaldin, Nicola [Univ. of California, Santa Barbara, CA (United States); Fattebert, Jean-Luc [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schwegler, Eric [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-16

    The focus of this SciDAC SAP (Scientific Application) is the development and use of quantum simulations techniques to understand materials and nanostructures at the microscopic level, predict their physical and chemical properties, and eventually design integrated materials with targeted properties. (Here the word ‘materials’ is used in a broad sense and it encompasses different thermodynamic states of matter, including solid, liquids and nanostructures.) Therefore our overarching goal is to enable scientific discoveries in the field of condensed matter and advanced materials through high performance computing.

  1. Nanotechnology and health safety--toxicity and risk assessments of nanostructured materials on human health.

    Science.gov (United States)

    Singh, Surya; Nalwa, Hari Singh

    2007-09-01

    The field of nanotechnology has recently emerged as the most commercially viable technology of this century because of its wide-ranging applications in our daily lives. Man-made nanostructured materials such as fullerenes, nanoparticles, nanopowders, nanotubes, nanowires, nanorods, nanofibers, quantum dots, dendrimers, nanoclusters, nanocrystals, and nanocomposites are globally produced in large quantities due to their wide potential applications, e.g., in skincare and consumer products, healthcare, electronics, photonics, biotechnology, engineering products, pharmaceuticals, drug delivery, and agriculture. Human exposure to these nanostructured materials is inevitable, as they can enter the body through the lungs or other organs via food, drink, and medicine and affect different organs and tissues such as the brain, liver, kidney, heart, colon, spleen, bone, blood, etc., and may cause cytotoxic effects, e.g., deformation and inhibition of cell growth leading to various diseases in humans and animals. Since a very wide variety of nanostructured materials exits, their interactions with biological systems and toxicity largely depend upon their properties, such as size, concentration, solubility, chemical and biological properties, and stability. The toxicity of nanostructured materials could be reduced by chemical approaches such by surface treatment, functionalization, and composite formation. This review summarizes the sources of various nanostructured materials and their human exposure, biocompatibility in relation to potential toxicological effects, risk assessment, and safety evaluation on human and animal health as well as on the environment.

  2. Nanostructured oxides for energy storage applications in batteries and supercapacitors

    International Nuclear Information System (INIS)

    Chandra, A.; Roberts, A. J.; Yee, E. L. H.; Slade, R. C. T.

    2009-01-01

    Nanostructured materials are extensively investigated for application in energy storage and power generation devices. This paper deals with the synthesis and characterization of nanomaterials based on oxides of vanadium and with their application as electrode materials for energy storage systems viz. supercapacitors. These nano-oxides have been synthesized using a hydrothermal route in the presence of templates: 1-hexadecylamine, Tweens and Brij types. Using templates during synthesis enables tailoring of the particle morphology and physical characteristics of synthesized powders. Broad X-ray diffraction peaks show the formation of nanoparticles, confirmed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. SEM studies show that a large range of nanostructures such as needles, fibers, particles, etc. can be synthesized. These particles have varying surface areas and electrical conductivity. Enhancement of surface area as much as seven times relative to surface areas of starting parent materials has been observed. These properties make such materials ideal candidates for application as electrode materials in super capacitors. Assembly and characterization of supercapacitors based on electrodes containing these active nano-oxides are discussed. Specific capacitance of >100 F g -1 has been observed. The specific capacitance decreases with cycling: causes of this phenomenon are presented. (authors)

  3. Hollow Micro-/Nanostructures: Synthesis and Applications

    KAUST Repository

    Lou, Xiong Wen (David)

    2008-11-03

    Hollow micro-nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA,.

  4. Lightweight structure design for wind energy by integrating nanostructured materials

    International Nuclear Information System (INIS)

    Li, Ying; Lu, Jian

    2014-01-01

    Highlights: • Integrate high-strength nano-materials into lightweight design. • Lightweight design scheme for wind turbine tower application. • Expand the bending formulae for tapered tubular structures with varying thickness. • We rewrite the Secant Formula for a tapered beam under eccentric compression. - Abstract: Wind power develops very fast nowadays with high expectation. Although at the mean time, the use of taller towers, however, smacks head-on into the issue of transportability. The engineering base and computational tools have to be developed to match machine size and volume. Consequently the research on the light weight structures of tower is carrying out in the main countries which are actively developing wind energy. This paper reports a new design scheme of light weight structure for wind turbine tower. This design scheme is based on the integration of the nanostructured materials produced by the Surface Mechanical Attrition Treatment (SMAT) process. The objective of this study is to accomplish the weight reduction by optimizing the wall thickness of the tapered tubular structure. The basic methods include the identification of the critical zones and the distribution of the high strength materials according to different necessities. The equivalent strength or stiffness design method and the high strength material properties after SMAT process are combined together. Bending and buckling are two main kinds of static loads concerned in consideration. The study results reveal that there is still enough margin for weight reduction in the traditional wind turbine tower design

  5. Advanced nanostructured materials for energy storage and conversion

    Science.gov (United States)

    Hutchings, Gregory S.

    Due to a global effort to reduce greenhouse gas emissions and to utilize renewable sources of energy, much effort has been directed towards creating new alternatives to fossil fuels. Identifying novel materials for energy storage and conversion can enable radical changes to the current fuel production infrastructure and energy utilization. The use of engineered nanostructured materials in these systems unlocks unique catalytic activity in practical configurations. In this work, research efforts have been focused on the development of nanostructured materials to address the need for both better energy conversion and storage, with applications toward Li-O2 battery electrocatalysts, electrocatalytic generation of H2, conversion of furfural to useful chemicals and fuels, and Li battery anode materials. Highly-active alpha-MnO2 materials were synthesized for use as bifunctional oxygen reduction (ORR) and evolution (OER) catalysts in Li-O2 batteries, and were evaluated under operating conditions with a novel in situ X-ray absorption spectroscopy configuration. Through detailed analysis of local coordination and oxidation states of Mn atoms at key points in the electrochemical cycle, a self-switching behavior affecting the bifunctional activity was identified and found to be critical. In an additional study of materials for lithium batteries, nanostructured TiO2 anode materials doped with first-row transition metals were synthesized and evaluated for improving battery discharge capacity and rate performance, with Ni and Co doping at low levels found to cause the greatest enhancement. In addition to battery technology research, I have also sought to find inexpensive and earth-abundant electrocatalysts to replace state-of-the-art Pt/C in the hydrogen evolution reaction (HER), a systematic computational study of Cu-based bimetallic electrocatalysts was performed. During the screening of dilute surface alloys of Cu mixed with other first-row transition metals, materials with

  6. One-dimensional titania nanostructures: Synthesis and applications in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hao [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials and Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Guo, Zhiguang, E-mail: zguo@licp.cas.cn [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials and Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Shimin [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials and Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062 (China); Liu, Weimin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-05-02

    One-dimensional (1D) titania (TiO{sub 2}) in the form of nanorods, nanowires, nanobelts and nanotubes have attracted much attention due to their unique physical, chemical and optical properties enabling extraordinary performance in biomedicine, sensors, energy storage, solar cells and photocatalysis. In this review, we mainly focus on synthetic methods for 1D TiO{sub 2} nanostructures and the applications of 1D TiO{sub 2} nanostructures in dye-sensitized solar cells (DSCs). Traditional nanoparticle-based DSCs have numerous grain boundaries and surface defects, which increase the charge recombination from photoanode to electrolyte. 1D TiO{sub 2} nanostructures can provide direct and rapid electron transport to the electron collecting electrode, indicating a promising choice for DSCs. We divide the applications of 1D TiO{sub 2} nanostructures in DSCs into four parts, that is, 1D TiO{sub 2} nanostructures only, 1D TiO{sub 2} nanostructure/nanoparticle composites, branched 1D TiO{sub 2} nanostructures, and 1D TiO{sub 2} nanostructures combined with other materials. This work will provide guidance for preparing 1D TiO{sub 2} nanostructures, and using them as photoanodes in efficient DSCs. - Graphical abstract: 1D TiO{sub 2} nanostructures which can provide direct and rapid pathways for electron transport have promising applications in dye-sensitized solar cells (DSCs). The synthetic methods and applications of 1D TiO{sub 2} nanostructures in DSCs are summarized in this review article.

  7. Metal Oxide Nanostructures in Food Applications: Quality Control and Packaging

    Directory of Open Access Journals (Sweden)

    Vardan Galstyan

    2018-04-01

    Full Text Available Metal oxide materials have been applied in different fields due to their excellent functional properties. Metal oxides nanostructuration, preparation with the various morphologies, and their coupling with other structures enhance the unique properties of the materials and open new perspectives for their application in the food industry. Chemical gas sensors that are based on semiconducting metal oxide materials can detect the presence of toxins and volatile organic compounds that are produced in food products due to their spoilage and hazardous processes that may take place during the food aging and transportation. Metal oxide nanomaterials can be used in food processing, packaging, and the preservation industry as well. Moreover, the metal oxide-based nanocomposite structures can provide many advantageous features to the final food packaging material, such as antimicrobial activity, enzyme immobilization, oxygen scavenging, mechanical strength, increasing the stability and the shelf life of food, and securing the food against humidity, temperature, and other physiological factors. In this paper, we review the most recent achievements on the synthesis of metal oxide-based nanostructures and their applications in food quality monitoring and active and intelligent packaging.

  8. Nanostructured films of inorganic-organic hybrid materials for application in photovoltaics; Nanostrukturierte Filme aus anorganisch-organischen Hybridmaterialien fuer die Photovoltaik

    Energy Technology Data Exchange (ETDEWEB)

    Perlich, Jan

    2009-06-25

    Nanostructured thin films of crystalline TiO{sub 2} for applications in photovoltaics were studied. The fabrication of the thin films is based on a hybrid approach. The anorganic metal oxide prepared via a sol-gel synthesis is structurated by the template properties of the applied organic block-copolymer. Via the film epitaxy by means of centrifugal coating first hybrid films (polymer-nanocomposite films) were fabricated, which were changed by calcination into crystalline TiO{sub 2} films with taylored morphology. The successful development of novel preparation approaches to the adaption to consisting conditions in the application field of photovoltaics contains a route to the fine-tuning of the morphology as well as the fabrication of hierarchical morphologies in different configurations. The structural study of the single nanostructurated TiO{sub 2} films up to the functional multilayer arrangement as photovoltaic demonstration cell was performed with conventionally imaging methods, as for instance scanning force microscopy and electron microscopy as well as the special small-angle X-ray scattering method under rigid incident angle (GISAXS). [German] Es wurden nanostrukturierte duenne Filme aus kristallinem TiO{sub 2} fuer Anwendungen in der Photovoltaik untersucht. Die Herstellung der duennen Filme basiert auf einem Hybridansatz. Das ueber eine Sol-Gel-Synthese bereitgestellte anorganische Metalloxid wird durch die Template-Eigenschaften des eingesetzten organischen Block-Copolymers strukturiert. Ueber die Filmaufbringung mittels Schleuderbeschichtung wurden zunaechst Hybridfilme (Polymer-Nanokompositfilme) hergestellt, die durch Kalzinierung in kristalline TiO{sub 2}-Filme mit massgeschneiderter Morphologie umgewandelt werden. Die erfolgreiche Entwicklung von neuartigen Praeparationsansaetzen zur Adaption an bestehende Gegebenheiten im Anwendungsgebiet der Photovoltaik beinhaltet eine Route zur Feineinstellung der Morphologie sowie die Herstellung von

  9. Functional nanostructured materials for stormwater runoff treatment

    DEFF Research Database (Denmark)

    Ko, Dongah

    Numerous heavy metal removal practices for stormwater runoff have been studied and applied; however, there is still room for improvement. Among these practices, adsorption has proven to be the most efficient way of removing heavy metals. Commonly used adsorbents have an innate sorption capacity...... in relation to high concentrations of heavy metal ions, but if they are to be used for stormwater runoff, high affinity with rapid sorption kinetics for low concentrations of heavy metals is necessary. Therefore, in this study, new types of functional nanostructured polymer sorbents for effective heavy metal...... removal from stormwater are suggested. First, comparison studies of several existing polymer sorbents were conducted, to find decisive functional groups for removing heavy metals from the solution. To enhance the sorption kinetics and affinity of polymer sorbents in the presence of competing ions, sulphur...

  10. Nanostructured silver sulfide: synthesis of various forms and their application

    Science.gov (United States)

    Sadovnikov, S. I.; Rempel, A. A.; Gusev, A. I.

    2018-04-01

    The results of experimental studies on nanostructured silver sulfide are analyzed and generalized. The influence of small particle size on nonstoichiometry of silver sulfide is discussed. Methods for the synthesis of various forms of nanostructured Ag2S including nanopowders, stable colloidal solutions, quantum dots, core–shell nanoparticles and heteronanostructures are described. The advantages and drawbacks of different synthetic procedures are analyzed. Main fields of application of nanostructured silver sulfide are considered. The bibliography includes 184 references.

  11. The Physics and Applications of a 3D Plasmonic Nanostructure

    Science.gov (United States)

    Terranova, Brandon B.

    In this work, the dynamics of electromagnetic field interactions with free electrons in a 3D metallic nanostructure is evaluated theoretically. This dissertation starts by reviewing the relevant fundamentals of plasmonics and modern applications of plasmonic systems. Then, motivated by the need to have a simpler way of understanding the surface charge dynamics on complex plasmonic nanostructures, a new plasmon hybridization tree method is introduced. This method provides the plasmonicist with an intuitive way to determine the response of free electrons to incident light in complex nanostructures within the electrostatic regime. Next, a novel 3D plasmonic nanostructure utilizing reflective plasmonic coupling is designed to perform biosensing and plasmonic tweezing applications. By applying analytical and numerical methods, the effectiveness of this nanostructure at performing these applications is determined from the plasmonic response of the nanostructure to an excitation beam of coherent light. During this analysis, it was discovered that under certain conditions, this 3D nanostructure exhibits a plasmonic Fano resonance resulting from the interference of an in-plane dark mode and an out-of-plane bright mode. In evaluating this nanostructure for sensing changes in the local dielectric environment, a figure of merit of 68 is calculated, which is competitive with current localized surface plasmon resonance refractometric sensors. By evaluating the Maxwell stress tensor on a test particle in the vicinity of the nanostructure, it was found that under the right conditions, this plasmonic nanostructure design is capable of imparting forces greater than 10.5 nN on dielectric objects of nanoscale dimensions. The results obtained in these studies provides new routes to the design and engineering of 3D plasmonic nanostructures and Fano resonances in these systems. In addition, the nanostructure presented in this work and the design principles it utilizes have shown

  12. Diverse Near-Infrared Resonant Gold Nanostructures for Biomedical Applications

    KAUST Repository

    Huang, Jianfeng; Han, Yu

    2015-01-01

    -light-mediated diagnostic and therapeutic applications. We begin by describing the unique biological, chemical and physical properties of gold nanostructures that make them excellent candidates for biomedical applications. From here, we make an account of the basic

  13. Current status of nanostructured tungsten-based materials development

    International Nuclear Information System (INIS)

    Kurishita, H; Matsuo, S; Arakawa, H; Hatakeyama, M; Shikama, T; Sakamoto, T; Kobayashi, S; Nakai, K; Okano, H; Watanabe, H; Yoshida, N; Torikai, Y; Hatano, Y; Takida, T; Kato, M; Ikegaya, A; Ueda, Y

    2014-01-01

    Nanostructured tungsten (W)-based materials offer many advantages for use as plasma facing materials and components exposed to heavy thermal loads combined with irradiation with high-energy neutron and low-energy ion. This paper first presents the recent progress in nanostructured toughened, fine grained, recrystallized W materials. Thermal desorption spectrometry apparatus equipped with an ion gun has been installed in the radiation controlled area in our Center at Tohoku University to systematically investigate the effects of displacement damage due to high-energy neutron irradiation on hydrogen isotope retention in connection with the nano- or micro-structures in W-based materials. In this paper, the effects of high-energy heavy ion irradiation on deuterium retention in W with different microstructures are described as a preliminary work with the prospective view of neutron irradiation effects. (paper)

  14. Nanostructured Semiconductor Materials for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Carmen Cavallo

    2017-01-01

    Full Text Available Since O’Regan and Grätzel’s first report in 1991, dye-sensitized solar cells (DSSCs appeared immediately as a promising low-cost photovoltaic technology. In fact, though being far less efficient than conventional silicon-based photovoltaics (being the maximum, lab scale prototype reported efficiency around 13%, the simple design of the device and the absence of the strict and expensive manufacturing processes needed for conventional photovoltaics make them attractive in small-power applications especially in low-light conditions, where they outperform their silicon counterparts. Nanomaterials are at the very heart of DSSC, as the success of its design is due to the use of nanostructures at both the anode and the cathode. In this review, we present the state of the art for both n-type and p-type semiconductors used in the photoelectrodes of DSSCs, showing the evolution of the materials during the 25 years of history of this kind of devices. In the case of p-type semiconductors, also some other energy conversion applications are touched upon.

  15. Nanoscience with liquid crystals from self-organized nanostructures to applications

    CERN Document Server

    Li, Quan

    2014-01-01

    This book focuses on the exciting topic of nanoscience with liquid crystals: from self-organized nanostructures to applications. The elegant self-organized liquid crystalline nanostructures, the synergetic characteristics of liquid crystals and nanoparticles, liquid crystalline nanomaterials, synthesis of nanomaterials using liquid crystals as templates, nanoconfinement and nanoparticles of liquid crystals are covered and discussed, and the prospect of fabricating functional materials is highlighted. Contributions, collecting the scattered literature of the field from leading and active player

  16. Diverse Near-Infrared Resonant Gold Nanostructures for Biomedical Applications

    KAUST Repository

    Huang, Jianfeng

    2015-12-08

    The ability of near-infrared (NIR) light to penetrate tissues deeply and to target malignant sites with high specificity via precise temporal and spatial control of light illumination makes it useful for diagnosing and treating diseases. Owing to their unique biocompatibility, surface chemistry and optical properties, gold nanostructures offer advantages as in vivo NIR photosensitizers. This chapter describes the recent progress in the varied use of NIR-resonant gold nanostructures for NIR-light-mediated diagnostic and therapeutic applications. We begin by describing the unique biological, chemical and physical properties of gold nanostructures that make them excellent candidates for biomedical applications. From here, we make an account of the basic principles involved in the diagnostic and therapeutic applications where gold nanostructures have set foot. Finally, we review recent developments in the fabrication and use of diverse NIR-resonant gold nanostructures for cancer imaging and cancer therapy.

  17. Zinc oxide nanostructures: new properties for advances applications

    International Nuclear Information System (INIS)

    Lupan, Oleg; Chow, Lee; Pauporte, Thierry

    2011-01-01

    Zinc oxide is a material which exhibits a variety of new properties at nanometer dimensions. Various synthesis techniques have been carried out to provide growth of nanowires, nanorods, nanorings, nanosprings, and nanobelts of ZnO under various conditions. These nanostructures show that ZnO possesses probably the richest family of nanoarchitectures among all materials, including their structures and properties. Such nanoarchitectures are potential building blocks for novel applications in optoelectronics, sensors, photovoltaic and nano-biomedical sciences. This work presents a review of various nano architectures of ZnO grown by the electrochemical, hydrothermal and solid-vapor phase techniques and their properties. The possible applications of ZnO nanowires as sensors, nano-DSSC, photodetectors and nano-LEDs will be presented.

  18. Micromirror array nanostructures for anticounterfeiting applications

    Science.gov (United States)

    Lee, Robert A.

    2004-06-01

    The optical characteristics of pixellated passive micro mirror arrays are derived and applied in the context of their use as reflective optically variable device (OVD) nanostructures for the protection of documents from counterfeiting. The traditional design variables of foil based diffractive OVDs are shown to be able to be mapped to a corresponding set of design parameters for reflective optical micro mirror array (OMMA) devices. The greatly increased depth characteristics of micro mirror array OVDs provides an opportunity for directly printing the OVD microstructure onto the security document in-line with the normal printing process. The micro mirror array OVD architecture therefore eliminates the need for hot stamping foil as the carrier of the OVD information, thereby reducing costs. The origination of micro mirror array devices via a palette based data format and a combination electron beam lithography and photolithography techniques is discussed via an artwork example and experimental tests. Finally the application of the technology to the design of a generic class of devices which have the interesting property of allowing for both application and customer specific OVD image encoding and data encoding at the end user stage of production is described. Because of the end user nature of the image and data encoding process these devices are particularly well suited to ID document applications and for this reason we refer this new OVD concept as biometric OVD technology.

  19. Towards highly sensitive strain sensing based on nanostructured materials

    International Nuclear Information System (INIS)

    Dao, Dzung Viet; Nakamura, Koichi; Sugiyama, Susumu; Bui, Tung Thanh; Dau, Van Thanh; Yamada, Takeo; Hata, Kenji

    2010-01-01

    This paper presents our recent theoretical and experimental study of piezo-effects in nanostructured materials for highly sensitive, high resolution mechanical sensors. The piezo-effects presented here include the piezoresistive effect in a silicon nanowire (SiNW) and single wall carbon nanotube (SWCNT) thin film, as well as the piezo-optic effect in a Si photonic crystal (PhC) nanocavity. Firstly, the electronic energy band structure of the silicon nanostructure is discussed and simulated by using the First-Principles Calculations method. The result showed a remarkably different energy band structure compared with that of bulk silicon. This difference in the electronic state will result in different physical, chemical, and therefore, sensing properties of silicon nanostructures. The piezoresistive effects of SiNW and SWCNT thin film were investigated experimentally. We found that, when the width of ( 110 ) p-type SiNW decreases from 500 to 35 nm, the piezoresistive effect increases by more than 60%. The longitudinal piezoresistive coefficient of SWCNT thin film was measured to be twice that of bulk p-type silicon. Finally, theoretical investigations of the piezo-optic effect in a PhC nanocavity based on Finite Difference Time Domain (FDTD) showed extremely high resolution strain sensing. These nanostructures were fabricated based on top-down nanofabrication technology. The achievements of this work are significant for highly sensitive, high resolution and miniaturized mechanical sensors

  20. Novel nanostructured materials for high energy density supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, C.Z.; Zhang, X.G. [Nanjing Univ. of Aeronautics and Astronautics (China). College of Material Science and Engineering

    2010-07-01

    Researchers are currently examining methods of improving energy density while not sacrificing the high power density of supercapacitors. In this study, nanostructured materials assembled from nanometer-sized building blocks with mesoporosity were synthesized in order investigate diffusion time, kinetics, and capacitances. Petal-like cobalt hydroxide Co(OH){sub 2} mesocrystals, urchin-like Co(OH){sub 2} and dicobalt tetroxide (Co{sub 2}O{sub 4}) ordered arrays as well as N{sub i}O microspheres were assembled from 0-D nanoparticles, 1-D mesoporous nanowires and nanobelts, and 2-D mesoporous nanopetals. The study showed that all the synthesized nanostructured materials delivered larger energy densities while showing electrochemical stability at high rates.

  1. Ceramic nanostructure materials, membranes and composite layers

    NARCIS (Netherlands)

    Burggraaf, A.J.; Keizer, Klaas; van Hassel, B.A.

    1989-01-01

    Synthesis methods to obtain nanoscale materials will be briefly discussed with a focus on sol-gel methods. Three types of nanoscale composites (powders, membranes and ion implanted layers) will be discussed and exemplified with recent original research results. Ceramic membranes with a thickness of

  2. Recent advances in ZnO nanostructures and thin films for biosensor applications: Review

    International Nuclear Information System (INIS)

    Arya, Sunil K.; Saha, Shibu; Ramirez-Vick, Jaime E.; Gupta, Vinay; Bhansali, Shekhar; Singh, Surinder P.

    2012-01-01

    Graphical abstract: ZnO nanostructures have shown binding of biomolecules in desired orientation with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, their compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes them suitable candidate for future small integrated biosensor devices. This review highlights various approaches to synthesize ZnO nanostructures and thin films, and their applications in biosensor technology. Highlights: ► This review highlights various approaches to synthesize ZnO nanostructures and thin films. ► Article highlights the importance of ZnO nanostructures as biosensor matrix. ► Article highlights the advances in various biosensors based on ZnO nanostructures. ► Article describes the potential of ZnO based biosensor for new generation healthcare devices. - Abstract: Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e., the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf-life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface-to-volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes ZnO nanostructures suitable candidate for future small integrated biosensor devices. This review

  3. Recent advances in ZnO nanostructures and thin films for biosensor applications: Review

    Energy Technology Data Exchange (ETDEWEB)

    Arya, Sunil K., E-mail: sunilarya333@gmail.com [Bioelectronics Program, Institute of Microelectronics, A-Star 11 Science Park Road, Singapore Science Park II, Singapore 117685 (Singapore); Saha, Shibu [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Ramirez-Vick, Jaime E. [Engineering Science and Materials Department, University of Puerto Rico, Mayaguez, PR 00681 (United States); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Bhansali, Shekhar [Department of Electrical and Computer Engineering, Florida International University, Miami, FL (United States); Singh, Surinder P., E-mail: singh.uprm@gmail.com [National Physical Laboratory, Dr K.S. Krishnan Marg, New Delhi 110012 (India)

    2012-08-06

    Graphical abstract: ZnO nanostructures have shown binding of biomolecules in desired orientation with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, their compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes them suitable candidate for future small integrated biosensor devices. This review highlights various approaches to synthesize ZnO nanostructures and thin films, and their applications in biosensor technology. Highlights: Black-Right-Pointing-Pointer This review highlights various approaches to synthesize ZnO nanostructures and thin films. Black-Right-Pointing-Pointer Article highlights the importance of ZnO nanostructures as biosensor matrix. Black-Right-Pointing-Pointer Article highlights the advances in various biosensors based on ZnO nanostructures. Black-Right-Pointing-Pointer Article describes the potential of ZnO based biosensor for new generation healthcare devices. - Abstract: Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e., the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf-life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface-to-volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes Zn

  4. Topological insulator materials and nanostructures for future electronics, spintronics and energy conversion

    International Nuclear Information System (INIS)

    Kantser, Valeriu

    2011-01-01

    Two fundamental electrons attributes in materials and nanostructures - charge and spin - determine their electronic properties. The processing of information in conventional electronic devices is based only on the charge of the electrons. Spin electronics, or spintronics, uses the spin of electrons, as well as their charge, to process information. Metals, semiconductors and insulators are the basic materials that constitute the components of electronic devices, and these have been transforming all aspects of society for over a century. In contrast, magnetic metals, half-metals, magnetic semiconductors, dilute magnetic semiconductors and magnetic insulators are the materials that will form the basis for spintronic devices. Materials with topological band structure attributes and having a zero-energy band gap surface states are a special class of these materials that exhibit some fascinating and superior electronic properties compared to conventional materials allowing to combine both charge and spin functionalities. This article reviews a range of topological insulator materials and nanostructures with tunable surface states, focusing on nanolayered and nanowire like structures. These materials and nanostructures all have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors.

  5. Review on recent progress of nanostructured anode materials for Li-ion batteries

    KAUST Repository

    Goriparti, Subrahmanyam

    2014-07-01

    This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs). In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de-intercalation, alloy/de-alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.

  6. Review on recent progress of nanostructured anode materials for Li-ion batteries

    KAUST Repository

    Goriparti, Subrahmanyam; Miele, Ermanno; De Angelis, Francesco; Di Fabrizio, Enzo M.; Proietti Zaccaria, Remo; Capiglia, Claudio

    2014-01-01

    This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs). In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de-intercalation, alloy/de-alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.

  7. Porous Core-Shell Nanostructures for Catalytic Applications

    Science.gov (United States)

    Ewers, Trevor David

    Porous core-shell nanostructures have recently received much attention for their enhanced thermal stability. They show great potential in the field of catalysis, as reactant gases can diffuse in and out of the porous shell while the core particle is protected from sintering, a process in which particles coalesce to form larger particles. Sintering is a large problem in industry and is the primary cause of irreversible deactivation. Despite the obvious advantages of high thermal stability, porous core-shell nanoparticles can be developed to have additional interactive properties from the combination of the core and shell together, rather than just the core particle alone. This dissertation focuses on developing new porous core-shell systems in which both the core and shell take part in catalysis. Two types of systems are explored; (1) yolk-shell nanostructures with reducible oxide shells formed using the Kirkendall effect and (2) ceramic-based porous oxide shells formed using sol-gel chemistry. Of the Kirkendall-based systems, Au FexOy and Cu CoO were synthesized and studied for catalytic applications. Additionally, ZnO was explored as a potential shelling material. Sol-gel work focused on optimizing synthetic methods to allow for coating of small gold particles, which remains a challenge today. Mixed metal oxides were explored as a shelling material to make dual catalysts in which the product of a reaction on the core particle becomes a reactant within the shell.

  8. Nanostructured refractory thin films for solar applications

    Science.gov (United States)

    Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.

    2014-08-01

    Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.

  9. Light-matter interaction in nanostructured materials

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst

    the effect is observable in a given material. We focus on the case of inverse opal photonic crystals and locate the position in the crystal where the effect is most pronounced. Furthermore, we quantify the influence of absorptive loss and give example calculations with experimental parameters for Pb......Se quantum dots in Si inverse opals showing that absorption has a limiting but not prohibitive effect. In addition, we discuss how the resonant nature of the phenomenon puts rather severe restrictions on the stabilization of the system in possible experiments. Last, we examine the influence on the decay...

  10. Nanostructural Materials for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2011-01-01

    Full Text Available The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

  11. Structure and transport properties of nanostructured materials.

    Science.gov (United States)

    Sonwane, C G; Li, Q

    2005-03-31

    In the present manuscript, we have presented the simulation of nanoporous aluminum oxide using a molecular-dynamics approach with recently developed dynamic charge transfer potential using serial/parallel programming techniques (Streitz and Mintmire Phys. Rev. B 1994, 50, 11996). The structures resembling recently invented ordered nanoporous crystalline material, MCM-41/SBA-15 (Kresge et al. Nature 1992, 359, 710), and inverted porous solids (hollow nanospheres) with up to 10 000 atoms were fabricated and studied in the present work. These materials have been used for separation of gases and catalysis. On several occasions including the design of the reactor, the knowledge of surface diffusion is necessary. In the present work, a new method for estimating surface transport of gases based on a hybrid Monte Carlo method with unbiased random walk of tracer atom on the pore surface has been introduced. The nonoverlapping packings used in the present work were fabricated using an algorithm of very slowly settling rigid spheres from a dilute suspension into a randomly packed bed. The algorithm was modified to obtain unimodal, homogeneous Gaussian and segregated bimodal porous solids. The porosity of these solids was varied by densification using an arbitrary function or by coarsening from a highly densified pellet. The surface tortuosity for the densified solids indicated an inverted bell shape curve consistent with the fact that at very high porosities there is a reduction in the connectivity while at low porosities the pores become inaccessible or dead-end. The first passage time distribution approach was found to be more efficient in terms of computation time (fewer tracer atoms needed for the linearity of Einstein's plot). Results by hybrid discrete-continuum simulations were close to the discrete simulations for a boundary layer thickness of 5lambda.

  12. Nanostructured energetic materials derived from sol-gel chemistry

    International Nuclear Information System (INIS)

    Simpson, R L; Tillotson, T M; Hrubesh, L W; Gash, A E

    2000-01-01

    Initiation and detonation properties are dramatically affected by an energetic material's microstructural properties. Sol-gel chemistry allows intimacy of mixing to be controlled and dramatically improved over existing methodologies. One material goal is to create very high power energetic materials which also have high energy densities. Using sol-gel chemistry we have made a nanostructured composite energetic material. Here a solid skeleton of fuel, based on resorcinol-formaldehyde, has nanocrystalline ammonium perchlorate, the oxidizer, trapped within its pores. At optimum stoichiometry it has approximately the energy density of HMX. Transmission electron microscopy indicated no ammonium perchlorate crystallites larger than 20 nm while near-edge soft x-ray absorption microscopy showed that nitrogen was uniformly distributed, at least on the scale of less than 80 nm. Small-angle neutron scattering studies were conducted on the material. Those results were consistent with historical ones for this class of nanostructured materials. The average skeletal primary particle size was on the order of 2.7 nm, while the nanocomposite showed the growth of small 1 nm size crystals of ammonium perchlorate with some clustering to form particles greater than 10 nm

  13. Graphene directed architecture of fine engineered nanostructures with electrochemical applications

    DEFF Research Database (Denmark)

    Hou, Chengyi; Zhang, Minwei; Halder, Arnab

    2017-01-01

    , and polymers has led to the possibility to create new electroactive and multifunctional nanostructures, which can serve as promising material platforms for electrochemical purposes. However, the precise control and fine-tuning of material structures and properties are still challenging and in demand...... classified nanostructures, including metallic nanostructures, self-assembled organic and supramolecular structures, and fine engineered metal oxides. In these cases, graphene templates either sacrificed during templating synthesis or retained as support for final products. We also discuss remained challenges....... In this review, we aim to highlight some recent efforts devoted to rational design, assembly and fine engineering of electrochemically active nanostructures using graphene or/and its derivatives as soft templates for controlled synthesis and directed growth. We organize the contents according to the chemically...

  14. Mn-based nanostructured building blocks: Synthesis, characterization and applications

    Science.gov (United States)

    Beltran Huarac, Juan

    -up approaches towards the fabrication of different types of functional MBNs. Likewise, strategic procedures that advance the facile integration of these self-assembled nanostructures with carbon-based and magnetic/optical materials, chalcogenides, oxides, and ferroics are widely analyzed and discussed. Furthermore, we present the attractive peculiarities of three versatile MBN systems (bridging the gap between their advantageous properties and the lack of methods for their fabrication): single-crystal saw-like MnS NRs, and single-crystal MnS NWs conformally coated with carbon; doped rare-earth manganite NCs, and carbon NTs conformally coated with doped rare-earth manganite; and ZnS:Mn NPs, and Fe3O4/ZnS:Mn NCs. Concerning the applicative significance, the main features of these three systems obtained by our method are suitable to advance direct applications in nanotechnology. In this regard, this work represents a step ahead in the following areas: i) alternative anode materials to enhance the capacity and cycling performance of low-drain, long-life, low-cost, high-energy density light-weight and safer lithium-ion batteries; ii) promising luminescent materials to improve the optoelectronic performance of visible light emitters; iii) new elements for field-effect transistors that outperform the transport properties of conventional carbon-based channels; iv) bifunctional materials exhibiting optical response sensitive to external magnetic fields vital for DMS; v) novel types of nanocantilevers useful for nanosensors and nanotweezers; vi) unique multiferroics materials that exhibit magnetoelectric coupling at room temperature for spintronics; vii) potential core-shell materials showing stress-free and protective carbon shells for shock-resistance semiconductors; and viii) high-quality ceramics useful as starting materials to deposit films by pulsed laser deposition, sputtering and thermal evaporation techniques.

  15. Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications

    Science.gov (United States)

    Biaggi-Labiosa, Azlin M.; Hunter, Gary W.

    2013-01-01

    A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption The fabrication of chemical sensors involving nanostructured materials can provide these properties as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited in the ability to control their location on the sensor. Currently, our group at NASA Glenn Research Center has demonstrated the controlled placement of nanostructures in sensors using a sawtooth patterned electrode design. With this design the nanostructures are aligned between opposing sawtooth electrodes by applying an alternating current.

  16. Conducting polymer nanostructures: template synthesis and applications in energy storage.

    Science.gov (United States)

    Pan, Lijia; Qiu, Hao; Dou, Chunmeng; Li, Yun; Pu, Lin; Xu, Jianbin; Shi, Yi

    2010-07-02

    Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

  17. Conducting Polymer Nanostructures: Template Synthesis and Applications in Energy Storage

    Directory of Open Access Journals (Sweden)

    Lijia Pan

    2010-07-01

    Full Text Available Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

  18. Conducting Polymer Nanostructures: Template Synthesis and Applications in Energy Storage

    OpenAIRE

    Pan, Lijia; Qiu, Hao; Dou, Chunmeng; Li, Yun; Pu, Lin; Xu, Jianbin; Shi, Yi

    2010-01-01

    Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template met...

  19. Novel graphene-based nanostructures: physicochemical properties and applications

    International Nuclear Information System (INIS)

    Chernozatonskii, L A; Sorokin, P B; Artukh, A A

    2014-01-01

    The review concerns graphene-based nanostructures including graphene nanoribbons a few nanometres wide, structures functionalized with hydrogen and fluorine atoms as well as pure carbon composites. The physicochemical properties and the chemical engineering methods for their fabrication are considered. Methods for solving problems in modern nanotechnology are discussed. Possible applications of graphene and graphene-based nanostructures in various devices are outlined. The bibliography includes 286 references

  20. Functional zinc oxide nanostructures for electronic and energy applications

    Science.gov (United States)

    Prasad, Abhishek

    ZnO has proven to be a multifunctional material with important nanotechnological applications. ZnO nanostructures can be grown in various forms such as nanowires, nanorods, nanobelts, nanocombs etc. In this work, ZnO nanostructures are grown in a double quartz tube configuration thermal Chemical Vapor Deposition (CVD) system. We focus on functionalized ZnO Nanostructures by controlling their structures and tuning their properties for various applications. The following topics have been investigated: (1) We have fabricated various ZnO nanostructures using a thermal CVD technique. The growth parameters were optimized and studied for different nanostructures. (2) We have studied the application of ZnO nanowires (ZnONWs) for field effect transistors (FETs). Unintentional n-type conductivity was observed in our FETs based on as-grown ZnO NWs. We have then shown for the first time that controlled incorporation of hydrogen into ZnO NWs can introduce p-type characters to the nanowires. We further found that the n-type behaviors remained, leading to the ambipolar behaviors of hydrogen incorporated ZnO NWs. Importantly, the detected p- and n- type behaviors are stable for longer than two years when devices were kept in ambient conditions. All these can be explained by an ab initio model of Zn vacancy-Hydrogen complexes, which can serve as the donor, acceptors, or green photoluminescence quencher, depend on the number of hydrogen atoms involved. (3) Next ZnONWs were tested for electron field emission. We focus on reducing the threshold field (Eth) of field emission from non-aligned ZnO NWs. As encouraged by our results on enhancing the conductivity of ZnO NWs by hydrogen annealing described in Chapter 3, we have studied the effect of hydrogen annealing for improving field emission behavior of our ZnO NWs. We found that optimally annealed ZnO NWs offered much lower threshold electric field and improved emission stability. We also studied field emission from ZnO NWs at moderate

  1. Zinc-oxide-based nanostructured materials for heterostructure solar cells

    International Nuclear Information System (INIS)

    Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A.; Somov, P. A.; Terukov, E. I.

    2015-01-01

    Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics

  2. Computational design of surfaces, nanostructures and optoelectronic materials

    Science.gov (United States)

    Choudhary, Kamal

    Properties of engineering materials are generally influenced by defects such as point defects (vacancies, interstitials, substitutional defects), line defects (dislocations), planar defects (grain boundaries, free surfaces/nanostructures, interfaces, stacking faults) and volume defects (voids). Classical physics based molecular dynamics and quantum physics based density functional theory can be useful in designing materials with controlled defect properties. In this thesis, empirical potential based molecular dynamics was used to study the surface modification of polymers due to energetic polyatomic ion, thermodynamics and mechanics of metal-ceramic interfaces and nanostructures, while density functional theory was used to screen substituents in optoelectronic materials. Firstly, polyatomic ion-beams were deposited on polymer surfaces and the resulting chemical modifications of the surface were examined. In particular, S, SC and SH were deposited on amorphous polystyrene (PS), and C2H, CH3, and C3H5 were deposited on amorphous poly (methyl methacrylate) (PMMA) using molecular dynamics simulations with classical reactive empirical many-body (REBO) potentials. The objective of this work was to elucidate the mechanisms by which the polymer surface modification took place. The results of the work could be used in tailoring the incident energy and/or constituents of ion beam for obtaining a particular chemistry inside the polymer surface. Secondly, a new Al-O-N empirical potential was developed within the charge optimized many body (COMB) formalism. This potential was then used to examine the thermodynamic stability of interfaces and mechanical properties of nanostructures composed of aluminum, its oxide and its nitride. The potentials were tested for these materials based on surface energies, defect energies, bulk phase stability, the mechanical properties of the most stable bulk phase, its phonon properties as well as with a genetic algorithm based evolution theory of

  3. Fabrication of bioinspired nanostructured materials via colloidal self-assembly

    Science.gov (United States)

    Huang, Wei-Han

    Through millions of years of evolution, nature creates unique structures and materials that exhibit remarkable performance on mechanicals, opticals, and physical properties. For instance, nacre (mother of pearl), bone and tooth show excellent combination of strong minerals and elastic proteins as reinforced materials. Structured butterfly's wing and moth's eye can selectively reflect light or absorb light without dyes. Lotus leaf and cicada's wing are superhydrophobic to prevent water accumulation. The principles of particular biological capabilities, attributed to the highly sophisticated structures with complex hierarchical designs, have been extensively studied. Recently, a large variety of novel materials have been enabled by natural-inspired designs and nanotechnologies. These advanced materials will have huge impact on practical applications. We have utilized bottom-up approaches to fabricate nacre-like nanocomposites with "brick and mortar" structures. First, we used self-assembly processes, including convective self-assembly, dip-coating, and electrophoretic deposition to form well oriented layer structure of synthesized gibbsite (aluminum hydroxide) nanoplatelets. Low viscous monomer was permeated into layered nanoplatelets and followed by photo-curing. Gibbsite-polymer composite displays 2 times higher tensile strength and 3 times higher modulus when compared with pure polymer. More improvement occurred when surface-modified gibbsite platelets were cross-linked with the polymer matrix. We observed ˜4 times higher strength and nearly 1 order of magnitude higher modulus than pure polymer. To further improve the mechanical strength and toughness of inorganicorganic nanocomposites, we exploited ultrastrong graphene oxide (GO), a single atom thick hexagonal carbon sheet with pendant oxidation groups. GO nanocomposite is made by co-filtrating GO/polyvinyl alcohol suspension on 0.2 im pore-sized membrane. It shows ˜2 times higher strength and ˜15 times higher

  4. Assembling and properties of the polymer-particle nanostructured materials

    Science.gov (United States)

    Sheparovych, Roman

    Complementary properties of the soft and hard matter explain its common encounter in many natural and manmade applications. A combination of flexible organic macromolecules and hard mineral clusters results in new materials far advantageous than its constituents alone. In this work we study assembling of colloidal nanocrystals and polymers into complex nanostructures. Magnetism, surface wettability and adhesion comprise properties of interest for the obtained nanocomposites. Applying a magnetic field induces a reversible 1D ordering of the magnetically susceptible particles. This property was employed in the fabrication of the permanent chains of magnetite nanocrystals (d=15nm). In the assembling process the aligned particles were bound together using polyelectrolyte macromolecules. The basics of the binding process involved an electrostatic interaction between the positively charged polyelectrolyte and the negative surface of the particles (aqueous environment). Adsorption of the polymer molecules onto several adjacent particles in the aligned 1D aggregate results in the formation of the permanent particulate chains. Positive charges of the adsorbed polyelectrolyte molecules stabilize the dispersion of the obtained nanostructures in water. Magnetization measurements revealed that superparamagnetic nanoparticles, being assembled into 1D ordered structures, attain magnetic coercivity. This effect originates from the magnetostatic interaction between the neighboring magnetite nanocrystals. The preferable dipole alignment of the assembled nanoparticles is directed along the chain axis. Another system studied in this project includes polymer-particle responsive surface coatings. Tethered polymer chains and particles bearing different functionalities change surface properties upon restructuring of the composite layer. When the environment favors polymer swelling (good solvent), the polymer chains segregate to the surface and cover the particles. In the opposite case

  5. 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.

  6. Synthesis, Morphologies and Building Applications of Nanostructured Polymers

    Directory of Open Access Journals (Sweden)

    Yong Lu

    2017-10-01

    Full Text Available Nanostructured polymers (NSPs are polymeric materials in the size of nanoscale, normally consisting of nanoparticles, nanofibers, nanowires, nanospheres and other morphologies. Polymer nanoparticles (PNPs can be fabricated either by physical methods (i.e., solvent evaporation, nanoprecipitation, salting out or by direct nanosynthesis, using micro- or nanoemulsions with nanoreactor compartments to perform polymerization. Polymer nanofibers (PNFs can be produced via various techniques and the most commonly used approach is electrospinning, whereby a charged solution of a polymer when exposed to an opposite high electric field is pulled into long thin nanofibers. NSPs in general exhibit enhanced properties such as excellent structural and mechanical properties, making them promising candidates for some particular building applications. A variety of PNFs have been developed and used for noise and air pollution filtration. Moreover, PNFs can also be fabricated with phase change materials which are usually employed for thermal energy storage in construction industry. In this review, we will summarize the morphologies and nanosynthesis methods of NSPs, in particular, PNPs and PNFs. In addition, representative NSPs mainly used in construction are introduced for building applications.

  7. Structure, hardness and fracture features of nanostructural materials

    International Nuclear Information System (INIS)

    Noskova, N.I.; Korznikov, A.V.; Idrisova, S.R.

    2000-01-01

    A study is made into nanocrystalline metals Cu and Mo, nanocrystalline intermetallic compound Ni 3 Al produced using severe plastic deformation; nanophase alloys Fe 73.5 Cu 1 Nb 3 Si 1.35 B 9 and Pd 81 Cu 7 Si 12 produced by crystallization from amorphous state as well as nanophase materials TiN and Al 2 O 3 produced by nano powder compacting in the temperature range of 273-573 K. Methods of transmission and scanning electron microscopy, X-ray diffraction analysis, mechanical testing and microhardness measurement are applied to study structure, internal elastic stress, phase composition, hardness, strength and plastic properties, surface fracture mode of nanostructural materials [ru

  8. Nanostructured carbon and carbon nanocomposites for electrochemical energy storage applications.

    Science.gov (United States)

    Su, Dang Sheng; Schlögl, Robert

    2010-02-22

    Electrochemical energy storage is one of the important technologies for a sustainable future of our society, in times of energy crisis. Lithium-ion batteries and supercapacitors with their high energy or power densities, portability, and promising cycling life are the cores of future technologies. This Review describes some materials science aspects on nanocarbon-based materials for these applications. Nanostructuring (decreasing dimensions) and nanoarchitecturing (combining or assembling several nanometer-scale building blocks) are landmarks in the development of high-performance electrodes for with long cycle lifes and high safety. Numerous works reviewed herein have shown higher performances for such electrodes, but mostly give diverse values that show no converging tendency towards future development. The lack of knowledge about interface processes and defect dynamics of electrodes, as well as the missing cooperation between material scientists, electrochemists, and battery engineers, are reasons for the currently widespread trial-and-error strategy of experiments. A concerted action between all of these disciplines is a prerequisite for the future development of electrochemical energy storage devices.

  9. Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

    Science.gov (United States)

    Guan, Bu Yuan; Yu, Xin Yao; Wu, Hao Bin; Lou, Xiong Wen David

    2017-12-01

    Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Diamond-based materials for biomedical applications

    CERN Document Server

    Narayan, Roger

    2013-01-01

    Carbon is light-weight, strong, conductive and able to mimic natural materials within the body, making it ideal for many uses within biomedicine. Consequently a great deal of research and funding is being put into this interesting material with a view to increasing the variety of medical applications for which it is suitable. Diamond-based materials for biomedical applications presents readers with the fundamental principles and novel applications of this versatile material. Part one provides a clear introduction to diamond based materials for medical applications. Functionalization of diamond particles and surfaces is discussed, followed by biotribology and biological behaviour of nanocrystalline diamond coatings, and blood compatibility of diamond-like carbon coatings. Part two then goes on to review biomedical applications of diamond based materials, beginning with nanostructured diamond coatings for orthopaedic applications. Topics explored include ultrananocrystalline diamond for neural and ophthalmologi...

  11. Bottom-Up Synthesis and Sensor Applications of Biomimetic Nanostructures

    Directory of Open Access Journals (Sweden)

    Li Wang

    2016-01-01

    Full Text Available The combination of nanotechnology, biology, and bioengineering greatly improved the developments of nanomaterials with unique functions and properties. Biomolecules as the nanoscale building blocks play very important roles for the final formation of functional nanostructures. Many kinds of novel nanostructures have been created by using the bioinspired self-assembly and subsequent binding with various nanoparticles. In this review, we summarized the studies on the fabrications and sensor applications of biomimetic nanostructures. The strategies for creating different bottom-up nanostructures by using biomolecules like DNA, protein, peptide, and virus, as well as microorganisms like bacteria and plant leaf are introduced. In addition, the potential applications of the synthesized biomimetic nanostructures for colorimetry, fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrical resistance, electrochemistry, and quartz crystal microbalance sensors are presented. This review will promote the understanding of relationships between biomolecules/microorganisms and functional nanomaterials in one way, and in another way it will guide the design and synthesis of biomimetic nanomaterials with unique properties in the future.

  12. Adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: A review.

    Science.gov (United States)

    Burakov, Alexander E; Galunin, Evgeny V; Burakova, Irina V; Kucherova, Anastassia E; Agarwal, Shilpi; Tkachev, Alexey G; Gupta, Vinod K

    2018-02-01

    The problem of water pollution is of a great concern. Adsorption is one of the most efficient techniques for removing noxious heavy metals from the solvent phase. This paper presents a detailed information and review on the adsorption of noxious heavy metal ions from wastewater effluents using various adsorbents - i.e., conventional (activated carbons, zeolites, clays, biosorbents, and industrial by-products) and nanostructured (fullerenes, carbon nanotubes, graphenes). In addition to this, the efficiency of developed materials for adsorption of the heavy metals is discussed in detail along with the comparison of their maximum adsorption capacity in tabular form. A special focus is made on the perspectives of further wider applications of nanostructured adsorbents (especially, carbon nanotubes and graphenes) in wastewater treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Thermoelectric nanomaterials materials design and applications

    CERN Document Server

    Koumoto, Kunihito

    2014-01-01

    Presently, there is an intense race throughout the world to develop good enough thermoelectric materials which can be used in wide scale applications. This book focuses comprehensively on very recent up-to-date breakthroughs in thermoelectrics utilizing nanomaterials and methods based in nanoscience. Importantly, it provides the readers with methodology and concepts utilizing atomic scale and nanoscale materials design (such as superlattice structuring, atomic network structuring and properties control, electron correlation design, low dimensionality, nanostructuring, etc.). Furthermore, also

  14. Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Valdirene Aparecida [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Folgueras, Luiza de Castro; Candido, Geraldo Mauricio; Paula, Adriano Luiz de; Rezende, Mirabel Cerqueira, E-mail: mirabelmcr@iae.cta.br [Instituto de Aeronautica e Espaco (IAE), Sao Jose dos Campos, SP (Brazil). Div. de Materiais; Costa, Michelle Leali [Universidade Estadual Paulista Julio de Mesquita Filho (DMT/UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia

    2013-07-01

    Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multi walled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations (author)

  15. Nanostructured diamond coatings for orthopaedic applications

    Science.gov (United States)

    CATLEDGE, S.A.; THOMAS, V.; VOHRA, Y.K.

    2013-01-01

    With increasing numbers of orthopaedic devices being implanted, greater emphasis is being placed on ceramic coating technology to reduce friction and wear in mating total joint replacement components, in order to improve implant function and increase device lifespan. In this chapter, we consider ultra-hard carbon coatings, with emphasis on nanostructured diamond, as alternative bearing surfaces for metallic components. Such coatings have great potential for use in biomedical implants as a result of their extreme hardness, wear resistance, low friction and biocompatibility. These ultra-hard carbon coatings can be deposited by several techniques resulting in a wide variety of structures and properties. PMID:25285213

  16. Nanostructured Thermoelectric Oxides for Energy Harvesting Applications

    KAUST Repository

    Abutaha, Anas I.

    2015-11-24

    As the world strives to adapt to the increasing demand for electrical power, sustainable energy sources are attracting significant interest. Around 60% of energy utilized in the world is wasted as heat. Different industrial processes, home heating, and exhausts in cars, all generate a huge amount of unused waste heat. With such a huge potential, there is also significant interest in discovering inexpensive technologies for power generation from waste heat. As a result, thermoelectric materials have become important for many renewable energy research programs. While significant advancements have been done in improving the thermoelectric properties of the conventional heavy-element based materials (such as Bi2Te3 and PbTe), high-temperature applications of thermoelectrics are still limited to one materials system, namely SiGe, since the traditional thermoelectric materials degrade and oxidize at high temperature. Therefore, oxide thermoelectrics emerge as a promising class of materials since they can operate athigher temperatures and in harsher environments compared to non-oxide thermoelectrics. Furthermore, oxides are abundant and friendly to the environment. Among oxides, crystalline SrTiO3 and ZnO are promising thermoelectric materials. The main objective of this work is therefore to pursue focused investigations of SrTiO3 and ZnO thin films and superlattices grown by pulsed laser deposition (PLD), with the goal of optimizing their thermoelectric properties by following different strategies. First, the effect of laser fluence on the thermoelectric properties of La doped epitaxial SrTiO3 films is discussed. Films grown at higher laser fluences exhibit better thermoelectric performance. Second, the role of crystal orientation in determining the thermoelectric properties of epitaxial Al doped ZnO (AZO) films is explained. Vertically aligned (c-axis) AZO films have superior thermoelectric properties compared to other films with different crystal orientations. Third

  17. Comprehensive Enhancement of Nanostructured Lithium-Ion Battery Cathode Materials via Conformal Graphene Dispersion.

    Science.gov (United States)

    Chen, Kan-Sheng; Xu, Rui; Luu, Norman S; Secor, Ethan B; Hamamoto, Koichi; Li, Qianqian; Kim, Soo; Sangwan, Vinod K; Balla, Itamar; Guiney, Linda M; Seo, Jung-Woo T; Yu, Xiankai; Liu, Weiwei; Wu, Jinsong; Wolverton, Chris; Dravid, Vinayak P; Barnett, Scott A; Lu, Jun; Amine, Khalil; Hersam, Mark C

    2017-04-12

    Efficient energy storage systems based on lithium-ion batteries represent a critical technology across many sectors including consumer electronics, electrified transportation, and a smart grid accommodating intermittent renewable energy sources. Nanostructured electrode materials present compelling opportunities for high-performance lithium-ion batteries, but inherent problems related to the high surface area to volume ratios at the nanometer-scale have impeded their adoption for commercial applications. Here, we demonstrate a materials and processing platform that realizes high-performance nanostructured lithium manganese oxide (nano-LMO) spinel cathodes with conformal graphene coatings as a conductive additive. The resulting nanostructured composite cathodes concurrently resolve multiple problems that have plagued nanoparticle-based lithium-ion battery electrodes including low packing density, high additive content, and poor cycling stability. Moreover, this strategy enhances the intrinsic advantages of nano-LMO, resulting in extraordinary rate capability and low temperature performance. With 75% capacity retention at a 20C cycling rate at room temperature and nearly full capacity retention at -20 °C, this work advances lithium-ion battery technology into unprecedented regimes of operation.

  18. Recent developments in the nanostructured materials functionalized with ruthenium complexes for targeted drug delivery to tumors

    Directory of Open Access Journals (Sweden)

    Thangavel P

    2017-04-01

    Full Text Available Prakash Thangavel,1 Buddolla Viswanath,1 Sanghyo Kim1,2 1Department of Bionanotechnology, Gachon University, Bokjeong-Dong, Sujeong-Gu, Seongnam-Si, Gyeonggi-Do, 2Graduate Gachon Medical Research Institute, Gil Medical Center, Incheon, Republic of Korea Abstract: In recent years, the field of metal-based drugs has been dominated by other existing precious metal drugs, and many researchers have focused their attention on the synthesis of various ruthenium (Ru complexes due to their potential medical and pharmaceutical applications. The beneficial properties of Ru, which make it a highly promising therapeutic agent, include its variable oxidation states, low toxicity, high selectivity for diseased cells, ligand exchange properties, and the ability to mimic iron binding to biomolecules. In addition, Ru complexes have favorable adsorption properties, along with excellent photochemical and photophysical properties, which make them promising tools for photodynamic therapy. At present, nanostructured materials functionalized with Ru complexes have become an efficient way to administer Ru-based anticancer drugs for cancer treatment. In this review, the recent developments in the nanostructured materials functionalized with Ru complexes for targeted drug delivery to tumors are discussed. In addition, information on “traditional” (ie, non-nanostructured Ru-based cancer therapies is included in a precise manner. Keywords: metallodrugs, nanotechnology, cancer treatment, cell apoptosis, DNA damage, toxicity

  19. Quantum Mechanical Simulations of Complex Nanostructures for Photovoltaic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhigang [Colorado School of Mines, Golden, CO (United States)

    2017-05-31

    A quantitative understanding of the electronic excitations in nanostructures, especially complex nanostructures, is crucial for making new-generation photovoltaic (PV) cells based on nanotechnology, which have high efficiency and low cost. Yet current quantum mechanical simulation methods are either computationally too expensive or not accurate and reliable enough, hindering the rational design of the nanoscale PV cells. The PI seeks to develop new methodologies to overcome the challenges in this very difficult and long-lasting problem, pushing the field forward so that electronic excitations can be accurately predicted for systems involving thousands of atoms. The primary objective of this project is to develop new approaches for electronic excitation calculations that are more accurate than traditional density functional theory (DFT) and are applicable to systems larger than what current beyond-DFT methods can treat. In this proposal, the PI will first address the excited-state problem within the DFT framework to obtain quasiparticle energies from both Kohn-Sham (KS) eigenvalues and orbitals; and the electron-hole binding energy will be computed based on screened Coulomb interaction of corresponding DFT orbitals. The accuracy of these approaches will be examined against many-body methods of GW/BSE and quantum Monte Carlo (QMC). The PI will also work on improving the accuracy and efficiency of the GW/BSE and QMC methods in electronic excitation computations by using better KS orbitals obtained from orbital-dependent DFT as inputs. Then an extended QMC database of ground- and excited-state properties will be developed, and this will be spot checked and supplemented with data from GW/BSE calculations. The investigation will subsequently focus on the development of an improved exchange-correlation (XC) density functional beyond the current generalized gradient approximation (GGA) level of parameterization, with parameters fitted to the QMC database. This will allow

  20. Proceedings of the two day national workshop on advanced materials for engineering applications

    International Nuclear Information System (INIS)

    John Alexis, S.; Jayakumar, S.

    2012-01-01

    The subjects like material preparation, material forming, material properties, materials testing, material mechanics, material structure, metal materials, non-metallic materials, composite materials, medical materials, chemical materials, food materials, electrician/electrical materials, building materials, biological materials, electronic/magnetic/optical materials, advanced materials applications in engineering are included in the workshop. Processing of advanced materials, studies on novel ceramic coatings, high strength, light weight and nanostructured materials are discussed in this proceedings. Papers relevant to INIS are indexed separately

  1. Nanostructured Transparent Conducting Oxides for Device Applications

    Science.gov (United States)

    Dutta, Titas

    2011-12-01

    ) based on these surfaces modified TCO layers have shown an increase in the open circuit voltage (Voc) and/or increase in Fill factor (FF) and the power conversion efficiency of these devices. These results suggest that the surface modified GZO films have a potential to substitute for ITO in transparent electrode applications. To gain a better understanding of the fundamentals and factors affecting the properties of p-type TCO, NiO thin films have been grown on c-sapphire and glass substrates with controlled properties. Growth of NiO on c-sapphire occurs epitaxially in [111] direction with two types of crystalline grains rotated by 60° with respect to each other. We have also investigated the effects of the deposition parameters and Li doping concentration variations on the electrical and optical properties of NiO thin films. The analysis of the resistivity measurement showed that doped Li+ ions occupy the substitutional sites in the NiO films, enhancing the p-type conductivity. The minimum resistivity of 0.15 O-cm was obtained for Li0.07Ni 0.93O film. The results of this research help to understand the conduction mechanisms in TCOs and are critical to further improvement and optimization of TCO properties. This work has also demonstrated interesting possibilities for fabricating a p-LixNi1-xO/ i-MgZnO /n-ZnO heterojunction diode on c-sapphire. It has been demonstrated that epitaxial LixNi 1-xO can be grown on ZnO integrated with c-sapphire. Heteroeptaxial growth of the p-n junction is technologically important as it minimizes the electron scattering at the interface. The insertion of i-MgZnO between the p and n layer led to improved current-voltage characteristics with reduced leakage current. An attempt has been made to elucidate the role of point defects, in controlling the carrier concentration and transport characteristics of nanostructured TCO films. This study presents the systematic changes in structural, electrical and optical properties of NiO thin films

  2. Nanostructured Thermoelectric Oxides for Energy Harvesting Applications

    KAUST Repository

    Abutaha, Anas I.

    2015-01-01

    of thermoelectrics are still limited to one materials system, namely SiGe, since the traditional thermoelectric materials degrade and oxidize at high temperature. Therefore, oxide thermoelectrics emerge as a promising class of materials since they can operate

  3. Present and future applications of magnetic nanostructures grown by FEBID

    Energy Technology Data Exchange (ETDEWEB)

    Teresa, J.M. de [CSIC-Universidad de Zaragoza, Departamento de Fisica de la Materia Condensada, Instituto de Ciencia de Materiales de Aragon (ICMA), Saragossa (Spain); Universidad de Zaragoza, Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Saragossa (Spain); Fernandez-Pacheco, A. [University of Cambridge, TFM Group, Cavendish Laboratory, Cambridge (United Kingdom)

    2014-12-15

    Currently, magnetic nanostructures are routinely grown by focused electron beam induced deposition (FEBID). In the present article, we review the milestones produced in the topic in the past as well as the future applications of this technology. Regarding past milestones, we highlight the achievement of high-purity cobalt and iron deposits, the high lateral resolution obtained, the growth of 3D magnetic deposits, the exploration of magnetic alloys and the application of magnetic deposits for Hall sensing and in domain-wall conduit and magnetologic devices. With respect to future perspectives of the topic, we emphasize the potential role of magnetic nanostructures grown by FEBID for applications related to highly integrated 2D arrays, 3D nanowires devices, fabrication of advanced scanning-probe systems, basic studies of magnetic structures and their dynamics, small sensors (including biosensors) and new applications brought by magnetic alloys and even exchange biased systems. (orig.)

  4. Methods for and products of processing nanostructure nitride, carbonitride and oxycarbonitride electrode power materials by utilizing sol gel technology for supercapacitor applications

    Science.gov (United States)

    Huang, Yuhong; Wei, Oiang; Chu, Chung-tse; Zheng, Haixing

    2001-01-01

    Metal nitride, carbonitride, and oxycarbonitride powder with high surface area (up to 150 m.sup.2 /g) is prepared by using sol-gel process. The metal organic precursor, alkoxides or amides, is synthesized firstly. The metal organic precursor is modified by using unhydrolyzable organic ligands or templates. A wet gel is formed then by hydrolysis and condensation process. The solvent in the wet gel is then be removed supercritically to form porous amorphous hydroxide. This porous hydroxide materials is sintered to 725.degree. C. under the ammonia flow and porous nitride powder is formed. The other way to obtain high surface area nitride, carbonitride, and oxycarbonitride powder is to pyrolyze polymerized templated metal amides aerogel in an inert atmosphere. The electrochemical capacitors are prepared by using sol-gel prepared nitride, carbonitride, and oxycarbonitride powder. Two methods are used to assemble the capacitors. Electrode is formed either by pressing the mixture of nitride powder and binder to a foil, or by depositing electrode coating onto metal current collector. The binder or coating is converted into a continuous network of electrode material after thermal treatment to provide enhanced energy and power density. Liquid electrolyte is soaked into porous electrode. The electrochemical capacitor assembly further has a porous separator layer between two electrodes/electrolyte and forming a unit cell.

  5. Impact of Nanostructuring on the Phase Behavior of Insertion Materials: The Hydrogenation Kinetics of a Magnesium Thin Film

    NARCIS (Netherlands)

    Bannenberg, L.J.; Schreuders, H.; van Eijck, L.; Heringa, J.R.; Steinke, N.J.; Dalgliesh, RM; Dam, B.; Mulder, F.M.; van Well, A.A.

    2016-01-01

    Nanostructuring is widely applied in both battery and hydrogen materials to improve the performance of these materials as energy carriers. Nanostructuring changes the diffusion length as well as the thermodynamics of materials. We studied the impact of nanostructuring on the hydrogenation in a model

  6. Nanostructured carbon materials based electrothermal air pump actuators

    Science.gov (United States)

    Liu, Qing; Liu, Luqi; Kuang, Jun; Dai, Zhaohe; Han, Jinhua; Zhang, Zhong

    2014-05-01

    Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid films as heating elements to transfer electrical stimulus into thermal energy, and finally convert it into mechanical energy. Both the actuation displacement and working temperature of the actuator films show the monotonically increasing trend with increasing driving voltage within the actuation process. Compared with common polymer nanocomposites based electrothermal actuators, our actuators exhibited better actuation performances with a low driving voltage (film actuator due to the intrinsic gas-impermeability nature of graphene platelets. In addition, the high modulus of the r-GO and GO/SWCNT films also guaranteed the large generated stress and high work density. Specifically, the generated stress and gravimetric work density of the GO/SWCNT hybrid film actuator could reach up to more than 50 MPa and 30 J kg-1, respectively, under a driving voltage of 10 V. The resulting stress value is at least two orders of magnitude higher than that of natural muscles (~0.4 MPa).Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid films as heating elements to transfer electrical stimulus into thermal energy, and finally convert it into mechanical energy. Both the actuation displacement and working temperature of the actuator films show the monotonically increasing trend with increasing driving voltage within the actuation process. Compared with

  7. Solution growth of single crystal methylammonium lead halide perovskite nanostructures for optoelectronic and photovoltaic applications.

    Science.gov (United States)

    Fu, Yongping; Meng, Fei; Rowley, Matthew B; Thompson, Blaise J; Shearer, Melinda J; Ma, Dewei; Hamers, Robert J; Wright, John C; Jin, Song

    2015-05-06

    Understanding crystal growth and improving material quality is important for improving semiconductors for electronic, optoelectronic, and photovoltaic applications. Amidst the surging interest in solar cells based on hybrid organic-inorganic lead halide perovskites and the exciting progress in device performance, improved understanding and better control of the crystal growth of these perovskites could further boost their optoelectronic and photovoltaic performance. Here, we report new insights on the crystal growth of the perovskite materials, especially crystalline nanostructures. Specifically, single crystal nanowires, nanorods, and nanoplates of methylammonium lead halide perovskites (CH3NH3PbI3 and CH3NH3PbBr3) are successfully grown via a dissolution-recrystallization pathway in a solution synthesis from lead iodide (or lead acetate) films coated on substrates. These single crystal nanostructures display strong room-temperature photoluminescence and long carrier lifetime. We also report that a solid-liquid interfacial conversion reaction can create a highly crystalline, nanostructured MAPbI3 film with micrometer grain size and high surface coverage that enables photovoltaic devices with a power conversion efficiency of 10.6%. These results suggest that single-crystal perovskite nanostructures provide improved photophysical properties that are important for fundamental studies and future applications in nanoscale optoelectronic and photonic devices.

  8. ZnO Nanostructures for Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Marco Laurenti

    2017-11-01

    Full Text Available This review focuses on the most recent applications of zinc oxide (ZnO nanostructures for tissue engineering. ZnO is one of the most investigated metal oxides, thanks to its multifunctional properties coupled with the ease of preparing various morphologies, such as nanowires, nanorods, and nanoparticles. Most ZnO applications are based on its semiconducting, catalytic and piezoelectric properties. However, several works have highlighted that ZnO nanostructures may successfully promote the growth, proliferation and differentiation of several cell lines, in combination with the rise of promising antibacterial activities. In particular, osteogenesis and angiogenesis have been effectively demonstrated in numerous cases. Such peculiarities have been observed both for pure nanostructured ZnO scaffolds as well as for three-dimensional ZnO-based hybrid composite scaffolds, fabricated by additive manufacturing technologies. Therefore, all these findings suggest that ZnO nanostructures represent a powerful tool in promoting the acceleration of diverse biological processes, finally leading to the formation of new living tissue useful for organ repair.

  9. Recent Progress in Metal-Organic Frameworks and Their Derived Nanostructures for Energy and Environmental Applications.

    Science.gov (United States)

    Xie, Zhiqiang; Xu, Wangwang; Cui, Xiaodan; Wang, Ying

    2017-04-22

    Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted increasing interest from research communities due to their extremely high surface areas, diverse nanostructures, and unique properties. In recent years, there is a growing body of evidence to indicate that MOFs can function as ideal templates to prepare various nanostructured materials for energy and environmental cleaning applications. Recent progress in the design and synthesis of MOFs and MOF-derived nanomaterials for particular applications in lithium-ion batteries, sodium-ion batteries, supercapacitors, dye-sensitized solar cells, and heavy-metal-ion detection and removal is reviewed herein. In addition, the remaining major challenges in the above fields are discussed and some perspectives for future research efforts in the development of MOFs are also provided. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Center for Fundamental and Applied Research in Nanostructured and Lightweight Materials. Final Technical Summary

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, Michael; Rogers, Tony; King, Julia; Keith, Jason; Cornilsen, Bahne; Allen, Jeffrey; Gilbert, Ryan; Holles, Joseph

    2010-09-28

    The core projects for this DOE-sponsored Center at Michigan Tech have focused on several of the materials problems identified by the NAS. These include: new electrode materials, enhanced PEM materials, lighter and more effective bipolar plates, and improvement of the carbon used as a current carrier. This project involved fundamental and applied research in the development and testing of lightweight and nanostructured materials to be used in fuel cell applications and for chemical synthesis. The advent of new classes of materials engineered at the nanometer level can produce materials that are lightweight and have unique physical and chemical properties. The grant was used to obtain and improve the equipment infrastructure to support this research and also served to fund seven research projects. These included: 1. Development of lightweight, thermally conductive bipolar plates for improved thermal management in fuel cells; 2. Exploration of pseudomorphic nanoscale overlayer bimetallic catalysts for fuel cells; 3. Development of hybrid inorganic/organic polymer nanocomposites with improved ionic and electronic properties; 4. Development of oriented polymeric materials for membrane applications; 5. Preparation of a graphitic carbon foam current collectors; 6. The development of lightweight carbon electrodes using graphitic carbon foams for battery and fuel cell applications; and 7. Movement of water in fuel cell electrodes.

  11. Plasmonic nanostructures: synthesis, functionalization & sensing applications

    OpenAIRE

    Yang, Wenjuan

    2017-01-01

    Nobel metal nanoparticles possess unique materials properties different from their corresponding bulk materials, which have sparked extensive research developments in the field of nanofabrication over the past few decades. In particular, the rational design of plasmonic nanoparticles (“artificial atoms”) is emerging as an exciting route for engineering material properties with high accuracy. Synthetic advances enable the sophisticated control over their size, shape, composition, and morpholog...

  12. Nanostructure of highly aromatic graphene nanosheets -- From optoelectronics to electrochemical energy storage applications

    Science.gov (United States)

    Biswas, Sanjib

    The exceptional electrical properties along with intriguing physical and chemical aspects of graphene nanosheets can only be realized by nanostructuring these materials through the homogeneous and orderly distribution of these nanosheets without compromising the aromaticity of the native basal plane. Graphene nanosheets prepared by direct exfoliation as opposed to the graphene oxide route are necessary in order to preserve the native chemical properties of graphene basal planes. This research has been directed at optimally combining the diverse physical and chemical aspects of graphene nanosheets such as particle size, surface area and edge chemistry to fabricate nanostructured architectures for optoelectronics and high power electrochemical energy storage applications. In the first nanostructuring effort, a monolayer of these ultrathin, highly hydrophobic graphene nanosheets was prepared on a large area substrate via self-assembly at the liquid-liquid interface. Driven by the minimization of interfacial energy these planar graphene nanosheets produce a close packed monolayer structure at the liquid-liquid interface. The resulting monolayer film exhibits high electrical conductivity of more than 1000 S/cm and an optical transmission of more than 70-80% between wavelengths of 550 nm and 2000 nm making it an ideal candidate for optoelectronic applications. In the second part of this research, nanostructuring was used to create a configuration suitable for supercapacitor applications. A free standing, 100% binder free multilayer, flexible film consisting of monolayers of graphene nanosheets was prepared by utilizing the van der Waals forces of attraction between the basal plans of the graphene nanosheets coupled with capillary driven and drying-induced collapse. A major benefit in this approach is that the graphene nanosheet's attractive physical and chemical characteristics can be synthesized into an architecture consisting of large and small nanosheets to create an

  13. Multifunctional magnetoelectric materials for device applications

    International Nuclear Information System (INIS)

    Ortega, N; Katiyar, Ram S; Kumar, Ashok; Scott, J F

    2015-01-01

    Over the past decade magnetoelectric (ME) mutiferroic (MF) materials and their devices are one of the highest priority research topics that has been investigated by the scientific ferroics community to develop the next generation of novel multifunctional materials. These systems show the simultaneous existence of two or more ferroic orders, and cross-coupling between them, such as magnetic spin, polarisation, ferroelastic ordering, and ferrotoroidicity. Based on the type of ordering and coupling, they have drawn increasing interest for a variety of device applications, such as magnetic field sensors, nonvolatile memory elements, ferroelectric photovoltaics, nano-electronics etc. Since single-phase materials exist rarely in nature with strong cross-coupling properties, intensive research activity is being pursued towards the discovery of new single-phase multiferroic materials and the design of new engineered materials with strong magneto-electric (ME) coupling. This review article summarises the development of different kinds of multiferroic material: single-phase and composite ceramic, laminated composite and nanostructured thin films. Thin-film nanostructures have higher magnitude direct ME coupling values and clear evidence of indirect ME coupling compared with bulk materials. Promising ME coupling coefficients have been reported in laminated composite materials in which the signal to noise ratio is good for device fabrication. We describe the possible applications of these materials. (topical review)

  14. Reduction reactions applied for synthesizing different nano-structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque Brocchi, Eduardo de; Correia de Siqueira, Rogério Navarro [Department of Materials Engineering, PUC-Rio, Rua Marquês de São Vicente, 225, Gávea, 22453-900 Rio de Janeiro, RJ (Brazil); Motta, Marcelo Senna [Basck Ltd. (United Kingdom); Moura, Francisco José, E-mail: moura@puc-rio.br [Department of Materials Engineering, PUC-Rio, Rua Marquês de São Vicente, 225, Gávea, 22453-900 Rio de Janeiro, RJ (Brazil); Solórzano-Naranjo, Ivan Guillermo [Department of Materials Engineering, PUC-Rio, Rua Marquês de São Vicente, 225, Gávea, 22453-900 Rio de Janeiro, RJ (Brazil)

    2013-06-15

    Different materials have been synthesized by alternative routes: nitrates thermal decomposition to prepare oxide or co-formed oxides and reduction by hydrogen or graphite to obtain mixed oxides, composites or alloys. These chemical-based synthesis routes are described and thermodynamics studies and kinetics data are presented to support its feasibility. In addition, selective reduction reactions have been applied to successfully produce metal/ceramic composites, and alloys. Structural characterization has been carried out by X-ray Diffraction and, more extensively, Transmission Electron Microscopy operating in conventional diffraction contrast (CTEM) and high-resolution mode (HRTEM), indicated the possibility of obtaining oxide and alloy crystals of sizes ranging between 20 and 40 nm. - Highlights: • The viability in obtaining Ni–Co, Cu–Al, Mn–Al co-formed nano oxides was evaluated. • Partial and complete H{sub 2} reduction were used to produce alloy, composite and Spinel. • XRD, TEM and HREM techniques were used to characterize the obtained nanostructures.

  15. Synthesis, characterization and applications of nanostructural ...

    Indian Academy of Sciences (India)

    various methods [4] like coagulation and precipitation process (named as Nalgo- nda technique) ... cially available metal oxides like activated alumina, magnesia and other materials .... Nanomaterials NANO-2005, July 13–15, 2005 (Mepco.

  16. Electrostatic interactions for directed assembly of high performance nanostructured energetic materials of Al/Fe2O3/multi-walled carbon nanotube (MWCNT)

    International Nuclear Information System (INIS)

    Zhang, Tianfu; Ma, Zhuang; Li, Guoping; Wang, Zhen; Zhao, Benbo; Luo, Yunjun

    2016-01-01

    Electrostatic self-assembly in organic solvent without intensively oxidative or corrosive environments, was adopted to prepare Al/Fe 2 O 3 /MWCNT nanostructured energetic materials as an energy generating material. The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe 2 O 3 (oxide) nanoparticles. This spontaneous assembly method without any surfactant chemistry or other chemical and biological moieties decreased the aggregation of the same nanoparticles largely, moreover, the poor interfacial contact between the Al (fuel) and Fe 2 O 3 (oxide) nanoparticles was improved significantly, which was the key characteristic of high performance nanostructured energetic materials. In addition, the assembly process was confirmed as Diffusion-Limited Aggregation. The assembled Al/Fe 2 O 3 /MWCNT nanostructured energetic materials showed excellent performance with heat release of 2400 J/g, peak pressure of 0.42 MPa and pressurization rate of 105.71 MPa/s, superior to that in the control group Al/Fe 2 O 3 nanostructured energetic materials prepared by sonication with heat release of 1326 J/g, peak pressure of 0.19 MPa and pressurization rate of 33.33 MPa/s. Therefore, the approach, which is facile, opens a promising route to the high performance nanostructured energetic materials. - Graphical abstract: The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe 2 O 3 (oxide) nanoparticles. - Highlights: • A facile spontaneous electrostatic assembly strategy without surfactant was adopted. • The fuels and oxidizers assembled into densely packed nanostructured composites. • The assembled nanostructured energetic materials have excellent performance. • This high performance energetic material can be scaled up for practical application. • This strategy can be applied into other nanostructured

  17. Functionalized surfaces and nanostructures for nanotechnological applications

    Science.gov (United States)

    2003-01-01

    not know where to look. Over the last decade, technology has become synonymous with computers, software and communications, whether the internet or mobile telephones. Many of the initial applications of nanotechnology are materials related, such as additives for plastics, nanocarbon particles for improved steels, coatings and improved catalysts for the petrochemical industry. All of these are technology based industries, maybe not new ones, but industries with multi-billion dollar markets. 5. The nanotechnology industry It is increasingly common to hear people referring to `the nanotechnology industry', just like the software or mobile phone industries, but will such a thing ever exist? Many of the companies working with nanotechnology are simply applying our knowledge of the nanoscale to existing industries, whether it is improved drug delivery mechanisms for the pharmaceutical industry, or producing nanoclay particles for the plastics industry. In fact nanotechnology is an enabling technology rather than an industry in its own right. No one would ever describe Microsoft or Oracle as being part of the electricity industry, even though without electricity the software industry could not exist. Rather, nanotechnology is a fundamental understanding of how nature works at the atomic scale. New industries will be generated as a result of this understanding, just as the understanding of how electrons can be moved in a conductor by applying a potential difference led to electric lighting, the telephone, computing, the internet and many other industries, all of which would not have been possible without it. While it is possible to buy a packet of nanotechnology, a gram of nanotubes for example, it would have zero intrinsic value. The real value of the nanotubes would be in their application, whether within existing industry, or to enable the creation of a whole new one. 6. Fantastic voyage Shrinking machines down to the size where they can be inserted into the human body in

  18. Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application

    Directory of Open Access Journals (Sweden)

    Lili Yang

    2017-11-01

    Full Text Available Since the initial discovery of surface-enhanced Raman scattering (SERS in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0–3 dimensions. Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

  19. Morphology and growth of titania nanotubes. Nanostructuring and applications

    Energy Technology Data Exchange (ETDEWEB)

    Albu, Sergiu P.

    2012-10-26

    Self-ordering phenomena during anodic oxidation of metals and the formation of porous oxides have been of a great interest to science and technology for more than 50 years. Particularly, after Masuda et al. demonstrated ideally ordered porous alumina by fine tuning the experimental parameters during aluminum anodization, these structures were increasingly used as a template for the deposition and growth of large varieties of 1D functional materials. For some time, such self-organized oxide structures seemed to be limited to Al{sub 2}O{sub 3}, but in 1999 Zwilling et al. reported self-organized oxide structures (aligned nanotubes) anodically grown on Ti in a dilute fluoride solution. Dilute fluoride electrolytes were then found suitable to grow ordered tubular or porous oxides on a large range of other metals and alloys. Subsequently, the control over the morphology (diameter, length, smoothness of the walls) was strongly improved by continuously optimizing the anodizing conditions. Most research work has been directed towards TiO{sub 2} nanotubes, as TiO{sub 2} with its semiconductive nature makes the nanotubular structures promising for use in solar cells, photocatalysis and sensors, and also its ion insertion properties and its high degree of biocompatibility have attracted wide interest. The experimental optimization of growth parameters led to various semi-quantitative or qualitative models that provide a mechanistic reasoning for the occurrence of self-organization. Although theoretical modeling of self-ordered structures grown anodically on valve metals was increasingly refined, a main source of difficulty remained, namely the multitude of experimental factors which influence the growth of self-ordered nanostructures. The present work represents an attempt to provide a detailed experimental view over the growth of TiO{sub 2} nanotubes in organic electrolytes. The first part is based on describing the methods and set-ups used for growth and characterization of

  20. Hierarchical oxide-based composite nanostructures for energy, environmental, and sensing applications

    Science.gov (United States)

    Gao, Pu-Xian; Shimpi, Paresh; Cai, Wenjie; Gao, Haiyong; Jian, Dunliang; Wrobel, Gregory

    2011-02-01

    Self-assembled composite nanostructures integrate various basic nano-elements such as nanoparticles, nanofilms and nanowires toward realizing multifunctional characteristics, which promises an important route with potentially high reward for the fast evolving nanoscience and nanotechnology. A broad array of hierarchical metal oxide based nanostructures have been designed and fabricated in our research group, involving semiconductor metal oxides, ternary functional oxides such as perovskites and spinels and quaternary dielectric hydroxyl metal oxides with diverse applications in efficient energy harvesting/saving/utilization, environmental protection/control, chemical sensing and thus impacting major grand challenges in the area of materials and nanotechnology. Two of our latest research activities have been highlighted specifically in semiconductor oxide alloy nanowires and metal oxide/perovskite composite nanowires, which could impact the application sectors in ultraviolet/blue lighting, visible solar absorption, vehicle and industry emission control, chemical sensing and control for vehicle combustors and power plants.

  1. Self-assembly strategies for the synthesis of functional nanostructured materials

    International Nuclear Information System (INIS)

    Perego, M.; Seguini, G.

    2016-01-01

    Self-assembly is the autonomous organization of components into patterns or structures without human intervention. This is the approach followed by nature to generate living cells and represents one of the practical strategies to fabricate ensembles of nanostructures. In static self-assembly the formation of ordered structures could require energy but once formed the structures are stable. The introduction of additional regular features in the environment could be used to template the self-assembly guiding the organization of the components and determining the final structure they form. In this regard self-assembly of block copolymers represents a potent platform for fundamental studies at the nanoscale and for application-driven investigation as a tool to fabricate functional nanostructured materials. Block copolymers can hierarchically assemble into chemically distinct domains with size and periodicity on the order of 10 nm or below, offering a potentially inexpensive route to generate large-area nanostructured materials. The final structure characteristics of these materials are dictated by the properties of the elementary block copolymers, like chain length, volume fraction or degree of block incompatibility. Modern synthetic chemistry offers the possibility to design these macromolecules with very specific length scales and geometries, directly embodying in the block copolymers the code that drives their self- assembling process. The understanding of the kinetics and thermodynamics of the block copolymer selfassembly process in the bulk phase as well as in thin films represents a fundamental prerequisite toward the exploitation of these materials. Incorporating block copolymer into device fabrication procedures or directly into devices, as active elements, will lead to the development of a new generation of devices fabricated using the fundamental law of nature to our advantage in order to minimize cost and power consumption in the fabrication process

  2. Self-assembly strategies for the synthesis of functional nanostructured materials

    Science.gov (United States)

    Perego, M.; Seguini, G.

    2016-06-01

    Self-assembly is the autonomous organization of components into patterns or structures without human intervention. This is the approach followed by nature to generate living cells and represents one of the practical strategies to fabricate ensembles of nanostructures. In static self-assembly the formation of ordered structures could require energy but once formed the structures are stable. The introduction of additional regular features in the environment could be used to template the self-assembly guiding the organization of the components and determining the final structure they form. In this regard self-assembly of block copolymers represents a potent platform for fundamental studies at the nanoscale and for application-driven investigation as a tool to fabricate functional nanostructured materials. Block copolymers can hierarchically assemble into chemically distinct domains with size and periodicity on the order of 10nm or below, offering a potentially inexpensive route to generate large-area nanostructured materials. The final structure characteristics of these materials are dictated by the properties of the elementary block copolymers, like chain length, volume fraction or degree of block incompatibility. Modern synthetic chemistry offers the possibility to design these macromolecules with very specific length scales and geometries, directly embodying in the block copolymers the code that drives their self- assembling process. The understanding of the kinetics and thermodynamics of the block copolymer self-assembly process in the bulk phase as well as in thin films represents a fundamental prerequisite toward the exploitation of these materials. Incorporating block copolymer into device fabrication procedures or directly into devices, as active elements, will lead to the development of a new generation of devices fabricated using the fundamental law of nature to our advantage in order to minimize cost and power consumption in the fabrication process

  3. The development of biopolymer-based nanostructured materials : plastics, gels, IPNs and nanofoams

    NARCIS (Netherlands)

    Soest, van J.J.G.

    2006-01-01

    The ability to design products with structural features on a nanometric scale is a major technology driver in materials research Nanostructured materials are defined as materials with structural features on a sub-micron scale determining specific properties They consist of materials such as metals,

  4. Fabrication and Applications of Micro/Nanostructured Devices for Tissue Engineering

    KAUST Repository

    Limongi, Tania

    2016-09-02

    Nanotechnology allows the realization of new materials and devices with basic structural unit in the range of 1-100 nm and characterized by gaining control at the atomic, molecular, and supramolecular level. Reducing the dimensions of a material into the nanoscale range usually results in the change of its physiochemical properties such as reactivity, crystallinity, and solubility. This review treats the convergence of last research news at the interface of nanostructured biomaterials and tissue engineering for emerging biomedical technologies such as scaffolding and tissue regeneration. The present review is organized into three main sections. The introduction concerns an overview of the increasing utility of nanostructured materials in the field of tissue engineering. It elucidates how nanotechnology, by working in the submicron length scale, assures the realization of a biocompatible interface that is able to reproduce the physiological cell-matrix interaction. The second, more technical section, concerns the design and fabrication of biocompatible surface characterized by micro- and submicroscale features, using microfabrication, nanolithography, and miscellaneous nanolithographic techniques. In the last part, we review the ongoing tissue engineering application of nanostructured materials and scaffolds in different fields such as neurology, cardiology, orthopedics, and skin tissue regeneration.

  5. Fabrication and Applications of Micro/Nanostructured Devices for Tissue Engineering

    KAUST Repository

    Limongi, Tania; Tirinato, Luca; Pagliari, Francesca; Giugni, Andrea; Allione, Marco; Perozziello, Gerardo; Candeloro, Patrizio; Di Fabrizio, Enzo M.

    2016-01-01

    Nanotechnology allows the realization of new materials and devices with basic structural unit in the range of 1-100 nm and characterized by gaining control at the atomic, molecular, and supramolecular level. Reducing the dimensions of a material into the nanoscale range usually results in the change of its physiochemical properties such as reactivity, crystallinity, and solubility. This review treats the convergence of last research news at the interface of nanostructured biomaterials and tissue engineering for emerging biomedical technologies such as scaffolding and tissue regeneration. The present review is organized into three main sections. The introduction concerns an overview of the increasing utility of nanostructured materials in the field of tissue engineering. It elucidates how nanotechnology, by working in the submicron length scale, assures the realization of a biocompatible interface that is able to reproduce the physiological cell-matrix interaction. The second, more technical section, concerns the design and fabrication of biocompatible surface characterized by micro- and submicroscale features, using microfabrication, nanolithography, and miscellaneous nanolithographic techniques. In the last part, we review the ongoing tissue engineering application of nanostructured materials and scaffolds in different fields such as neurology, cardiology, orthopedics, and skin tissue regeneration.

  6. Advanced Materials for Space Applications

    Science.gov (United States)

    Pater, Ruth H.; Curto, Paul A.

    2005-01-01

    Since NASA was created in 1958, over 6400 patents have been issued to the agency--nearly one in a thousand of all patents ever issued in the United States. A large number of these inventions have focused on new materials that have made space travel and exploration of the moon, Mars, and the outer planets possible. In the last few years, the materials developed by NASA Langley Research Center embody breakthroughs in performance and properties that will enable great achievements in space. The examples discussed below offer significant advantages for use in small satellites, i.e., those with payloads under a metric ton. These include patented products such as LaRC SI, LaRC RP 46, LaRC RP 50, PETI-5, TEEK, PETI-330, LaRC CP, TOR-LM and LaRC LCR (patent pending). These and other new advances in nanotechnology engineering, self-assembling nanostructures and multifunctional aerospace materials are presented and discussed below, and applications with significant technological and commercial advantages are proposed.

  7. A New Probe for Mechanical Testing of Nanostructures in Soft Materials

    International Nuclear Information System (INIS)

    Hough, L.A.; Ou-Yang, H.D.

    1999-01-01

    We report a new application of the optical tweezers, where a harmonically driven oscillating tweezer is combined with the forward light scattering and lock-in amplification techniques, for probing the mechanics of nanostructures in soft materials in a broad frequency range. Model independent dynamic moduli G' and G'' of the material at a localized, sub-micron area can be measured directly from the displacement and the phase shift of the particle in the oscillating trap. The probe particles can be as small as 200 nm and the displacement of the particle was in the range of a few nanometers. To illustrate the new methodology, we show the microscopic viscoelastic properties of a transient polymer network in the vicinity of a silica bead

  8. Surface-Enhanced Raman Spectroscopy as a Probe of the Surface Chemistry of Nanostructured Materials.

    Science.gov (United States)

    Dick, Susan; Konrad, Magdalena P; Lee, Wendy W Y; McCabe, Hannah; McCracken, John N; Rahman, Taifur M D; Stewart, Alan; Xu, Yikai; Bell, Steven E J

    2016-07-01

    Surface-enhanced Raman spectroscopy (SERS) is now widely used as a rapid and inexpensive tool for chemical/biochemical analysis. The method can give enormous increases in the intensities of the Raman signals of low-concentration molecular targets if they are adsorbed on suitable enhancing substrates, which are typically composed of nanostructured Ag or Au. However, the features of SERS that allow it to be used as a chemical sensor also mean that it can be used as a powerful probe of the surface chemistry of any nanostructured material that can provide SERS enhancement. This is important because it is the surface chemistry that controls how these materials interact with their local environment and, in real applications, this interaction can be more important than more commonly measured properties such as morphology or plasmonic absorption. Here, the opportunity that this approach to SERS provides is illustrated with examples where the surface chemistry is both characterized and controlled in order to create functional nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Integration of nanostructured materials with MEMS microhotplate platforms to enhance chemical sensor performance

    International Nuclear Information System (INIS)

    Benkstein, Kurt D.; Martinez, Carlos J.; Li, Guofeng; Meier, Douglas C.; Montgomery, Christopher B.; Semancik, Steve

    2006-01-01

    The development of miniaturized chemical sensors is an increasingly active area of research. Such devices, particularly when they feature low mass and low power budgets, can impact a broad range of applications including industrial process monitoring, building security and extraterrestrial exploration. Nanostructured materials, because of their high surface area, can provide critical enhancements in the performance of chemical microsensors. We have worked to integrate nanomaterial films with MEMS (microelectromechanical systems) microhotplate platforms developed at the National Institute of Standards and Technology in order to gain the benefits of both the materials and the platforms in high-performance chemical sensor arrays. Here, we describe our success in overcoming the challenges of integration and the benefits that we have achieved with regard to the critical sensor performance characteristics of sensor response, speed, stability and selectivity. Nanostructured metal oxide sensing films were locally deposited onto microhotplates via chemical vapor deposition and microcapillary pipetting, and conductive polymer nanoparticle films were deposited via electrophoretic patterning. All films were characterized by scanning electron microscopy and evaluated as conductometric gas sensors

  10. Graphitic Carbon-Based Nanostructures for Energy and Environmental Applications

    Science.gov (United States)

    Chan, Ka Long Donald

    This thesis focuses on the synthesis and characterization of graphitic carbonbased photocatalytic nanostructures for energy and environmental applications. The preparation of carbon- and oxygen-rich graphitic carbon nitride with enhanced photocatalytic hydrogen evolution property was investigated. Composite materials based on graphene quantum dots were also prepared. These composites were used for photocatalytic degradation of organic pollutants and photoelectrocatalytic disinfection. The first part of this thesis describes a facile method for the preparation of carbon- and oxygen-rich graphitic carbon nitride by thermal condensation. Incorporation of carbon and oxygen enhanced the photoresponse of carbon nitride in the visible-light region. After exfoliation, the product was c.a. 45 times more active than bulk graphitic carbon nitride in photocatalytic hydrogen evolution under visible-light irradiation. In the second part, a simple approach to enhance the photocatalytic activity of red phosphorus was developed. Mechanical ball milling was applied to reduce the size of red phosphorus and to deposit graphene quantum dots (GQDs) onto red phosphorus. The product exhibited high visible-light-driven photocatalytic performance in the photodegradation of Rhodamine B. The incorporation of GQDs in titanium dioxide could also extend the absorption spectrum of TiO2 into the visible-light range. The third part of this thesis reports on the fabrication of a visible-light-driven composite photocatalyst of TiO2 nanotube arrays (TNAs) and GQDs. Carboxyl-containing GQDs were covalently coupled to amine-modified TNAs. The product exhibited enhanced photocurrent and high photoelectrocatalytic performance in the inactivation of E. coli under visible-light irradiation. The role of various reactive species in the photoelectrocatalytic process was investigated.

  11. Influence of Nanotechnology and the Role of Nanostructures in Biomimetic Studies and Their Potential Applications

    Directory of Open Access Journals (Sweden)

    Puneet Garg

    2017-05-01

    Full Text Available With the advent of nanotechnology, by looking further deep down into the molecular level, today, we are able to understand basic and applied sciences even better than ever before. Not only has nanoscience and nanotechnology allowed us to study the composing structures of materials in detail, it has also allowed us to fabricate and synthesize such nanostructures using top-down and bottom-up approaches. One such field, which has been significantly influenced by the dawn of nanotechnology is biomimetics. With powerful spectroscopic and microscopic tools presenting us with images like double nanostructured pillars on the lotus surface for superhydrophobicity, the conical protuberances of moth eye demonstrating anti-reflection properties and nanostructured spatulae of gecko feet for high adhesivity, we are now able to fabricate these structures in the lab with properties showing close resemblance to their natural counterparts. Here, we present a review of various nanostructures that exist in nature, their fabrication techniques and some of their promising future applications. We hope this review will provide the reader with a basic understanding of what biomimetics is and how nanotechnology has significantly influenced this field.

  12. Nanostructured Conjugated Polymers for Energy-Related Applications beyond Solar Cells.

    Science.gov (United States)

    Xie, Jian; Zhao, Cui-E; Lin, Zong-Qiong; Gu, Pei-Yang; Zhang, Qichun

    2016-05-20

    To meet the ever-increasing requirements for the next generation of sustainable and versatile energy-related devices, conjugated polymers, which have potential advantages over small molecules and inorganic materials, are among the most promising types of green candidates. The properties of conjugated polymers can be tuned through modification of the structure and incorporation of different functional moieties. In addition, superior performances can be achieved as a result of the advantages of nanostructures, such as their large surface areas and the shortened pathways for charge transfer. Therefore, nanostructured conjugated polymers with different properties can be obtained to be applied in different energy-related organic devices. This review focuses on the application and performance of the recently reported nanostructured conjugated polymers for high-performance devices, including rechargeable lithium batteries, microbial fuel cells (MFCs), thermoelectric generators, and photocatalytic systems. The design strategies, reaction mechanisms, advantages, and limitations of nanostructured conjugated polymers are further discussed in each section. Finally, possible routes to improve the performances of the current systems are also included in the conclusion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Development of nanostructures for application in food technology: evaluation of their in vitro behaviour

    Science.gov (United States)

    Pinheiro, Ana Cristina Braga

    The emerging field of nanotechnology offers new challenges to the food industry either by offering novel tools for the development of strategies to improve food quality and human health, or by the introduction of questions about the behaviour of nanostructures within the human body. Nanotechnology holds a great potential to generate very innovative solutions and to provide food technologists and manufacturers with instruments to meet the evergrowing consumer demands in very diverse aspects related with the foods they eat: safety, quality, health-promotion and novelty. However, the application of nanostructures to foods is hindered by very pertinent problems, which could be summarized in two issues: edibility (only edible materials must be used for their production) and functionality/behaviour once inside the human body, that is raising safety concerns among the consumers, and therefore demands an evaluation (ideally) in vivo, or at least in vitro. In this context, the two main challenges addressed in this thesis were to develop stable nanostructures for food applications and to evaluate their in vitro behaviour. The strategy adopted included the development and characterization of edible nanostructures, incorporation of bioactive compounds and evaluation of their behaviour when subjected to digestion in artificial gastrointestinal (GI) systems. In particular, the research undertaken was based on three different nanostructures: nanofilms composed of kappa-carrageenan and chitosan, curcumin nanoemulsions stabilized by different emulsifiers and multilayer nanocapsules composed of chitosan and fucoidan. The nanostructures developed in this work can be used as platforms for the production of new products with improved characteristics targeted at the most recent consumer trends. This work contributes to the understanding of the behaviour of those nanostructures inside the human body during digestion (e.g. release phenomena involved at the nano-scale and bioavailability

  14. Advanced Magnetic Nanostructures

    CERN Document Server

    Sellmyer, David

    2006-01-01

    Advanced Magnetic Nanostructures is devoted to the fabrication, characterization, experimental investigation, theoretical understanding, and utilization of advanced magnetic nanostructures. Focus is on various types of 'bottom-up' and 'top-down' artificial nanostructures, as contrasted to naturally occurring magnetic nanostructures, such as iron-oxide inclusions in magnetic rocks, and to structures such as perfect thin films. Chapter 1 is an introduction into some basic concepts, such as the definitions of basic magnetic quantities. Chapters 2-4 are devoted to the theory of magnetic nanostructures, Chapter 5 deals with the characterization of the structures, and Chapters 6-10 are devoted to specific systems. Applications of advanced magnetic nanostructures are discussed in Chapters11-15 and, finally, the appendix lists and briefly discusses magnetic properties of typical starting materials. Industrial and academic researchers in magnetism and related areas such as nanotechnology, materials science, and theore...

  15. Nanostructured Thin Film Synthesis by Aerosol Chemical Vapor Deposition for Energy Storage Applications

    Science.gov (United States)

    Chadha, Tandeep S.

    structures, due to a combination of high surface area, improved lithium diffusivity and electronic conductivity. The model developed allows for the prediction of optimized nanostructure geometry depending on the end-use application. Increasing demand for lithium-ion batteries, posing concerns for lithium supply and costs in future, have motivated research in sodium-ion batteries as alternatives. In this work, the nanostructured TiO2 electrodes have been studied as anodes for sodium ion batteries. To improve the performance, a new multi-component ACVD process has been developed to achieve single-step synthesis of doped nanostructured thin films. One-dimensional niobium doped TiO2 thin films have been synthesized and characterized as a novel anode material for sodium-ion batteries. The doped nanostructured thin films deliver significant improvements on capacity over their undoped counterparts and demonstrate feasibility of sodium-ion batteries. In summary, the studies conducted in this dissertation develop a detailed understanding of the ACVD process and demonstrate its ability to synthesize superior nanostructured thin films for energy storage applications, thereby motivating process scalability for commercial applications.

  16. Recent progress on fabrication and drug delivery applications of nanostructured hydroxyapatite.

    Science.gov (United States)

    Mondal, Sudip; Dorozhkin, Sergy V; Pal, Umapada

    2018-07-01

    Through this brief review, we provide a comprehensive historical background of the development of nanostructured hydroxyapatite (nHAp), and its application potentials for controlled drug delivery, drug conjugation, and other biomedical treatments. Aspects associated with efficient utilization of hydroxyapatite (HAp) nanostructures such as their synthesis, interaction with drug molecules, and other concerns, which need to be resolved before they could be used as a potential drug carrier in body system, are discussed. This review focuses on the evolution of perceptions, practices, and accomplishments in providing improved delivery systems for drugs until date. The pioneering developments that have presaged today's fascinating state of the art drug delivery systems based on HAp and HAp-based composite nanostructures are also discussed. Special emphasis has been given to describe the application and effectiveness of modified HAp as drug carrier agent for different diseases such as bone-related disorders, carriers for antibiotics, anti-inflammatory, carcinogenic drugs, medical imaging, and protein delivery agents. As only a very few published works made comprehensive evaluation of HAp nanostructures for drug delivery applications, we try to cover the three major areas: concepts, practices and achievements, and applications, which have been consolidated and patented for their practical usage. The review covers a broad spectrum of nHAp and HAp modified inorganic drug carriers, emphasizing some of their specific aspects those needed to be considered for future drug delivery applications. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Nanotechnology Approaches to Biology > Cells at the Nanoscale. © 2017 Wiley Periodicals, Inc.

  17. Nanostructured Diamond Device for Biomedical Applications.

    Science.gov (United States)

    Fijalkowski, M; Karczemska, A; Lysko, J M; Zybala, R; KozaneckI, M; Filipczak, P; Ralchenko, V; Walock, M; Stanishevsky, A; Mitura, S

    2015-02-01

    Diamond is increasingly used in biomedical applications because of its unique properties such as the highest thermal conductivity, good optical properties, high electrical breakdown voltage as well as excellent biocompatibility and chemical resistance. Diamond has also been introduced as an excellent substrate to make the functional microchip structures for electrophoresis, which is the most popular separation technique for the determination of analytes. In this investigation, a diamond electrophoretic chip was manufactured by a replica method using a silicon mold. A polycrystalline 300 micron-thick diamond layer was grown by the microwave plasma-assisted CVD (MPCVD) technique onto a patterned silicon substrate followed by the removal of the substrate. The geometry of microstructure, chemical composition, thermal and optical properties of the resulting free-standing diamond electrophoretic microchip structure were examined by CLSM, SFE, UV-Vis, Raman, XRD and X-ray Photoelectron Spectroscopy, and by a modified laser flash method for thermal property measurements.

  18. Quantitative Scanning Transmission Electron Microscopy of Electronic and Nanostructured Materials

    Science.gov (United States)

    Yankovich, Andrew B.

    Electronic and nanostructured materials have been investigated using advanced scanning transmission electron microscopy (STEM) techniques. The first topic is the microstructure of Ga and Sb-doped ZnO. Ga-doped ZnO is a candidate transparent conducting oxide material. The microstructure of GZO thin films grown by MBE under different growth conditions and different substrates were examined using various electron microscopy (EM) techniques. The microstructure, prevalent defects, and polarity in these films strongly depend on the growth conditions and substrate. Sb-doped ZnO nanowires have been shown to be the first route to stable p-type ZnO. Using Z-contrast STEM, I have showed that an unusual microstructure of Sb-decorated head-to-head inversion domain boundaries and internal voids contain all the Sb in the nanowires and cause the p-type conduction. InGaN thin films and InGaN / GaN quantum wells (QW) for light emitting diodes are the second topic. Low-dose Z-contrast STEM, PACBED, and EDS on InGaN QW LED structures grown by MOCVD show no evidence for nanoscale composition variations, contradicting previous reports. In addition, a new extended defect in GaN and InGaN was discovered. The defect consists of a faceted pyramid-shaped void that produces a threading dislocation along the [0001] growth direction, and is likely caused by carbon contamination during growth. Non-rigid registration (NRR) and high-precision STEM of nanoparticles is the final topic. NRR is a new image processing technique that corrects distortions arising from the serial nature of STEM acquisition that previously limited the precision of locating atomic columns and counting the number of atoms in images. NRR was used to demonstrate sub-picometer precision in STEM images of single crystal Si and GaN, the best achieved in EM. NRR was used to measure the atomic surface structure of Pt nanoacatalysts and Au nanoparticles, which revealed new bond length variation phenomenon of surface atoms. In

  19. First Principles Investigations of Technologically and Environmentally Important Nano-structured Materials and Devices

    Science.gov (United States)

    Paul, Sujata

    In the course of my PhD I have worked on a broad range of problems using simulations from first principles: from catalysis and chemical reactions at surfaces and on nanostructures, characterization of carbon-based systems and devices, and surface and interface physics. My research activities focused on the application of ab-initio electronic structure techniques to the theoretical study of important aspects of the physics and chemistry of materials for energy and environmental applications and nano-electronic devices. A common theme of my research is the computational study of chemical reactions of environmentally important molecules (CO, CO2) using high performance simulations. In particular, my principal aim was to design novel nano-structured functional catalytic surfaces and interfaces for environmentally relevant remediation and recycling reactions, with particular attention to the management of carbon dioxide. We have studied the carbon-mediated partial sequestration and selective oxidation of carbon monoxide (CO), both in the presence and absence of hydrogen, on graphitic edges. Using first-principles calculations we have studied several reactions of CO with carbon nanostructures, where the active sites can be regenerated by the deposition of carbon decomposed from the reactant (CO) to make the reactions self-sustained. Using statistical mechanics, we have also studied the conditions under which the conversion of CO to graphene and carbon dioxide is thermodynamically favorable, both in the presence and in the absence of hydrogen. These results are a first step toward the development of processes for the carbon-mediated partial sequestration and selective oxidation of CO in a hydrogen atmosphere. We have elucidated the atomic scale mechanisms of activation and reduction of carbon dioxide on specifically designed catalytic surfaces via the rational manipulation of the surface properties that can be achieved by combining transition metal thin films on oxide

  20. Promising applications of graphene and graphene-based nanostructures

    Science.gov (United States)

    Nguyen, Bich Ha; Hieu Nguyen, Van

    2016-06-01

    densities; fabrication of anodes for lithium ion batteries from crumpled graphene-encapsulated Si nanoparticles; liquid-mediated dense integration of graphene materials for compact capacitive energy storage; scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage; superior micro-supercapacitors based on graphene quantum dots; all-graphene core-sheat microfibres for all-solid-state, stretchable fibriform supercapacitors and wearable electronic textiles; micro-supercapacitors with high electrochemical performance based on three-dimensional graphene-carbon nanotube carpets; macroscopic nitrogen-doped graphene hydrogels for ultrafast capacitors; manufacture of scalable ultra-thin and high power density graphene electrochemical capacitor electrodes by aqueous exfoliation and spray deposition; scalable synthesis of hierarchically structured carbon nanotube-graphene fibers for capacitive energy storage; phosphorene-graphene hybrid material as a high-capacity anode material for sodium-ion batteries. Beside above-presented promising applications of graphene and graphene-based nanostructures, other less widespread, but perhaps not less important, applications of graphene and graphene-based nanomaterials, are also briefly discussed.

  1. MnO2 Based Nanostructures for Supercapacitor Energy Storage Applications

    KAUST Repository

    Chen, Wei

    2013-11-01

    Nanostructured materials provide new and exciting approaches to the development of supercapacitor electrodes for high-performance electrochemical energy storage applications. One of the biggest challenges in materials science and engineering, however, is to prepare the nanomaterials with desirable characteristics and to engineer the structures in proper ways. This dissertation presents the successful preparation and application of very promising materials in the area of supercapacitor energy storage, including manganese dioxide and its composites, polyaniline and activated carbons. Attention has been paid to understanding their growth process and performance in supercapacitor devices. The morphological and electrochemical cycling effects, which contribute to the understanding of the energy storage mechanism of MnO2 based supercapacitors is thoroughly investigated. In addition, MnO2 based binary (MnO2-carbon nanocoils, MnO2-graphene) and ternary (MnO2-carbon nanotube-graphene) nanocomposites, as well as two novel electrodes (MnO2-carbon nanotube-textile and MnO2-carbon nanotube-sponge) have been studied as supercapacitor electrode materials, showing much improved electrochemical storage performance with good energy and power densities. Furthermore, a general chemical route was introduced to synthesize different conducting polymers and activated carbons by taking the MnO2 nanostructures as reactive templates. The electrochemical behaviors of the polyaniline and activated nanocarbon supercapacitors demonstrate the morphology-dependent enhancement of capacitance. Excellent energy and power densities were obtained from the template-derived polyaniline and activated carbon based supercapacitors, indicating the success of our proposed chemical route toward the preparation of high performance supercapacitor materials. The work discussed in this dissertation conclusively showed the significance of the preparation of desirable nanomaterials and the design of effective

  2. Review of Fabrication Methods, Physical Properties, and Applications of Nanostructured Copper Oxides Formed via Electrochemical Oxidation

    Directory of Open Access Journals (Sweden)

    Wojciech J. Stepniowski

    2018-05-01

    Full Text Available Typically, anodic oxidation of metals results in the formation of hexagonally arranged nanoporous or nanotubular oxide, with a specific oxidation state of the transition metal. Recently, the majority of transition metals have been anodized; however, the formation of copper oxides by electrochemical oxidation is yet unexplored and offers numerous, unique properties and applications. Nanowires formed by copper electrochemical oxidation are crystalline and composed of cuprous (CuO or cupric oxide (Cu2O, bringing varied physical and chemical properties to the nanostructured morphology and different band gaps: 1.44 and 2.22 eV, respectively. According to its Pourbaix (potential-pH diagram, the passivity of copper occurs at ambient and alkaline pH. In order to grow oxide nanostructures on copper, alkaline electrolytes like NaOH and KOH are used. To date, no systemic study has yet been reported on the influence of the operating conditions, such as the type of electrolyte, its temperature, and applied potential, on the morphology of the grown nanostructures. However, the numerous reports gathered in this paper will provide a certain view on the matter. After passivation, the formed nanostructures can be also post-treated. Post-treatments employ calcinations or chemical reactions, including the chemical reduction of the grown oxides. Nanostructures made of CuO or Cu2O have a broad range of potential applications. On one hand, with the use of surface morphology, the wetting contact angle is tuned. On the other hand, the chemical composition (pure Cu2O and high surface area make such materials attractive for renewable energy harvesting, including water splitting. While compared to other fabrication techniques, self-organized anodization is a facile, easy to scale-up, time-efficient approach, providing high-aspect ratio one-dimensional (1D nanostructures. Despite these advantages, there are still numerous challenges that have to be faced, including the

  3. Nanostructured MnO₂ as Electrode Materials for Energy Storage.

    Science.gov (United States)

    Julien, Christian M; Mauger, Alain

    2017-11-17

    Manganese dioxides, inorganic materials which have been used in industry for more than a century, now find great renewal of interest for storage and conversion of energy applications. In this review article, we report the properties of MnO₂ nanomaterials with different morphologies. Techniques used for the synthesis, structural, physical properties, and electrochemical performances of periodic and aperiodic frameworks are discussed. The effect of the morphology of nanosized MnO₂ particles on their fundamental features is evidenced. Applications as electrodes in lithium batteries and supercapacitors are examined.

  4. Nanostructured pseudocapacitive materials decorated 3D graphene foam electrodes for next generation supercapacitors.

    Science.gov (United States)

    Patil, Umakant; Lee, Su Chan; Kulkarni, Sachin; Sohn, Ji Soo; Nam, Min Sik; Han, Suhyun; Jun, Seong Chan

    2015-04-28

    Nowadays, advancement in performance of proficient multifarious electrode materials lies conclusively at the core of research concerning energy storage devices. To accomplish superior capacitance performance the requirements of high capacity, better cyclic stability and good rate capability can be expected from integration of electrochemical double layer capacitor based carbonaceous materials (high power density) and pseudocapacitive based metal hydroxides/oxides or conducting polymers (high energy density). The envisioned three dimensional (3D) graphene foams are predominantly advantageous to extend potential applicability by offering a large active surface area and a highly conductive continuous porous network for fast charge transfer with decoration of nanosized pseudocapacitive materials. In this article, we review the latest methodologies and performance evaluation for several 3D graphene based metal oxides/hydroxides and conducting polymer electrodes with improved electrochemical properties for next-generation supercapacitors. The most recent research advancements of our and other groups in the field of 3D graphene based electrode materials for supercapacitors are discussed. To assess the studied materials fully, a careful interpretation and rigorous scrutiny of their electrochemical characteristics is essential. Auspiciously, both nano-structuration as well as confinement of metal hydroxides/oxides and conducting polymers onto a conducting porous 3D graphene matrix play a great role in improving the performance of electrodes mainly due to: (i) active material access over large surface area with fast charge transportation; (ii) synergetic effect of electric double layer and pseudocapacitive based charge storing.

  5. Doping in controlling the type of conductivity in bulk and nanostructured thermoelectric materials

    International Nuclear Information System (INIS)

    Fuks, D.; Komisarchik, G.; Kaller, M.; Gelbstein, Y.

    2016-01-01

    Doping of materials for thermoelectric applications is widely used nowadays to control the type of conductivity. We report the results of ab-initio calculations aimed at developing the consistent scheme for determining the role of impurities that may change the type of conductivity in two attractive thermoelectric classes of materials. It is demonstrated that alloying of TiNiSn with Cu makes the material of n-type, and alloying with Fe leads to p-type conductivity. Similar calculations for PbTe with small amount of Na substituting for Pb leads to p-type conductivity, while Cl substituting for Te makes PbTe an n-type material. It is shown also that for nano-grained materials the n-type conductivity should be observed. The effect of impurities segregating to the grain boundaries in nano-structured PbTe is also discussed. - Highlights: • Bulk and nano-grained TE materials were analyzed by DFT. • The electronic effects on both PbTe and TiNiSn were demonstrated. • The role of impurities on the conductivity type was analyzed. • Interfacial states in nano-grained PbTe affect the conductivity type.

  6. Photorefractive Materials and Their Applications 2 Materials

    CERN Document Server

    Günter, Peter

    2007-01-01

    Photorefractive Materials and Their Applications 2: Materials is the second of three volumes within the Springer Series in Optical Sciences. The book gives a comprehensive review of the most important photorefractive materials and discusses the physical properties of organic and inorganic crystals as well as poled polymers. In this volume, photorefractive effects have been investigated at wavelengths covering the UV, visible and near infrared. Researchers in the field and graduate students of solid-state physics and engineering will gain a thorough understanding of the properties of materials in photorefractive applications. The other two volumes are: Photorefractive Materials and Their Applications 1: Basic Effects. Photorefractive Materials and Their Applications 3: Applications.

  7. Epicrystal modification of construction composites of different purpose with application of granulated nanostructured aggregate

    Directory of Open Access Journals (Sweden)

    STROKOVA Valeria Valerievna

    2016-10-01

    Full Text Available The paper shows that the volume impregnation of the concrete matrix in case of using granular nanostructured aggregate is an example of several anthropogenic metasomatosis such as phase replacement with the change of the chemical composition, as well as formation of new paragenesises, transformation of characteristics of final material. It is shown the impregnation of concrete with modifying solution results in microstructure impaction and homogenization; grain surface is covered with micro- and nano-sized new formations with different morphology. Considering the relevance of researches related to the development of new lightweight concrete aggregates and modification of traditionally used aggregates application of nanostructured granular aggregate for the implementation epicrystal modification of lightweight concrete based on inorganic binders is proposed. It allows creating composite macroporous structure with joint modification of the matrix on nano- and microlevel. Also, in view of increase in number of researches devoted to alkali-activated silicate and aluminosilicate systems for application as individually and as modifiers for increasing of hydrophobic properties of building materials, the possibility of creating a fine-grained concrete with low water absorption by the introduction of hydrophobic additives into the composition of granular nanostructured aggregate is demonstrated. During the steam treatment the fluids from solutions of sodium polysilicates and hydrophobic additives are form at the core of the granular aggregate with its later migration through the shell of the granules and spreading in the volume of the concrete matrix. Improving of performance characteristics presented construction composites for various purposes is defined by the infiltrational metasomatic transformation of crystalline matrix with the activated functional systems, obtained during the thermal activation of granulated nanostructured aggregate.

  8. Carbon fiber CVD coating by carbon nanostructured for space materials protection against atomic oxygen

    Science.gov (United States)

    Pastore, Roberto; Bueno Morles, Ramon; Micheli, Davide

    2016-07-01

    adhesion and durability in the environment. Though these coatings are efficient in protecting polymer composites, their application imposes severe constraints. Their thermal expansion coefficients may differ markedly from those of polymer composite substrates: as a result, cracks develop in the coatings on thermal cycling and AO can penetrate through them to the substrate. In addition to the technicalities of forming an effective barrier, such factors as cost, convenience of application and ease of repair are important considerations in the selection of a coating for a particular application. The latter issues drive the aerospace research toward the development of novel light composite materials, like the so called polymer nanocomposites, which are materials with a polymer matrix and a filler with at least one dimension less than 100 nanometers. Current interest in nanocomposites has been generated and maintained because nanoparticle-filled polymers exhibit unique combinations of properties not achievable with traditional composites. These combinations of properties can be achieved because of the small size of the fillers, the large surface area the fillers provide, and in many cases the unique properties of the fillers themselves. In particular, the carbon fiber-based polymeric composite materials are the basic point of interest: the aim of the present study is to find new solution to produce carbon fiber-based composites with even more upgraded performances. One intriguing strategy to tackle such an issue has been picked out in the coupling between the carbon fibers and the carbon nanostructures. That for two main reasons: first, carbon nanostructures have shown fancy potentialities for any kind of technological applications since their discovery, second, the chemical affinity between fiber and nanostructure (made of the same element) should be a likely route to approach the typical problems due to thermo-mechanical compatibility. This work is joined in such framework

  9. Self-assembled nanostructures

    CERN Document Server

    Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

    2003-01-01

    Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

  10. Electrospinning: A versatile technique for making of 1D growth of nanostructured nanofibers and its applications: An experimental approach

    Science.gov (United States)

    Patil, Jyoti V.; Mali, Sawanta S.; Kamble, Archana S.; Hong, Chang K.; Kim, Jin H.; Patil, Pramod S.

    2017-11-01

    One dimensional (1D) metal oxide nanostructures (1D-MONS) play a key role in the development of functional devices including energy conversion, energy storage and environmental devices. They are also used for some important biomedical products like wound dressings, filter media, drug delivery and tissue engineering. The electrospinning (ES) is the versatile technique for making of 1D growth of nanostructured nanofibers, an experimental approach and its applications. The present review is focused on the 1D growth of nanostructured nanofibers in different applications like dye sensitized solar cells, perovskite solar cells, fuel cells, lithium ion batteries, redox flow batteries, supercapacitor, photocatalytic, and gas sensors based on ZnO, TiO2, MnO2, WO3, V2O5, NiO, SnO2, Fe2O3 etc. metal oxides, their composites and carbon. This review article presents an introduction to various types of ES techniques and their technical details. Also, the advantages and disadvantages of each ES technique are summarized. The various technical details such as preparative parameters, post-deposition methods, applied electric field, solution feed rate and a distance between a tip to the collector are the key factors in order to obtain exotic 1D nanostructured materials. Also, the lucid literature survey on the growth of nanostructures of various metal oxides and application in different fields are covered in this review. Further, the future perspectives has also been discussed.

  11. Polymeric Bicontinuous Microemulsions as Templates for Nanostructured Materials

    Science.gov (United States)

    Jones, Brad Howard

    nanoporous materials with well-defined pore structures prepared from a single PE template. They are anticipated to have potential application in diverse technological areas, including catalysis, separations, sensors, and electronic devices.

  12. Epitaxial growth of hybrid nanostructures

    Science.gov (United States)

    Tan, Chaoliang; Chen, Junze; Wu, Xue-Jun; Zhang, Hua

    2018-02-01

    Hybrid nanostructures are a class of materials that are typically composed of two or more different components, in which each component has at least one dimension on the nanoscale. The rational design and controlled synthesis of hybrid nanostructures are of great importance in enabling the fine tuning of their properties and functions. Epitaxial growth is a promising approach to the controlled synthesis of hybrid nanostructures with desired structures, crystal phases, exposed facets and/or interfaces. This Review provides a critical summary of the state of the art in the field of epitaxial growth of hybrid nanostructures. We discuss the historical development, architectures and compositions, epitaxy methods, characterization techniques and advantages of epitaxial hybrid nanostructures. Finally, we provide insight into future research directions in this area, which include the epitaxial growth of hybrid nanostructures from a wider range of materials, the study of the underlying mechanism and determining the role of epitaxial growth in influencing the properties and application performance of hybrid nanostructures.

  13. Nanostructured Si-substituted hydroxyapatite coatings for biomedical applications

    International Nuclear Information System (INIS)

    Rau, Julietta V.; Fosca, Marco; Cacciotti, Ilaria; Laureti, Sara; Bianco, Alessandra; Teghil, Roberto

    2013-01-01

    In the present work, the Si-HAp coatings were deposited on titanium substrates by Pulsed Laser Deposition technique. For deposition, the Si-HAp targets (1.4 wt.% of Si), produced starting from wet synthesized powders, were used. The properties of coatings were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and Vickers microhardness. The obtained Si-HAp coatings presented a nanosized structure, proper thickness and hardness for applications in orthopedical and dental surgery, aimed at improving the stability and the osteointegration of bone implants. - Highlights: ► Pulsed Laser Deposition method was applied to coat heated Titanium supports. ► Films were deposited using a target of Silicon-Hydroxyapatite sintered ceramics. ► Nanostructured crystalline hard film was grown replicating target composition. ► Prepared coating could be used for orthopedic and dental implants applications

  14. Nanostructured Si-substituted hydroxyapatite coatings for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Julietta V., E-mail: giulietta.rau@ism.cnr.it [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Fosca, Marco [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Cacciotti, Ilaria [Università di Roma “Tor Vergata”, Dipartimento di Ingegneria Industriale,UR INSTM “Roma Tor Vergata”, Via del Politecnico, 1-00133 Rome (Italy); Laureti, Sara [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via Salaria km 29.300-00016 Monterotondo Scalo (RM) (Italy); Bianco, Alessandra [Università di Roma “Tor Vergata”, Dipartimento di Ingegneria Industriale,UR INSTM “Roma Tor Vergata”, Via del Politecnico, 1-00133 Rome (Italy); Teghil, Roberto [Università della Basilicata, Dipartimento di Scienze, Via dell' Ateneo Lucano 10-85100, Potenza (Italy)

    2013-09-30

    In the present work, the Si-HAp coatings were deposited on titanium substrates by Pulsed Laser Deposition technique. For deposition, the Si-HAp targets (1.4 wt.% of Si), produced starting from wet synthesized powders, were used. The properties of coatings were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and Vickers microhardness. The obtained Si-HAp coatings presented a nanosized structure, proper thickness and hardness for applications in orthopedical and dental surgery, aimed at improving the stability and the osteointegration of bone implants. - Highlights: ► Pulsed Laser Deposition method was applied to coat heated Titanium supports. ► Films were deposited using a target of Silicon-Hydroxyapatite sintered ceramics. ► Nanostructured crystalline hard film was grown replicating target composition. ► Prepared coating could be used for orthopedic and dental implants applications.

  15. Tailoring the Optical Properties of Silicon with Ion Beam Created Nanostructures for Advanced Photonics Applications

    Science.gov (United States)

    Akhter, Perveen

    In today's fast life, energy consumption has increased more than ever and with that the demand for a renewable and cleaner energy source as a substitute for the fossil fuels has also increased. Solar radiations are the ultimate source of energy but harvesting this energy in a cost effective way is a challenging task. Si is the dominating material for microelectronics and photovoltaics. But owing to its indirect band gap, Si is an inefficient light absorber, thus requiring a thickness of solar cells beyond tens of microns which increases the cost of solar energy. Therefore, techniques to increase light absorption in thin film Si solar cells are of great importance and have been the focus of research for a few decades now. Another big issue of technology in this fast-paced world is the computing rate or data transfer rate between components of a chip in ultra-fast processors. Existing electronic interconnects suffering from the signal delays and heat generation issues are unable to handle high data rates. A possible solution to this problem is in replacing the electronic interconnects with optical interconnects which have large data carrying capacity. However, optical components are limited in size by the fundamental laws of diffraction to about half a wavelength of light and cannot be combined with nanoscale electronic components. Tremendous research efforts have been directed in search of an advanced technology which can bridge the size gap between electronic and photonic worlds. An emerging technology of "plasmonics'' which exploits the extraordinary optical properties of metal nanostructures to tailor the light at nanoscale has been considered a potential solution to both of the above-mentioned problems. Research conducted for this dissertation has an overall goal to investigate the optical properties of silicon with metal nanostructures for photovoltaics and advanced silicon photonics applications. The first part of the research focuses on achieving enhanced

  16. Thermoelectricity: materials and applications

    International Nuclear Information System (INIS)

    Elberg, S.; Mathonnet, P.

    1975-01-01

    After a brief recall of the basic principles of thermoelectricity, the essential characteristics intervening in the different thermoelectric devices operating modes are defined. Properties of the materials the most used nowadays and performances of the apparatus that they allow to realize are indicated. Advantages and drawbacks of the principal applications in the form of electrical generators, refrigerators and heat pumps are pointed out [fr

  17. Near-term nanotechnology: the molecular fabrication of nanostructured materials

    Science.gov (United States)

    Gillett, Stephen L.

    1996-09-01

    The remarkably short timescales commonly predicted for achieving full molecular nanotechnology (MNT) are not realistic, as an enormous investment must be made up-front for a distant and ill-defined payoff. The reason is that technology, per se, is not an economic driver; economics instead drives technology. Hence, markets that could motivate the ongoing, incremental development of MNT must be sought. Such markets exist: they fundamentally consist of the molecular assembly of nano structured materials such as semipermeable membranes, catalysts, perfect crystalline fibres, and others. Although in theory atomically precise, such materials have no molecular moving parts and thus will be both easier to build and more robust. Some of these applications (e.g. catalysis), moreover, have huge, mature markets. Once a demand is established, further incremental development of primitive molecular assemblers, or `molecular looms', might then justify the analogies with the explosive development of computer hardware over the last few decades. Finally, the fact that many such applications are likely to be rendered obsolete by full MNT is irrelevant to their interim value as technology drivers.

  18. Application of nano-structured conducting polymers to humidity sensing

    Science.gov (United States)

    Park, Pilyeon

    Nanostructures, such as nanowires, nanocolumns, and nanotubes, have attracted a lot of attention because of their huge potential impact on a variety of applications. For sensor applications, nanostructures provide high surface area to volume ratios. The high surface area to volume ratio allows more reaction areas between target species and detection materials and also improves the detection sensitivity and response time. The main goal of this research was to exploit the advantages and develop innovative methods to accomplish the synthesis of nanowires and nano-coulmn conducting polymers used in humidity detection. To accomplish this, two fabrication methods are used. The first one utilizes the geometric confinement effect of a temporary nanochannel template to orient, precisely position, and assemble Polyaniline (PANI) nanowires as they are synthesized. The other approach is to simply spin-coat a polymer onto a substrate, and then oxygen plasma etch to generate a nano-columned Polyethylenedioxythiophene (PEDOT) thin film. 200 nm silicon oxide coated wafers with embedded platinum electrodes are used as a substrate for both fabrication methods. The biggest advantage of this first method is that it is simple, requires a single-step, i.e., synthesizing and positioning procedures are carried out simultaneously. The second method is potentially manufacturable and economic yet environmentally safe. These two methods do not produce extra nano-building materials to discard or create a health hazard. Both PANI nanowires and nano-columned PEDOT films have been tested for humidity detection using a system designed and built for this research to monitor response (current changes) to moisture, To explain the surface to volume ratio effect, 200 nm PANI nanowires and 10 microm PANI wires were directly compared for detecting moisture, and it was shown that the PANI nanowire had a better sensitivity. It was found difficult to monitor the behaviors of the PEDOT reaction to varying

  19. Dendrite-like Co3O4 nanostructure and its applications in sensors, supercapacitors and catalysis.

    Science.gov (United States)

    Pang, Huan; Gao, Feng; Chen, Qun; Liu, Rongmei; Lu, Qingyi

    2012-05-21

    Dendrite-like Co(3)O(4) nanostructure, made up of many nanorods with diameters of 15-20 nm and lengths of 2-3 μm, has been successfully prepared by calcining the corresponding nanostructured Co-8-hydroxyquinoline coordination precursor in air. The Co(3)O(4) nanostructure was evaluated as an electrochemical sensor for H(2)O(2) detection and the results reveal that it has good linear dependence and high sensitivity to H(2)O(2) concentration changes. As an electrode material of a supercapacitor, it was found that the nanostructured Co(3)O(4) electrode exhibits high specific capacitance and long cycle life. The Co(3)O(4) nanostructure also has good catalytic properties and is steadily active for CO oxidation, giving 100% CO conversion at low temperatures. The multifunctional Co(3)O(4) nanostructure would be a promising functional nanomaterial applied in multi industrialized fields.

  20. Materials for Photovoltaic Applications

    Science.gov (United States)

    Dimova-Malinovska, Doriana

    Energy priorities are changing nowadays. As mankind will probably have to face energy crisis, factors such as energy independence, energy security, stability of energy supply and the variety of energy sources become much more vital these days. Photovoltaics is exceptional compared to other renewable sources of energy due to its wide opportunity to gain energetic and environmental benefits. An overview of the present state of knowledge of the materials aspects of photovoltaic cells will be given, and new semiconductor materials, including nanomaterials, with potential for application in photovoltaic devices will be identified.

  1. Micro/Nanostructured Films and Adhesives for Biomedical Applications.

    Science.gov (United States)

    Lee, Jungkyu K; Kang, Sung Min; Yang, Sung Ho; Cho, Woo Kyung

    2015-12-01

    The advanced technologies available for micro/nanofabrication have opened new avenues for interdisciplinary approaches to solve the unmet medical needs of regenerative medicine and biomedical devices. This review highlights the recent developments in micro/nanostructured adhesives and films for biomedical applications, including waterproof seals for wounds or surgery sites, drug delivery, sensing human body signals, and optical imaging of human tissues. We describe in detail the fabrication processes required to prepare the adhesives and films, such as tape-based adhesives, nanofilms, and flexible and stretchable film-based electronic devices. We also discuss their biomedical functions, performance in vitro and in vivo, and the future research needed to improve the current systems.

  2. Nature of radiative recombination processes in layered semiconductor PbCdI{sub 2} nanostructural scintillation material

    Energy Technology Data Exchange (ETDEWEB)

    Bukivskii, A.P. [Institute of Physics of the National Academy of Sciences of Ukraine, 03028 Kyiv (Ukraine); Gnatenko, Yu.P., E-mail: yuriygnatenko@ukr.net [Institute of Physics of the National Academy of Sciences of Ukraine, 03028 Kyiv (Ukraine); Piryatinskii, Yu.P. [Institute of Physics of the National Academy of Sciences of Ukraine, 03028 Kyiv (Ukraine); Gamernyk, R.V. [Lviv National University, 8 Kyryl o and Mefodiy Str., 29005 Lviv (Ukraine)

    2017-05-15

    We report on the efficient photoluminescence (PL) and radioluminescence (RL) of the PbI{sub 2} nanoclusters (NCLs), which are naturally formed in the nanostructured Pb{sub 1-X}Cd{sub x}I{sub 2} alloys (X=0.70). Here, we carried out the studies of the nature of radiative recombination processes in the NCLs of various sizes by measuring PL temperature evolution. Our results indicate that at low temperatures the PL is mainly caused by exciton emission and recombination of donor-acceptor pairs, generated in volume of large NCLs. The broad bands, which are associated with the deep intrinsic surface states, including self-trapped excitons (STEs), are dominant in the PL spectra at higher temperature (>100 K). Our work shows that the nature of emission, associated with RL bands is analogous to that for PL bands. It was shown that the investigated nanostructured material is strongly radiation-resistant. Thus, the Pb{sub 1-X}Cd{sub X}I{sub 2} alloys can be considered as new effective layered semiconductor nanostructured materials which can be suitable for the elaboration of perspective semiconductor scintillators. These nanomaterials have promising prospects for applications in new generations of devices for biomedical diagnostics and industrial imaging applications. - Highlights: •The intense PL and RL of nanostructural PbCdI{sub 2} alloys were observed. •The nature of recombination processes of the nanoscintillators was established. •The low temperature PL is caused by exciton and donor-acceptor pairs recombination. •The broad PL bands are due to the deep intrinsic states formed on the NCLs surface. •The PL associated with STEs for NCLs of different sizes was analyzed in detail. •It was shown that the nature of PL and RL spectra is same.

  3. Manipulating Adsorption-Insertion Mechanisms in Nanostructured Carbon Materials for High-Efficiency Sodium Ion Storage

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Shen [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Xiao, Lifen [College of Chemistry, Central China Normal University, Wuhan 430079 China; Pacific Northwest National Laboratory, Richland WA 99352 USA; Sushko, Maria L. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Han, Kee Sung [Pacific Northwest National Laboratory, Richland WA 99352 USA; Shao, Yuyan [Pacific Northwest National Laboratory, Richland WA 99352 USA; Yan, Mengyu [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 China; Liang, Xinmiao [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071 China; Mai, Liqiang [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 China; Feng, Jiwen [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071 China; Cao, Yuliang [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Ai, Xinping [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Yang, Hanxi [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Liu, Jun [Pacific Northwest National Laboratory, Richland WA 99352 USA

    2017-05-12

    Hard carbon is one of the most promising anode materials for sodium-ion batteries, but the low coulombic efficiency is still a key barrier. In this paper we synthesized a series of nanostructured hard carbon materials with controlled architectures. Using a combination of in-situ XRD mapping, ex-situ NMR, EPR, electrochemical techniques and simulations, an “adsorption-intercalation” (A-I) mechanism is established for Na ion storage. During the initial stages of Na insertion, Na ions adsorb on the defect sites of hard carbon with a wide adsorption energy distribution, producing a sloping voltage profile. In the second stage, Na ions intercalate into graphitic layers with suitable spacing to form NaCx compounds similar to the Li ion intercalation process in graphite, producing a flat low voltage plateau. The cation intercalation with a flat voltage plateau should be enhanced and the sloping region should be avoided. Guided by this knowledge, non-porous hard carbon material has been developed which has achieved high reversible capacity and coulombic efficiency to fulfill practical application.

  4. Superconductivity: materials and applications

    International Nuclear Information System (INIS)

    Duchateau, J.L.; Kircher, F.; Leveque, J.; Tixador, P.

    2008-01-01

    This digest paper presents the different types of superconducting materials: 1 - the low-TC superconductors: the multi-filament composite as elementary constituent, the world production of NbTi, the superconducting cables of the LHC collider and of the ITER tokamak; 2 - the high-TC superconductors: BiSrCaCuO (PIT 1G) ribbons and wires, deposited coatings; 3 - application to particle physics: the the LHC collider of the CERN, the LHC detectors; 4 - applications to thermonuclear fusion: Tore Supra and ITER tokamaks; 5 - NMR imaging: properties of superconducting magnets; 6 - applications in electrotechnics: cables, motors and alternators, current limiters, transformers, superconducting energy storage systems (SMES). (J.S.)

  5. Synthesis and integration of one-dimensional nanostructures for chemical gas sensing applications

    Science.gov (United States)

    Parthangal, Prahalad Madhavan

    The need for improved measurement technology for the detection and monitoring of gases has increased tremendously for maintenance of domestic and industrial health and safety, environmental surveys, national security, food-processing, medical diagnostics and various other industrial applications. Among the several varieties of gas sensors available in the market, solid-state sensors are the most popular owing to their excellent sensitivity, ruggedness, versatility and low cost. Semiconducting metal oxides such as tin oxide (SnO2), zinc oxide (ZnO), and tungsten oxide (WO3) are routinely employed as active materials in these sensors. Since their performance is directly linked to the exposed surface area of the sensing material, one-dimensional nanostructures possessing very high surface to volume ratios are attractive candidates for designing the next generation of sensors. Such nano-sensors also enable miniaturization thereby reducing power consumption. The key to achieve success in one-dimensional nanotechnologies lies in assembly. While synthesis techniques and capabilities continue to expand rapidly, progress in controlled assembly has been sluggish due to numerous technical challenges. In this doctoral thesis work, synthesis and characterization of various one-dimensional nanostructures including nanotubes of SnO2, and nanowires of WO3 and ZnO, as well as their direct integration into miniature sensor platforms called microhotplates have been demonstrated. The key highlights of this research include devising elegant strategies for growing metal oxide nanotubes using carbon nanotubes as templates, substantially reducing process temperatures to enable growth of WO3 nanowires on microhotplates, and successfully fabricating a ZnO nanowire array based sensor using a hybrid nanowire-nanoparticle assembly approach. In every process, the gas-sensing properties of one-dimensional nanostructures were observed to be far superior in comparison with thin films of the same

  6. Nanostructured materials for selective recognition and targeted drug delivery

    International Nuclear Information System (INIS)

    Kotrotsiou, O; Kotti, K; Dini, E; Kammona, O; Kiparissides, C

    2005-01-01

    Selective recognition requires the introduction of a molecular memory into a polymer matrix in order to make it capable of rebinding an analyte with a very high specificity. In addition, targeted drug delivery requires drug-loaded vesicles which preferentially localize to the sites of injury and avoid uptake into uninvolved tissues. The rapid evolution of nanotechnology is aiming to fulfill the goal of selective recognition and optimal drug delivery through the development of molecularly imprinted polymeric (MIP) nanoparticles, tailor-made for a diverse range of analytes (e.g., pharmaceuticals, pesticides, amino acids, etc.) and of nanostructured targeted drug carriers (e.g., liposomes and micelles) with increased circulation lifetimes. In the present study, PLGA microparticles containing multilamellar vesicles (MLVs), and MIP nanoparticles were synthesized to be employed as drug carriers and synthetic receptors respectively

  7. High-capacity nanostructured germanium-containing materials and lithium alloys thereof

    Science.gov (United States)

    Graetz, Jason A.; Fultz, Brent T.; Ahn, Channing; Yazami, Rachid

    2010-08-24

    Electrodes comprising an alkali metal, for example, lithium, alloyed with nanostructured materials of formula Si.sub.zGe.sub.(z-1), where 0electrodes made from graphite. These electrodes are useful as anodes for secondary electrochemical cells, for example, batteries and electrochemical supercapacitors.

  8. Development of Nanostructured Materials with Improved Radiation Tolerance for Advanced Nuclear Systems

    International Nuclear Information System (INIS)

    Zinghang Zhang; Hartwig, K. Ted

    2009-01-01

    This project will explore the fundamental mechanisms through which interfaces in nanolayered structures and grain boundaries of bulk nanomaterials are able to attract and rapidly eliminate point defects and unwanted foreign species. Candidate materials that will be studied include both nanostructured multilayer composites synthesized by magnetron sputtering and structural bulk nanomaterials produced by severed plastic deformation, equal channel angular extrusion

  9. Mechanical properties of BixSb2−xTe3 nanostructured thermoelectric material

    International Nuclear Information System (INIS)

    Li, G; Gadelrab, K R; Souier, T; Chiesa, M; Potapov, P L; Chen, G

    2012-01-01

    Research on thermoelectric (TE) materials has been focused on their transport properties in order to maximize their overall performance. Mechanical properties, which are crucial for system reliability, are often overlooked. The recent development of a new class of high-performance, low-dimension thermoelectric materials calls for a better understanding of their mechanical behavior to achieve the desired system reliability. In the present study we investigate the mechanical behavior of nanostructure bulk TE material p-type Bi x Sb 2−x Te 3 by means of nanoindentation and 3D finite element analysis. The Young’s modulus of the material was estimated by the Oliver–Pharr (OP) method and by means of numerically assisted nanoindentation analysis yielding comparable values about 40 GPa. Enhanced hardness and yield strength can be predicted for this nanostructured material. Microstructure is studied and correlation with mechanical properties is discussed. (paper)

  10. Morphology evolution and nanostructure of chemical looping transition metal oxide materials upon redox processes

    International Nuclear Information System (INIS)

    Qin, Lang; Cheng, Zhuo; Guo, Mengqing; Fan, Jonathan A.; Fan, Liang-Shih

    2017-01-01

    Transition metal are heavily used in chemical looping technologies because of their high oxygen carrying capacity and high thermal reactivity. These oxygen activities result in the oxide formation and oxygen vacancy formation that affect the nanoscale crystal phase and morphology within these materials and their subsequent bulk chemical behavior. In this study, two selected earlier transition metals manganese and cobalt as well as two selected later transition metals copper and nickel that are important to chemical looping reactions are investigated when they undergo cyclic redox reactions. We found Co microparticles exhibited increased CoO impurity presence when oxidized to Co_3O_4 upon cyclic oxidation; CuO redox cycles prefer to be limited to a reduced form of Cu_2O and an oxidized form of CuO; Mn microparticles were oxidized to a mixed phases of MnO and Mn_3O_4, which causes delamination during oxidation. For Ni microparticles, a dense surface were observed during the redox reaction. The atomistic thermodynamics methods and density functional theory (DFT) calculations are carried out to elucidate the effect of oxygen dissociation and migration on the morphological evolution of nanostructures during the redox processes. Our results indicate that the earlier transition metals (Mn and Co) tend to have stronger interaction with O_2 than the later transition metals (Ni and Cu). Also, our modified Brønsted−Evans−Polanyi (BEP) relationship for reaction energies and total reaction barriers reveals that reactions of earlier transition metals are more exergonic and have lower oxygen dissociation barriers than those of later transition metals. In addition, it was found that for these transition metal oxides the oxygen vacancy formation energies increase with the depth. The oxide in the higher oxidation state of transition metal has lower vacancy formation energy, which can facilitate forming the defective nanostructures. The fundamental understanding of these metal

  11. Neutron scattering—The key characterization tool for nanostructured magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Fitzsimmons, M.R., E-mail: fitz@lanl.gov [Los Alamos National Laboratory (United States); Schuller, Ivan K. [University of California, San Diego (United States)

    2014-01-15

    The novel properties of materials produced using nanoscale manufacturing processes often arise from interactions across interfaces between dissimilar materials. Thus, to characterize the structure and magnetism of nanoscale materials demands tools with interface specificity. Neutron scattering has long been known to provide unique and quantitative information about nuclear and magnetic structures of bulk materials. Moreover, the specialty techniques of polarized neutron reflectometry and small angle neutron scattering (SANS) with polarized neutron beams and polarization analysis, are ideally and often uniquely suited to studies of nanostructured magnetic materials. Since neutron scattering is a weakly interacting probe, it gives quantifiable and easily-interpreted information on properties of statistically representative quantities of bulk, thin film and interfacial materials. In addition, neutron scattering can provide information to complement that obtained with bulk probes (magnetization, Kerr effect) or surface measurements obtained with scanning probe microscopy or resonant soft x-ray scattering. The straightforward interpretation and the simultaneous availability of structural information, make neutron scattering the technique of choice for the structural and physical characterization of many novel materials, especially those with buried interfaces, ones allowing for isotopic substitutions to decorate buried interfaces, or cases where the magnetic response to an external stimulus can be measured. We describe recent applications of neutron scattering to important thin film materials systems and future opportunities. Unquestionably, neutron scattering has played a decisive role in the development and study of new emergent phenomena. We argue with the advent of new techniques in neutron scattering and sample environment, neutron scattering's role in such studies will become even more dominant. In particular, neutron scattering will clarify and distinguish

  12. Nanostructured piezoelectric energy harvesters

    CERN Document Server

    Briscoe, Joe

    2014-01-01

    This book covers a range of devices that use piezoelectricity to convert mechanical deformation into electrical energy and relates their output capabilities to a range of potential applications. Starting with a description of the fundamental principles and properties of piezo- and ferroelectric materials, where applications of bulk materials are well established, the book shows how nanostructures of these materials are being developed for energy harvesting applications. The authors show how a nanostructured device can be produced, and put in context some of the approaches that are being invest

  13. PARAMETERS OPTIMIZATION OF METAL-DIELECTRIC NANOSTRUCTURES FOR SENSOR APPLICATIONS

    Directory of Open Access Journals (Sweden)

    V. I. Egorov

    2014-07-01

    Full Text Available We present calculation results of optical properties of silver nanoparticles with dielectric shell in relation to their applications in chemical and biosensors. Absorption cross-section calculation for spherical silver nanoparticles was performed by quasi static dipole approximation. It is shown that dielectric shell thickness equal to 2-3 nm and its refraction index equal to 1,5-1,75 are optimal. Calculation results were compared to experimental data. Experimental investigation of metal-dielectric nanostructures sensitivity to external refraction index was performed. Synthesis of silver nanoparticles with dielectric shell on glass surface was performed by nanosecond laser ablation method in near-surface glass layer at 1,06 μm wavelength (Solar LQ129. Synthesis of silver nanoparticles without a shell on the glass surface with silver ions was performed using thermal treatment in wet atmosphere. Spectrophotometer Cary 500 (Varyan was used for spectral measurements. In case of laser ablation method application, external refraction index changes from 1 (the air to 1,33 (water and plasmon resonance band shift for 6 nm occurs. In case of another method application at the same conditions the registered shift was equal to 13 nm. However, in the latter case the particles can be easily removed from the substrate surface. Obtained results will be useful for developing chemical and biological sensors based on plasmon resonance band shift.

  14. Computer simulation of radiation-induced nanostructure formation in amorphous materials

    International Nuclear Information System (INIS)

    Li, K.-D.; Perez-Bergquist, Alejandro; Wang, Lumin

    2009-01-01

    In this study, 3D simulations based on a theoretical model were developed to investigate radiation-induced nanostructure formation in amorphous materials. Model variables include vacancy production and recombination rates, ion sputtering effects, and redeposition of sputtered atoms. In addition, a phase field model was developed to predict vacancy diffusion as a function of free energies of mixing and interfacial energies. The distribution profile of the vacancy production rate along the depth of an irradiated matrix was considered as a near Gaussian approximation according to Monte-Carlo TRIM code calculations. Dynamic processes responsible for nanostructure evolution were simulated by updating the vacancy concentration profile over time. Simulated morphologies include cellular nanoholes, nanowalls, nanovoids, and nanofibers, with the resultant morphology dependant upon the incident ion species and ion fluence. These simulated morphologies are consistent with experimental observations achieved under comparable experimental conditions. Our model provides a distinct numerical approach to accurately predicting morphological results for ion-irradiation-induced nanostructures.

  15. Electrodeposited nanostructured raspberry-like gold-modified electrodes for electrocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Manivannan, Shanmugam; Ramaraj, Ramasamy, E-mail: ramarajr@yahoo.com [Madurai Kamaraj University, Centre for Photoelectrochemistry, School of Chemistry (India)

    2013-10-15

    A facile method for fabrication of raspberry-like Au nanostructures (Au NRBs)-modified electrode by electrodeposition and its applications toward the electrocatalytic oxidation of methanol (MOR) in alkaline medium and oxygen reduction reaction (ORR) in both alkaline and acidic media are demonstrated. The Au NRBs are characterized by UV-Vis absorption spectra, SEM, X-ray diffraction, and electrochemical measurements. The growth of Au NRBs was monitored by recording the in-situ absorption spectral changes during electrodeposition using spectroelectrochemical technique. Here we systematically studied the MOR by varying several reaction parameters such as potential scan rate and methanol concentration. The electrocatalytic poisoning effect due to the MOR products are not observed at the Au NRBs-modified electrode. At the alkaline medium the Au NRBs-modified electrode shows the better catalytic activities toward the MOR and ORR when compared to the poly crystalline gold and bare glassy carbon electrodes. The Au NRBs-modified electrode is a promising and inexpensive electrode material for other electrocatalytic applications.Graphical AbstractRaspberry-like Au nanostructures modified electrode is prepared and used for electrocatalytic applications.

  16. GREENER PRODUCTION OF NOBLE METAL NANOSTRUCTURES AND NANOCOMPOSITES: RISK REDUCTION AND APPLICATIONS

    Science.gov (United States)

    The synthesis of nanometal/nano metal oxide/nanostructured polymer and their stabilization (through dispersant, biodegradable polymer) involves the use of natural renewable resources such plant material extract, biodegradable polymers, sugars, vitamins and finally efficient and s...

  17. Swell Gels to Dumbbell Micelles: Construction of Materials and Nanostructure with Self-assembly

    Science.gov (United States)

    Pochan, Darrin

    2007-03-01

    Bionanotechnology, the emerging field of using biomolecular and biotechnological tools for nanostructure or nanotecnology development, provides exceptional opportunity in the design of new materials. Self-assembly of molecules is an attractive materials construction strategy due to its simplicity in application. By considering peptidic or charged synthetic polymer molecules in the bottom-up materials self-assembly design process, one can take advantage of inherently biomolecular attributes; intramolecular folding events, secondary structure, and electrostatic interactions; in addition to more traditional self-assembling molecular attributes such as amphiphilicty, to define hierarchical material structure and consequent properties. Several molecular systems will be discussed. Synthetic block copolymers with charged corona blocks can be assembled in dilute solution containing multivalent organic counterions to produce micelle structures such as toroids. These ring-like micelles are similar to the toroidal bundling of charged semiflexible biopolymers like DNA in the presence of multivalent counterions. Micelle structure can be tuned between toroids, cylinders, and disks simply by using different concentrations or molecular volumes of organic counterion. In addition, these charged blocks can consist of amino acids as monomers producing block copolypeptides. In addition to the above attributes, block copolypeptides provide the control of block secondary structure to further control self-assembly. Design strategies based on small (less than 24 amino acids) beta-hairpin peptides will be discussed. Self-assembly of the peptides is predicated on an intramolecular folding event caused by desired solution properties. Importantly, the intramolecular folding event impart a molecular-level mechanism for environmental responsiveness at the material level (e.g. infinite change in viscosity of a solution to a gel with changes in pH, ionic strength, temperature).

  18. Emerging Prototype Sodium-Ion Full Cells with Nanostructured Electrode Materials.

    Science.gov (United States)

    Ren, Wenhao; Zhu, Zixuan; An, Qinyou; Mai, Liqiang

    2017-06-01

    Due to steadily increasing energy consumption, the demand of renewable energy sources is more urgent than ever. Sodium-ion batteries (SIBs) have emerged as a cost-effective alternative because of the earth abundance of Na resources and their competitive electrochemical behaviors. Before practical application, it is essential to establish a bridge between the sodium half-cell and the commercial battery from a full cell perspective. An overview of the major challenges, most recent advances, and outlooks of non-aqueous and aqueous sodium-ion full cells (SIFCs) is presented. Considering the intimate relationship between SIFCs and electrode materials, including structure, composition and mutual matching principle, both the advance of various prototype SIFCs and the electrochemistry development of nanostructured electrode materials are reviewed. It is noted that a series of SIFCs combined with layered oxides and hard carbon are capable of providing a high specific gravimetric energy above 200 Wh kg -1 , and an NaCrO 2 //hard carbon full cell is able to deliver a high rate capability over 100 C. To achieve industrialization of SIBs, more systematic work should focus on electrode construction, component compatibility, and battery technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Contribution of tin in electrochemical properties of zinc antimonate nanostructures: An electrode material for supercapacitors

    Science.gov (United States)

    Balasubramaniam, M.; Balakumar, S.

    2018-04-01

    Tin (Sn) doped ZnSb2O6 nanostructures was synthesized by chemical precipitation method and was used as an electrode material for supercapacitors to explore its electrochemical stability and potentiality as energy storage materials. Their characteristic structural, morphological and compositional features were investigated through XRD, FESEM and XPS analysis. Results showed that the nanostructures have well ordered crystalline features with spherical particle morphology. As the size and morphology are the vital parameters in exhibiting better electrochemical properties, the prepared nanostructures exhibited a significant specific capacitance of 222 F/g at a current density of 0.5 A/g respectively. While charging and discharging for 1000 cycles, the capacitance retention was enhanced to 105.0% which depicts the stability and activeness of electrochemical sites present in the Sn doped ZnSb2O6 nanostructures even after cycling. Hence, the inclusion of Sn into ZnSb2O6 has contributed in improving the electrochemical properties thereby it represents itself as a potential electrode material for supercapacitors.

  20. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials.

    Science.gov (United States)

    Hesemann, Peter; Nguyen, Thy Phung; Hankari, Samir El

    2014-04-11

    The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the "anionic templating" strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  1. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials

    Directory of Open Access Journals (Sweden)

    Peter Hesemann

    2014-04-01

    Full Text Available The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA, mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the “anionic templating” strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  2. Application of nanodimensional particles and aluminum hydroxide nanostructures for cancer diagnosis and therapy

    Science.gov (United States)

    Korovin, M. S.; Fomenko, A. N.

    2017-09-01

    Nanoparticles and nanostructured materials are one of the most promising developments for cancer therapy. Gold nanoparticles, magnetic nanoparticles based on iron and its oxides and other metal oxides have been widely used in diagnosis and treatment of cancer. Much less researchers' attention has been paid to nanoparticles and nanostructures based on aluminum oxides and hydroxides as materials for cancer diagnosis and treatment. However, recent investigations have shown promising results regarding these objects. Here, we review the antitumor results obtained with different aluminum oxide/hydroxide nanoparticles and nanostructures.

  3. Novel DNA materials and their applications.

    Science.gov (United States)

    Yang, Dayong; Campolongo, Michael J; Nhi Tran, Thua Nguyen; Ruiz, Roanna C H; Kahn, Jason S; Luo, Dan

    2010-01-01

    The last two decades have witnessed the exponential development of DNA as a generic material instead of just a genetic material. The biological function, nanoscale geometry, biocompatibility, biodegradability, and molecular recognition capacity of DNA make it a promising candidate for the construction of novel functional nanomaterials. As a result, DNA has been recognized as one of the most appealing and versatile nanomaterial building blocks. Scientists have used DNA in this way to construct various amazing nanostructures, such as ordered lattices, origami, supramolecular assemblies, and even three-dimensional objects. In addition, DNA has been utilized as a guide and template to direct the assembly of other nanomaterials including nanowires, free-standing membranes, and crystals. Furthermore, DNA can also be used as structural components to construct bulk materials such as DNA hydrogels, demonstrating its ability to behave as a unique polymer. Overall, these novel DNA materials have found applications in various areas in the biomedical field in general, and nanomedicine in particular. In this review, we summarize the development of DNA assemblies, describe the innovative progress of multifunctional and bulk DNA materials, and highlight some real-world nanomedical applications of these DNA materials. We also show our insights throughout this article for the future direction of DNA materials. © 2010 John Wiley & Sons, Inc.

  4. Supercapacitors - nanostructured materials and nanoscale processes contributing to the next mobile generation

    International Nuclear Information System (INIS)

    Mahon, P.J.; Drummond, C.J.

    2001-01-01

    Supercapacitors, alternatively known as ultracapacitors, electrical double-layer capacitors or electrochemical capacitors, are energy storage devices that have considerably more specific capacitance than conventional capacitors. In recent years there have been major advancements in the design of low impedance (low resistance) Supercapacitors, which are ideally suited for high-power applications for mobile devices, particularly those using GSM (Global System for Mobile communication) and GPRS (General Packet Radio Service) wireless technologies. Cap-XX Pty Ltd is a global leader in supercapacitor technology. Cap-XX was established in 1997 and evolved from a collaboration that began in 1994 between Plessey Ducon Pty Ltd, a company that manufactured metallized film capacitors, and what is now CSIRO Energy Technology. In this article we outline the physical chemistry, and in particular, the colloid and surface, electro-, and polymer chemistry, elements that underpin supercapacitor performance. The emphasis is placed on high surface area, particulate-carbon-based supercapacitor technology. This is the cap-XX technology. It is a good example of nanostructured materials and nanoscale processes governing device performance. Some application areas for Supercapacitors are highlighted at the end of this article. Copyright (2001) CSIRO Australia

  5. Electrostatic interactions for directed assembly of high performance nanostructured energetic materials of Al/Fe{sub 2}O{sub 3}/multi-walled carbon nanotube (MWCNT)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tianfu; Ma, Zhuang; Li, Guoping; Wang, Zhen; Zhao, Benbo; Luo, Yunjun, E-mail: yjluo@bit.edu.cn

    2016-05-15

    Electrostatic self-assembly in organic solvent without intensively oxidative or corrosive environments, was adopted to prepare Al/Fe{sub 2}O{sub 3}/MWCNT nanostructured energetic materials as an energy generating material. The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles. This spontaneous assembly method without any surfactant chemistry or other chemical and biological moieties decreased the aggregation of the same nanoparticles largely, moreover, the poor interfacial contact between the Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles was improved significantly, which was the key characteristic of high performance nanostructured energetic materials. In addition, the assembly process was confirmed as Diffusion-Limited Aggregation. The assembled Al/Fe{sub 2}O{sub 3}/MWCNT nanostructured energetic materials showed excellent performance with heat release of 2400 J/g, peak pressure of 0.42 MPa and pressurization rate of 105.71 MPa/s, superior to that in the control group Al/Fe{sub 2}O{sub 3} nanostructured energetic materials prepared by sonication with heat release of 1326 J/g, peak pressure of 0.19 MPa and pressurization rate of 33.33 MPa/s. Therefore, the approach, which is facile, opens a promising route to the high performance nanostructured energetic materials. - Graphical abstract: The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles. - Highlights: • A facile spontaneous electrostatic assembly strategy without surfactant was adopted. • The fuels and oxidizers assembled into densely packed nanostructured composites. • The assembled nanostructured energetic materials have excellent performance. • This high performance energetic material can be scaled up for practical application. • This

  6. Surface Modification for Improved Design and Functionality of Nanostructured Materials and Devices

    Science.gov (United States)

    Keiper, Timothy Keiper

    Progress in nanotechnology is trending towards applications which require the integration of soft (organic or biological) and hard (semiconductor or metallic) materials. Many applications for functional nanomaterials are currently being explored, including chemical and biological sensors, flexible electronics, molecular electronics, etc., with researchers aiming to develop new paradigms of nanoelectronics through manipulation of the physical properties by surface treatments. This dissertation focuses on two surface modification techniques important for integration of hard and soft materials: thermal annealing and molecular modification of semiconductors. First, the effects of thermal annealing are investigated directly for their implication in the fundamental understanding of transparent conducting oxides with respect to low resistivity contacts for electronic and optoelectronic applications and the response to environmental stimuli for sensing applications. The second focus of this dissertation covers two aspects of the importance of molecular modification on semiconductor systems. The first of these is the formation of self-assembled monolayers in patterned arrays which leads explicitly to the directed self-assembly of nanostructures. The second aspect concerns the modification of the underlying magnetic properties of the preeminent dilute magnetic semiconductor, manganese-doped gallium arsenide. Tin oxide belongs to a class of materials known as transparent conducting oxides which have received extensive interest due to their sensitivity to environmental stimuli and their potential application in transparent and flexible electronics. Nanostructures composed of SnO2 have been demonstrated as an advantageous material for high performance, point-of-care nanoelectronic sensors, capable of detecting and distinguishing gaseous or biomolecular interactions on unprecedented fast timescales. Through bottom-up fabrication techniques, binary oxide nanobelts synthesized

  7. Method of producing catalytic material for fabricating nanostructures

    Science.gov (United States)

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

    2018-01-30

    Methods of fabricating nano-catalysts are described. In some embodiments the nano-catalyst is formed from a powder-based substrate material and is some embodiments the nano-catalyst is formed from a solid-based substrate material. In some embodiments the substrate material may include metal, ceramic, or silicon or another metalloid. The nano-catalysts typically have metal nanoparticles disposed adjacent the surface of the substrate material. The methods typically include functionalizing the surface of the substrate material with a chelating agent, such as a chemical having dissociated carboxyl functional groups (--COO), that provides an enhanced affinity for metal ions. The functionalized substrate surface may then be exposed to a chemical solution that contains metal ions. The metal ions are then bound to the substrate material and may then be reduced, such as by a stream of gas that includes hydrogen, to form metal nanoparticles adjacent the surface of the substrate.

  8. Multifunctional Materials Based on Self Assembly of Molecular Nanostructures

    National Research Council Canada - National Science Library

    Stupp, Samuel

    2001-01-01

    .... The objective was to integrate self assembly, encoded in the triblock structure, luminescent properties, and the properties characteristic of materials that have macroscopically polar structure...

  9. HgI2 nanostructures obtained hydrothermally for application in ionizing radiation detection

    International Nuclear Information System (INIS)

    Pérez Barthaburu, María; Bentos Pereira, Heinkel; Fornaro, Laura; Galain, Isabel; Aguiar, Ivana

    2016-01-01

    The compound semiconductor HgI 2 has been widely studied and employed as a material for ionizing radiation detection. Monocrystal growth is an intricate method for obtaining materials for this application. With the aim of finding a simpler and more effective way to develop ionizing radiation detectors, we employed HgI 2 nanostructures subjected to a hydrothermal treatment and then pressed for this purpose. In the synthesis procedure, aqueous solutions of Hg(NO 3 ) 2 and NaI were mixed until their reaction completed and the suspension obtained was then placed in a homemade autoclave and heated at 120 °C for 2, 10 or 24 h. We confirmed the HgI 2 tetragonal phase by powder XRD in all cases, independently of the synthesis conditions employed. Nanoparticles were characterized by their size and morphology by TEM. We used the HgI 2 nanostructures to obtain a pellet by applying 0.7 GPa of pressure at room temperature. The pellet was then used to construct the detector, and we studied the electrical properties of the detector and its response to 241 Am sources of different exposure rates. The resistivity and signal-to-noise ratio obtained are of the order of those reported for HgI 2 detectors assembled with monocrystals. The results obtained in this work encourage us to work further on this topic, improving the method, scaling the detector’s size and studying its spectrometric grade. (paper)

  10. Boron carbide nanostructures: A prospective material as an additive in concrete

    Science.gov (United States)

    Singh, Paviter; Kaur, Gurpreet; Kumar, Rohit; Kumar, Umesh; Singh, Kulwinder; Kumar, Manjeet; Bala, Rajni; Meena, Ramovatar; Kumar, Akshay

    2018-05-01

    In recent decades, manufacture and ingestion of concrete have increased particularly in developing countries. Due to its low cost, safety and strength, concrete have become an economical choice for protection of radiation shielding material in nuclear reactors. As boron carbide has been known as a neutron absorber material makes it a great candidate as an additive in concrete for shielding radiation. This paper presents the synthesis of boron carbide nanostructures by using ball milling method. The X-ray diffraction pattern, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope analysis confirms the formation of boron carbide nanostructures. The effect of boron carbide nanostructures on the strength of concrete samples was demonstrated. The compressive strength tests of concrete cube B4C powder additives for 0 % and 5 % of total weight of cement was compared for different curing time period such as 7, 14, 21 and 28 days. The high compressive strength was observed when 5 wt % boron carbide nanostructures were used as an additive in concrete samples after 28 days curing time and showed significant improvement in strength.

  11. Realization of New and Enhanced Materials Properties Through Nanostructural Control

    National Research Council Canada - National Science Library

    Dalton, Larry

    2006-01-01

    ... transmitter/receiver systems. During this period of time, the Dalton research group served as the national resource for state-of-the-art electro-optic materials providing materials to DoD laboratories, DoE labs, NIST researchers...

  12. Realization of New and Enhanced Materials Properties through Nanostructural Control

    National Research Council Canada - National Science Library

    Lee, Charles

    2003-01-01

    ...) transmitter/receiver systems. During this period of time, the Dalton research group served as the national resource for state-of-the-art electro-optic materials providing materials to DoD laboratories, DoE labs, NIST researchers...

  13. Composite materials processing, applications, characterizations

    CERN Document Server

    2017-01-01

    Composite materials are used as substitutions of metals/traditional materials in aerospace, automotive, civil, mechanical and other industries. The present book collects the current knowledge and recent developments in the characterization and application of composite materials. To this purpose the volume describes the outstanding properties of this class of advanced material which recommend it for various industrial applications.

  14. A nanostructured graphene/polyaniline hybrid material for supercapacitors

    Science.gov (United States)

    Wang, Hualan; Hao, Qingli; Yang, Xujie; Lu, Lude; Wang, Xin

    2010-10-01

    A flexible graphene/polyaniline hybrid material as a supercapacitor electrode was synthesized by an in situ polymerization-reduction/dedoping-redoping process. This product was first prepared in an ethylene glycol medium, then treated with hot sodium hydroxide solution to obtain the reduced graphene oxide/polyaniline hybrid material. Sodium hydroxide also acted as a dedoping reagent for polyaniline in the composite. After redoping in an acidic solution, the thin, uniform and flexible conducting graphene/polyaniline product was obtained with unchanged morphology. The chemical structure of the materials was characterized by X-ray photoelectron spectroscopy and Raman spectroscopy. The composite material showed better electrochemical performances than the pure individual components. A high specific capacitance of 1126 F g-1 was obtained with a retention life of 84% after 1000 cycles for supercapacitors. The energy density and power density were also better than those of pure component materials.

  15. Growth, characterization and electrochemical properties of hierarchical CuO nanostructures for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamoorthy, Karthikeyan [Nanomaterials and System Laboratory, Department of Mechanical Engineering, Jeju National University, Jeju 690 756 (Korea, Republic of); Kim, Sang-Jae, E-mail: kimsangj@jejunu.ac.kr [Nanomaterials and System Laboratory, Department of Mechanical Engineering, Jeju National University, Jeju 690 756 (Korea, Republic of); Department of Mechatronics Engineering, Jeju National University, Jeju 690 756 (Korea, Republic of)

    2013-09-01

    Graphical abstract: - Highlights: • Hierarchical CuO nanostructures were grown on Cu foil. • Monoclinic phase of CuO was grown. • XPS analysis revealed the presence of Cu(2p{sub 3/2}) and Cu(2p{sub 1/2}) on the surfaces. • Specific capacitance of 94 F/g was achieved for the CuO using cyclic voltammetry. • Impedance spectra show their pseudo capacitor applications. - Abstract: In this paper, we have investigated the electrochemical properties of hierarchical CuO nanostructures for pseudo-supercapacitor device applications. Moreover, the CuO nanostructures were formed on Cu substrate by in situ crystallization process. The as-grown CuO nanostructures were characterized using X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR), X-ray photoelectron spectroscopy and field emission-scanning electron microscope (FE-SEM) analysis. The XRD and FT-IR analysis confirm the formation of monoclinic CuO nanostructures. FE-SEM analysis shows the formation of leave like hierarchical structures of CuO with high uniformity and controlled density. The electrochemical analysis such as cyclic voltammetry and electrochemical impedance spectroscopy studies confirms the pseudo-capacitive behavior of the CuO nanostructures. Our experimental results suggest that CuO nanostructures will create promising applications of CuO toward pseudo-supercapacitors.

  16. Growth, characterization and electrochemical properties of hierarchical CuO nanostructures for supercapacitor applications

    International Nuclear Information System (INIS)

    Krishnamoorthy, Karthikeyan; Kim, Sang-Jae

    2013-01-01

    Graphical abstract: - Highlights: • Hierarchical CuO nanostructures were grown on Cu foil. • Monoclinic phase of CuO was grown. • XPS analysis revealed the presence of Cu(2p 3/2 ) and Cu(2p 1/2 ) on the surfaces. • Specific capacitance of 94 F/g was achieved for the CuO using cyclic voltammetry. • Impedance spectra show their pseudo capacitor applications. - Abstract: In this paper, we have investigated the electrochemical properties of hierarchical CuO nanostructures for pseudo-supercapacitor device applications. Moreover, the CuO nanostructures were formed on Cu substrate by in situ crystallization process. The as-grown CuO nanostructures were characterized using X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR), X-ray photoelectron spectroscopy and field emission-scanning electron microscope (FE-SEM) analysis. The XRD and FT-IR analysis confirm the formation of monoclinic CuO nanostructures. FE-SEM analysis shows the formation of leave like hierarchical structures of CuO with high uniformity and controlled density. The electrochemical analysis such as cyclic voltammetry and electrochemical impedance spectroscopy studies confirms the pseudo-capacitive behavior of the CuO nanostructures. Our experimental results suggest that CuO nanostructures will create promising applications of CuO toward pseudo-supercapacitors

  17. Design of hybrid two-dimensional and three-dimensional nanostructured arrays for electronic and sensing applications

    Science.gov (United States)

    Ko, Hyunhyub

    This dissertation presents the design of organic/inorganic hybrid 2D and 3D nanostructured arrays via controlled assembly of nanoscale building blocks. Two representative nanoscale building blocks such as carbon nanotubes (one-dimension) and metal nanoparticles (zero-dimension) are the core materials for the study of solution-based assembly of nanostructured arrays. The electrical, mechanical, and optical properties of the assembled nanostructure arrays have been investigated for future device applications. We successfully demonstrated the prospective use of assembled nanostructure arrays for electronic and sensing applications by designing flexible carbon nanotube nanomembranes as mechanical sensors, highly-oriented carbon nanotubes arrays for thin-film transistors, and gold nanoparticle arrays for SERS chemical sensors. In first section, we fabricated highly ordered carbon nanotube (CNT) arrays by tilted drop-casting or dip-coating of CNT solution on silicon substrates functionalized with micropatterned self-assembled monolayers. We further exploited the electronic performance of thin-film transistors based on highly-oriented, densely packed CNT micropatterns and showed that the carrier mobility is largely improved compared to randomly oriented CNTs. The prospective use of Raman-active CNTs for potential mechanical sensors has been investigated by studying the mechano-optical properties of flexible carbon nanotube nanomembranes, which contain freely-suspended carbon nanotube array encapsulated into ultrathin (optical waveguide properties of nano-canals. We demonstrated the ability of this SERS substrate for trace level sensing of nitroaromatic explosives by detecting down to 100 zeptogram (˜330 molecules) of DNT.

  18. Lifetime of ALD Al2O3 Passivated Black Silicon Nanostructured for Photovoltaic Applications

    DEFF Research Database (Denmark)

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

    Black silicon nano-structures provide significant reduction of silicon surface reflection due to highly corrugated nano-structures with excellent light trapping properties. However, most recent RIE techniques for black silicon nano-structuring have one very important limitation for PV applications...

  19. Nanoscale materials in chemistry

    National Research Council Canada - National Science Library

    Klabunde, Kenneth J; Richards, Ryan

    2009-01-01

    ...: Disordered, Porous Nanostructures Stephanie L. Brock 209 9 Ordered Microporous and Mesoporous Materials Freddy Kleitz 243 10 Applications of Microporous and Mesoporous Materials Anirban Ghosh,...

  20. Acoustic charge manipulation in semiconductor nanostructures for optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Voelk, Stefan

    2010-07-30

    Within this thesis, the influence of a surface acoustic wave (SAW) on the luminescence of semiconductor nanostructures is investigated. Beginning with the physics of low-dimensional semiconductor structures, the quantum mechanical and optical properties of quantum dot (QD) systems are discussed. In particular, intrinsic parameters of QDs such as morphology, composition, strain and occupation with carriers are taken into account. Subsequently, the influence of an applied electric field and of externally induced strain are introduced. From this general approach, the discussion is focused to quantum posts (QPs) which are columnar shaped semiconductor nanostructures. In contrast to conventional self-assembled QDs, the height of the QPs can be controlled by the epitaxial growth process. Due to the adjustable height, electronic states and therefore the exciton transition energies can be tailored. Furthermore, QPs are embedded in a matrix-quantum-well structure which has important influence on the carrier dynamic if a SAW is excited on the sample. Mainly, two effects have to be considered regarding the interaction of charge carriers with SAWs: deformation potential coupling and acousto-electric coupling. For the investigated material and used SAW frequencies, acousto-electric coupling dominates the interaction between charges and SAW. For a quantum well (QW) structure, the periodic band modulation dissociates excitons into sequential stripes of electrons and holes which then are conveyed by the SAW. This so called bipolar transport or charge conveyance effect can be used to inject carriers into remote QD structures and has already been demonstrated for QD ensembles. The injection of carriers into individual quantum posts is successfully demonstrated for the first time within this work. The spectrally resolved photoluminescence (PL) data of individual QPs show an unexpected switching of PL lines which cannot be induced by varying other parameters, e.g. the laser intensity

  1. Nanostructured glass–ceramic coatings for orthopaedic applications

    Science.gov (United States)

    Wang, Guocheng; Lu, Zufu; Liu, Xuanyong; Zhou, Xiaming; Ding, Chuanxian; Zreiqat, Hala

    2011-01-01

    Glass–ceramics have attracted much attention in the biomedical field, as they provide great possibilities to manipulate their properties by post-treatments, including strength, degradation rate and coefficient of thermal expansion. In this work, hardystonite (HT; Ca2ZnSi2O7) and sphene (SP; CaTiSiO5) glass–ceramic coatings with nanostructures were prepared by a plasma spray technique using conventional powders. The bonding strength and Vickers hardness for HT and SP coatings are higher than the reported values for plasma-sprayed hydroxyapatite coatings. Both types of coatings release bioactive calcium (Ca) and silicon (Si) ions into the surrounding environment. Mineralization test in cell-free culture medium showed that many mushroom-like Ca and phosphorus compounds formed on the HT coatings after 5 h, suggesting its high acellular mineralization ability. Primary human osteoblasts attach, spread and proliferate well on both types of coatings. Higher proliferation rate was observed on the HT coatings compared with the SP coatings and uncoated Ti-6Al-4V alloy, probably due to the zinc ions released from the HT coatings. Higher expression levels of Runx2, osteopontin and type I collagen were observed on both types of coatings compared with Ti-6Al-4V alloy, possibly due to the Ca and Si released from the coatings. Results of this study point to the potential use of HT and SP coatings for orthopaedic applications. PMID:21292725

  2. Advanced Materials Deposition for Semiconductor Nanostructures Using Supercritical Fluids

    National Research Council Canada - National Science Library

    Wai, Chien M

    2007-01-01

    ... able to dissolve solutes like a liquid and transport dissolved materials like a gas. Metal and metal sulfide nanoparticles of controllable size can be synthesized in supercritical fluid carbon dioxide using water-in-CO2 microemulsion as template...

  3. Fabrication of nanostructured graphene/polyaniline hybrid material for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.L.; Hao, Q.L.; Wang, X.; Lu, L.D.; Yang, X.J. [Nanjing Univ. of Science and Technology (China). Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education

    2010-07-01

    In this study, a flexible graphene/polyaniline hybrid material was prepared using an in situ polymerization-reduction/dedoping-redoping process for use as a supercapacitor electrode. Graphene oxide and a single layer of graphite oxide were used as a substrate material for the graphene oxide-polyaniline composite using an in situ polymerization method. The composite was then treated with a hot sodium hydroxide solution in order to produce a reduced graphene oxide/polyaniline hybrid material. The sodium hydroxide was also used as a dedoping reagent for the polyaniline in the composite. A thin, uniform and flexible conducting graphene/polyaniline product with an unchanged morphology was obtained using the process. Analyses of the material demonstrated that the composite showed an improved electrochemical performance than the pure individual components, with a specific capacitance of 1126 F per g and a retention life of 84 per cent after 1000 cycles. 4 refs., 1 fig.

  4. Metal-polymer composites comprising nanostructures and applications thereof

    Science.gov (United States)

    Wang, Hsing-Lin [Los Alamos, NM; Jeon, Sea Ho [Dracut, MA; Mack, Nathan H [Los Alamos, NM

    2011-08-02

    Metal-polymer composites, and methods of making and use thereof, said composites comprising a thermally-cured dense polyaniline substrate; an acid dopant; and, metal nanostructure deposits wherein the deposits have a morphology dependent upon the acid dopant.

  5. Innovative applications of femtosecond laser induced self-organized nanostructure

    International Nuclear Information System (INIS)

    Shimotsuma, Yasuhiko; Miura, Kiyotaka; Sakakura, Masaaki

    2015-01-01

    The nanostructure induced by the direct-writing of femtosecond-laser pulses can open a new opportunity to develop avant-garde devices such as a 5D optical storage, polarization imaging sensor, thermoelectric conversion elements. (author)

  6. Nanostructured Boron Nitride: From Molecular Design to Hydrogen Storage Application

    Directory of Open Access Journals (Sweden)

    Georges Moussa

    2014-07-01

    Full Text Available The spray-pyrolysis of borazine at 1400 °C under nitrogen generates boron nitride (BN nanoparticles (NPs. The as-prepared samples form elementary blocks containing slightly agglomerated NPs with sizes ranging from 55 to 120 nm, a Brunauer-Emmett-Teller (BET-specific surface area of 34.6 m2 g−1 and a helium density of 1.95 g cm−3. They are relatively stable in air below 850 °C in which only oxidation of the NP surface proceeds, whereas under nitrogen, their lower size affects their high temperature thermal behavior in the temperature range of 1450–2000 °C. Nitrogen heat-treated nanostructures have been carefully analyzed using X-ray diffraction, electron microscopy and energy-dispersive X-ray spectroscopy. The high temperature treatment (2000 °C gives hollow-cored BN-NPs that are strongly facetted, and after ball-milling, hollow core-mesoporous shell NPs displaying a BET-specific surface area of 200.5 m2·g−1 and a total pore volume of 0.287 cm3·g−1 were produced. They have been used as host material to confine, then destabilize ammonia borane (AB, thus improving its dehydrogenation properties. The as-formed AB@BN nanocomposites liberated H2 at 40 °C, and H2 is pure in the temperature range 40–80 °C, leading to a safe and practical hydrogen storage composite material.

  7. A facile synthesis of a novel optoelectric material: a nanocomposite of SWCNT/ZnO nanostructures embedded in sulfonated polyaniline

    Directory of Open Access Journals (Sweden)

    Rajesh K. Agrawalla

    2014-07-01

    Full Text Available Functionalized single-walled carbon nanotubes (f-SWCNTs hybridized with freshly prepared zinc oxide (ZnO nanocrystals have been found to be good luminescent material with tuned emission properties. A three-phase nanocomposite of sulfonated polyaniline embedded with such SWCNT/ZnO nanostructures has been prepared by a simple solution mixing chemical process and characterized by using high-resolution transmission electron microscopy, X-ray diffractometry, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The study of UV-visible absorption and photoluminescence spectroscopies reveal that the ternary polymer nanocomposite is a luminescent material with enhanced emission intensity. Also an increase in DC conductivity indicates that the nanocomposite is also a good conductive material, satisfying Mott’s variable range hopping model for a two-dimensional conduction. Such a three-phase nanocomposite may find extensive application in dye-sensitized solar cells, sensors, and supercapacitors.

  8. Estimation of attenuation and moderation by nanostructured materials

    International Nuclear Information System (INIS)

    Artem'ev, V.A.

    2003-01-01

    Peculiarities of the attenuation and slowing down of neutrons in ultradispersed powder with the size of particles ∼ 10 nm are discussed. It is noted that at temperature ∼ 10 K ultradispersed powder possesses the best captured ability of thermal neutrons than ordinary compact material or finely divided powder. Slow neutrons capture is size of ultradispersed particles dependent: captured ability of the material tends to widen with the decrease of particles sizes. Use of ultradispersed powder as moderator is advantageous for the cold neutrons moderation to very cold or for the production of ultracold neutrons [ru

  9. Nanostructured materials for advanced energy conversion and storage devices

    Science.gov (United States)

    Aricò, Antonino Salvatore; Bruce, Peter; Scrosati, Bruno; Tarascon, Jean-Marie; van Schalkwijk, Walter

    2005-05-01

    New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

  10. Processing and nanostructure influences on mechanical properties of thermoelectric materials

    Science.gov (United States)

    Schmidt, Robert David

    Thermoelectric (TE) materials are materials that can generate an electric current from a thermal gradient, with possible service in recovery of waste heat such as engine exhaust. Significant progress has been made in improving TE conversion efficiency, typically reported according to the figure of merit, ZT, with several recent papers publishing ZT values above 2. Furthermore, cost reductions may be made by the use of lower cost elements such as Mg, Si, Sn, Pb, Se and S in TE materials, while achieving ZT values between 1.3 and 1.8. To be used in a device, the thermoelectric material must be able to withstand the applied thermal and mechanical forces without failure. However, these materials are brittle, with low fracture toughness typically less than 1.5 MPa-m1/2, and often less than 0.5 MPa-m1/2. For comparison, window glass is approximately 0.75 MPa-m1/2. They have been optimized with nanoprecipitates, nanoparticles, doping, alterations in stoichiometry, powder processing and other techniques, all of which may alter the mechanical properties. In this study, the effect of SiC nanoparticle additions in Mg2Si, SnTe and Ag nanoparticle additions in the skutterudite Ba0.3Co 4Sb12 on the elastic moduli, hardness and fracture toughness are measured. Large changes (˜20%) in the elastic moduli in SnTe 1+x as a function of x at 0 and 0.016 are shown. The effect on mechanical properties of doping and precipitates of CdS or ZnS in a PbS or PbSe matrix have been reported. Changes in sintering behavior of the skutterudite with the Ag nanoparticle additions were explored. Possible liquid phase sintering, with associated benefits in lower processing temperature, faster densification and lower cost, has been shown. A technique has been proposed for determining additional liquid phase sintering aids in other TE materials. The effects of porosity, grain size, powder processing method, and sintering method were explored with YbAl3 and Ba0.3Co4Sb 12, with the porosity dependence of

  11. Nanostructured silicon for photonics from materials to devices

    CERN Document Server

    Gaburro, Z; Daldosso, N

    2006-01-01

    The use of light to channel signals around electronic chips could solve several current problems in microelectronic evolution including: power dissipation, interconnect bottlenecks, input/output from/to optical communication channels, poor signal bandwidth, etc. It is unfortunate that silicon is not a good photonic material: it has a poor light-emission efficiency and exhibits a negligible electro-optical effect. Silicon photonics is a field having the objective of improving the physical properties of silicon; thus turning it into a photonic material and permitting the full convergence of elec

  12. In situ neutron scattering study of nanostructured PbTe-PbS bulk thermoelectric material

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Fei [Temple University; Schmidt, Robert D [ORNL; Case, Eldon D [Michigan State University, East Lansing; An, Ke [ORNL

    2016-01-01

    Nanostructures play an important role in thermoelectric materials. Their thermal stability, such as phase change and evolution at elevated temperatures, is thus of great interest to the thermoelectric community. In this study, in situ neutron diffraction was used to examine the phase evolution of nanostructured bulk PbTe-PbS materials fabricated using hot pressing and pulsed electrical current sintering (PECS). The PbS second phase was observed in all samples in the as-pressed condition. The temperature dependent lattice parameter and phase composition data show an initial formation of PbS precipitates followed by a redissolution during heating. The redissolution process started around 570 600 K, and completed at approximately 780 K. During cooling, the PECS sample followed a reversible curve while the heating/cooling behavior of the hot pressed sample was irreversible.

  13. LDRD final report on adaptive-responsive nanostructures for sensing applications.

    Energy Technology Data Exchange (ETDEWEB)

    Shelnutt, John Allen; van Swol, Frank B.; Wang, Zhongchun; Medforth, Craig J.

    2005-11-01

    Functional organic nanostructures such as well-formed tubes or fibers that can easily be fabricated into electronic and photonic devices are needed in many applications. Especially desirable from a national security standpoint are nanostructures that have enhanced sensitivity for the detection of chemicals and biological (CB) agents and other environmental stimuli. We recently discovered the first class of highly responsive and adaptive porphyrin-based nanostructures that may satisfy these requirements. These novel porphyrin nanostructures, which are formed by ionic self-assembly of two oppositely charged porphyrins, may function as conductors, semiconductors, or photoconductors, and they have additional properties that make them suitable for device fabrication (e.g., as ultrasensitive colorimetric CB microsensors). Preliminary studies with porphyrin nanotubes have shown that these nanostructures have novel optical and electronic properties, including strong resonant light scattering, quenched fluorescence, and electrical conductivity. In addition, they are photochemically active and capable of light-harvesting and photosynthesis; they may also have nonlinear optical properties. Remarkably, the nanotubes and potentially other porphyrin nanostructure are mechanically responsive and adaptive (e.g., the rigidity of the micrometers-long nanotubes is altered by light, ultrasound, or chemicals) and they self-heal upon removal the environmental stimulus. Given the tremendous degree of structural variation possible in the porphyrin subunits, additional types of nanostructures and greater control over their morphology can be anticipated. Molecular modification also provides a means of controlling their electronic, photonic, and other functional properties. In this work, we have greatly broadened the range of ionic porphyrin nanostructures that can be made, and determined the optical and responsivity properties of the nanotubes and other porphyrin nanostructures. We have

  14. Hydrogen bonded columnar liquid crystals for nanostructured functional materials

    NARCIS (Netherlands)

    Fitié, C.F.C.

    2010-01-01

    Many functional materials rely on a well-organized internal structure for their functional properties. The length scale of this organization can vary from the atomic level (e.g., piezoelectric crystals) to a macroscopic length scale exceeding the dimensions of individual molecules (e.g., porous

  15. High-capacity nanostructured germanium-containing materials and lithium alloys thereof

    Energy Technology Data Exchange (ETDEWEB)

    Graetz, Jason A. (Upton, NY); Fultz, Brent T. (Pasadena, CA); Ahn, Channing (Pasadena, CA); Yazami, Rachid (Los Angeles, CA)

    2010-08-24

    Electrodes comprising an alkali metal, for example, lithium, alloyed with nanostructured materials of formula Si.sub.zGe.sub.(z-1), where 0

  16. Synthesis and applications of one-dimensional nano-structured polyaniline: An overview

    International Nuclear Information System (INIS)

    Zhang Donghua; Wang Yangyong

    2006-01-01

    This paper summarizes and reviews the various synthesizing approaches of one-dimensional nano-structured polyaniline (PANI) and several potential applications of the nanomaterial. The synthesizing approaches can be generally categorized into template synthesis and non-template synthesis according to whether template(s), hard (physical template) or soft (chemical template), is (are) used or not. However, though the various approaches established, preparation of one-dimensional nano-structured PANI with controllable morphologies and sizes, especially well oriented arrays on a large scale is still a major challenge. Furthermore, the formation mechanisms of the nanostructures are still unclear. On the other hand, one-dimensional nano-structured PANI exhibits high surface area, high conductivity, as well as controllable chemical/physical properties and good environmental stability, rendering the nanomaterial promising candidate for application ranging from sensors, energy storage and flash welding to digital nonvolatile memory

  17. Dynamically Reconfigurable Metadevice Employing Nanostructured Phase-Change Materials.

    Science.gov (United States)

    Zhu, Zhihua; Evans, Philip G; Haglund, Richard F; Valentine, Jason G

    2017-08-09

    Mastering dynamic free-space spectral control and modulation in the near-infrared (NIR) and optical regimes remains a challenging task that is hindered by the available functional materials at high frequencies. In this work, we have realized an efficient metadevice capable of spectral control by minimizing the thermal mass of a vanadium dioxide phase-change material (PCM) and placing the PCM at the feed gap of a bow-tie field antenna. The device has an experimentally measured tuning range of up to 360 nm in the NIR and a modulation depth of 33% at the resonant wavelength. The metadevice is configured for integrated and local heating, leading to faster switching and more precise spatial control compared with devices based on phase-change thin films. We envisage that the combined advantages of this device will open new opportunities for signal processing, memory, security, and holography at optical frequencies.

  18. Polarization catastrophe in nanostructures doped in photonic band gap materials

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)], E-mail: msingh@uwo.ca

    2008-11-30

    In the presence of the dipole-dipole interaction, we have studied a possible dielectric catastrophe in photonic band gap materials doped with an ensemble of four-level nanoparticles. It is found that the dielectric constant of the system has a singularity when the resonance energy lies within the bands. This phenomenon is known as the dielectric catastrophe. It is also found that this phenomenon depends on the strength of the dipole-dipole interaction.

  19. Interface chemistry of nanostructured materials: ion adsorption on mesoporous alumina.

    Science.gov (United States)

    Wang, Yifeng; Bryan, Charles; Xu, Huifang; Pohl, Phil; Yang, Yi; Brinker, C Jeffrey

    2002-10-01

    This paper presents a part of our work on understanding the effect of nanoscale pore space confinement on ion sorption by mesoporous materials. Acid-base titration experiments were performed on both mesoporous alumina and alumina particles under various ionic strengths. The point of zero charge (PZC) for mesoporous alumina was measured to be approximately 9.1, similar to that for nonmesoporous alumina materials, indicating that nanoscale pore space confinement does not have a significant effect on the PZC of pore surfaces. However, for a given pH deviation from the PZC, (pH-PZC), the surface charge per mass on mesoporous alumina was as much as 45 times higher than that on alumina particles. This difference cannot be fully explained by the surface area difference between the two materials. Our titration data have demonstrated that nanoscale confinement has a significant effect, most likely via the overlap of the electric double layer (EDL), on ion sorption onto mesopore surfaces. This effect cannot be adequately modeled by existing surface complexation models, which were developed mostly for an unconfined solid-water interface. Our titration data have also indicated that the rate of ion uptake by mesoporous alumina is relatively slow, probably due to diffusion into mesopores, and complete equilibration for sorption could take 4-5 min. A molecular simulation using a density functional theory was performed to calculate ion adsorption coefficients as a function of pore size. The calculation has shown that as pore size is reduced to nanoscales (<10 nm), the adsorption coefficients of ions can vary by more than two orders of magnitude relative to those for unconfined interfaces. The prediction is supported by our experimental data on Zn sorption onto mesoporous alumina. Owing to their unique surface chemistry, mesoporous materials can potentially be used as effective ion adsorbents for separation processes and environmental cleanup.

  20. Magnetic Nanostructures Patterned by Self-Organized Materials

    Science.gov (United States)

    2016-01-05

    Palma , J. Escrig, J. C. Denardin Angular dependence of the coercivity and remanence of ordered arrays of Co nanowires Journal of...J. L. Palma , C. Gallardo, L. Spinu, J. M. Vargas, L. S. Dorneles, J. C. Denardin, J. Escrig, Magnetic properties of Fe20 Ni80 antidots: Pore size and...array disorder, Journal of Magnetism and Magnetic Materials., 344, 2013, 8-13 7. E. Vargas, P. Toro, J.L. Palma , J. Escrig, C. Chaneac,

  1. Hierarchical Assembly of Multifunctional Oxide-based Composite Nanostructures for Energy and Environmental Applications

    Directory of Open Access Journals (Sweden)

    Hui-Jan Lin

    2012-06-01

    Full Text Available Composite nanoarchitectures represent a class of nanostructured entities that integrates various dissimilar nanoscale building blocks including nanoparticles, nanowires, and nanofilms toward realizing multifunctional characteristics. A broad array of composite nanoarchitectures can be designed and fabricated, involving generic materials such as metal, ceramics, and polymers in nanoscale form. In this review, we will highlight the latest progress on composite nanostructures in our research group, particularly on various metal oxides including binary semiconductors, ABO3-type perovskites, A2BO4 spinels and quaternary dielectric hydroxyl metal oxides (AB(OH6 with diverse application potential. Through a generic template strategy in conjunction with various synthetic approaches—such as hydrothermal decomposition, colloidal deposition, physical sputtering, thermal decomposition and thermal oxidation, semiconductor oxide alloy nanowires, metal oxide/perovskite (spinel composite nanowires, stannate based nanocompostes, as well as semiconductor heterojunction—arrays and networks have been self-assembled in large scale and are being developed as promising classes of composite nanoarchitectures, which may open a new array of advanced nanotechnologies in solid state lighting, solar absorption, photocatalysis and battery, auto-emission control, and chemical sensing.

  2. Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

    Science.gov (United States)

    Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.; hide

    2012-01-01

    Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.

  3. Active brazed diamond and cubic boron nitride interfacial nanostructure and application

    International Nuclear Information System (INIS)

    Klotz, U.E.; Elsener, H.R.; Elsener, H.R.

    2005-01-01

    Active brazing is an effective technique for joining diamond or cBN grit onto metallic substrates. Current use of this technique is being made for super abrasive, high performance tools. The lecture will give an overview over different aspects such as (i) tool performance in selected applications, (ii) interfacial nanostructure between super abrasive grit and brazing alloys matrix, (iii) attempts to computer model such interface reactions and (iv) recent improvements of the abrasion resistance of the brazing alloy itself. Super abrasive tools with outstanding performance in applications such as grinding, honing or stone cutting can be manufactured by a single-layer of brazed diamond or cBN grit. A method to obtain regular grit patterns will be presented. Examples of prototype tools and their performance in different applications will be shown. The investigation of interface reactions between diamond and active brazing alloys plays an important role to further improve the brazing process and resulting tool performance. The interfacial nanostructure is characterised by a thin reaction layer of Ti with diamond and cBN, respectively. Results for Ag- and Cu-based brazing alloys will be presented and discussed in view of the influence of brazing process parameters and brazing alloy matrix. Computer modelling of the thermodynamics and kinetics of the interface reactions may allow optimising the process parameters. This requires reliable databases currently being built up. The potential of such methods in ceramic to metal joining will be described. The abrasion resistance of brazing alloys itself plays an important role for tool performance. A new method to achieve a dispersion of nano sized TiC precipitates in the alloy matrix by addition of an organic binder, decomposing during brazing will be presented. In an outlook further applications of brazed diamond grit, such as thermal management materials will be discussed. (author)

  4. Influence of ZnO nanostructures in liquid crystal interfaces for bistable switching applications

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Kaushik, E-mail: kaushikpal@whu.edu.cn [School of Power and Mechanical Engineering, Wuhan University, 8 East Lake South Road, Wuhan 430072 (China); Zhan, Bihong, E-mail: bihong_zhan@whu.edu.cn [School of Power and Mechanical Engineering, Wuhan University, 8 East Lake South Road, Wuhan 430072 (China); Madhu Mohan, M.L.N. [Liquid Crystal Research Laboratory (LCRL), Bannari Amman Institute of Technology, Sathyamangalam 638 401 (India); Schirhagl, Romana [University Medical Center Groningen, Department of BioMedical Engineering, Ant. Deusinglaan 1, 9713 AV Groningen (Netherlands); Wang, Guoping, E-mail: guopingwang@whu.edu.cn [School of Power and Mechanical Engineering, Wuhan University, 8 East Lake South Road, Wuhan 430072 (China)

    2015-12-01

    Graphical abstract: - Highlights: • One step bench top novel synthesis and growth dynamics of ZnO structures are successfully performed. • Nanostructures dispersing liquid crystals (NDLC) is recently found to have significant influence on the nucleation and growth of many functional nanocrystals (NCs), and provide a fundamental approach to modify the crystallographic phase, size, morphology, and electronic configuration of nanomaterials. • Electro-optical switching application ensures the bright field droplet design marble pattern of smectic G phase, nematic and most significant twist nematic phase pattern are obtained. • Spontaneous polarization, rotational viscosity and response time study, exploring smart applications in LCD technology. - Abstract: The controlled fabrication of nanometer-scale objects is without doubt one of the central issues in current science and technology. In this article, we exhibit a simple, one-step bench top synthesis of zinc oxide nano-tetrapods and nano-spheres which were tailored by the facial growth of nano-wires (diameter ≈ 24 nm; length ≈ 118 nm) and nano-cubes (≈395 nm edge) to nano-sphere (diameter ≈ 585 nm) appeaded. The possibilities of inexpensive, simple solvo-chemical synthesis of nanostructures were considered. In this article, a successful attempt has been made that ZnO nano-structures dispersed on well aligned hydrogen bonded liquid crystals (HBLC) comprising azelaic acid (AC) with p-n-alkyloxy benzoic acid (nBAO) by varying the respective alkyloxy carbon number (n = 5). The dispersion of nanomaterials with HBLC is an effective route to enhance the existing functionalities. A series of these composite materials were analyzed by polarizing optical microscope's electro-optical switching. An interesting feature of AC + nBAO is the inducement of tilted smectic G phase with increasing carbon chain length. Phase diagrams of the above hybrid ZnO nanomaterial influenced LC complex and pure LC were

  5. Synthetic opal as a template for nanostructured materials

    Science.gov (United States)

    White, Paul A.; Heales, Lindsey; Barber, Richard L.; Turney, Terence W.

    2001-04-01

    Synthetic opal has been used as a template for making 3D inverse opals of silica, titania and silicone rubber. The materials are mesoporous with connected pores and channels and have better opalescence than the opal templates they replace. Thin films of synthetic opal have been grown onto glass substrates by spin coating and these have also been used as templates for making thin films of inverse opal and as masks for depositing metal nanodots. This method produced hexagonally patterned 50 nm gold dots on a flat graphite substrate.

  6. Failure of metals III: Fracture and fatigue of nanostructured metallic materials

    International Nuclear Information System (INIS)

    Pineau, André; Amine Benzerga, A.; Pardoen, Thomas

    2016-01-01

    Pushing the internal or external dimensions of metallic alloys down to the nanometer scale gives rise to strong materials, though most often at the expense of a low ductility and a low resistance to cracking, with negative impact on the transfer to engineering applications. These characteristics are observed, with some exceptions, in bulk ultra-fine grained and nanocrystalline metals, nano-twinned metals, thin metallic coatings on substrates and freestanding thin metallic films and nanowires. This overview encompasses all these systems to reveal commonalities in the origins of the lack of ductility and fracture resistance, in factors governing fatigue resistance, and in ways to improve properties. After surveying the various processing methods and key deformation mechanisms, we systematically address the current state of the art in terms of plastic localization, damage, static and fatigue cracking, for three classes of systems: (1) bulk ultra-fine grained and nanocrystalline metals, (2) thin metallic films on substrates, and (3) 1D and 2D freestanding micro and nanoscale systems. In doing so, we aim to favour cross-fertilization between progress made in the fields of mechanics of thin films, nanomechanics, fundamental researches in bulk nanocrystalline metals and metallurgy to impart enhanced resistance to fracture and fatigue in high-strength nanostructured systems. This involves exploiting intrinsic mechanisms, e.g. to enhance hardening and rate-sensitivity so as to delay necking, or improve grain-boundary cohesion to resist intergranular cracks or voids. Extrinsic methods can also be utilized such as by hybridizing the metal with another material to delocalize the deformation - as practiced in stretchable electronics. Fatigue crack initiation is in principle improved by a fine structure, but at the expense of larger fatigue crack growth rates. Extrinsic toughening through hybridization allows arresting or bridging cracks. The content and discussions are based on

  7. CuO-PANI nanostructure with tunable spectral selectivity for solar selective coating application

    Energy Technology Data Exchange (ETDEWEB)

    Cindrella, L., E-mail: cind@nitt.edu; Prabhu, S., E-mail: sprabhuk@gmail.com

    2016-08-15

    Highlights: • CuO-PANI nanostructure has been reported as the solar selective absorber coating. • Solar selectivity and efficiency of the coatings have been evaluated. • PANI provides a surface texture favourable for multiple reflection. - Abstract: CuO-PANI nanostructure has been demonstrated as the solar selective absorber coating for the first time. The effortless chemical methods and easily scalable techniques such as precipitation, in-situ polymerization and spray coating were adopted for the fabrication of CuO nanorods and CuO-PANI nanostructures for solar application. The synthesis was carried out without using any template. The morphology and phase structure of fabricated CuO nanorods and CuO-PANI nanostructure coatings were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction analysis. The energy dispersive X-ray spectra and elemental mapping confirm the presence of the chosen elements in the nanostructure. The solar absorptance (α{sub s}), thermal emittance (ε{sub t}) and selectivity (ξ) of the nanostructure coatings on glass substrate were optimized to 0.94, 0.01 and 94 respectively by changing the polyaniline content on the surface of the CuO nanorods. The efficiency of the solar selective coatings were evaluated. The optimized solar absorber coating of CuO-PANI nanostructure is highly promising for its selective optical properties.

  8. Application of focused ion beam technology for photonic nanostructures

    NARCIS (Netherlands)

    Ay, F.; Gadgil, V.J.; Geskus, D.; Aravazhi, S.; Worhoff, Kerstin; Pollnau, Markus

    Al2O3 and KY(WO4)2 are promising materials for photonic applications with excellent optical properties and of interest for obtaining on chip resonator structures. However, there is no method available to fabricate these structures except FIB technology. We will discuss strategies to optimize the

  9. Electrosorption capacitance of nanostructured carbon-based materials.

    Science.gov (United States)

    Hou, Chia-Hung; Liang, Chengdu; Yiacoumi, Sotira; Dai, Sheng; Tsouris, Costas

    2006-10-01

    The fundamental mechanism of electrosorption of ions developing a double layer inside nanopores was studied via a combination of experimental and theoretical studies. A novel graphitized-carbon monolithic material has proven to be a good electrical double-layer capacitor that can be applied in the separation of ions from aqueous solutions. An extended electrical double-layer model indicated that the pore size distribution plays a key role in determining the double-layer capacitance in an electrosorption process. Because of the occurrence of double-layer overlapping in narrow pores, mesopores and micropores make significantly different contributions to the double-layer capacitance. Mesopores show good electrochemical accessibility. Micropores present a slow mass transfer of ions and a considerable loss of double-layer capacitance, associated with a shallow potential distribution inside pores. The formation of the diffuse layer inside the micropores determines the magnitude of the double-layer capacitance at low electrolyte concentrations and at conditions close to the point of zero charge of the material. The effect of the double-layer overlapping on the electrosorption capacitance can be reduced by increasing the pore size, electrolyte concentration, and applied potential. The results are relevant to water deionization.

  10. Thermoelectric and thermospintronic transport in Dirac material-based nanostructures

    Science.gov (United States)

    Chang, Po-Hao

    The growing need for power due to the rapid developments of the technologies has urged both engineers and scientists to study more sustainable types of energy. On the other hand, the improvement of our abilities although enable us, for example, to double the number of transistors in a dense integrated circuit approximately every two years (Moore's law), comes with side effect due to overheating. Taking advantage of thermoelectric effect has thus become one of the obvious solutions for the problems. But due to the poor efficiency of electricity-heat conversion, there are still challenges to be overcome in order to fully utilize the idea. In the past few years, the realization of graphene along with the discoveries of topological insulators (TI) which are both considered as Dirac material (DM) have offer alternative routs for improving the energy conversion efficiency through different approaches as well as novel quantum effects of materials themselves for investigation. The aim of this thesis is to present contributions to improving the efficiency of thermoelectric conversion as well as analyzing spin transport phenomena that occur in nano-devices. This thesis spans the areas of thermoelectric (TE) effect, spin-Seebeck effect (SSE) and the spin transport on the 3D topological insulator (TI). The different methods have been applied ranging from tight-binding (TB) approximation to density function theory (DFT) combined with non-equilibrium function (NEGF) techniques.

  11. Nanostructured enzymatic biosensor based on fullerene and gold nanoparticles: preparation, characterization and analytical applications.

    Science.gov (United States)

    Lanzellotto, C; Favero, G; Antonelli, M L; Tortolini, C; Cannistraro, S; Coppari, E; Mazzei, F

    2014-05-15

    In this work a novel electrochemical biosensing platform based on the coupling of two different nanostructured materials (gold nanoparticles and fullerenols) displaying interesting electrochemical features, has been developed and characterized. Gold nanoparticles (AuNPs) exhibit attractive electrocatalytic behavior stimulating in the last years, several sensing applications; on the other hand, fullerene and its derivatives are a very promising family of electroactive compounds although they have not yet been fully employed in biosensing. The methodology proposed in this work was finalized to the setup of a laccase biosensor based on a multilayer material consisting in AuNPs, fullerenols and Trametes versicolor Laccase (TvL) assembled layer by layer onto a gold (Au) electrode surface. The influence of different modification step procedures on the electroanalytical performance of biosensors has been evaluated. Cyclic voltammetry, chronoamperometry, surface plasmon resonance (SPR) and scanning tunneling microscopy (STM) were used to characterize the modification of surface and to investigate the bioelectrocatalytic biosensor response. This biosensor showed fast amperometric response to gallic acid, which is usually considered a standard for polyphenols analysis of wines, with a linear range 0.03-0.30 mmol L(-1) (r(2)=0.9998), with a LOD of 0.006 mmol L(-1) or expressed as polyphenol index 5.0-50 mg L(-1) and LOD 1.1 mg L(-1). A tentative application of the developed nanostructured enzyme-based biosensor was performed evaluating the detection of polyphenols either in buffer solution or in real wine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Nanostructure multilayer dielectric materials for capacitors and insulators

    Science.gov (United States)

    Barbee, Jr., Troy W.; Johnson, Gary W.

    1998-04-21

    A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3) in alternating layers to form a nano-laminate.

  13. Nanostructure characterization of high k materials by spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Pereira, L.; Aguas, H.; Fortunato, E.; Martins, R.

    2006-01-01

    In this work, the optical and structural properties of high k materials such as tantalum oxide and titanium oxide were studied by spectroscopic ellipsometry, where a Tauc-Lorentz dispersion model based in one (amorphous films) or two oscillators (microcrystalline films) was used. The samples were deposited at room temperature by radio frequency magnetron sputtering and then annealed at temperatures from 100 to 500 deg. C. Concerning the tantalum oxide films, the increase of the annealing temperature, up to 500 deg. C does not change the amorphous nature of the films, increasing, however, their density. The same does not happen with the titanium oxide films that are microcrystalline, even when deposited at room temperature. Data concerning the use of a four-layer model based on one and two Tauc-Lorentz dispersions is also discussed, emphasizing its use for the detection of an amorphous incubation layer, normally present on microcrystalline films grown by sputtering

  14. Biomimetic polymeric superhydrophobic surfaces and nanostructures: from fabrication to applications.

    Science.gov (United States)

    Wen, Gang; Guo, ZhiGuang; Liu, Weimin

    2017-03-09

    Numerous research studies have contributed to the development of mature superhydrophobic systems. The fabrication and applications of polymeric superhydrophobic surfaces have been discussed and these have attracted tremendous attention over the past few years due to their excellent properties. In general, roughness and chemical composition, the two most crucial factors with respect to surface wetting, provide the basic criteria for yielding polymeric superhydrophobic materials. Furthermore, with their unique properties and flexible configurations, polymers have been one of the most efficient materials for fabricating superhydrophobic materials. This review aims to summarize the most recent progress in polymeric superhydrophobic surfaces. Significantly, the fundamental theories for designing these materials will be presented, and the original methods will be introduced, followed by a summary of multifunctional superhydrophobic polymers and their applications. The principles of these methods can be divided into two categories: the first involves adding nanoparticles to a low surface energy polymer, and the other involves combining a low surface energy material with a textured surface, followed by chemical modification. Notably, surface-initiated radical polymerization is a versatile method for a variety of vinyl monomers, resulting in controlled molecular weights and low polydispersities. The surfaces produced by these methods not only possess superhydrophobicity but also have many applications, such as self-cleaning, self-healing, anti-icing, anti-bioadhesion, oil-water separation, and even superamphiphobic surfaces. Interestingly, the combination of responsive materials and roughness enhances the responsiveness, which allows the achievement of intelligent transformation between superhydrophobicity and superhydrophilicity. Nevertheless, surfaces with poor physical and chemical properties are generally unable to withstand the severe conditions of the outside world

  15. The toxicological mode of action and the safety of synthetic amorphous silica—A nanostructured material

    International Nuclear Information System (INIS)

    Fruijtier-Pölloth, Claudia

    2012-01-01

    Synthetic amorphous silica (SAS), in the form of pyrogenic (fumed), precipitated, gel or colloidal SAS, has been used in a wide variety of industrial and consumer applications including food, cosmetics and pharmaceutical products for many decades. Based on extensive physico-chemical, ecotoxicology, toxicology, safety and epidemiology data, no environmental or health risks have been associated with these materials if produced and used under current hygiene standards and use recommendations. With internal structures in the nanoscale size range, pyrogenic, precipitated and gel SAS are typical examples of nanostructured materials as recently defined by the International Organisation for Standardisation (ISO). The manufacturing process of these SAS materials leads to aggregates of strongly (covalently) bonded or fused primary particles. Weak interaction forces (van der Waals interactions, hydrogen bonding, physical adhesion) between aggregates lead to the formation of micrometre (μm)-sized agglomerates. Typically, isolated nanoparticles do not occur. In contrast, colloidal SAS dispersions may contain isolated primary particles in the nano-size range which can be considered nano-objects. The size of the primary particle resulted in the materials often being considered as “nanosilica” and in the inclusion of SAS in research programmes on nanomaterials. The biological activity of SAS can be related to the particle shape and surface characteristics interfacing with the biological milieu rather than to particle size. SAS adsorbs to cellular surfaces and can affect membrane structures and integrity. Toxicity is linked to mechanisms of interactions with outer and inner cell membranes, signalling responses, and vesicle trafficking pathways. Interaction with membranes may induce the release of endosomal substances, reactive oxygen species, cytokines and chemokines and thus induce inflammatory responses. None of the SAS forms, including colloidal nano-sized particles, were

  16. The toxicological mode of action and the safety of synthetic amorphous silica-a nanostructured material.

    Science.gov (United States)

    Fruijtier-Pölloth, Claudia

    2012-04-11

    Synthetic amorphous silica (SAS), in the form of pyrogenic (fumed), precipitated, gel or colloidal SAS, has been used in a wide variety of industrial and consumer applications including food, cosmetics and pharmaceutical products for many decades. Based on extensive physico-chemical, ecotoxicology, toxicology, safety and epidemiology data, no environmental or health risks have been associated with these materials if produced and used under current hygiene standards and use recommendations. With internal structures in the nanoscale size range, pyrogenic, precipitated and gel SAS are typical examples of nanostructured materials as recently defined by the International Organisation for Standardisation (ISO). The manufacturing process of these SAS materials leads to aggregates of strongly (covalently) bonded or fused primary particles. Weak interaction forces (van der Waals interactions, hydrogen bonding, physical adhesion) between aggregates lead to the formation of micrometre (μm)-sized agglomerates. Typically, isolated nanoparticles do not occur. In contrast, colloidal SAS dispersions may contain isolated primary particles in the nano-size range which can be considered nano-objects. The size of the primary particle resulted in the materials often being considered as "nanosilica" and in the inclusion of SAS in research programmes on nanomaterials. The biological activity of SAS can be related to the particle shape and surface characteristics interfacing with the biological milieu rather than to particle size. SAS adsorbs to cellular surfaces and can affect membrane structures and integrity. Toxicity is linked to mechanisms of interactions with outer and inner cell membranes, signalling responses, and vesicle trafficking pathways. Interaction with membranes may induce the release of endosomal substances, reactive oxygen species, cytokines and chemokines and thus induce inflammatory responses. None of the SAS forms, including colloidal nano-sized particles, were shown

  17. Review of Recent Progress of Plasmonic Materials and Nano-Structures for Surface-Enhanced Raman Scattering

    Directory of Open Access Journals (Sweden)

    Alan X. Wang

    2015-05-01

    Full Text Available Surface-enhanced Raman scattering (SERS has demonstrated single-molecule sensitivity and is becoming intensively investigated due to its significant potential in chemical and biomedical applications. SERS sensing is highly dependent on the substrate, where excitation of the localized surface plasmons (LSPs enhances the Raman scattering signals of proximate analyte molecules. This paper reviews research progress of SERS substrates based on both plasmonic materials and nano-photonic structures. We first discuss basic plasmonic materials, such as metallic nanoparticles and nano-rods prepared by conventional bottom-up chemical synthesis processes. Then, we review rationally-designed plasmonic nano-structures created by top-down approaches or fine-controlled synthesis with high-density hot-spots to provide large SERS enhancement factors (EFs. Finally, we discuss the research progress of hybrid SERS substrates through the integration of plasmonic nano-structures with other nano-photonic devices, such as photonic crystals, bio-enabled nanomaterials, guided-wave systems, micro-fluidics and graphene.

  18. Nanostructured inorganic materials: Synthesis and associated electrochemical properties

    Science.gov (United States)

    Yau, Shali Zhu

    Synthetic strategy for preparing potential battery materials at low temperature was developed. Magnetite (Fe3O4), silver hollandnite (AgxMn8O16), magnesium manganese oxide (MgxMnO 2˙yH2O), and silver vanadium phosphorous oxide (Ag 2VO2PO4) were studied. Magnetite (Fe3O4) was prepared by coprecipitation induced by triethylamine from aqueous iron(II) and iron(III) chloride solutions of varying concentrations. Variation of the iron(II) and iron(III) concentrations results in crystallite size control of the Fe3O4 products. Materials characterization of the Fe3O4 samples is reported, including Brunauer-Emmitt-Teller (BET) surface area, x-ray powder diffraction (XRD), transmission electron microscopy (TEM), particle size, and saturation magnetization results. A strong correlation between discharge capacity and voltage recovery behavior versus crystallite size was observed when tested as an electrode material in lithium electrochemical cells. Silver hollandite (AgxMn8O16) was successfully synthesized through a low temperature reflux reaction. The crystallite size and silver content of AgxMn8O16 by varying the reactant ratio of silver permanganate (AgMnO4) and manganese sulfate monohydrate (MnSO4˙H2O). Silver hollandite was characterized by Brunauer-Emmitt-Teller (BET) surface area, inductively coupled plasma-optical emission (ICP-OES) spectrometry, helium pycnometry, simultaneous thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), and x-ray powder diffraction (XRD). The crystallite size showed a strong correlation with silver content, BET surface area, and particle sizes. The silver hollandite cathode showed good discharge capacity retention in 30 cycles of discharge-charge. There were a good relationship between crystallite size and rate capability and pulse ability. Magnesium manganese oxide (MgxMnO2˙yH 2O) was made by redox reaction by mixing sodium hydroxide (NaOH), manganese sulfate monohydrate (MnSO4˙HO2), and potassium persulfate (K2S2O8

  19. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo; Car, Anja; Peinemann, Klaus-Viktor

    2010-01-01

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  20. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo

    2010-03-15

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  1. Combination of SANS and 3D stochastic reconstruction techniques for the study of nanostructured materials

    CERN Document Server

    Kikkinides, E S; Steriotis, T A; Kanellopoulos, N K; Mitropoulos, A C; Treimer, W

    2002-01-01

    Ceramic nanostructured materials have recently received scientific and industrial interest due to their unique properties. A series of such nanoporous structures were characterised by SANS techniques. The resulting scattering curves were analysed to obtain basic structural information regarding the pore size distribution and autocorrelation function of each material. Furthermore, stochastic reconstruction models were employed to generate 3D images with the same basic structural characteristics obtained from SANS. Finally, simulation results of permeation on the reconstructed images provide very good agreement with experimental data. (orig.)

  2. Fabrication and applications of copper sulfide (CuS) nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Shamraiz, Umair, E-mail: umairshamraiz@gmail.com; Hussain, Raja Azadar, E-mail: hussainazadar@gamil.com; Badshah, Amin, E-mail: aminbadshah@yahoo.com

    2016-06-15

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite). - Highlights: • This review article presents the synthesis and applications of copper sulfide. • CuS has been used over the years for different applications in nanoscience. • Different synthetic protocols are followed for their preparation which help in the possible modifications in the morphology of CuS.

  3. Modification of implant material surface properties by means of oxide nano-structured coatings deposition

    Science.gov (United States)

    Safonov, Vladimir; Zykova, Anna; Smolik, Jerzy; Rogowska, Renata; Lukyanchenko, Vladimir; Kolesnikov, Dmitrii

    2014-08-01

    The deposition of functional coatings on the metal surface of artificial joints is an effective way of enhancing joint tribological characteristics. It is well-known that nanostructured oxide coatings have specific properties advantageous for future implant applications. In the present study, we measured the high hardness parameters, the adhesion strength and the low friction coefficient of the oxide magnetron sputtered coatings. The corrosion test results show that the oxide coating deposition had improved the corrosion resistance by a factor of ten for both stainless steel and titanium alloy substrates. Moreover, the hydrophilic nature of coated surfaces in comparison with the metal ones was investigated in the tensiometric tests. The surfaces with nanostructured oxide coatings demonstrated improved biocompatibility for in vitro and in vivo tests, attributed to the high dielectric constants and the high values of the surface free energy parameters.

  4. NATO Advanced Research Workshop on New Materials for Thermoelectric Applications

    CERN Document Server

    Hewson, Alex

    2013-01-01

    Thermoelectric devices could play an important role in making efficient use of our energy resources but their efficiency would need to be increased for their wide scale application. There is a multidisciplinary search for materials with an enhanced thermoelectric responses for use in such devices. This volume covers the latest ideas and developments in this research field, covering topics ranging from the fabrication and characterization of new materials, particularly those with strong electron correlation, use of nanostructured, layered materials and composites, through to theoretical work to gain a deeper understanding of thermoelectric behavior. It should be a useful guide and stimulus to all working in this very topical field.

  5. Nanostructured materials with plasmonic nanobiosensors for early cancer detection: A past and future prospect.

    Science.gov (United States)

    Sugumaran, Sathish; Jamlos, Mohd Faizal; Ahmad, Mohd Noor; Bellan, Chandar Shekar; Schreurs, Dominique

    2018-02-15

    Early cancer detection and treatment is an emerging and fascinating field of plasmonic nanobiosensor research. It paves to enrich a life without affecting living cells leading to a possible survival of the patient. This review describes a past and future prospect of an integrated research field on nanostructured metamaterials, microwave transmission, surface plasmonic resonance, nanoantennas, and their manifested versatile properties with nano-biosensors towards early cancer detection to preserve human health. Interestingly, (i) microwave transmission shows more advantages than other electromagnetic radiation in reacting with biological tissues, (ii) nanostructured metamaterial (Au) with special properties like size and shape can stimulate plasmonic effects, (iii) plasmonic based nanobiosensors are to explore the efficacy for early cancer tumour detection or single molecular detection and (iv) nanoantenna wireless communication by using microwave inverse scattering nanomesh (MISN) technique instead of conventional techniques can be adopted to characterize the microwave scattered signals from the biomarkers. It reveals that the nanostructured material with plasmonic nanobiosensor paves a fascinating platform towards early detection of cancer tumour and is anticipated to be exploited as a magnificent field in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Synthesis of In2O3 nanostructures with different morphologies as potential supercapacitor electrode materials

    Science.gov (United States)

    Tuzluca, Fatma Nur; Yesilbag, Yasar Ozkan; Ertugrul, Mehmet

    2018-01-01

    In this study performed using a chemical vapor deposition (CVD) system, one-dimensional (1-D) single crystal indium oxide (In2O3) nanotowers, nanobouqets, nanocones, and nanowires were investigated as a candidate for a supercapacitor electrode material. These nanostructures were grown via Vapor-Liquid-Solid (VLS) and Vapor-Solid (VS) mechanisms according to temperature differences (1000-600 °C). The morphologies, growth mechanisms and crystal structures of these 1-D single crystal In2O3 nanostructures were defined by Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HR-TEM), X-Ray Diffraction (XRD) and Raman Spectroscopy analyses. The elemental analyses of the nanostructures were carried out by energy dispersive X-Ray Spectroscopy (EDS); they gave photoluminescence (PL) spectra with 3.39, 2.65, and 1.95 eV band gap values, corresponding to 365 nm, 467 nm, and 633 wavelengths, respectively. The electrochemical performances of these 1-D single crystal In2O3 nanostructures in an aqueous electrolyte solution (1 M Na2SO4) were determined by Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) analyses. According to GCD measurements at 0.04 mA cm-2 current density, areal capacitance values were 10.1 mF cm-2 and 6.7 mF cm-2 for nanotowers, 12.5 mF cm-2 for nanobouquets, 4.9 mF cm-2 for nanocones, and 16.6 mF cm-2 for nanowires. The highest areal capacitance value was observed in In2O3 nanowires, which retained 66.8% of their initial areal capacitance after a 10000 charge-discharge cycle, indicating excellent cycle stability.

  7. Nanostructured Carbon Materials as Supports in the Preparation of Direct Methanol Fuel Cell Electrocatalysts

    Directory of Open Access Journals (Sweden)

    María Jesús Lázaro

    2013-08-01

    Full Text Available Different advanced nanostructured carbon materials, such as carbon nanocoils, carbon nanofibers, graphitized ordered mesoporous carbons and carbon xerogels, presenting interesting features such as high electrical conductivity and extensively developed porous structure were synthesized and used as supports in the preparation of electrocatalysts for direct methanol fuel cells (DMFCs. The main advantage of these supports is that their physical properties and surface chemistry can be tailored to adapt the carbonaceous material to the catalytic requirements. Moreover, all of them present a highly mesoporous structure, diminishing diffusion problems, and both graphitic character and surface area can be conveniently modified. In the present work, the influence of the particular features of each material on the catalytic activity and stability was analyzed. Results have been compared with those obtained for commercial catalysts supported on Vulcan XC-72R, Pt/C and PtRu/C (ETEK. Both a highly ordered graphitic and mesopore-enriched structure of these advanced nanostructured materials resulted in an improved electrochemical performance in comparison to the commercial catalysts assayed, both towards CO and alcohol oxidation.

  8. Immobilization of lipase and keratinase on functionalized SBA-15 nanostructured materials

    Science.gov (United States)

    Le, Hy G.; Vu, Tuan A.; Tran, Hoa T. K.; Dang, Phuong T.

    2013-12-01

    SBA-15 nanostructured materials were synthesized via hydrothermal treatment and were functionalized with 3- aminopropyltriethoxysilane (APTES). The obtained samples were characterized by different techniques such as XRD, BET, TEM, IR and DTA. After functionalization, it showed that these nanostrucrured materials still maintained the hexagonal pore structure of the parent SBA-15. The model enzyms chosen in this study were lipase and keratinase. Lipase was a biocatalyst for hydrolyzation of long chain triglycerides or methyl esters of long chain alcohols and fatty acids; keratinase is a proteolytic enzyme that catalyzes the cleavage of keratin. The functionalized SBA-15 materials were used to immobilize lipase and keratinase, exhibiting higher activity than that of the unfunctionalized pure silica SBA-15 ones. This might be due to the enhancing of surface hydrophobicity upon functionalization. The surface functionalization of the nanostructured silicas with organic groups can favor the interaction between enzyme and the supports and consequently increasing the operational stability of the immobilized enzymes. The loading of lipase on functionalized SBA-15 materials was higher than that of keratinase. This might be rationalized by the difference in size of enzyms.

  9. Fabrication, Characterization, Properties, and Applications of Low-Dimensional BiFeO3 Nanostructures

    Directory of Open Access Journals (Sweden)

    Heng Wu

    2014-01-01

    Full Text Available Low-dimensional BiFeO3 nanostructures (e.g., nanocrystals, nanowires, nanotubes, and nanoislands have received considerable attention due to their novel size-dependent properties and outstanding multiferroic properties at room temperature. In recent years, much progress has been made both in fabrications and (microstructural, electrical, and magnetic in characterizations of BiFeO3 low-dimensional nanostructures. An overview of the state of art in BiFeO3 low-dimensional nanostructures is presented. First, we review the fabrications of high-quality BiFeO3 low-dimensional nanostructures via a variety of techniques, and then the structural characterizations and physical properties of the BiFeO3 low-dimensional nanostructures are summarized. Their potential applications in the next-generation magnetoelectric random access memories and photovoltaic devices are also discussed. Finally, we conclude this review by providing our perspectives to the future researches of BiFeO3 low-dimensional nanostructures and some key problems are also outlined.

  10. Large scale atomistic approaches to thermal transport and phonon scattering in nanostructured materials

    Science.gov (United States)

    Savic, Ivana

    2012-02-01

    Decreasing the thermal conductivity of bulk materials by nanostructuring and dimensionality reduction, or by introducing some amount of disorder represents a promising strategy in the search for efficient thermoelectric materials [1]. For example, considerable improvements of the thermoelectric efficiency in nanowires with surface roughness [2], superlattices [3] and nanocomposites [4] have been attributed to a significantly reduced thermal conductivity. In order to accurately describe thermal transport processes in complex nanostructured materials and directly compare with experiments, the development of theoretical and computational approaches that can account for both anharmonic and disorder effects in large samples is highly desirable. We will first summarize the strengths and weaknesses of the standard atomistic approaches to thermal transport (molecular dynamics [5], Boltzmann transport equation [6] and Green's function approach [7]) . We will then focus on the methods based on the solution of the Boltzmann transport equation, that are computationally too demanding, at present, to treat large scale systems and thus to investigate realistic materials. We will present a Monte Carlo method [8] to solve the Boltzmann transport equation in the relaxation time approximation [9], that enables computation of the thermal conductivity of ordered and disordered systems with a number of atoms up to an order of magnitude larger than feasible with straightforward integration. We will present a comparison between exact and Monte Carlo Boltzmann transport results for small SiGe nanostructures and then use the Monte Carlo method to analyze the thermal properties of realistic SiGe nanostructured materials. This work is done in collaboration with Davide Donadio, Francois Gygi, and Giulia Galli from UC Davis.[4pt] [1] See e.g. A. J. Minnich, M. S. Dresselhaus, Z. F. Ren, and G. Chen, Energy Environ. Sci. 2, 466 (2009).[0pt] [2] A. I. Hochbaum et al, Nature 451, 163 (2008).[0pt

  11. Nanostructured Materials

    Science.gov (United States)

    2012-08-30

    potassium hydroxide (2.088 mg) were added to a 10 mL volumetric flask. The balance of the volume to 10 mL was filled with ethanol. The contents were...water (0.27 g), and potassium hydroxide (2.088 mg) were added to a 10 mL volumetric flask. The balance of the volume to 10 mL was filled with ethanol...modification of metals, fill- ers, and composites can be prepared. Preferred reactive groups include but are not limited to silanols, siloxides, meth- acrylates

  12. Chemical Sensors Based on Metal Oxide Nanostructures

    Science.gov (United States)

    Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.; Kulis, Mike J.; Liu, Chung-Chiun

    2006-01-01

    This paper is an overview of sensor development based on metal oxide nanostructures. While nanostructures such as nanorods show significan t potential as enabling materials for chemical sensors, a number of s ignificant technical challenges remain. The major issues addressed in this work revolve around the ability to make workable sensors. This paper discusses efforts to address three technical barriers related t o the application of nanostructures into sensor systems: 1) Improving contact of the nanostructured materials with electrodes in a microse nsor structure; 2) Controling nanostructure crystallinity to allow co ntrol of the detection mechanism; and 3) Widening the range of gases that can be detected by using different nanostructured materials. It is concluded that while this work demonstrates useful tools for furt her development, these are just the beginning steps towards realizati on of repeatable, controlled sensor systems using oxide based nanostr uctures.

  13. Oxygen- and nitrogen-chemisorbed carbon nanostructures for Z-scheme photocatalysis applications

    International Nuclear Information System (INIS)

    Qian Zhao; Pathak, Biswarup; Nisar, Jawad; Ahuja, Rajeev

    2012-01-01

    Here focusing on the very new experimental finding on carbon nanomaterials for solid-state electron mediator applications in Z-scheme photocatalysis, we have investigated different graphene-based nanostructures chemisorbed by various types and amounts of species such as oxygen (O), nitrogen (N) and hydroxyl (OH) and their electronic structures using density functional theory. The work functions of different nanostructures have also been investigated by us to evaluate their potential applications in Z-scheme photocatalysis for water splitting. The N-, O–N-, and N–N-chemisorbed graphene-based nanostructures (32 carbon atoms supercell, corresponding to lattice parameter of about 1 nm) are found promising to be utilized as electron mediators between reduction level and oxidation level of water splitting. The O- or OH-chemisorbed nanostructures have potential to be used as electron conductors between H 2 -evolving photocatalysts and the reduction level (H + /H 2 ). This systematic study is proposed to understand the properties of graphene-based carbon nanostructures in Z-scheme photocatalysis and guide experimentalists to develop better carbon-based nanomaterials for more efficient Z-scheme photocatalysis applications in the future.

  14. Three-Dimensional ZnO Hierarchical Nanostructures: Solution Phase Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    Xiaoliang Wang

    2017-11-01

    Full Text Available Zinc oxide (ZnO nanostructures have been studied extensively in the past 20 years due to their novel electronic, photonic, mechanical and electrochemical properties. Recently, more attention has been paid to assemble nanoscale building blocks into three-dimensional (3D complex hierarchical structures, which not only inherit the excellent properties of the single building blocks but also provide potential applications in the bottom-up fabrication of functional devices. This review article focuses on 3D ZnO hierarchical nanostructures, and summarizes major advances in the solution phase synthesis, applications in environment, and electrical/electrochemical devices. We present the principles and growth mechanisms of ZnO nanostructures via different solution methods, with an emphasis on rational control of the morphology and assembly. We then discuss the applications of 3D ZnO hierarchical nanostructures in photocatalysis, field emission, electrochemical sensor, and lithium ion batteries. Throughout the discussion, the relationship between the device performance and the microstructures of 3D ZnO hierarchical nanostructures will be highlighted. This review concludes with a personal perspective on the current challenges and future research.

  15. Supper strong nanostructured TWIP steels for automotive applications

    Directory of Open Access Journals (Sweden)

    G.W. Yuan

    2014-02-01

    Full Text Available A ductile and super strong nanostructured twinning-induced plasticity (TWIP steels were fabricated by cold rolling and recovery treatment. This strong and ductile nanostructured alloy can be used for the anti-intrusion part of body-in-white. Cold rolling was used to produce intensive nano-twins so that the microstructure was greatly refined. Recovery is employed to anneal dislocations for improving the ductility. A physical model is proposed to describe the relationship between the yield stress and the twin density. Furthermore, the present work also found that the activation energy for recovery is ~160 J/mol, which implies that the recovery mechanism is governed by dislocation core diffusion.

  16. Recent Advances in Metal Chalcogenides (MX; X = S, Se) Nanostructures for Electrochemical Supercapacitor Applications: A Brief Review

    Science.gov (United States)

    Theerthagiri, Jayaraman; Durai, Govindarajan; Rana, Abu ul Hassan Sarwar; Sangeetha, Kirubanandam; Kuppusami, Parasuraman; Kim, Hyun-Seok

    2018-01-01

    Supercapacitors (SCs) have received a great deal of attention and play an important role for future self-powered devices, mainly owing to their higher power density. Among all types of electrical energy storage devices, electrochemical supercapacitors are considered to be the most promising because of their superior performance characteristics, including short charging time, high power density, safety, easy fabrication procedures, and long operational life. An SC consists of two foremost components, namely electrode materials, and electrolyte. The selection of appropriate electrode materials with rational nanostructured designs has resulted in improved electrochemical properties for high performance and has reduced the cost of SCs. In this review, we mainly spotlight the non-metallic oxide, especially metal chalcogenides (MX; X = S, Se) based nanostructured electrode materials for electrochemical SCs. Different non-metallic oxide materials are highlighted in various categories, such as transition metal sulfides and selenides materials. Finally, the designing strategy and future improvements on metal chalcogenide materials for the application of electrochemical SCs are also discussed. PMID:29671823

  17. Atomistic simulations of thermal transport in Si and SiGe based materials: From bulk to nanostructures

    Science.gov (United States)

    Savic, Ivana; Mingo, Natalio; Donadio, Davide; Galli, Giulia

    2010-03-01

    It has been recently proposed that Si and SiGe based nanostructured materials may exhibit low thermal conductivity and overall promising properties for thermoelectric applications. Hence there is a considerable interest in developing accurate theoretical and computational methods which can help interpret recent measurements, identify the physical origin of the reduced thermal conductivity, as well as shed light on the interplay between disorder and nanostructuring in determining a high figure of merit. In this work, we investigate the capability of an atomistic Green's function method [1] to describe phonon transport in several types of Si and SiGe based systems: amorphous Si, SiGe alloys, planar and nanodot Si/SiGe multilayers. We compare our results with experimental data [2,3], and with the findings of molecular dynamics simulations and calculations based on the Boltzmann transport equation. [1] I. Savic, N. Mingo, and D. A. Stewart, Phys. Rev. Lett. 101, 165502 (2008). [2] S.-M. Lee, D. G. Cahill, and R. Venkatasubramanian, Appl. Phys. Lett. 70, 2957 (1997). [3] G. Pernot et al., submitted.

  18. Photonic Nanostructures Design and Optimization for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2015-08-01

    Full Text Available In this paper, a semiconducting photonic nanostructure capable of wide range absorption and tunable optical resonance has been designed with a proposed theoretical optimization model. The design consists of ZnO/CdS core-shell nanowire arrays as well as multilayer thin films that act to absorb incident electromagnetic (EM waves over a broad frequency range. Theoretical, as well as numerical, studies of the nanostructure inside a solar cell plate have been conducted in order to validate the proposed microstructural design. Excellent energy absorption rates of EM waves have been achieved in the high frequency range by using the optical resonance of the nanowire array. By combining multilayer thin film with the core-shell nanowire in the unit cell of a photonic solar cell, a broadband high absorption has been achieved. Moreover, the geometry of the proposed photonic nanostructure is obtained through the implementation of a genetic algorithm. This avoids local minima and an optimized absorption rate of ~90% over the frequency range of 300 to 750 THz has been obtained in the solar cell.

  19. Zinc oxide nanostructured layers for gas sensing applications

    Science.gov (United States)

    Caricato, A. P.; Cretí, A.; Luches, A.; Lomascolo, M.; Martino, M.; Rella, R.; Valerini, D.

    2011-03-01

    Various kinds of zinc oxide (ZnO) nanostructures, such as columns, pencils, hexagonal pyramids, hexagonal hierarchical structures, as well as smooth and rough films, were grown by pulsed laser deposition using KrF and ArF excimer lasers, without use of any catalyst. ZnO films were deposited at substrate temperatures from 500 to 700°C and oxygen background pressures of 1, 5, 50, and 100 Pa. Quite different morphologies of the deposited films were observed using scanning electron microscopy when different laser wavelengths (248 or 193 nm) were used to ablate the bulk ZnO target. Photoluminescence studies were performed at different temperatures (down to 7 K). The gas sensing properties of the different nanostructures were tested against low concentrations of NO2. The variation in the photoluminescence emission of the films when exposed to NO2 was used as transduction mechanism to reveal the presence of the gas. The nanostructured films with higher surface-to-volume ratio and higher total surface available for gas adsorption presented higher responses, detecting NO2 concentrations down to 3 ppm at room temperature.

  20. Nanostructured Fe-Cr Alloys for Advanced Nuclear Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Scattergood, Ronald O. [North Carolina State Univ., Raleigh, NC (United States)

    2016-04-26

    We have completed research on the grain-size stabilization of model nanostructured Fe14Cr base alloys at high temperatures by the addition of non-equilibrium solutes. Fe14Cr base alloys are representative for nuclear reactor applications. The neutron flux in a nuclear reactor will generate He atoms that coalesce to form He bubbles. These can lead to premature failure of the reactor components, limiting their lifetime and increasing the cost and capacity for power generation. In order to mitigate such failures, Fe14Cr base alloys have been processed to contain very small nano-size oxide particles (less than 10 nm in size) that trap He atoms and reduce bubble formation. Theoretical and experimental results indicate that the grain boundaries can also be very effective traps for He atoms and bubble formation. An optimum grain size will be less than 100 nm, ie., nanocrystalline alloys must be used. Powder metallurgy methods based on high-energy ball milling can produce Fe-Cr base nanocrystalline alloys that are suitable for nuclear energy applications. The problem with nanocrystalline alloys is that excess grain-boundary energy will cause grains to grow at higher temperatures and their propensity for He trapping will be lost. The nano-size oxide particles in current generation nuclear alloys provide some grain size stabilization by reducing grain-boundary mobility (Zener pinning – a kinetic effect). However the current mitigation strategy minimizing bubble formation is based primarily on He trapping by nano-size oxide particles. An alternate approach to nanoscale grain size stabilization has been proposed. This is based on the addition of small amounts of atoms that are large compared to the base alloy. At higher temperatures these will diffuse to the grain boundaries and will produce an equilibrium state for the grain size at higher temperatures (thermodynamic stabilization – an equilibrium effect). This would be preferred compared to a kinetic effect, which is not

  1. Physical property control in core/shell inorganic nanostructures for fluorescence and magnetic targeting applications

    Science.gov (United States)

    Roberts, Stephen K.

    Nanomaterials show immense promise for the future in numerous areas of application. Properties that are unique from the bulk material and are tunable allow for innovation in material design. This thesis will focus on controlling the physical properties of core/shell nanostructures to enhance the utility of the materials. The first focus is on the impact of different solvent mixtures during the shell growth phase of SILAR based core/shell quantum dot synthesis is studied. Gaining insight into the mechanism for SILAR growth of core/shell nanoparticles allows improved synthetic yields and precursor binding, providing enhanced control to synthesis of core/shell nanoparticles. The second focus of this thesis is exploring the use of magnetic nanoparticles for magnetic drug targeting for cardiovascular conditions. Magnetic targeting for drug delivery enables increased local drug concentration, while minimizing non-specific interactions. In order to be effective for magnetic targeting, it must be shown that low magnetic strength is sufficient to capture flowing nanoparticles. By demonstrating the binding of a therapeutic agent to the surface at medicinal levels, the viability for use as a nanoparticle drug delivery system is improved.

  2. A Review on the Fabrication of Hierarchical ZnO Nanostructures for Photocatalysis Application

    Directory of Open Access Journals (Sweden)

    Yi Xia

    2016-11-01

    Full Text Available Semiconductor photocatalysis provides potential solutions for many energy and environmental-related issues. Recently, various semiconductors with hierarchical nanostructures have been fabricated to achieve efficient photocatalysts owing to their multiple advantages, such as high surface area, porous structures, as well as enhanced light harvesting. ZnO has been widely investigated and considered as the most promising alternative photocatalyst to TiO2. Herein, we present a review on the fabrication methods, growth mechanisms and photocatalytic applications of hierarchical ZnO nanostructures. Various synthetic strategies and growth mechanisms, including multistep sequential growth routes, template-based synthesis, template-free self-organization and precursor or self-templating strategies, are highlighted. In addition, the fabrication of multicomponent ZnO-based nanocomposites with hierarchical structures is also included. Finally, the application of hierarchical ZnO nanostructures and nanocomposites in typical photocatalytic reactions, such as pollutant degradation and H2 evolution, is reviewed.

  3. Synthesis and Application of One-Dimensional La(OH3 Nanostructures: An Overview

    Directory of Open Access Journals (Sweden)

    Xiang Xiao

    2014-01-01

    Full Text Available One-dimensional (1D semiconductor nanomaterials are of particular importance owing to their unique properties and potential applications. This review attempts to provide a comprehensive introduction of 1D La(OH3 nanostructures including nanowires, nanoneedles, nanobelts, and nanorods. Firstly, various strategies developed to fabricate the 1D La(OH3 nanostructures are discussed, such as precipitation and composite-hydroxide-mediated, hydrothermal, and solvothermal methods, accompanying the description of the corresponding growth mechanisms. Then, the unique properties such as novel physical properties of 1D La(OH3 nanostructures resulting from their unique electronic structures and numerous transition modes involving the 4f shells of these ions are represented in detail. Also, the wide applications in photocatalyst, capacitors, and photoluminescence based on the unique properties are discussed. Finally, the paper ends with a summary and some perspectives on the challenges and new directions in this emerging area.

  4. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

    Energy Technology Data Exchange (ETDEWEB)

    Hilty, F M; Hurrell, R F; Zimmermann, M B [Human Nutrition Laboratory, Institute of Food Science and Nutrition, ETH Zurich (Switzerland); Teleki, A; Buechel, R; Pratsinis, S E [Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich (Switzerland); Krumeich, F, E-mail: michael.zimmermann@ilw.agrl.ethz.c [Electron Microscopy Center (EMEZ), ETH Zurich (Switzerland)

    2009-11-25

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe{sub 2}O{sub 4}) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  5. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

    International Nuclear Information System (INIS)

    Hilty, F M; Hurrell, R F; Zimmermann, M B; Teleki, A; Buechel, R; Pratsinis, S E; Krumeich, F

    2009-01-01

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe 2 O 4 ) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  6. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications.

    Science.gov (United States)

    Hilty, F M; Teleki, A; Krumeich, F; Büchel, R; Hurrell, R F; Pratsinis, S E; Zimmermann, M B

    2009-11-25

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe2O4) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  7. Understanding and application of superconducting materials

    International Nuclear Information System (INIS)

    Moon, Byeong Mu; Lee, Chun Heung

    1997-02-01

    This book deals with superconducting materials, which contains from basic theory to application of superconducting materials. The contents of this book are mystery of superconducting materials, properties of superconducting materials, thermodynamics of superconducting materials, theoretical background of superconducting materials, tunnelling and quantum interference, classification and properties of superconducting materials, high temperature superconducting materials, production and analysis of superconducting materials and application of superconducting materials.

  8. Synthesis and functional properties of nanostructured ceria materials; Synthese und funktionelle Eigenschaften nanostrukturierter Ceroxidmaterialien

    Energy Technology Data Exchange (ETDEWEB)

    Naumann, Meike

    2014-06-02

    Nanostructured ceria tubes have been synthesised using electro spun polymer fibers as templating material. These polymer mats are produced by electro spinning starting with a polymer solution. In a next step polymer fibers are decorated with cer containing sol, which is then dried. To receive ceria tubes the polymer is removed on the one hand by thermal decomposition of the polymer or on the other hand by oxygen plasma treatment of ceria/polymer hybrid material. The resulting ceria tubes have a specific surface area of 98 m2 g-1. TEM, XRD, SAED and Raman investigations show a fully nanostructured crystallinity with cubic fluorine type structure. This obtained material shows a photo catalytic activity within decomposition of methylene blue in the Vis part of the electromagnetic spectrum. This photo catalytic activity can be increased using doping ions of transition and rare earth elements that are introduced in the sol-gel synthesis. Also here XRD and TEM investigations show a fully nano crystalline structure of ceria. Raman spectroscopy verifies the doping of ceria by transition and rare earth elements up to 22% of doping. No phase separation can be observed. The photo catalytic activity can be increased using these doped materials. Additionally a catalytic activity of pure ceria and mixed ceria/zirconia materials have been investigated synthesis of dimethylcarboxilate without water addition. Here a direct dependence between turn over and doping cannot be detected. The dependence can be deduced to the synthesis process of the catalyst. Terminal sensoric properties of doped and undoped ceria (n-type semiconductor) are investigated. The prepared materials are used as chemiresistors against oxygen at temperatures of 700 C. These investigations show a reversible increase of the electrical resistance against oxygen.

  9. Electrochemical supercapacitor application of electroless surface polymerization of polyaniline nanostructures

    International Nuclear Information System (INIS)

    Amarnath, Chellachamy A.; Chang, Jin Ho; Kim, Doyoung; Mane, Rajaram S.; Han, Sung-Hwan; Sohn, Daewon

    2009-01-01

    Electrochemical supercapacitive behaviour of polyaniline nanostructures, i.e., nanorods and nanospheres fabricated on aniline-primed conducting indium-tin oxide substrate via electroless surface polymerization using ammonium persulfate as initiator and selenious acid as efficient dopant is investigated. The self-assembled monolayer of urea derivative in presence of 3-(triethoxysilyl)-propyl isocyanate and aniline plays role of aniline-primed substrate. Polyaniline electrode composed of nanorods of excess surface area responsible for large redox reactions has shown 592 F g -1 specific capacitance which is significantly greater than closely compact polyaniline nanospheres, i.e., 214 F g -1

  10. Oriented ZnO nanostructures and their application in photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Man, Minh Tan [Department of Physics, Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 54896 (Korea, Republic of); Kim, Ji-Hee [Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419 (Korea, Republic of); Sungkyunkwan University (SKKU), Suwon, 16419 (Korea, Republic of); Jeong, Mun Seok [Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419 (Korea, Republic of); Department of Energy Science, Sungkyunkwan University, Suwon, 16419 (Korea, Republic of); Do, Anh-Thu Thi [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi (Viet Nam); Lee, Hong Seok, E-mail: hslee1@jbnu.ac.kr [Department of Physics, Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 54896 (Korea, Republic of)

    2017-05-15

    We report a chemical bath deposition approach for the preparation of large arrays of oriented ZnO nanostructures by activated substrate processes, and precipitated ZnO nanorods by passive occupation of the crystal surface. Photoluminescence dynamics showed that various visible emission characteristics associated with defects such as oxygen vacancy, zinc interstitial or their complexes. In addition, the precipitated ZnO nanorods exhibited excellent performance in the adsorption and photocatalytic decomposition of organic dyes, achieving 95% photodegradation of Rhodamine 6B. Moreover, oxygen defects function as trap sites with strong adsorption abilities towards organic dyes and showed high performance in the photocatalytic degradation of the dye molecules.

  11. The Process of Nanostructuring of Metal (Iron Matrix in Composite Materials for Directional Control of the Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Elena Zemtsova

    2014-01-01

    Full Text Available We justified theoretical and experimental bases of synthesis of new class of highly nanostructured composite nanomaterials based on metal matrix with titanium carbide nanowires as dispersed phase. A new combined method for obtaining of metal iron-based composite materials comprising the powder metallurgy processes and the surface design of the dispersed phase is considered. The following stages of material synthesis are investigated: (1 preparation of porous metal matrix; (2 surface structuring of the porous metal matrix by TiC nanowires; (3 pressing and sintering to give solid metal composite nanostructured materials based on iron with TiC nanostructures with size 1–50 nm. This material can be represented as the material type “frame in the frame” that represents iron metal frame reinforcing the frame of different chemical compositions based on TiC. Study of material functional properties showed that the mechanical properties of composite materials based on iron with TiC dispersed phase despite the presence of residual porosity are comparable to the properties of the best grades of steel containing expensive dopants and obtained by molding. This will solve the problem of developing a new generation of nanostructured metal (iron-based materials with improved mechanical properties for the different areas of technology.

  12. Uncovering New Thermal and Elastic Properties of Nanostructured Materials Using Coherent EUV Light

    Science.gov (United States)

    Hernandez Charpak, Jorge Nicolas

    Advances in nanofabrication have pushed the characteristic dimensions of nanosystems well below 100nm, where physical properties are often significantly different from their bulk counterparts, and accurate models are lacking. Critical technologies such as thermoelectrics for energy harvesting, nanoparticle-mediated thermal therapy, nano-enhanced photovoltaics, and efficient thermal management in integrated circuits depend on our increased understanding of the nanoscale. However, traditional microscopic characterization tools face fundamental limits at the nanoscale. Theoretical efforts to build a fundamental picture of nanoscale thermal dynamics lack experimental validation and still struggle to account for newly reported behaviors. Moreover, precise characterization of the elastic behavior of nanostructured systems is needed for understanding the unique physics that become apparent in small-scale systems, such as thickness-dependent or fabrication-dependent elastic properties. In essence, our ability to fabricate nanosystems has outstripped our ability to understand and characterize them. In my PhD thesis, I present the development and refinement of coherent extreme ultraviolet (EUV) nanometrology, a novel tool used to probe material properties at the intrinsic time- and length-scales of nanoscale dynamics. By extending ultrafast photoacoustic and thermal metrology techniques to very short probing wavelengths using tabletop coherent EUV beams from high-harmonic upconversion (HHG) of femtosecond lasers, coherent EUV nanometrology allows for a new window into nanoscale physics, previously unavailable with traditional techniques. Using this technique, I was able to probe both thermal and acoustic dynamics in nanostructured systems with characteristic dimensions below 50nm with high temporal (sub-ps) and spatial (size and spacing of the nanoscale heat sources with the phonon spectrum of a material. This makes our technique one of the only experimental routes to

  13. Plastic Materials for Insulating Applications.

    Science.gov (United States)

    Wang, S. F.; Grossman, S. J.

    1987-01-01

    Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

  14. Surface modification of plasmonic nanostructured materials with thiolated oligonucleotides in 10 seconds using selective microwave heating

    International Nuclear Information System (INIS)

    Abel, B.; Aslan, K.

    2012-01-01

    This study demonstrates the proof-of-principle of rapid surface modification of plasmonic nanostructured materials with oligonucleotides using low power microwave heating. Due to their interesting optical and electronic properties, silver nanoparticle films (SNFs, 2 nm thick) deposited onto glass slides were used as the model plasmonic nanostructured materials. Rapid surface modification of SNFs with oligonucleotides was carried out using two strategies (1) Strategy 1: for ss-oligonucleotides, surface hybridization and (2) Strategy 2: for ds-oligonucleotides, solution hybridization, where the samples were exposed to 10, 15, 30 and 60 seconds microwave heating. To assess the efficacy of our new rapid surface modification technique, identical experiments carried out without the microwave heating (i.e., conventional method), which requires 24 hours for the completion of the identical steps. It was found that SNFs can be modified with ss- and ds-oligonucleotides in 10 seconds, which typically requires several hours of incubation time for the chemisorption of thiol groups on to the planar metal surface using conventional techniques. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Prevention of microbial biofilms - the contribution of micro and nanostructured materials.

    Science.gov (United States)

    Grumezescu, Alexandru Mihai; Chifiriuc, Carmen Mariana

    2014-01-01

    Microbial biofilms are associated with drastically enhanced resistance to most of the antimicrobial agents and with frequent treatment failures, generating the search for novel strategies which can eradicate infections by preventing the persistent colonization of the hospital environment, medical devices or human tissues. Some of the current approaches for fighting biofilms are represented by the development of novel biomaterials with increased resistance to microbial colonization and by the improvement of the current therapeutic solutions with the aid of nano (bio)technology. This special issues includes papers describing the applications of nanotechnology and biomaterials science for the development of improved drug delivery systems and nanostructured surfaces for the prevention and treatment of medical biofilms. Nanomaterials display unique and well-defined physical and chemical properties making them useful for biomedical applications, such as: very high surface area to volume ratio, biocompatibility, biodegradation, safety for human ingestion, capacity to support surface modification and therefore, to be combined with other bioactive molecules or substrata and more importantly being seemingly not attracting antimicrobial resistance. The use of biomaterials is significantly contributing to the reduction of the excessive use of antibiotics, and consequently to the decrease of the emergence rate of resistant microorganisms, as well as of the associated toxic effects. Various biomaterials with intrinsic antimicrobial activity (inorganic nanoparticles, polymers, composites), medical devices for drug delivery, as well as factors influencing their antimicrobial properties are presented. One of the presented papers reviews the recent literature on the use of magnetic nanoparticles (MNP)-based nanomaterials in antimicrobial applications for biomedicine, focusing on the growth inhibition and killing of bacteria and fungi, and, on viral inactivation. The anti

  16. Assigned and unassigned distance geometry: applications to biological molecules and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Billinge, Simon J. L. [Columbia Univ., New York, NY (United States). Applied Physics and Applied Mathematics; Brookhaven National Lab. (BNL), Upton, NY (United States). X-ray Scattering Group; Duxbury, Phillip M. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Gonçalves, Douglas S. [Univ. Federal de Santa Catarina,; Lavor, Carlile [Univ. of Campinas (UNICAMP), Sao Paulo (Brazil). Dept. of Applied Mathematics (IMECC-UNICAMP); Mucherino, Antonio [Univ. de Rennes, Rennes (France). Institut de Recherche en Informatique et Systemes Aleatoires

    2016-04-04

    Here, considering geometry based on the concept of distance, the results found by Menger and Blumenthal originated a body of knowledge called distance geometry. This survey covers some recent developments for assigned and unassigned distance geometry and focuses on two main applications: determination of three-dimensional conformations of biological molecules and nanostructures.

  17. Plasmonic enhancement of scattering and emission of light in nanostructures: from basic science to biomedical applications

    International Nuclear Information System (INIS)

    Gaponenko, Sergey

    2013-01-01

    Advances and challenges of plasmonic enhancement of Raman scattering and fluorescence with metal-dielectric nanostructures are discussed. Theoretical predictions and experimental implementation are presented and compared. Reasonable agreement of experimental data with the theory is outlined. Special attention is given to biomedical applications including fluorescent and Raman immunospectroscopy. (author)

  18. Experimental Study of Nonequilibrium Electrodeposition of Nanostructures on Copper and Nickel for Photochemical Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Rajesh K. Shanmugam

    2011-01-01

    Full Text Available To increase the performance of photochemical fuel cells, nonequilibrium electrodeposition has been performed on Cu and Ni to make photosensitive anodes. Processing parameters including electrolyte concentration, and electrode potential were studied using cyclic voltammetry. Scanning electron microscopy (SEM and X-ray Spectroscopy (EDS were performed to understand the formation of the nanostructures during the nonequilibrium deposition of copper fractals. An increase in the deposition rate was observed with the increase in electrolyte concentration (from 0.05 M to 1.0 M. Similar trend was found when the cathode potential was decreased from −0.5 V to −4.5 V. The effect of substrate material was also examined. Porous fractal structures on copper were achieved, while the deposited material showed high density of surface cracks on nickel. The fractal structures deposited on copper electrode with the increased surface area were converted into copper oxide by oxidation in air. Such oxide samples were made into anodes for photochemical fuel cell application. We demonstrated that an increase in the magnitude of open circuit output voltage is associated with the increase in the fractal surface area under the ultraviolet irradiation test conditions. However, the electrodeposited fractals on nickel showed very limited increase in the magnitude of open circuit voltage.

  19. Microwave materials for wireless applications

    CERN Document Server

    Cruickshank, David B

    2011-01-01

    This practical resource offers you an in-depth, up-to-date understanding of the use of microwave magnetic materials for cutting-edge wireless applications. The book discusses device applications used in wireless infrastructure base stations, point-to-point radio links, and a range of more specialized microwave systems. You find detailed discussions on the attributes of each family of magnetic materials with respect to specific wireless applications. Moreover, the book addresses two of the hottest topics in the field today - insertion loss and intermodulation. This comprehensive reference also

  20. Leading research on super metal. 3. Amorphous and nanostructured metallic materials; Super metal no sendo kenkyu. 3. Kogata buzai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Very fine structure control technique for amorphous and nanostructured metallic materials was reviewed to exceed the marginal performance of small metallic member materials. In Japan, high strength alloys and anticorrosion alloys are currently developed as an amorphous structure control technique, and ultra fine powder production and nano-compaction molding are studied for nanostructured materials. Fabrication of amorphous alloy wire materials and metal glass in USA are also introduced. Fabrication of metallic nanocrystals deposited within gas phase in Germany are attracting attention. The strength and abrasion resistance are remarkably enhanced by making nanostructured crystals and dispersing them. It may be most suitable to utilize amorphous and nanostructured metallic materials for earth-friendly materials having anticorrosion, and catalyst and biomaterial affinities, and also for magnetic materials. It is important for controlling micro-structures to clarify the formation mechanism of structures. For their processing techniques, the diversity and possibility are suggested, as to the condensation and solidification of gaseous and liquid phase metals, the molding and processing of very fine solid phase alloys, and the manufacturing members by heat treatment. 324 refs., 109 figs., 21 tabs.

  1. Multi-particle assembled porous nanostructured MgO: its application in fluoride removal

    International Nuclear Information System (INIS)

    Gangaiah, Vijayakumar; Chandrappa, Gujjarahalli Thimanna; Siddaramanna, Ashoka

    2014-01-01

    In this article, a simple and economical route based on ethylene glycol mediated process was developed to synthesize one-dimensional (1D) multiparticle assembled nanostructured MgO using magnesium acetate and urea as reactants. Porous multiparticle chain-like MgO has been synthesized by the calcination of a solvothermally derived single nanostructured precursor. The prepared products were characterized by an x-ray diffraction (XRD) pattern, thermogravimetry, scanning/transmission electron microscopy (SEM/TEM) and N 2 adsorption (BET). As a proof of concept, the porous multiparticle chain-like MgO has been applied in a water treatment for isolated and rural communities, and it has exhibited an excellent adsorption capability to remove fluoride in waste water. In addition, this method could be generalized to prepare other 1D nanostructures with great potential for various attractive applications. (paper)

  2. Nanostructure-based proton exchange membrane for fuel cell applications at high temperature.

    Science.gov (United States)

    Li, Junsheng; Wang, Zhengbang; Li, Junrui; Pan, Mu; Tang, Haolin

    2014-02-01

    As a clean and highly efficient energy source, the proton exchange membrane fuel cell (PEMFC) has been considered an ideal alternative to traditional fossil energy sources. Great efforts have been devoted to realizing the commercialization of the PEMFC in the past decade. To eliminate some technical problems that are associated with the low-temperature operation (such as catalyst poisoning and poor water management), PEMFCs are usually operated at elevated temperatures (e.g., > 100 degrees C). However, traditional proton exchange membrane (PEM) shows poor performance at elevated temperature. To achieve a high-performance PEM for high temperature fuel cell applications, novel PEMs, which are based on nanostructures, have been developed recently. In this review, we discuss and summarize the methods for fabricating the nanostructure-based PEMs for PEMFC operated at elevated temperatures and the high temperature performance of these PEMs. We also give an outlook on the rational design and development of the nanostructure-based PEMs.

  3. Magnetic resonance of semiconductors and their nanostructures basic and advanced applications

    CERN Document Server

    Baranov, Pavel G; Jelezko, Fedor; Wrachtrup, Jörg

    2017-01-01

    This book explains different magnetic resonance (MR) techniques and uses different combinations of these techniques to analyze defects in semiconductors and nanostructures. It also introduces novelties such as single defects MR and electron-paramagnetic-resonance-based methods: electron spin echo, electrically detected magnetic resonance, optically detected magnetic resonance and electron-nuclear double resonance – the designated tools for investigating the structural and spin properties of condensed systems, living matter, nanostructures and nanobiotechnology objects. Further, the authors address problems existing in semiconductor and nanotechnology sciences that can be resolved using MR, and discuss past, current and future applications of MR, with a focus on advances in MR methods. The book is intended for researchers in MR studies of semiconductors and nanostructures wanting a comprehensive review of what has been done in their own and related fields of study, as well as future perspectives.

  4. Nanostructured porous graphene and its composites for energy storage applications

    Science.gov (United States)

    Ramos Ferrer, Pablo; Mace, Annsley; Thomas, Samantha N.; Jeon, Ju-Won

    2017-10-01

    Graphene, 2D atomic-layer of sp2 carbon, has attracted a great deal of interest for use in solar cells, LEDs, electronic skin, touchscreens, energy storage devices, and microelectronics. This is due to excellent properties of graphene, such as a high theoretical surface area, electrical conductivity, and mechanical strength. The fundamental structure of graphene is also manipulatable, allowing for the formation of an even more extraordinary material, porous graphene. Porous graphene structures can be categorized as microporous, mesoporous, or macroporous depending on the pore size, all with their own unique advantages. These characteristics of graphene, which are further explained in this paper, may be the key to greatly improving a wide range of applications in energy storage systems.

  5. Nanostructured Titanium-10 wt% 45S5 Bioglass-Ag Composite Foams for Medical Applications

    Directory of Open Access Journals (Sweden)

    Karolina Jurczyk

    2015-03-01

    Full Text Available The article presents an investigation on the effectiveness of nanostructured titanium-10 wt% 45S5 Bioglass-1 wt% Ag composite foams as a novel class of antibacterial materials for medical applications. The Ti-based composite foams were prepared by the combination of mechanical alloying and a “space-holder” sintering process. In the first step, the Ti-10 wt% 45S5 Bioglass-1 wt% Ag powder synthesized by mechanical alloying and annealing mixed with 1.0 mm diameter of saccharose crystals was finally compacted in the form of pellets. In the next step, the saccharose crystals were dissolved in water, leaving open spaces surrounded by metallic-bioceramic scaffold. The sintering of the scaffold leads to foam formation. It was found that 1:1 Ti-10 wt% 45S5 Bioglass-1 wt% Ag/sugar ratio leads to porosities of about 70% with pore diameter of about 0.3–1.1 mm. The microstructure, corrosion resistance in Ringer’s solution of the produced foams were investigated. The value of the compression strength for the Ti-10 wt% 45S5 Bioglass-1 wt% Ag foam with 70% porosity was 1.5 MPa and the Young’s modulus was 34 MPa. Silver modified Ti-10 wt% 45S5 Bioglass composites possess excellent antibacterial activities against Staphylococcus aureus. Porous Ti-10 wt% 45S5 Bioglass-1 wt% foam could be a possible candidate for medical implants applications.

  6. Recent developments of nano-structured materials as the catalysts for oxygen reduction reaction

    Science.gov (United States)

    Kang, SungYeon; Kim, HuiJung; Chung, Yong-Ho

    2018-04-01

    Developments of high efficient materials for electrocatalyst are significant topics of numerous researches since a few decades. Recent global interests related with energy conversion and storage lead to the expansion of efforts to find cost-effective catalysts that can substitute conventional catalytic materials. Especially, in the field of fuel cell, novel materials for oxygen reduction reaction (ORR) have been noticed to overcome disadvantages of conventional platinum-based catalysts. Various approaching methods have been attempted to achieve low cost and high electrochemical activity comparable with Pt-based catalysts, including reducing Pt consumption by the formation of hybrid materials, Pt-based alloys, and not-Pt metal or carbon based materials. To enhance catalytic performance and stability, numerous methods such as structural modifications and complex formations with other functional materials are proposed, and they are basically based on well-defined and well-ordered catalytic active sites by exquisite control at nanoscale. In this review, we highlight the development of nano-structured catalytic materials for ORR based on recent findings, and discuss about an outlook for the direction of future researches.

  7. Synchrotron SAXS Studies of Nanostructured Materials and Colloidal Solutions: A Review

    Directory of Open Access Journals (Sweden)

    Craievich A.F.

    2002-01-01

    Full Text Available Structural characterisations using the SAXS technique in a number of nanoheterogeneous materials and liquid solutions are reviewed. The studied systems are protein (lysozyme/water solutions, colloidal ZnO particles/water sols, nanoporous NiO-based xerogels, hybrid organic-inorganic siloxane-PEG and PPG nanocomposites and PbTe semiconductor nanocrystals embedded in a glass matrix. These investigations also focus on the transformations of time-varying structures and on structural changes related to variations in temperature and composition. The reviewed investigations aim at explaining the unusual and often interesting properties of nanostructured materials and solutions. Most of the reported studies were carried out using the SAXS beamline at the National Synchrotron Light Laboratory (LNLS, Campinas, Brazil.

  8. An investigation into carbon nanostructured materials as catalyst support in proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Veltzé, Sune

    acid treatment on the Vapour Grown Carbon Fibers™ manufactured by Showa Denko K. K. From these fibres, twelve platinised samples were investigated, of which one was platinised by a platinum phtalocyanine impregnation method, two were platinised by the polyol method and the remaining by the Bönnemann......Polymer electrolyte fuel cells (PEFCs) are among the key research areas concerning clean cost-effective energy. Carbon nano fibres (CNF), single walled carbon nano tubes (SWCNT), multi walled carbon nano tubes (MWCNT) and other related materials are among the possible successors to standard carbon...... black support materials for low platinum containing electrocatalyst. This is partly due to their high electronic conductivity. Partly due to their high surface area needed for the dispersion of nanoparticulate metal-clusters. In addition carbon nano-structures (CNF, SWCNT, MWCNT etc.) are more durable...

  9. Superhard nanophase cutter materials for rock drilling applications; FINAL

    International Nuclear Information System (INIS)

    Voronov, O.; Tompa, G.; Sadangi, R.; Kear, B.; Wilson, C.; Yan, P.

    2000-01-01

    The Low Pressure-High Temperature (LPHT) System has been developed for sintering of nanophase cutter and anvil materials. Microstructured and nanostructured cutters were sintered and studied for rock drilling applications. The WC/Co anvils were sintered and used for development of High Pressure-High Temperature (HPHT) Systems. Binderless diamond and superhard nanophase cutter materials were manufactured with help of HPHT Systems. The diamond materials were studied for rock machining and drilling applications. Binderless Polycrystalline Diamonds (BPCD) have high thermal stability and can be used in geothermal drilling of hard rock formations. Nanophase Polycrystalline Diamonds (NPCD) are under study in precision machining of optical lenses. Triphasic Diamond/Carbide/Metal Composites (TDCC) will be commercialized in drilling and machining applications

  10. Laser Photolysis and Thermolysis of Organic Selenides and Tellurides for Chemical Gas-phase Deposition of Nanostructured Materials

    Directory of Open Access Journals (Sweden)

    Josef Pola

    2009-03-01

    Full Text Available Laser radiation-induced decomposition of gaseous organic selenides and tellurides resulting in chemical deposition of nanostructured materials on cold surfaces is reviewed with regard to the mechanism of the gas-phase decomposition and properties of the deposited materials. The laser photolysis and laser thermolysis of the Se and Te precursors leading to chalcogen deposition can also serve as a useful approach to nanostructured chalcogen composites and IVA group (Si, Ge, Sn element chalcogenides provided that it is carried out simultaneously with laser photolysis or thermolysis of polymer and IVA group element precursor.

  11. Superhydrophobic Materials for Biomedical Applications

    Science.gov (United States)

    Colson, Yolonda L.; Grinstaff, Mark W.

    2016-01-01

    Superhydrophobic surfaces are actively studied across a wide range of applications and industries, and are now finding increased use in the biomedical arena as substrates to control protein adsorption, cellular interaction, and bacterial growth, as well as platforms for drug delivery devices and for diagnostic tools. The commonality in the design of these materials is to create a stable or metastable air state at the material surface, which lends itself to a number of unique properties. These activities are catalyzing the development of new materials, applications, and fabrication techniques, as well as collaborations across material science, chemistry, engineering, and medicine given the interdisciplinary nature of this work. The review begins with a discussion of superhydrophobicity, and then explores biomedical applications that are utilizing superhydrophobicity in depth including material selection characteristics, in vitro performance, and in vivo performance. General trends are offered for each application in addition to discussion of conflicting data in the literature, and the review concludes with the authors’ future perspectives on the utility of superhydrophobic surfaces for biomedical applications. PMID:27449946

  12. Synthesis, characterization, properties, and applications of nanosized ferroelectric, ferromagnetic, or multiferroic materials

    International Nuclear Information System (INIS)

    Dhak, Debasis; Das, Soma; Communication Engineering.); Dhak, Prasanta

    2015-01-01

    Recently, there has been an enormous increase in research activity in the field of ferroelectrics and ferromagnetics especially in multiferroic materials which possess both ferroelectric and ferromagnetic properties simultaneously. However, the ferroelectric, ferromagnetic, and multiferroic properties should be further improved from the utilitarian and commercial viewpoints. Nanostructural materials are central to the evolution of future electronics and information technologies. Ferroelectrics and ferromagnetics have already been established as a dominant branch in electronics sector because of their diverse applications. The ongoing dimensional downscaling of materials to allow packing of increased numbers of components into integrated circuits provides the momentum for evolution of nanostructural devices. Nanoscaling of the above materials can result in a modification of their functionality. Furthermore, nanoscaling can be used to form high density arrays of nanodomain nanostructures, which is desirable for miniaturization of devices

  13. Thermoelectric properties and nanostructures of materials prepared from rice husk ash

    Energy Technology Data Exchange (ETDEWEB)

    Pukird, S.; Tipparach, U.; Kasian, P. [Ubon Ratchathani Univ., Ubon Ratchathani (Thailand). Dept. of Physics; Limsuwan, P. [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Dept. of Physics

    2009-07-01

    Thailand produces large amounts of agricultural residues such as rice husk and coconut shells. Rice husk is considered to be a potential source for solar grade silicon. Studies have shown that reasonably pure polycrystalline silicon can be prepared from rice husk white ash by a metallothermic reduction process. This paper reported on a study that investigated the thermoelectric properties of ceramic material prepared by mixing silica from rice husk ash and carbon obtained from coconut shell charcoal. The thermoelectric properties of the materials were examined along with their microstructures. The materials were made from burning rice husk ash and coconut shell at different temperatures and then doped with metal oxides. Pellets were heated at temperature of 700 degrees C for 1-3 hours. The voltage on both sides of the pellets was observed. The electromotive force was found when different temperatures were applied on both sides of the pellet specimens. The Seebeck coefficient was then calculated. The results showed that these materials can be used as thermoelectric devices. Scanning electron microscope (SEM) and energy dispersive X-rays (EDX) were used to investigate the source of materials and the products on the substrates. The images of SEM and EDX showed nanostructures of materials such as nanowires, nanorods and nanoparticles of the products and sources. 22 refs., 2 tabs., 9 figs.

  14. Facile synthesis of hierarchical gold nanostructures and their catalytic application

    Science.gov (United States)

    Ma, Ying; Siang Yi, Edward Ng

    2016-08-01

    We demonstrate a one-step, surfactant-free method to prepare gold (Au) nanostructures using a synthesized aniline (ANI) derivative N-(3-amidino)-aniline (NAAN) as a reducing agent. By simply mixing NAAN with a Au precursor, raspberry-like Au particles (RSPs) were formed. The presence of Ag+ resulted in the formation of Au nanoflowers (AuNFs). The size and shape of the AuNFs can be tuned by the reaction conditions such as the NAAN/HAuCl4 ratio, the temperature and the solvent composition. Under the same reaction conditions, bowling-pin-like particles (BPLPs) were reported for the first time using commercial ANI as a reducing agent. The AuNFs exhibited good ability to oxidize peroxidase substrate 3, 3‧, 5, 5‧-tetramethylbenzidine (TMB) by H2O2, allowing them as a peroxidase mimetic.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhuiykov, Serge, E-mail: serge.zhuiykov@ugent.be [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-Gu, Incheon 406-840 (Korea, Republic of); Kawaguchi, Toshikazu [Global Station for Food, Land and Water Resources, Global Institution for Collaborative Research and Education, Hokkaido University, N10W5 Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Graduate School of Environmental Science, Hokkaido University, N10W5 Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Hai, Zhenyin; Karbalaei Akbari, Mohammad; Heynderickx, Philippe M. [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-Gu, Incheon 406-840 (Korea, Republic of)

    2017-01-15

    Highlights: • Advantages of atomic layer deposition technology (ALD) for two-dimensional nano-crystals. • Conformation of ALD technique and chemistry of precursors. • ALD of semiconductor oxide thin films. • Ultra-thin (∼1.47 nm thick) ALD-developed tungsten oxide nano-crystals on large area. - Abstract: 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 (WO{sub 3}) 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.

  16. Nano-Structured Bio-Inorganic Hybrid Material for High Performing Oxygen Reduction Catalyst.

    Science.gov (United States)

    Jiang, Rongzhong; Tran, Dat T; McClure, Joshua P; Chu, Deryn

    2015-08-26

    In this study, we demonstrate a non-Pt nanostructured bioinorganic hybrid (BIH) catalyst for catalytic oxygen reduction in alkaline media. This catalyst was synthesized through biomaterial hemin, nanostructured Ag-Co alloy, and graphene nano platelets (GNP) by heat-treatment and ultrasonically processing. This hybrid catalyst has the advantages of the combined features of these bio and inorganic materials. A 10-fold improvement in catalytic activity (at 0.8 V vs RHE) is achieved in comparison of pure Ag nanoparticles (20-40 nm). The hybrid catalyst reaches 80% activity (at 0.8 V vs RHE) of the state-of-the-art catalyst (containing 40% Pt and 60% active carbon). Comparable catalytic stability for the hybrid catalyst with the Pt catalyst is observed by chronoamperometric experiment. The hybrid catalyst catalyzes 4-electron oxygen reduction to produce water with fast kinetic rate. The rate constant obtained from the hybrid catalyst (at 0.6 V vs RHE) is 4 times higher than that of pure Ag/GNP catalyst. A catalytic model is proposed to explain the oxygen reduction reaction at the BIH catalyst.

  17. Preface to the Viewpoint Set: Nanostructured metals - Advances in processing, characterization and application

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2009-01-01

    with increasingly finer structures in order to improve properties and sustainability. The structural scale of interest in such materials is therefore reduced to the nanometer range, which means that characterization and modeling of nanostructured metals now address an audience including not only physicists...... and materials scientists but also technologists and engineers. The present Viewpoint Set therefore covers metallic materials with a structural scale ranging from micrometer to nanometer in dimensions and focuses on processing techniques such as plastic deformation and phase transformations. As a result......The theme of two viewpoint sets has been nanostructured metals: one in 2003 on “Mechanical properties of fully dense nanocrystalline metals” (Scripta Materialia 2003;49:625–680) and one in 2004 on “Metals and alloys with a structural scale from the micrometer to the atomic dimensions” (Scripta...

  18. Processing and evaluation of x-ray line profiles measured from nanostructured materials produced by severe plastic deformation

    International Nuclear Information System (INIS)

    KEXrber, M.; Schafler, E.; Zehetbauer, M.

    2005-01-01

    Full text: The classification of the microstructure of nanostructured materials and its relation to macroscopic properties is essential for the development and application of nanomaterials. X-ray line profile analysis is a nondestructive method yielding a series of interesting microstructural parameters: the Bragg reflection of an ideal crystal is a narrow delta-function liKEX peak. Distortions of the regular crystal lattice as well as a finite size of the coherently scattering domains lead to a significant broadening of the peak. By using physical models describing the individual types of broadening it is possible to relate the broadening of the peak to the microstructure of the material. The most successful applications to date assume mainly size and strain broadening. From these models various techniques have been developed to evaluate the same physical quantities via individual methods. Among these methods are the Williamson-Hall and Warren Averbach methods, their so called 'modified' variants and multiple-whole-profile-fitting/modeling. A number of typical problems arising during data preparation and evaluation are presented and a procedure to optimize the processing of the experimental data is given. Refs. 9 (author)

  19. Multistage electrodeposition of supported platinum-based nanostructured systems for electrocatalytic applications

    CSIR Research Space (South Africa)

    Mkwizu, TS

    2011-05-01

    Full Text Available .R. Modibedi and Mkhulu K. Mathe* *kmathe@csir.co.za 219th ECS Meeting, 1 ? 6 May, 2011, Montreal, Canada Multistage Electrodeposition of Supported Platinum-based Nanostructured Systems for Electrocatalytic Applications Overview ? Acknowledgements... of constituent elements of the given electrode surface. ? Applications areas: Fuel cells, electrochemical sensors, electrolyzers Introduction e- A B 5 Introduction Atomic-level processes during electrocatalysis www...

  20. Graphene-Metal Oxide Hybrid Nanostructured Materials for Electrocatalytic Sensing and Sustainable Energy Storage

    DEFF Research Database (Denmark)

    Halder, Arnab; Zhang, Minwei; Chi, Qijin

    2016-01-01

    Graphene based materials have attracted tremendous attention, attributed to their unique physicochemical properties and versatile applications. In general, these materials are very promising candidates for the development of next-generation electrochemical systems for energy and environmental tec...

  1. The effect of dimensionality of nanostructured carbon on the architecture of organic-inorganic hybrid materials.

    Science.gov (United States)

    Misra, R D K; Depan, D; Shah, J

    2013-08-21

    The natural tendency of carbon nanotubes (CNTs) to agglomerate is an underlying reason that prevents the realization of their full potential. On the other hand, covalent functionalization of CNTs to control dispersion leads to disruption of π-conjugation in CNTs and the non-covalent functionalization leads to a weak CNT-polymer interface. To overcome these challenges, we describe the characteristics of fostering of direct nucleation of polymers on nanostructured carbon (CNTs of diameters (~2-200 nm), carbon nanofibers (~200-300 nm), and graphene), which culminates in interfacial adhesion, resulting from electrostatic and van der Waals interaction in the hybrid nanostructured carbon-polymer architecture. Furthermore, the structure is tunable through a change in undercooling. High density polyethylene and polypropylene were selected as two model polymers and two sets of experiments were carried out. The first set of experiments was carried out using CNTs of diameter ~2-5 nm to explore the effect of undercooling and polymer concentration. The second set of experiments was focused on studying the effect of dimensionality on geometrical confinements. The periodic crystallization of polyethylene on small diameter CNTs is demonstrated to be a consequence of the geometrical confinement effect, rather than epitaxy, such that petal-like disks nucleate on large diameter CNTs, carbon nanofibers, and graphene. The application of the process is illustrated in terms of fabricating a system for cellular uptake and bioimaging.

  2. Physics and Mechanics of New Materials and Their Applications

    CERN Document Server

    Chang, Shun-Hsyung; Gupta, Vijay

    2018-01-01

    This book presents selected peer-reviewed contributions from the 2017 International Conference on “Physics and Mechanics of New Materials and Their Applications”, PHENMA 2017 (Jabalpur, India, 14–16 October, 2017), which is devoted to processing techniques, physics, mechanics, and applications of advanced materials. The book focuses on a wide spectrum of nanostructures, ferroelectric crystals, materials and composites as well as promising materials with special properties. It presents nanotechnology approaches, modern environmentally friendly piezoelectric and ferromagnetic techniques and physical and mechanical studies of the structural and physical–mechanical properties of materials. Various original mathematical and numerical methods are applied to the solution of different technological, mechanical and physical problems that are interesting from theoretical, modeling and experimental points of view. Further, the book highlights novel devices with high accuracy, longevity and extended capabilities ...

  3. Ferroelectric materials and their applications

    CERN Document Server

    Xu, Y

    2013-01-01

    This book presents the basic physical properties, structure, fabrication methods and applications of ferroelectric materials. These are widely used in various devices, such as piezoelectric/electrostrictive transducers and actuators, pyroelectric infrared detectors, optical integrated circuits, optical data storage, display devices, etc. The ferroelectric materials described in this book include a relatively complete list of practical and promising ferroelectric single crystals, bulk ceramics and thin films. Included are perovskite-type, lithium niobate, tungsten-bronze-type, water-soluable

  4. Hierarchical adaptive nanostructured PVD coatings for extreme tribological applications: the quest for nonequilibrium states and emergent behavior

    Directory of Open Access Journals (Sweden)

    German S Fox-Rabinovich, Kenji Yamamoto, Ben D Beake, Iosif S Gershman, Anatoly I Kovalev, Stephen C Veldhuis, Myram H Aguirre, Goulnara Dosbaeva and Jose L Endrino

    2012-01-01

    Full Text Available Adaptive wear-resistant coatings produced by physical vapor deposition (PVD are a relatively new generation of coatings which are attracting attention in the development of nanostructured materials for extreme tribological applications. An excellent example of such extreme operating conditions is high performance machining of hard-to-cut materials. The adaptive characteristics of such coatings develop fully during interaction with the severe environment. Modern adaptive coatings could be regarded as hierarchical surface-engineered nanostructural materials. They exhibit dynamic hierarchy on two major structural scales: (a nanoscale surface layers of protective tribofilms generated during friction and (b an underlying nano/microscaled layer. The tribofilms are responsible for some critical nanoscale effects that strongly impact the wear resistance of adaptive coatings. A new direction in nanomaterial research is discussed: compositional and microstructural optimization of the dynamically regenerating nanoscaled tribofilms on the surface of the adaptive coatings during friction. In this review we demonstrate the correlation between the microstructure, physical, chemical and micromechanical properties of hard coatings in their dynamic interaction (adaptation with environment and the involvement of complex natural processes associated with self-organization during friction. Major physical, chemical and mechanical characteristics of the adaptive coating, which play a significant role in its operating properties, such as enhanced mass transfer, and the ability of the layer to provide dissipation and accumulation of frictional energy during operation are presented as well. Strategies for adaptive nanostructural coating design that enhance beneficial natural processes are outlined. The coatings exhibit emergent behavior during operation when their improved features work as a whole. In this way, as higher-ordered systems, they achieve multifunctionality

  5. Hierarchical adaptive nanostructured PVD coatings for extreme tribological applications: the quest for nonequilibrium states and emergent behavior.

    Science.gov (United States)

    Fox-Rabinovich, German S; Yamamoto, Kenji; Beake, Ben D; Gershman, Iosif S; Kovalev, Anatoly I; Veldhuis, Stephen C; Aguirre, Myriam H; Dosbaeva, Goulnara; Endrino, Jose L

    2012-08-01

    Adaptive wear-resistant coatings produced by physical vapor deposition (PVD) are a relatively new generation of coatings which are attracting attention in the development of nanostructured materials for extreme tribological applications. An excellent example of such extreme operating conditions is high performance machining of hard-to-cut materials. The adaptive characteristics of such coatings develop fully during interaction with the severe environment. Modern adaptive coatings could be regarded as hierarchical surface-engineered nanostructural materials. They exhibit dynamic hierarchy on two major structural scales: (a) nanoscale surface layers of protective tribofilms generated during friction and (b) an underlying nano/microscaled layer. The tribofilms are responsible for some critical nanoscale effects that strongly impact the wear resistance of adaptive coatings. A new direction in nanomaterial research is discussed: compositional and microstructural optimization of the dynamically regenerating nanoscaled tribofilms on the surface of the adaptive coatings during friction. In this review we demonstrate the correlation between the microstructure, physical, chemical and micromechanical properties of hard coatings in their dynamic interaction (adaptation) with environment and the involvement of complex natural processes associated with self-organization during friction. Major physical, chemical and mechanical characteristics of the adaptive coating, which play a significant role in its operating properties, such as enhanced mass transfer, and the ability of the layer to provide dissipation and accumulation of frictional energy during operation are presented as well. Strategies for adaptive nanostructural coating design that enhance beneficial natural processes are outlined. The coatings exhibit emergent behavior during operation when their improved features work as a whole. In this way, as higher-ordered systems, they achieve multifunctionality and high wear

  6. IrOx-carbon nanotube hybrids: a nanostructured material for electrodes with increased charge capacity in neural systems.

    Science.gov (United States)

    Carretero, Nina M; Lichtenstein, Mathieu P; Pérez, Estela; Cabana, Laura; Suñol, Cristina; Casañ-Pastor, Nieves

    2014-10-01

    Nanostructured iridium oxide-carbon nanotube hybrids (IrOx-CNT) deposited as thin films by dynamic electrochemical methods are suggested as novel materials for neural electrodes. Single-walled carbon nanotubes (SWCNT) serve as scaffolds for growing the oxide, yielding a tridimensional structure with improved physical, chemical and electrical properties, in addition to high biocompatibility. In biological environments, SWCNT encapsulation by IrOx makes more resistant electrodes and prevents the nanotube release to the media, preventing cellular toxicity. Chemical, electrochemical, structural and surface characterization of the hybrids has been accomplished. The high performance of the material in electrochemical measurements and the significant increase in cathodal charge storage capacity obtained for the hybrid in comparison with bare IrOx represent a significant advance in electric field application in biosystems, while its cyclability is also an order of magnitude greater than pure IrOx. Moreover, experiments using in vitro neuronal cultures suggest high biocompatibility for IrOx-CNT coatings and full functionality of neurons, validating this material for use in neural electrodes. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  7. Molecular Design of Bioinspired Nanostructures for Biomedical Applications: Synthesis, Self-Assembly and Functional Properties

    Science.gov (United States)

    Xu, Hesheng Victor; Zheng, Xin Ting; Mok, Beverly Yin Leng; Ibrahim, Salwa Ali; Yu, Yong; Tan, Yen Nee

    2016-08-01

    Biomolecules are the nanoscale building blocks of cells, which play multifaceted roles in the critical biological processes such as biomineralization in a living organism. In these processes, the biological molecules such as protein and nucleic acids use their exclusive biorecognition properties enabled from their unique chemical composition, shape and function to initiate a cascade of cellular events. The exceptional features of these biomolecules, coupled with the recent advancement in nanotechnology, have led to the emergence of a new research field that focuses on the molecular design of bioinspired nanostructures that inherit the extraordinary function of natural biomaterials. These “bioinspired” nanostructures could be formulated by biomimetic approaches through either self-assembling of biomolecules or acting as a biomolecular template/precursor to direct the synthesis of nanocomposite. In either situation, the resulting nanomaterials exhibit phenomenal biocompatibility, superb aqueous solubility and excellent colloidal stability, branding them exceptionally desirable for both in vitro and in vivo biomedical applications. In this review, we will present the recent developments in the preparation of “bioinspired” nanostructures through biomimetic self-assembly and biotemplating synthesis, as well as highlight their functional properties and potential applications in biomedical diagnostics and therapeutic delivery. Lastly, we will conclude this topic with some personal perspective on the challenges and future outlooks of the “bioinspired” nanostructures for nanomedicine.

  8. Advanced Materials for Automotive Application

    International Nuclear Information System (INIS)

    Tisza, M

    2013-01-01

    In this paper some recent material developments will be overviewed mainly from the point of view of automotive industry. In car industry, metal forming is one of the most important manufacturing processes imposing severe restrictions on materials; these are often contradictory requirements, e.g. high strength simultaneously with good formability, etc. Due to these challenges and the ever increasing demand new material classes have been developed; however, the more and more wide application of high strength materials meeting the requirements stated by the mass reduction lead to increasing difficulties concerning the formability which requires significant technological developments as well. In this paper, the recent materials developments will be overviewed from the point of view of the automotive industry

  9. Nanostructured 2D cellular materials in silicon by sidewall transfer lithography NEMS

    Science.gov (United States)

    Syms, Richard R. A.; Liu, Dixi; Ahmad, Munir M.

    2017-07-01

    Sidewall transfer lithography (STL) is demonstrated as a method for parallel fabrication of 2D nanostructured cellular solids in single-crystal silicon. The linear mechanical properties of four lattices (perfect and defected diamond; singly and doubly periodic honeycomb) with low effective Young’s moduli and effective Poisson’s ratio ranging from positive to negative are modelled using analytic theory and the matrix stiffness method with an emphasis on boundary effects. The lattices are fabricated with a minimum feature size of 100 nm and an aspect ratio of 40:1 using single- and double-level STL and deep reactive ion etching of bonded silicon-on-insulator. Nanoelectromechanical systems (NEMS) containing cellular materials are used to demonstrate stretching, bending and brittle fracture. Predicted edge effects are observed, theoretical values of Poisson’s ratio are verified and failure patterns are described.

  10. Cathodes for lithium ion batteries: the benefits of using nanostructured materials

    International Nuclear Information System (INIS)

    Bazito, Fernanda F.C.; Torresi, Roberto M.

    2006-01-01

    Commercially available lithium ion cells, which are the most advanced among rechargeable batteries available so far, employ microcrystalline transition metal oxides as cathodes, which function as Li insertion hosts. In search for better electrochemical performance the use of nanomaterials in place of these conventional ones has emerged as excellent alternative. In this review we present a brief introduction about the motivations to use nanostructured materials as cathodes in lithium ion batteries. To illustrate such advantages we present some examples of research directed toward preparations and electrochemical data of the most used cathodes in nanoscale, such as LiCoO 2 , LiMn 2 O 4 , LiMnO 2 , LiV 2 O 5 e LiFePO 4 . (author)

  11. Coherent spectroscopic methods for monitoring pathogens, genetically modified products and nanostructured materials in colloidal solution

    International Nuclear Information System (INIS)

    Moguilnaya, T.; Suminov, Y.; Botikov, A.; Ignatov, S.; Kononenko, A.; Agibalov, A.

    2017-01-01

    We developed the new automatic method that combines the method of forced luminescence and stimulated Brillouin scattering. This method is used for monitoring pathogens, genetically modified products and nanostructured materials in colloidal solution. We carried out the statistical spectral analysis of pathogens, genetically modified soy and nano-particles of silver in water from different regions in order to determine the statistical errors of the method. We studied spectral characteristics of these objects in water to perform the initial identification with 95% probability. These results were used for creation of the model of the device for monitor of pathogenic organisms and working model of the device to determine the genetically modified soy in meat.

  12. Attosecond nanotechnology: NEMS of energy storage and nanostructural transformations in materials

    Energy Technology Data Exchange (ETDEWEB)

    Beznosyuk, Sergey A., E-mail: bsa1953@mail.ru; Maslova, Olga A., E-mail: maslova-o.a@mail.ru [Altai State University, Barnaul, 656049 (Russian Federation); Zhukovsky, Mark S., E-mail: zhukovsky@list.ru [Altai State Technical University, Barnaul, 656038 (Russian Federation)

    2015-10-27

    The attosecond technology of the nanoelectromechanical system (NEMS) energy storage as active center fast transformation of nanostructures in materials is considered. The self-organizing relaxation of the NEMS active center containing nanocube of 256-atoms limited by planes (100) in the FCC lattice matrix of 4d-transition metals (Ru, Rh, Pd) is described by the quantum NEMS-kinetics (NK) method. Typical for these metals change of the NEMS active center physicochemical characteristics during the time of relaxation is presented. There are three types of intermediate quasistationary states of the NEMS active center. Their forms are plainly distinguishable. The full relaxed NEMS active centers (Ru{sub 256}, Rh{sub 256}, Pd{sub 256}) accumulate next storage energies: E{sub Ru} = 2.27 eV/at, E{sub Rh} = 1.67 eV/at, E{sub Pd} = 3.02 eV/at.

  13. Highly porous CeO2 nanostructures prepared via combustion synthesis for supercapacitor applications

    DEFF Research Database (Denmark)

    Kadirvelayutham, Prasanna; Santhoshkumar, P.; Jo, Yong Nam

    2017-01-01

    We report highly porous CeO2 nanostructures (CeO2 NSs) suitable for supercapacitor applications, synthesized using a fast and cost effective combustion approach. Due to its prominent valence states of Ce3+/Ce4+, CeO2 has emerged as a promising pseudocapacitive material. The drawback of using CeO2...... as a supercapacitor electrode is its poor electrical conductivity. We overcame this drawback of CeO2 by creating oxygen vacancies on its surface, which act to enhance its electrical conductivity. The physical interpretation of the as-synthesized CeO2 NSs shows that they have dense active sites and diffusion pathways...... that enhance the performance of the electrode in a supercapacitor. Electrodes prepared using the synthesized CeO2 NSs exhibited the initial specific capacitance of 134.6 F g-1 and superior cycling stability of 92.5% after 1000 cycles at a constant current density of 1 A g-1, indicating their potential...

  14. Nanostructure of self-assembled rod-coil block copolymer films for photovoltaic applications

    International Nuclear Information System (INIS)

    Heiser, T.; Adamopoulos, G.; Brinkmann, M.; Giovanella, U.; Ould-Saad, S.; Brochon, C.; Wetering, K. van de; Hadziioannou, G.

    2006-01-01

    The nanostructures of a series of rod-coil block copolymers, designed for photovoltaic applications, are studied by atomic force microscopy and transmission electron microscopy. The copolymers are composed of a semiconducting poly-p-phenylenevinylene rod with (2'-ethyl)-hexyloxy side chains and a functionalized coil block of various length and flexibility. Both, as deposited and annealed block copolymer films were investigated. The results show that highly ordered structures are only obtained if the coil block is characterized by a glass transition temperature which is significantly lower than the melting temperature of the alkyl side chains. For this material a high molecular mobility and strong driving force for crystallization of the rigid block can be achieved simultaneously. For the smallest coil to rod length ratio, we found a lamellar morphology with perpendicularly oriented lamellae with respect to the substrate. Electron diffraction data show the presence of a periodical molecular arrangement with a characteristic distance of 0.94 nm that is attributed to the distance between conjugated chains separated by the layers of alkyl sidechains

  15. Nanostructure of self-assembled rod-coil block copolymer films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Heiser, T. [Institut d' Electronique du Solide et des Systemes (InESS), CNRS/ULP, 23, rue du Loess, F-67037 Strasbourg Cedex 2 (France)]. E-mail: Thomas.Heiser@iness.c-strasbourg.fr; Adamopoulos, G. [Laboratoire d' Ingenierie des Polymeres pour les Hautes Technologies (LIPHT), Ecole Europeenne de Chimie Polymeres et Materiaux (ECPM), 25, rue Becquerel, F-67087 Strasbourg Cedex 2 (France); Brinkmann, M. [Institut Charles Sadron (ICS), CNRS, 6, rue Boussingault, F-67083 Strasbourg Cedex (France); Giovanella, U. [Laboratoire d' Ingenierie des Polymeres pour les Hautes Technologies (LIPHT), Ecole Europeenne de Chimie Polymeres et Materiaux (ECPM), 25, rue Becquerel, F-67087 Strasbourg Cedex 2 (France); Ould-Saad, S. [Institut d' Electronique du Solide et des Systemes (InESS), CNRS/ULP, 23, rue du Loess, F-67037 Strasbourg Cedex 2 (France); Brochon, C. [Laboratoire d' Ingenierie des Polymeres pour les Hautes Technologies (LIPHT), Ecole Europeenne de Chimie Polymeres et Materiaux (ECPM), 25, rue Becquerel, F-67087 Strasbourg Cedex 2 (France); Wetering, K. van de [Laboratoire d' Ingenierie des Polymeres pour les Hautes Technologies (LIPHT), Ecole Europeenne de Chimie Polymeres et Materiaux (ECPM), 25, rue Becquerel, F-67087 Strasbourg Cedex 2 (France); Hadziioannou, G. [Laboratoire d' Ingenierie des Polymeres pour les Hautes Technologies (LIPHT), Ecole Europeenne de Chimie Polymeres et Materiaux (ECPM), 25, rue Becquerel, F-67087 Strasbourg Cedex 2 (France)

    2006-07-26

    The nanostructures of a series of rod-coil block copolymers, designed for photovoltaic applications, are studied by atomic force microscopy and transmission electron microscopy. The copolymers are composed of a semiconducting poly-p-phenylenevinylene rod with (2'-ethyl)-hexyloxy side chains and a functionalized coil block of various length and flexibility. Both, as deposited and annealed block copolymer films were investigated. The results show that highly ordered structures are only obtained if the coil block is characterized by a glass transition temperature which is significantly lower than the melting temperature of the alkyl side chains. For this material a high molecular mobility and strong driving force for crystallization of the rigid block can be achieved simultaneously. For the smallest coil to rod length ratio, we found a lamellar morphology with perpendicularly oriented lamellae with respect to the substrate. Electron diffraction data show the presence of a periodical molecular arrangement with a characteristic distance of 0.94 nm that is attributed to the distance between conjugated chains separated by the layers of alkyl sidechains.

  16. Carbon Nanofibrous Materials from Electrospinning: Preparation and Energy Applications

    Science.gov (United States)

    Aboagye, Alex

    Carbon nanofibers with diameters that fall into submicron and nanometer range have attracted growing attention in recent years due to their superior chemical, electrical, and mechanical properties in combination with their unique one-dimensional nanostructures. Unlike catalytic synthesis, electrospinning polyacrylonitrile (PAN) followed by stabilization and carbonization has become a straightforward and convenient route to make continuous carbon nanofibers. The overall objective of this research was the design and production fiber based carbon nanomaterials, investigation of their structures and use in functional applications. Specifically, these carbon nanofibrous materials were employed as electrode material for energy storage and conversion devices such as dye sensitized solar cells and supercapacitors Morphology and structure of the carbon nanofibrous materials were investigated and their performance in corresponding applications were evaluated.

  17. Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103

    NARCIS (Netherlands)

    Callini, Elsa; Aguey-Zinsou, Kondo Francois; Ahuja, Rajeev; Ares, Jos Ramon; Bals, Sara; Biliskov, Nikola; Chakraborty, Sudip; Charalambopoulou, Georgia; Chaudhary, Anna Lisa; Cuevas, Fermin; Dam, Bernard; de Jongh, Petra; Dornheim, Martin; Filinchuk, Yaroslav; Novakovic, Jasmina G.; Hirscher, Michael; Hirscher, M.; Jensen, Torben R.; Jensen, Peter Bjerre; Novakovic, Nikola; Lai, Qiwen; Leardini, Fabrice; Gattia, Daniele Mirabile; Pasquini, Luca; Steriotis, Theodore; Turner, Stuart; Vegge, Tejs; Zuttel, Andreas; Montone, Amelia

    2016-01-01

    In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated

  18. Nanoparticle Decorated Ultrathin Porous Nanosheets as Hierarchical Co3O4 Nanostructures for Lithium Ion Battery Anode Materials

    DEFF Research Database (Denmark)

    Mujtaba, Jawayria; Sun, Hongyu; Huang, Guoyong

    2016-01-01

    We report a facile synthesis of a novel cobalt oxide (Co3O4) hierarchical nanostructure, in which crystalline core-amorphous shell Co3O4 nanoparticles with a bimodal size distribution are uniformly dispersed on ultrathin Co3O4 nanosheets. When tested as anode materials for lithium ion batteries...

  19. Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103

    DEFF Research Database (Denmark)

    Callini, Elsa; Aguey-Zinsou, Kondo-Francois; Ahuja, Rajeev

    2016-01-01

    In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated...

  20. Ferrite materials for memory applications

    CERN Document Server

    Saravanan, R

    2017-01-01

    The book discusses the synthesis and characterization of various ferrite materials used for memory applications. The distinct feature of the book is the construction of charge density of ferrites by deploying the maximum entropy method (MEM). This charge density gives the distribution of charges in the ferrite unit cell, which is analyzed for charge related properties.

  1. Nanostructured Porous Silicon Photonic Crystal for Applications in the Infrared

    Directory of Open Access Journals (Sweden)

    G. Recio-Sánchez

    2012-01-01

    Full Text Available In the last decades great interest has been devoted to photonic crystals aiming at the creation of novel devices which can control light propagation. In the present work, two-dimensional (2D and three-dimensional (3D devices based on nanostructured porous silicon have been fabricated. 2D devices consist of a square mesh of 2 μm wide porous silicon veins, leaving 5×5 μm square air holes. 3D structures share the same design although multilayer porous silicon veins are used instead, providing an additional degree of modulation. These devices are fabricated from porous silicon single layers (for 2D structures or multilayers (for 3D structures, opening air holes in them by means of 1 KeV argon ion bombardment through the appropriate copper grids. For 2D structures, a complete photonic band gap for TE polarization is found in the thermal infrared range. For 3D structures, there are no complete band gaps, although several new partial gaps do exist in different high-symmetry directions. The simulation results suggest that these structures are very promising candidates for the development of low-cost photonic devices for their use in the thermal infrared range.

  2. Nanostructured mesophase electrode materials: modulating charge-storage behavior by thermal treatment.

    Science.gov (United States)

    Kong, Hye Jeong; Kim, Saerona; Le, Thanh-Hai; Kim, Yukyung; Park, Geunsu; Park, Chul Soon; Kwon, Oh Seok; Yoon, Hyeonseok

    2017-11-16

    3D nanostructured carbonaceous electrode materials with tunable capacitive phases were successfully developed using graphene/particulate polypyrrole (PPy) nanohybrid (GPNH) precursors without a separate process for incorporating heterogeneous species. The electrode material, namely carbonized GPNHs (CGPNHs) featured a mesophase capacitance consisting of both electric double-layer (EDL) capacitive and pseudocapacitive elements at the molecular level. The ratio of EDL capacitive element to pseudocapacitive element (E-to-P) in the mesophase electrode materials was controlled by varying the PPy-to-graphite weight (P w /G w ) ratio and by heat treatment (T H ), which was demonstrated by characterizing the CGPNHs with elemental analysis, cyclic voltammetry, and a charge/discharge test. The concept of the E-to-P ratio (EPR) index was first proposed to easily identify the capacitive characteristics of the mesophase electrode using a numerical algorithm, which was reasonably consistent with the experimental findings. Finally, the CGPNHs were integrated into symmetric two-electrode capacitor cells, which rendered excellent energy and power densities in both aqueous and ionic liquid electrolytes. It is anticipated that our approach could be widely extended to fabricating versatile hybrid electrode materials with estimation of their capacitive characteristics.

  3. Synthesis, characterization, and applications of electroactive polymeric nanostructures for organic coatings

    Science.gov (United States)

    Suryawanshi, Abhijit Jagnnath

    Electroactive polymers (EAP) such as polypyrrole (PPy) and polyaniline (PANI) are being explored intensively in the scientific community. Nanostructures of EAPs have low dimensions and high surface area enabling them to be considered for various useful applications. These applications are in several fields including corrosion inhibition, capacitors, artificial muscles, solar cells, polymer light emitting diodes, and energy storage devices. Nanostructures of EAPs have been synthesized in different morphologies such as nanowires, nanorods, nanotubes, nanospheres, and nanocapsules. This variety in morphology is traditionally achieved using soft templates, such as surfactant micelles, or hard templates, such as anodized aluminum oxide (AAO). Templates provide stability and groundwork from which the polymer can grow, but the templates add undesirable expense to the process and can change the properties of the nanoparticles by integrating its own properties. In this study a template free method is introduced to synthesize EAP nanostructures of PPy and PANI utilizing ozone oxidation. The simple techniques involve ozone exposure to the monomer solution to produce aqueous dispersions of EAP nanostructures. The synthesized nanostructures exhibit uniform morphology, low particle size distribution, and stability against agglomeration. Ozone oxidation is further explored for the synthesis of silver-PPy (Ag-PPy) core-shell nanospheres (CSNs). Coatings containing PPy nanospheres were formulated to study the corrosion inhibition efficiency of PPy nanospheres. Investigation of the coatings using electrochemical techniques revealed that the PPy nanospheres may provide corrosion inhibition against filiform corrosion by oxygen scavenging mechanism. Finally, organic corrosion inhibitors were incorporated in PPy to develop efficient corrosion inhibiting systems, by using the synergistic effects from PPy and organic corrosion inhibitors.

  4. International Conference (4th) on Nanostructured Materials Held in Stockholm, Sweden on 14-19 June 1998. Special Volume - Part A. Volume 12, Numbers 1-4, 1999

    National Research Council Canada - National Science Library

    Tsakalakos, Thomas

    1998-01-01

    ... or phases at the nanoscale level (less than 100 nm). Capabilities for synthesizing such nanostructured materials are becoming available, so that it is possible to produce the quantities of materials needed for prototype development and testing...

  5. Nanostructure-Enabled and Macromolecule-Grafted Surfaces for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Madeline Small

    2018-05-01

    Full Text Available Advances in nanotechnology and nanomaterials have enabled the development of functional biomaterials with surface properties that reduce the rate of the device rejection in injectable and implantable biomaterials. In addition, the surface of biomaterials can be functionalized with macromolecules for stimuli-responsive purposes to improve the efficacy and effectiveness in drug release applications. Furthermore, macromolecule-grafted surfaces exhibit a hierarchical nanostructure that mimics nanotextured surfaces for the promotion of cellular responses in tissue engineering. Owing to these unique properties, this review focuses on the grafting of macromolecules on the surfaces of various biomaterials (e.g., films, fibers, hydrogels, and etc. to create nanostructure-enabled and macromolecule-grafted surfaces for biomedical applications, such as thrombosis prevention and wound healing. The macromolecule-modified surfaces can be treated as a functional device that either passively inhibits adverse effects from injectable and implantable devices or actively delivers biological agents that are locally based on proper stimulation. In this review, several methods are discussed to enable the surface of biomaterials to be used for further grafting of macromolecules. In addition, we review surface-modified films (coatings and fibers with respect to several biomedical applications. Our review provides a scientific update on the current achievements and future trends of nanostructure-enabled and macromolecule-grafted surfaces in biomedical applications.

  6. Nanostructured TiOx as a catalyst support material for proton exchange membrane fuel cells

    Science.gov (United States)

    Phillips, Richard S.

    Recent interest in the development of new catalyst support materials for proton exchange membrane fuel cells (PEMFCs) has stimulated research into the viability of TiO2-based support structures. Specifically, substoichiometric TiO2 (TiOx) has been reported to exhibit a combination of high conductivity, stability, and corrosion resistance. These properties make TiOx-based support materials a promising prospect when considering the inferior corrosion resistance of traditional carbon-based supports. This document presents an investigation into the formation of conductive and stable TiOx thin films employing atomic layer deposition (ALD) and a post deposition oxygen reducing anneal (PDORA). Techniques for manufacturing TiOx-based catalyst support nanostructures by means of ALD in conjunction with carbon black (CB), anodic aluminum oxide (AAO) and silicon nanowires (SiNWs) will also be presented. The composition and thickness of resulting TiOx thin films was determined with the aid of Auger electron spectroscopy (AES), Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Film crystal structure was determined with X-ray diffraction (XRD) analysis. Film conductivity was calculated using four-point probe (4-PP) and film thickness measurement data. Resulting thin films show a significant decrease of oxygen in ALD TiOx films corresponding with a great increase in conductivity following the PDORA. The effectiveness of the PDORA was also found to be highly dependent on ALD process parameters. TiOx-based nanostructures were coated with platinum using one of three Pt deposition techniques. First, liquid phase deposition (LPD), which was performed at room temperature, provided equal access to catalyst support material surfaces which were suspended in solution. Second, plasma enhanced atomic layer deposition (PEALD), which was performed at 450°C, provided good Pt

  7. Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

    2016-01-27

    This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

  8. Liquid crystal alignment in electro-responsive nanostructured thermosetting materials based on block copolymer dispersed liquid crystal

    Energy Technology Data Exchange (ETDEWEB)

    Tercjak, A; Garcia, I; Mondragon, I [Materials-Technologies Group, Departamento IngenierIa Quimica y M Ambiente, Escuela Politecnica, Universidad PaIs Vasco/Euskal Herriko Unibertsitatea, Plaza Europa 1, E-20018 Donostia-San Sebastian (Spain)], E-mail: scptesza@sc.ehu.es, E-mail: inaki.mondragon@ehu.es

    2008-07-09

    Novel well-defined nanostructured thermosetting systems were prepared by modification of a diglicydylether of bisphenol-A epoxy resin (DGEBA) with 10 or 15 wt% amphiphilic poly(styrene-b-ethylene oxide) block copolymer (PSEO) and 30 or 40 wt% low molecular weight liquid crystal 4'-(hexyl)-4-biphenyl-carbonitrile (HBC) using m-xylylenediamine (MXDA) as a curing agent. The competition between well-defined nanostructured materials and the ability for alignment of the liquid crystal phase in the materials obtained has been studied by atomic and electrostatic force microscopy, AFM and EFM, respectively. Based on our knowledge, this is the first time that addition of an adequate amount (10 wt%) of a block copolymer to 40 wt% HBC-(DGEBA/MXDA) leads to a well-organized nanostructured thermosetting system (between a hexagonal and worm-like ordered structure), which is also electro-responsive with high rate contrast. This behavior was confirmed using electrostatic force microscopy (EFM), by means of the response of the HBC liquid crystal phase to the voltage applied to the EFM tip. In contrast, though materials containing 15 wt% PSEO and 30 wt% HBC also form a well-defined nanostructured thermosetting system, they do not show such a high contrast between the uncharged and charged surface.

  9. Liquid crystal alignment in electro-responsive nanostructured thermosetting materials based on block copolymer dispersed liquid crystal.

    Science.gov (United States)

    Tercjak, A; Garcia, I; Mondragon, I

    2008-07-09

    Novel well-defined nanostructured thermosetting systems were prepared by modification of a diglicydylether of bisphenol-A epoxy resin (DGEBA) with 10 or 15 wt% amphiphilic poly(styrene-b-ethylene oxide) block copolymer (PSEO) and 30 or 40 wt% low molecular weight liquid crystal 4'-(hexyl)-4-biphenyl-carbonitrile (HBC) using m-xylylenediamine (MXDA) as a curing agent. The competition between well-defined nanostructured materials and the ability for alignment of the liquid crystal phase in the materials obtained has been studied by atomic and electrostatic force microscopy, AFM and EFM, respectively. Based on our knowledge, this is the first time that addition of an adequate amount (10 wt%) of a block copolymer to 40 wt% HBC-(DGEBA/MXDA) leads to a well-organized nanostructured thermosetting system (between a hexagonal and worm-like ordered structure), which is also electro-responsive with high rate contrast. This behavior was confirmed using electrostatic force microscopy (EFM), by means of the response of the HBC liquid crystal phase to the voltage applied to the EFM tip. In contrast, though materials containing 15 wt% PSEO and 30 wt% HBC also form a well-defined nanostructured thermosetting system, they do not show such a high contrast between the uncharged and charged surface.

  10. Liquid crystal alignment in electro-responsive nanostructured thermosetting materials based on block copolymer dispersed liquid crystal

    International Nuclear Information System (INIS)

    Tercjak, A; Garcia, I; Mondragon, I

    2008-01-01

    Novel well-defined nanostructured thermosetting systems were prepared by modification of a diglicydylether of bisphenol-A epoxy resin (DGEBA) with 10 or 15 wt% amphiphilic poly(styrene-b-ethylene oxide) block copolymer (PSEO) and 30 or 40 wt% low molecular weight liquid crystal 4'-(hexyl)-4-biphenyl-carbonitrile (HBC) using m-xylylenediamine (MXDA) as a curing agent. The competition between well-defined nanostructured materials and the ability for alignment of the liquid crystal phase in the materials obtained has been studied by atomic and electrostatic force microscopy, AFM and EFM, respectively. Based on our knowledge, this is the first time that addition of an adequate amount (10 wt%) of a block copolymer to 40 wt% HBC-(DGEBA/MXDA) leads to a well-organized nanostructured thermosetting system (between a hexagonal and worm-like ordered structure), which is also electro-responsive with high rate contrast. This behavior was confirmed using electrostatic force microscopy (EFM), by means of the response of the HBC liquid crystal phase to the voltage applied to the EFM tip. In contrast, though materials containing 15 wt% PSEO and 30 wt% HBC also form a well-defined nanostructured thermosetting system, they do not show such a high contrast between the uncharged and charged surface

  11. Nanostructured Inorganic Materials at Work in Electrochemical Sensing and Biofuel Cells

    Directory of Open Access Journals (Sweden)

    Yaovi Holade

    2017-01-01

    Full Text Available The future of analytical devices, namely (biosensors, which are currently impacting our everyday life, relies on several metrics such as low cost, high sensitivity, good selectivity, rapid response, real-time monitoring, high-throughput, easy-to-make and easy-to-handle properties. Fortunately, they can be readily fulfilled by electrochemical methods. For decades, electrochemical sensors and biofuel cells operating in physiological conditions have concerned biomolecular science where enzymes act as biocatalysts. However, immobilizing them on a conducting substrate is tedious and the resulting bioelectrodes suffer from stability. In this contribution, we provide a comprehensive, authoritative, critical, and readable review of general interest that surveys interdisciplinary research involving materials science and (bioelectrocatalysis. Specifically, it recounts recent developments focused on the introduction of nanostructured metallic and carbon-based materials as robust “abiotic catalysts” or scaffolds in bioelectrochemistry to boost and increase the current and readout signals as well as the lifetime. Compared to biocatalysts, abiotic catalysts are in a better position to efficiently cope with fluctuations of temperature and pH since they possess high intrinsic thermal stability, exceptional chemical resistance and long-term stability, already highlighted in classical electrocatalysis. We also diagnosed their intrinsic bottlenecks and highlighted opportunities of unifying the materials science and bioelectrochemistry fields to design hybrid platforms with improved performance.

  12. Ferroic materials synthesis and applications

    CERN Document Server

    Virk, Hardev Singh

    2015-01-01

    Ferroics is the generic name given to the study of ferromagnets, ferroelectrics, and ferroelastics. The basis of this study is to understand the large changes in physical characteristics that occur over a very narrow temperature range. In recent years, a new class of ferroic materials has been attracting increased interest. These multiferroics exhibit more than one ferroic property simultaneously in a single phase. The present volume: ""Ferroic Materials: Synthesis and Applications"" has ten Chapters, spread over areas as diverse as Magnetic Oxide Nanomaterials, Ferrites Synthesis, Hexaferrite

  13. The Role of pH in PEG-b-PAAc Modification of Gadolinium Oxide Nanostructures for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Eva Hemmer

    2012-01-01

    Full Text Available Upconversion and near-infrared emitting Gd2O3:Er3+,Yb3+ nanostructured phosphors (nanoparticles and nanorods for applications in bioimaging have been synthesized by precipitation methods and hydrothermal treatment. Variation of the material synthesis conditions (additives and pH allows controlling particle size (40 nm to μm range and rod aspect ratio (5 to 18. It was shown that PEG-b-PAAc (poly(ethylene glycol poly(acrylic acid block polymer is suitable to provide the required chemical durability, dispersion stability, and noncytotoxic behaviour for biomedical applications, where the coating of Gd2O3 with a protecting and biocompatible layer is essential in order to prevent the release of toxic Gd3+ ions. Physicochemical properties of the Gd2O3:Er3+,Yb3+ nanostructures modified with PEG-b-PAAc have been investigated by TG-DTA, FT-IR, and DLS revealing a strong influence of modification conditions, namely, pH of the reaction media, on the nature of the PEG-b-PAAc layer.

  14. Electrospinning Materials, Processing, and Applications

    CERN Document Server

    Wendorff, Joachim H; Greiner, Andreas

    2012-01-01

    Bringing together the world's experts in the field, this book summarizes the state-of-the art in electrospinning with detailed coverage of the various techniques, material systems, and their resulting fiber structures and properties, theoretical aspects, and applications. Throughout the book, the current status of knowledge is introduced with a critical view on accomplishments and novel persepectives. An experimental section gives hands-on guidance to beginners and experts alike.

  15. Uniform β-Co(OH)2 disc-like nanostructures prepared by low-temperature electrochemical rout as an electrode material for supercapacitors

    Science.gov (United States)

    Aghazadeh, Mustafa; Shiri, Hamid Mohammad; Barmi, Abbas-Ali Malek

    2013-05-01

    Uniform nanostructures of cobalt hydroxide were successfully prepared by a low-temperature electrochemical method via galvanostatically deposition from a 0.005 M Co(NO3)3 bath at 10 °C. The XRD and FT-IR analyses showed that the prepared sample has a single crystalline hexagonal phase of the brucite-like Co(OH)2. Morphological characterization by SEM and TEM revealed that the prepared β-Co(OH)2 was composed of uniform compact disc-like nanostructures with diameters of 40-50 nm. The electrochemical performance of the prepared β-Co(OH)2 was evaluated using cyclic voltammetry and charge-discharge tests. A maximum specific capacitance of 736.5 F g-1 was obtained in aqueous 1 M KOH with the potential range of -0.2-0.5 V (vs. Ag/AgCl) at the scan rate of 10 mV s-1, suggesting the potential application of the prepared nanostructures as an electrode material in electrochemical supercapacitors. The results of this work showed that the low-temperature cathodic electrodeposition method can be recognized as a new and facile route for the synthesis of cobalt hydroxide nanodiscs as a promising candidate for the electrochemical supercapacitors.

  16. Optoacoustic Microscopy for Investigation of Material Nanostructures-Embracing the Ultrasmall, Ultrafast, and the Invisible

    Energy Technology Data Exchange (ETDEWEB)

    Nurmikko, Arto; Humphrey, Maris

    2014-07-10

    The goal of this grant was the development of a new type of scanning acoustic microscope for nanometer resolution ultrasound imaging, based on ultrafast optoacoustics (>GHz). In the microscope, subpicosecond laser pulses was used to generate and detect very high frequency ultrasound with nanometer wavelengths. We report here on the outcome of the 3-year DOE/BES grant which involved the design, multifaceted construction, and proof-of-concept demonstration of an instrument that can be used for quantitative imaging of nanoscale material features – including features that may be buried so as to be inaccessible to conventional lightwave or electron microscopies. The research program has produced a prototype scanning optoacoustic microscope which, in combination with advanced computational modeling, is a system-level new technology (two patents issues) which offer novel means for precision metrology of material nanostructures, particularly those that are of contemporary interest to the frontline micro- and optoelectronics device industry. For accomplishing the ambitious technical goals, the research roadmap was designed and implemented in two phases. In Phase I, we constructed a “non-focusing” optoacoustic microscope instrument (“POAM”), with nanometer vertical (z-) resolution, while limited to approximately 10 micrometer scale lateral recolution. The Phase I version of the instrument which was guided by extensive acoustic and optical numerical modeling of the basic underlying acoustic and optical physics, featured nanometer scale close loop positioning between the optoacoustic transducer element and a nanostructured material sample under investigation. In phase II, we implemented and demonstrated a scanning version of the instrument (“SOAM”) where incident acoustic energy is focused, and scanned on lateral (x-y) spatial scale in the 100 nm range as per the goals of the project. In so doing we developed advanced numerical simulations to provide

  17. Trade-off between Photon Management Efficacy and Material Quality in Thin-Film Solar Cells on Nanostructured Substrates of High Aspect Ratio Structures

    Directory of Open Access Journals (Sweden)

    Alan H. Chin

    2018-04-01

    Full Text Available Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a process known as photon management, in thin-film solar cells. Despite the progress made in the development of photon management in thin-film solar cells using nanostructures substrates, the structural integrity of the thin-film solar cells deposited onto such nanostructured substrates is rarely considered. Here, we report the observation of the reduction in the open circuit voltage of amorphous silicon solar cells deposited onto a nanostructured substrate with increasing areal number density of high aspect ratio structures. For a nanostructured substrate with the areal number density of such nanostructures increasing in correlation with the distance from one edge of the substrate, a correlation between the open circuit voltage reduction and the increase of the areal number density of high aspect ratio nanostructures of the front electrode of the small-size amorphous silicon solar cells deposited onto different regions of the substrate with graded nanostructure density indicates the effect of the surface morphology on the material quality, i.e., a trade-off between photon management efficacy and material quality. This observed trade-off highlights the importance of optimizing the morphology of the nanostructured substrate to ensure conformal deposition of the thin-film solar cell.

  18. Mesoporous wormholelike carbon with controllable nanostructure for lithium ion batteries application

    International Nuclear Information System (INIS)

    Yang, Xiaoqing; Li, Xinxi; Li, Zhenghui; Zhang, Guoqing; Wu, Dingcai

    2015-01-01

    Highlights: • Wormholelike carbon (WMC) with controllable nanostructure is prepared by sol–gel method. • The reversible capacity of WMC is much higher than that of many other reported nanocarbons. • The effect of pore diameter on Li storage capacity is investigated. - Abstract: A class of mesoporous wormholelike carbon (WMC) with controllable nanostructure was prepared by sol–gel method and then used as the anode material of lithium-ion batteries. Based on the experimental results, it is found that the nanostructure of the as-prepared WMC plays an important role in the electrochemical performances. A suitable mesopore size is necessary for a high performance carbon-based anode material since it can not only guarantee effective mass transport channels but also provide large surface area. As a result, F30 with a mesopore size of 4.4 nm coupled with high surface area of 1077 m 2 g −1 shows a reversible capacity of 630 mAh g −1 , much higher than commercial graphite and many other reported nanocarbons

  19. Nanostructured titanium-based materials for medical implants: Modeling and development

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Levashov, Evgeny; Valiev, Ruslan Z.

    2014-01-01

    Nanostructuring of titanium-based implantable devices can provide them with superior mechanical properties and enhanced biocompatibity. An overview of advanced fabrication technologies of nanostructured, high strength, biocompatible Ti and shape memory Ni-Ti alloy for medical implants is given. C...

  20. Conductive transition metal oxide nanostructured electrochromic material and optical switching devices constructed thereof

    Science.gov (United States)

    Mattox, Tracy M.; Koo, Bonil; Garcia, Guillermo; Milliron, Delia J.; Trizio, Luca De; Dahlman, Clayton

    2017-10-10

    An electrochromic device includes a nanostructured transition metal oxide bronze layer that includes one or more transition metal oxide and one or more dopant, a solid state electrolyte, and a counter electrode. The nanostructured transition metal oxide bronze selectively modulates transmittance of near-infrared (NIR) spectrum and visible spectrum radiation as a function of an applied voltage to the device.

  1. Nanosecond laser pulses for mimicking thermal effects on nanostructured tungsten-based materials

    Science.gov (United States)

    Besozzi, E.; Maffini, A.; Dellasega, D.; Russo, V.; Facibeni, A.; Pazzaglia, A.; Beghi, M. G.; Passoni, M.

    2018-03-01

    In this work, we exploit nanosecond laser irradiation as a compact solution for investigating the thermomechanical behavior of tungsten materials under extreme thermal loads at the laboratory scale. Heat flux factor thresholds for various thermal effects, such as melting, cracking and recrystallization, are determined under both single and multishot experiments. The use of nanosecond lasers for mimicking thermal effects induced on W by fusion-relevant thermal loads is thus validated by direct comparison of the thresholds obtained in this work and the ones reported in the literature for electron beams and millisecond laser irradiation. Numerical simulations of temperature and thermal stress performed on a 2D thermomechanical code are used to predict the heat flux factor thresholds of the different thermal effects. We also investigate the thermal effect thresholds of various nanostructured W coatings. These coatings are produced by pulsed laser deposition, mimicking W coatings in tokamaks and W redeposited layers. All the coatings show lower damage thresholds with respect to bulk W. In general, thresholds decrease as the porosity degree of the materials increases. We thus propose a model to predict these thresholds for coatings with various morphologies, simply based on their porosity degree, which can be directly estimated by measuring the variation of the coating mass density with respect to that of the bulk.

  2. Development of nanocomposite polymer materials for electrical and electronic applications

    International Nuclear Information System (INIS)

    Chine, Bruno

    2007-01-01

    Some results and experimental procedures of laboratory are reported in the frame of researches conducted for the development of new nanostructured composite materials. These new materials, which are constituted by an organic phase: the polymer and an inorganic phase: the silicate, are being strongly investigated nowadays so it is expected that they could provide, among other, better electrical insulation properties and flame-delay in electrical and electronic applications. The laboratory experimental work has been developed from two families of polymers, thermoplastics and thermosets and clays silicates providing lamellar type. There are now some preliminary results, such as obtaining thin films of these nanocomposite materials, their complete characterization by X-ray diffraction, scanning microscopy and thermogravimetric analysis, they do well to wait for future research activities. (author) [es

  3. Study of resonant processes in plasmonic nanostructures for sensor applications (Conference Presentation)

    Science.gov (United States)

    Pirunčík, Jiří; Kwiecien, Pavel; Fiala, Jan; Richter, Ivan

    2017-05-01

    This contribution is focused on the numerical studies of resonant processes in individual plasmonic nanostructures, with the attention particularly given to rectangular nanoparticles and concominant localized surface plasmon resonance processes. Relevant models for the description and anylysis of localized surface plasmon resonance are introduced, in particular: quasistatic approximation, Mie theory and in particular, a generalized (quasi)analytical approach for treating rectangularly shaped nanostructures. The parameters influencing resonant behavior of nanoparticles are analyzed with special interest in morphology and sensor applications. Results acquired with Lumerical FDTD Solutions software, using finite-difference time-domain simulation method, are shown and discussed. Simulations were mostly performed for selected nanostructures composed of finite rectangular nanowires with square cross-sections. Systematic analysis is made for single nanowires with varying length, parallel couple of nanowires with varying gap (cut -wires) and selected dolmen structures with varying gap between one nanowire transversely located with respect to parallel couple of nanowires (in both in-plane and -out-of-plane arrangements). The dependence of resonant peaks of cross-section spectral behavior (absorption, scattering, extinction) and their tunability via suitable structuring and morphology changes are primarily researched. These studies are then followed with an analysis of the effect of periodic arrangements. The results can be usable with respect to possible sensor applications.

  4. Tailoring the optical constants in single-crystal silicon with embedded silver nanostructures for advanced silicon photonics applications

    International Nuclear Information System (INIS)

    Akhter, Perveen; Huang, Mengbing; Spratt, William; Kadakia, Nirag; Amir, Faisal

    2015-01-01

    Plasmonic effects associated with metal nanostructures are expected to hold the key to tailoring light emission/propagation and harvesting solar energy in materials including single crystal silicon which remains the backbone in the microelectronics and photovoltaics industries but unfortunately, lacks many functionalities needed for construction of advanced photonic and optoelectronics devices. Currently, silicon plasmonic structures are practically possible only in the configuration with metal nanoparticles or thin film arrays on a silicon surface. This does not enable one to exploit the full potential of plasmonics for optical engineering in silicon, because the plasmonic effects are dominant over a length of ∼50 nm, and the active device region typically lies below the surface much beyond this range. Here, we report on a novel method for the formation of silver nanoparticles embedded within a silicon crystal through metal gettering from a silver thin film deposited at the surface to nanocavities within the Si created by hydrogen ion implantation. The refractive index of the Ag-nanostructured layer is found to be 3–10% lower or higher than that of silicon for wavelengths below or beyond ∼815–900 nm, respectively. Around this wavelength range, the optical extinction values increase by a factor of 10–100 as opposed to the pure silicon case. Increasing the amount of gettered silver leads to an increased extinction as well as a redshift in wavelength position for the resonance. This resonance is attributed to the surface plasmon excitation of the resultant silver nanoparticles in silicon. Additionally, we show that the profiles for optical constants in silicon can be tailored by varying the position and number of nanocavity layers. Such silicon crystals with embedded metal nanostructures would offer novel functional base structures for applications in silicon photonics, optoelectronics, photovoltaics, and plasmonics

  5. Gold nanoparticle arrays directly grown on nanostructured indium tin oxide electrodes: Characterization and electroanalytical application

    International Nuclear Information System (INIS)

    Zhang Jingdong; Oyama, Munetaka

    2005-01-01

    This work describes an improved seed-mediated growth approach for the direct attachment and growth of mono-dispersed gold nanoparticles on nanostructured indium tin oxide (ITO) surfaces. It was demonstrated that, when the seeding procedure of our previously reported seed-mediated growth process on an ITO surface was modified, the density of gold nanospheres directly grown on the surface could be highly improved, while the emergence of nanorods was restrained. By field emission scanning electron microscopy (FE-SEM) and cyclic voltammetry, the growth of gold nanoparticles with increasing growth time on the defect sites of nanostructured ITO surface was monitored. Using a [Fe(China) 6 ] 3- /[Fe(China) 6 ] 4- redox probe, the increasingly facile heterogeneous electron transfer kinetics resulting from the deposition and growth of gold nanoparticle arrays was observed. The as-prepared gold nanoparticle arrays exhibited high catalytic activity toward the electrooxidation of nitric oxide, which could provide electroanalytical application for nitric oxide sensing

  6. A dual enzyme functionalized nanostructured thulium oxide based interface for biomedical application

    Science.gov (United States)

    Singh, Jay; Roychoudhury, Appan; Srivastava, Manish; Solanki, Pratima R.; Lee, Dong Won; Lee, Seung Hee; Malhotra, B. D.

    2013-12-01

    In this paper, we present results of the studies related to fabrication of a rare earth metal oxide based efficient biosensor using an interface based on hydrothermally prepared nanostructured thulium oxide (n-Tm2O3). A colloidal solution of prepared nanorods has been electrophoretically deposited (EPD) onto an indium-tin-oxide (ITO) glass substrate. The n-Tm2O3 nanorods are found to provide improved sensing characteristics to the electrode interface in terms of electroactive surface area, diffusion coefficient, charge transfer rate constant and electron transfer kinetics. The structural and morphological studies of n-Tm2O3 nanorods have been carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopic techniques. This interfacial platform has been used for fabrication of a total cholesterol biosensor by immobilizing cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) onto a Tm2O3 nanostructured surface. The results of response studies of the fabricated ChEt-ChOx/n-Tm2O3/ITO bioelectrode show a broad linear range of 8-400 mg dL-1, detection limit of 19.78 mg (dL cm-2)-1, and high sensitivity of 0.9245 μA (mg per dL cm-2)-1 with a response time of 40 s. Further, this bioelectrode has been utilized for estimation of total cholesterol with negligible interference (3%) from analytes present in human serum samples. The utilization of this n-Tm2O3 modified electrode for enzyme-based biosensor analysis offers an efficient strategy and a novel interface for application of the rare earth metal oxide materials in the field of electrochemical sensors and bioelectronic devices.In this paper, we present results of the studies related to fabrication of a rare earth metal oxide based efficient biosensor using an interface based on hydrothermally prepared nanostructured thulium oxide (n-Tm2O3). A colloidal solution of prepared

  7. Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Xu, Lin; Yang, Hai-Bo

    2016-06-01

    During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Morphology and Growth of Titania Nanotubes : Nanostructuring and Applications

    OpenAIRE

    Albu, Sergiu P.

    2012-01-01

    Self-ordering phenomena during anodic oxidation of metals and the formation of porous oxides have been of a great interest to science and technology for more than 50 years. Particularly, after Masuda et al. demonstrated ideally ordered porous alumina by fine tuning the experimental parameters during aluminum anodization, these structures were increasingly used as a template for the deposition and growth of large varieties of 1D functional materials. For some time, such self-organized oxide st...

  9. A review of nanostructured surfaces and materials for dental implants: surface coating, patterning and functionalization for improved performance.

    Science.gov (United States)

    Rasouli, Rahimeh; Barhoum, Ahmed; Uludag, Hasan

    2018-05-10

    The emerging field of nanostructured implants has enormous scope in the areas of medical science and dental implants. Surface nanofeatures provide significant potential solutions to medical problems by the introduction of better biomaterials, improved implant design, and surface engineering techniques such as coating, patterning, functionalization and molecular grafting at the nanoscale. This review is of an interdisciplinary nature, addressing the history and development of dental implants and the emerging area of nanotechnology in dental implants. After a brief introduction to nanotechnology in dental implants and the main classes of dental implants, an overview of different types of nanomaterials (i.e. metals, metal oxides, ceramics, polymers and hydrides) used in dental implant together with their unique properties, the influence of elemental compositions, and surface morphologies and possible applications are presented from a chemical point of view. In the core of this review, the dental implant materials, physical and chemical fabrication techniques and the role of nanotechnology in achieving ideal dental implants have been discussed. Finally, the critical parameters in dental implant design and available data on the current dental implant surfaces that use nanotopography in clinical dentistry have been discussed.

  10. Converting environmentally hazardous materials into clean energy using a novel nanostructured photoelectrochemical fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Yong X., E-mail: yong.gan@utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Gan, Bo J. [Ottawa Hills High School, 2532 Evergreen Road, Toledo, OH 43606 (United States); Clark, Evan; Su, Lusheng [Department of Mechanical, Industrial and Manufacturing Engineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Zhang, Lihua [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2012-09-15

    Highlights: ► A photoelectrochemical fuel cell has been made from TiO{sub 2} nanotubes. ► The fuel cell decomposes environmentally hazardous materials to produce electricity. ► Doping the anode with a transition metal oxide increases the visible light sensitivity. ► Loading the anode with a conducting polymer enhances the visible light absorption. -- Abstract: In this work, a novel photoelectrochemical fuel cell consisting of a titanium dioxide nanotube array photosensitive anode and a platinum cathode was made for decomposing environmentally hazardous materials to produce electricity and clean fuel. Titanium dioxide nanotubes (TiO{sub 2} NTs) were prepared via electrochemical oxidation of pure Ti in an ammonium fluoride and glycerol-containing solution. Scanning electron microscopy was used to analyze the morphology of the nanotubes. The average diameter, wall thickness and length of the as-prepared TiO{sub 2} NTs were determined. The photosensitive anode made from the highly ordered TiO{sub 2} NTs has good photo-catalytic property, as proven by the decomposition tests on urea, ammonia, sodium sulfide and automobile engine coolant under ultraviolet (UV) radiation. To improve the efficiency of the fuel cell, doping the TiO{sub 2} NTs with a transition metal oxide, NiO, was performed and the photosensitivity of the doped anode was tested under visible light irradiation. It is found that the NiO-doped anode is sensitive to visible light. Also found is that polyaniline-doped photosensitive anode can harvest photon energy in the visible light spectrum range much more efficiently than the NiO-doped one. It is concluded that the nanostructured photoelectrochemical fuel cell can generate electricity and clean fuel by decomposing hazardous materials under sunlight.

  11. Nanostructured functional multilayer coatings incorporating biomimetic macromolecules for biomedical applications

    OpenAIRE

    Costa, Rui Filipe Ramos da

    2013-01-01

    Tese de doutoramento do Programa Doutoral em Engenharia Biomédica The modification of surfaces has been a key aspect in biology and biotechnology, for applications including cell expansion, biomaterials development and preparation of substrates for regenerative medicine. In this thesis, the layer-by-layer (LbL) technique was employed in the modification of surfaces for multiple purposes, namely for films with improved adhesiveness, enhanced cell adhesion, drug delivery capsules...

  12. The Functionalization of Nanostructures and Their Potential Applications in Edible Coatings

    Directory of Open Access Journals (Sweden)

    Ricardo M. González-Reza

    2018-04-01

    Full Text Available Nowadays, edible coatings incorporated with nanostructures as systems of controlled release of flavors, colorants and/or antioxidants and antimicrobial substances, also used for thermal and environmental protection of active compounds, represent a gap of opportunity to increase the shelf life of food highly perishable, as well as for the development of new products. These functionalized nanostructures have the benefit of incorporating natural substances obtained from the food industry that are rich in polyphenols, dietary fibers, and antimicrobial substances. In addition, the polymers employed on its preparation, such as polysaccharides, solid lipids and proteins that are low cost and developed through sustainable processes, are friendly to the environment. The objective of this review is to present the materials commonly used in the preparation of nanostructures, the main ingredients with which they can be functionalized and used in the preparation of edible coatings, as well as the advances that these structures have represented when used as controlled release systems, increasing the shelf life and promoting the development of new products that meet the characteristics of functionality for fresh foods ready to eat.

  13. New advantages and challenges for laser-induced nanostructured cluster materials: functional capability for experimental verification of macroscopic quantum phenomena

    International Nuclear Information System (INIS)

    Abramov, D V; Antipov, A A; Arakelian, S M; Khor’kov, K S; Kucherik, A O; Kutrovskaya, S V; Prokoshev, V G

    2014-01-01

    The main goal of our work is the laser fabrication of nanostructured materials including the nano- and microclusters for control of electrical, optical and other properties of obtained structures. First, we took an opportunity to select nanoparticles in various sizes and weights and also in topology distribution for some materials (carbon, Ni, PbTe, etc). Second, for a deposited extended array of nanoparticles we used a method of laser-induced nanoparticle fabrication in colloid and deposition metal (and/or oxide) nanoparticles from colloidal systems (LDPCS) to obtain the multilayered nanostructures with controlled topology, including the fractal cluster structures (for Ni, Pb Te et al). Electrophysical properties are analyzed for such nanocluster systems as well. A brief analogy of the obtained nanocluster structures with a quantum correlated state evidence is carried out. (paper)

  14. Investigations on diamond nanostructuring of different morphologies by the reactive-ion etching process and their potential applications.

    Science.gov (United States)

    Kunuku, Srinivasu; Sankaran, Kamatchi Jothiramalingam; Tsai, Cheng-Yen; Chang, Wen-Hao; Tai, Nyan-Hwa; Leou, Keh-Chyang; Lin, I-Nan

    2013-08-14

    We report the systematic studies on the fabrication of aligned, uniform, and highly dense diamond nanostructures from diamond films of various granular structures. Self-assembled Au nanodots are used as a mask in the self-biased reactive-ion etching (RIE) process, using an O2/CF4 process plasma. The morphology of diamond nanostructures is a close function of the initial phase composition of diamond. Cone-shaped and tip-shaped diamond nanostructures result for microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) films, whereas pillarlike and grasslike diamond nanostructures are obtained for Ar-plasma-based and N2-plasma-based ultrananocrystalline diamond (UNCD) films, respectively. While the nitrogen-incorporated UNCD (N-UNCD) nanograss shows the most-superior electron-field-emission properties, the NCD nanotips exhibit the best photoluminescence properties, viz, different applications need different morphology of diamond nanostructures to optimize the respective characteristics. The optimum diamond nanostructure can be achieved by proper choice of granular structure of the initial diamond film. The etching mechanism is explained by in situ observation of optical emission spectrum of RIE plasma. The preferential etching of sp(2)-bonded carbon contained in the diamond films is the prime factor, which forms the unique diamond nanostructures from each type of diamond films. However, the excited oxygen atoms (O*) are the main etching species of diamond film.

  15. Diffusion-accomodated rigid-body translations along grain boundaries in nanostructured materials

    International Nuclear Information System (INIS)

    Bachurin, D.V.; Nazarov, A.A.; Shenderova, O.A.; Brenner, D.W.

    2003-01-01

    A model for the structural relaxation of grain boundaries (GBs) in nanostructured materials (NSMs) by diffusion-accommodated rigid body translations along GBs is proposed. The model is based on the results of recent computer simulations that have demonstrated that the GBs in NSMs retain a high-energy structure with random translational states due to severe geometrical constraints applied from neighboring grains (J. Appl. Phys. 78 (1995) 847; Scripta Metall. Mater. 33 (1995) 1245). The shear stresses within a GB caused by non-optimized rigid-body translations (RBTs) can be accommodated by diffusive flow of atoms along a GB. This mechanism is particularly important for low-angle and vicinal GBs, the energy of which noticeably depends on the rigid body translations. At moderate and high temperatures the model yields relaxation times that are very short and therefore GBs in NSMs can attain an equilibrium structure with optimized rigid body translations. In contrast, at room temperature the model predicts that in some metals non-equilibrium structures can be preserved for a long time, which may result in the observation of grain boundary structures different from those in coarse grained polycrystals

  16. Interpretation of diffusion coefficients in nanostructured materials from random walk numerical simulation.

    Science.gov (United States)

    Anta, Juan A; Mora-Seró, Iván; Dittrich, Thomas; Bisquert, Juan

    2008-08-14

    We make use of the numerical simulation random walk (RWNS) method to compute the "jump" diffusion coefficient of electrons in nanostructured materials via mean-square displacement. First, a summary of analytical results is given that relates the diffusion coefficient obtained from RWNS to those in the multiple-trapping (MT) and hopping models. Simulations are performed in a three-dimensional lattice of trap sites with energies distributed according to an exponential distribution and with a step-function distribution centered at the Fermi level. It is observed that once the stationary state is reached, the ensemble of particles follow Fermi-Dirac statistics with a well-defined Fermi level. In this stationary situation the diffusion coefficient obeys the theoretical predictions so that RWNS effectively reproduces the MT model. Mobilities can be also computed when an electrical bias is applied and they are observed to comply with the Einstein relation when compared with steady-state diffusion coefficients. The evolution of the system towards the stationary situation is also studied. When the diffusion coefficients are monitored along simulation time a transition from anomalous to trap-limited transport is observed. The nature of this transition is discussed in terms of the evolution of electron distribution and the Fermi level. All these results will facilitate the use of RW simulation and related methods to interpret steady-state as well as transient experimental techniques.

  17. Cauliflower-like CuI nanostructures: Green synthesis and applications as catalyst and adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Yi [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China); Gao Shuyan, E-mail: shuyangao@htu.cn [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China); Li Zhengdao; Jia Xiaoxia; Chen Yanli [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China)

    2011-08-15

    Highlights: > In this study we report a green, environment-friendly, efficient, and direct one-step process for the preparation of CuI cauliflower. > The as-formed CuI cauliflower shows excellent catalytic activity for coupling reaction between benzylamine and iodobenzene. > The cauliflower-like CuI nanostructures have been successfully demonstrated as adsorbent for Cd (II) with high removal capacity. > To the best of our knowledge, it is the first report that nanostructured CuI acts as catalyst for coupling reaction and adsorbent for heavy metal ion. > It is also a good example for the organic combination of green chemistry and functional materials. - Abstract: Cauliflower-like CuI nanostructures is realized by an ampicillin-assisted clean, nontoxic, environmentally friendly synthesis strategy at room temperature. The morphology, composition, and phase structure of as-prepared powders were characterized by field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results show that ampicillin plays dual roles, reducing and morphology-directing agents, in the formation of the products. A possible growth mechanism of the cauliflower-like CuI nanostructures is tentatively proposed. The preliminary investigations show that the cauliflower-like CuI structure not only exhibits high catalytic activity with respect to coupling reaction between benzylamine and iodobenzene but also possesses high removal capacity for Cd (II), which may be ascribed to the high specific surface area of the special configuration. To the best of our knowledge, it is the first report that cauliflower-like CuI nanoparticles act as catalyst for coupling reaction and adsorbent for heavy metal ion.

  18. Cauliflower-like CuI nanostructures: Green synthesis and applications as catalyst and adsorbent

    International Nuclear Information System (INIS)

    Jiang Yi; Gao Shuyan; Li Zhengdao; Jia Xiaoxia; Chen Yanli

    2011-01-01

    Highlights: → In this study we report a green, environment-friendly, efficient, and direct one-step process for the preparation of CuI cauliflower. → The as-formed CuI cauliflower shows excellent catalytic activity for coupling reaction between benzylamine and iodobenzene. → The cauliflower-like CuI nanostructures have been successfully demonstrated as adsorbent for Cd (II) with high removal capacity. → To the best of our knowledge, it is the first report that nanostructured CuI acts as catalyst for coupling reaction and adsorbent for heavy metal ion. → It is also a good example for the organic combination of green chemistry and functional materials. - Abstract: Cauliflower-like CuI nanostructures is realized by an ampicillin-assisted clean, nontoxic, environmentally friendly synthesis strategy at room temperature. The morphology, composition, and phase structure of as-prepared powders were characterized by field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results show that ampicillin plays dual roles, reducing and morphology-directing agents, in the formation of the products. A possible growth mechanism of the cauliflower-like CuI nanostructures is tentatively proposed. The preliminary investigations show that the cauliflower-like CuI structure not only exhibits high catalytic activity with respect to coupling reaction between benzylamine and iodobenzene but also possesses high removal capacity for Cd (II), which may be ascribed to the high specific surface area of the special configuration. To the best of our knowledge, it is the first report that cauliflower-like CuI nanoparticles act as catalyst for coupling reaction and adsorbent for heavy metal ion.

  19. Fiscal 1999 achievement report on regional consortium research and development project. Regional consortium on energy research in its 3rd year (Development of nano-structured materials for ceramic bearing applications); 1999 nendo ceramic bearing yo nano seigyo zairyo no kenkyu kaihatsu seika hokokusho. 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Coprecipitation in a chloride-containing water solution is utilized to deposit zirconia nano-particles on alumina particles for the manufacture of a composite powder and a sintered body. As compared with a conventional CIP (cold isostatic press)-molded compact, a slip-cast compact is improved in flexural strength from 1.1 to 1.36Gpa. A composite powder granulating unit is installed. Although it is known that use of the citric acid as gelatinizer in the coprecipitation process results in a homogenous ZrO{sub 2}-Al{sub 2}O{sub 3} composite powder, yet a method is contrived to achieve high crystallinity without gelatinizer by freezing and drying a chloride-containing water solution in a microgravity field. In the near-net molding of spherical ceramic particles, an error in diameter of not more than 50{mu}m is realized. A mass production technology is established by which an inexpensive general-purpose alumina nano-structured material is die-compacted for the manufacture of low-cost ceramic bearings. A high-speed super-flat spherical surface processing technology is developed. In a 25kg-load fatigue test conducted for a combination of nano-structured ceramic balls and steel flat plates that bear the balls, a 240-hour life is attained. The bearing steel stands comparison with those available on the market. (NEDO)

  20. Ultra-Lightweight High Efficiency Nanostructured Materials and Coatings for Deep Space Mission Environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has developed a nanostructured spray self-assembly manufacturing method that has resulted in ultra-lightweight ( 1000%), and multi-layer, high efficiency...

  1. Studies of Heterogeneous and Diffusion-Influenced Nucleation for Improved Processing of Nanostructural Materials

    National Research Council Canada - National Science Library

    Kellon, Kenneth F; Buhro, William E

    2005-01-01

    .... The purpose of this grant was to identify a suitable glass for studies of the nucleation processes leading to nanostructure formation and to investigate the possibility of using TiB2 for enhanced...

  2. The innovative applications of therapeutic nanostructures in dentistry.

    Science.gov (United States)

    Elkassas, Dina; Arafa, Abla

    2017-05-01

    Nanotechnology has paved multiple ways in preventing, reversing or restoring dental caries which is one of the major health care problems. Nanotechnology aided in processing variety of nanomaterials with innovative dental applications. Some showed antimicrobial effect helping in the preventive stage. Others have remineralizing potential intercepting early lesion progression as nanosized calcium phosphate, carbonate hydroxyapatite nanocrystals, nanoamorphous calcium phosphate and nanoparticulate bioactive glass particularly with provision of self-assembles protein that furnish essential role in biomimetic repair. The unique size of nanomaterials makes them fascinating carriers for dental products. Thus, it is recentlyclaimedthat fortifying the adhesives with nanomaterials that possess biological meritsdoes not only enhance the mechanical and physical properties of the adhesives, but also help to attain and maintain a durable adhesive joint and enhanced longevity. Accordingly, this review will focus on the current status and the future implications of nanotechnology in preventive and adhesive dentistry. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Coupling between plasmonic films and nanostructures: from basics to applications

    Directory of Open Access Journals (Sweden)

    Maurer Thomas

    2015-11-01

    Full Text Available Plasmonic film-nanoparticles coupled systems have had a renewed interest for the past 5 years both for the richness of the provided plasmonic modes and for their high technological potential. Many groups started to investigate the optical properties of film-nanoparticles coupled systems, as to whether the spacer layer thickness is tens of nanometers thick or goes down to a few nanometers or angstroms, even reaching contact. This article reviews the recent breakthroughs in the physical understanding of such coupled systems and the different systems where nanoparticles on top of the spacer layer are either isolated/random or form regular arrays. The potential for applications, especially as perfect absorbers or transmitters is also put into evidence.

  4. Materials, Applications and Processes in Photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Keller, N.; Robert, D.; Herrmann, J.M.; Keller, V. (eds.)

    2007-04-15

    Catalysis Today publishes special issues only. The Journal focuses on the rapid publication of invited papers devoted to currently important topics in catalysis and related subjects. Both fundamental and applied aspects of catalysis are covered. While many of the issues are concerned with heterogeneous catalysis, subjects such as homogeneous catalysis and enzymatic catalysis may also be included. Subjects related to catalysis such as techniques, adsorption, process technology and others are included if there is a clear relationship with catalysis. This special issue concerns 21 papers on Materials, Applications and Processes in Photocatalysis: (1) Photoactive titania nanostructured thin films: Synthesis and characteristics of ordered helical nanocoil array; (2) The design of highly active rectangular column-structured titanium oxide photocatalysts and their application in purification systems; (3) Photosensitization of TiO{sub 2} by M{sub x}O{sub y} and M{sub x}S{sub y} nanoparticles for heterogeneous photocatalysis applications; (4) Oxidation of nauseous sulfur compounds by photocatalysis or photosensitization; (5) In situ characterization of the highly dispersed Mo{sup 6+}-oxide species supported onto various oxides and their photocatalytic reactivities; (6) The photocatalytic reforming of methanol; (7) Photocatalysis for new energy production: Recent advances in photocatalytic water splitting reactions for hydrogen production; (8) Visible light induced hydrogen evolution over the heterosystem Bi{sub 2}S{sub 3}/TiO{sub 2}; (9) Modeling and optimizing irradiance on planar, folded, and honeycomb shapes to maximize photocatalytic air purification; (10) Dimensionless analysis of slurry photocatalytic reactors using two-flux and six-flux radiation absorption-scattering models; (11) Photoreactions occurring on metal-oxide surfaces are not all photocatalytic: Description of criteria and conditions for processes to be photocatalytic; (12) Temperature dependent

  5. Sensing behavior of acetone vapors on TiO_2 nanostructuresapplication of density functional theory

    Directory of Open Access Journals (Sweden)

    V. Nagarajan

    2017-12-01

    Full Text Available The electronic properties of TiO_2 nanostructure are explored using density functional theory. The adsorption properties of acetone on TiO_2 nanostructure are studied in terms of adsorption energy, average energy gap variation and Mulliken charge transfer. The density of states spectrum and the band structure clearly reveals the adsorption of acetone on TiO_2 nanostructures. The variation in the energy gap and changes in the density of charge are observed upon adsorption of acetone on n-type TiO_2 base material. The results of DOS spectrum reveal that the transfer of electrons takes place between acetone vapor and TiO_2 base material. The findings show that the adsorption property of acetone is more favorable on TiO_2 nanostructure. Suitable adsorption sites of acetone on TiO_2 nanostructure are identified at atomistic level. From the results, it is confirmed that TiO_2 nanostructure can be efficiently utilized as a sensing element for the detection of acetone vapor in a mixed environment.

  6. Novel nanostructured materials to develop oxygen-sensitive films for optical sensors

    International Nuclear Information System (INIS)

    Fernandez-Sanchez, Jorge F.; Cannas, Rita; Spichiger, Stefan; Steiger, Rolf; Spichiger-Keller, Ursula E.

    2006-01-01

    Novel nanostructured materials, such as aluminum oxide (AlOOH), silicon oxide (SiO 2 ) or zirconium oxide (ZrO 2 ) embedded into PVA, were investigated as potential matrices to incorporate organometallic compounds (OMCs) for the development of optical oxygen-sensitive sensors which make use of the principle of luminescence quenching. In order to assess the benefits and drawbacks of the nanoporous material, the luminescence quantum yield and the Stern-Volmer constants were investigated and compared with the values shown for the same OMCs solubilized in polymer films (polystyrene). Referred to polymer films, the incorporation of the dyes into nanoporous membranes increased the Stern-Volmer constant by more than a factor of 100. Their response time was less than 1 s and the optode membranes were stable at room temperature for at least 9 months. Sterilization by autoclavation and gamma irradiation resulted in a marginal loss in activity. The photostability and sterilizability of the oxygen-sensitive membranes and the performance of the optodes with respect to of different types of metal oxides are discussed in the paper, as well as the influence of the total pore volume (TPV), the pore diameter (PD), the transparency of the film and the geometry of the pores. The OMCs used in this work were: ETH T -3003 (tris(4,7-bis(4-octylphenyl)-1,10-phenanthroline) ruthenium(II)), N-926 (bis(2-phenylpyridinyl)-N 4 ,N 4 ,N 4 ',N 4 '-tetramethyl-(4,4'-diamine-2,2'-bipyridine) iridium(III) chlorate), N-833 (tetrabutylammonium bis(isothiocyanate) bis(2-phenylpyridinyl)-iridium(III)) and N-837 (tetrabutylammonium bis(cyanate) bis(2-phenylpyridinyl)-iridium(III))

  7. Zinc stannate nanostructures: hydrothermal synthesis

    International Nuclear Information System (INIS)

    Baruah, Sunandan; Dutta, Joydeep

    2011-01-01

    Nanostructured binary semiconducting metal oxides have received much attention in the last decade owing to their unique properties rendering them suitable for a wide range of applications. In the quest to further improve the physical and chemical properties, an interest in ternary complex oxides has become noticeable in recent times. Zinc stannate or zinc tin oxide (ZTO) is a class of ternary oxides that are known for their stable properties under extreme conditions, higher electron mobility compared to its binary counterparts and other interesting optical properties. The material is thus ideal for applications from solar cells and sensors to photocatalysts. Among the different methods of synthesizing ZTO nanostructures, the hydrothermal method is an attractive green process that is carried out at low temperatures. In this review, we summarize the conditions leading to the growth of different ZTO nanostructures using the hydrothermal method and delve into a few of its applications reported in the literature. (topical review)

  8. Giant magnetoresistance in lateral metallic nanostructures for spintronic applications.

    Science.gov (United States)

    Zahnd, G; Vila, L; Pham, V T; Marty, A; Beigné, C; Vergnaud, C; Attané, J P

    2017-08-25

    In this letter, we discuss the shift observed in spintronics from the current-perpendicular-to-plane geometry towards lateral geometries, illustrating the new opportunities offered by this configuration. Using CoFe-based all-metallic LSVs, we show that giant magnetoresistance variations of more than 10% can be obtained, competitive with the current-perpendicular-to-plane giant magnetoresistance. We then focus on the interest of being able to tailor freely the geometries. On the one hand, by tailoring the non-magnetic parts, we show that it is possible to enhance the spin signal of giant magnetoresistance structures. On the other hand, we show that tailoring the geometry of lateral structures allows creating a multilevel memory with high spin signals, by controlling the coercivity and shape anisotropy of the magnetic parts. Furthermore, we study a new device in which the magnetization direction of a nanodisk can be detected. We thus show that the ability to control the magnetic properties can be used to take advantage of all the spin degrees of freedom, which are usually occulted in current-perpendicular-to-plane devices. This flexibility of lateral structures relatively to current-perpendicular-to-plane structures is thus found to offer a new playground for the development of spintronic applications.

  9. Periodic nanostructures imprinted on high-temperature stable sol–gel films by ultraviolet-based nanoimprint lithography for photovoltaic and photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Back, Franziska [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany); Bockmeyer, Matthias; Rudigier-Voigt, Eveline [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Löbmann, Peer [Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany)

    2014-07-01

    Nanostructured sol–gel films with high-temperature stability are used in the area of electronics, photonics or biomimetic materials as light-trapping architectures in solar cells, displays, waveguides or as superhydrophobic surfaces with a lotus effect. In this work, high-temperature stable 2-μm nanostructured surfaces were prepared by ultraviolet-based nanoimprint lithography using an alkoxysilane binder incorporating modified silica nanoparticles. Material densification during thermal curing and microstructural evolution which are destined for a high structural fidelity of nanostructured films were investigated in relation to precursor chemistry, particle morphology and particle content of the imprint resist. The mechanism for densification and shrinkage of the films was clarified and correlated with the structural fidelity to explain the influence of the geometrical design on the optical properties. A high internal coherence of the microstructure of the nanostructured films results in a critical film thickness of > 5 μm. The structured glassy layers with high inorganic content show thermal stability up to 800 °C and have a high structural fidelity > 90% with an axial shrinkage of 16% and a horizontal shrinkage of 1%. This material allows the realization of highly effective light-trapping architectures for polycrystalline silicon thin-film solar cells on glass but also for the preparation of 2D photonic crystals for telecommunication wavelengths. - Highlights: • Fundamental research • Hybrid sol–gel material with high-temperature stability and contour accuracy • Ensuring of cost-efficient and industrially feasible processing • Application in photonic and photovoltaic.

  10. The investigation of nanostructures of magnetic recording media by TEM

    International Nuclear Information System (INIS)

    Peng Yingguo; Ohkubo, Tadakatsu; Laughlin, David E.

    2003-01-01

    Diverse applications of transmission electron microscopy techniques used in investigating the nanostructures of magnetic recording materials are presented. Specimen preparation methods are discussed for the specific case of magnetic thin film recording media. Investigations of the crystallographic orientation, grain size and distribution, and interfacial nanostructures are presented

  11. Effective Chemical Route to 2D Nanostructured Silicon Electrode Material: Phase Transition from Exfoliated Clay Nanosheet to Porous Si Nanoplate

    International Nuclear Information System (INIS)

    Adpakpang, Kanyaporn; Patil, Sharad B.; Oh, Seung Mi; Kang, Joo-Hee; Lacroix, Marc; Hwang, Seong-Ju

    2016-01-01

    Graphical abstract: Effective morphological control of porous silicon 2D nanoplate can be achieved by the magnesiothermically-induced phase transition of exfoliated silicate clay nanosheets. The promising lithium storage performance of the obtained silicon materials with huge capacity and excellent rate characteristics underscores the prime importance of porously 2D nanostructured morphology of silicon. - Highlights: • 2D nanostructured silicon electrode materials are successfully synthesized via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. • High discharge capacity and rate capability are achieved from the 2D nanoplates of silicon. • Silicon 2D nanoplates can enhance both Li"+ diffusion and charge-transfer kinetics. • 2D nanostructured silicon is beneficial for the cycling stability by minimizing the volume change during lithiation-delithiation. - Abstract: An efficient and economical route for the synthesis of porous two-dimensional (2D) nanoplates of silicon is developed via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. The magnesiothermic reaction of precursor clay nanosheets prepared by the exfoliation and restacking with Mg"2"+ cations yields porous 2D nanoplates of elemental silicon. The variation in the Mg:SiO_2 ratio has a significant effect on the porosity and connectivity of silicon nanoplates. The porous silicon nanoplates show a high discharge capacity of 2000 mAh g"−"1 after 50 cycles. Of prime importance is that this electrode material still retains a large discharge capacity at higher C-rates, which is unusual for the elemental silicon electrode. This is mainly attributed to the improved diffusion of lithium ions, charge-transfer kinetics, and the preservation of the electrical connection of the porous 2D plate-shaped morphology. This study highlights the usefulness of clay mineral as an economical and scalable precursor of high-performance silicon electrodes with

  12. Phase change materials science and applications

    CERN Document Server

    Raoux, Simone

    2009-01-01

    ""Phase Change Materials: Science and Applications"" provides a unique introduction of this rapidly developing field. This clearly written volume describes the material science of these fascinating materials from a theoretical and experimental perspective.

  13. Improved cladding nano-structured materials with self-repairing capabilities

    International Nuclear Information System (INIS)

    Popa-Simil, L.

    2012-01-01

    When designing nuclear reactors or the materials that go into them, one of the key challenges is finding materials that can withstand an outrageously extreme environment. In addition to constant bombardment by radiation, reactor materials may be subjected to extremes in temperature, physical stress, and corrosive conditions. A limitation in fuel burnup is and usage of the nuclear fuel material is related to the structural material radiation damage, that makes the fuel be removed with low-burnup and immobilized in the waste storage pools. The advanced burnup brings cladding material embitterment due to radiation damage effects corroborated with corrosion effects makes the fuel pellet life shorter. The novel nano-clustered structured sintered material may mitigate simultaneously the radiation damage and corrosion effects driving to more robust structural materials that may make the nuclear reactor safer and more reliable. The development of nano-clustered sinter alloys provides new avenues for further examination of the role of grain boundaries and engineered material interfaces in self-healing of radiation-induced defects driving to the design of highly radiation-tolerant materials for the next generation of nuclear energy applications. (authors)

  14. FULERENIC MATERIALS WITH BIOMEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Radu Claudiu FIERASCU

    2010-05-01

    Full Text Available Soluble fullerenic derivates are essential for numerous biomedical techniques that exploit the unique structural chemical and physical properties of carbon nanospheres. Their toxicity, demonstrated in vitro and in vivo is important for the characterization and limitation of those applications. The phototoxicity of some fullerene molecules was identified as a future therapeutical instrument. Other studies focused on the decrease of the phototoxicity of hydrosoluble fullerenes follow the use of those compounds as drug delivery systems or their use in environment protection. Starting from the characteristics of those compounds, which can be by themeselves cytotoxic, or could become during irradiation (photosensitizers we have tried to obtain new materials based on fullerenes and diads/triads fullerene/porphyrines or fullerenes/calixarenes.The obtained complexes were characterized by UV Vis and IR spectroscopy.

  15. Nanoparticle Decorated Ultrathin Porous Nanosheets as Hierarchical Co3O4 Nanostructures for Lithium Ion Battery Anode Materials

    Science.gov (United States)

    Mujtaba, Jawayria; Sun, Hongyu; Huang, Guoyong; Mølhave, Kristian; Liu, Yanguo; Zhao, Yanyan; Wang, Xun; Xu, Shengming; Zhu, Jing

    2016-01-01

    We report a facile synthesis of a novel cobalt oxide (Co3O4) hierarchical nanostructure, in which crystalline core-amorphous shell Co3O4 nanoparticles with a bimodal size distribution are uniformly dispersed on ultrathin Co3O4 nanosheets. When tested as anode materials for lithium ion batteries, the as-prepared Co3O4 hierarchical electrodes delivered high lithium storage properties comparing to the other Co3O4 nanostructures, including a high reversible capacity of 1053.1 mAhg−1 after 50 cycles at a current density of 0.2 C (1 C = 890 mAg−1), good cycling stability and rate capability. PMID:26846434

  16. Dwell-time effect on the synthesis of a nano-structured material in water by using Ni wire explosion

    International Nuclear Information System (INIS)

    Eom, Gyu Sub; Kwon, Hyeok Jung; Cho, Yong Sub; Paek, Kwang Hyun; Joo, Won Tae

    2014-01-01

    Nickel nano-structured materials are synthesized by using a wire explosion in water. Based on an analysis of each step of the wire explosion, we propose insufficient energy deposition before a plasma restrike as the cause for the inclusion of coarse particles in the wire-explosion product. We confirmed that more energy, in excess of 30%, could be deposited by increasing the dwell time, which resulted from a compression of vapor by the surrounding water and from suppression of plasma restrikes. Because of an increased energy loss into the surrounding water, the specific energy increased by two-fold compared to a gas atmosphere. The synthesized nano-structured nickel showed a uniform particle size of 20 nm with a few coarse particles that were mainly metallic nickel with a little oxide and hydroxide phases. The possibility for large-volume production through a continuous explosion of 300 shots was confirmed.

  17. Photochemical Synthesis of Silver Nanodecahedrons and Related Nanostructures for Plasmonic Field Enhancement Applications

    Science.gov (United States)

    Lu, Haifei

    Noble-metal nanocrystals have received considerable attention in recent years for their size and shape dependent localized surface Plasmon resonances (LSPR). Various applications based on colloidal nanoparticles, such as surface enhanced Raman scattering (SERS), surface enhanced fluorescence (SEF), plasmonic sensing, photothermal therapy etc., have been broadly explored in the field of biomedicine, because of their extremely large optical scattering and absorption cross sections, as well as giant electric field enhancement on their surface. However, despite its high chemical stability, gold exhibits quite large losses and electric field enhancement is comparatively weaker than silver. Silver nanoparticles synthesized by the traditional technique only cover an LSPR ranged from 420~500 nm. On the other hand, the range of 500~660 nm, which is covered by several easily available commercial laser lines, very limited colloidal silver nanostructures with controllable size and shape have been reported, and realization of tuning the resonance to longer wavelengths is very important for the practical applications. In this thesis, a systematic study on photochemical synthesis of silver nanodecahedrons (NDs) and related nanostructures, and their plasmonic field enhancements are presented. First, the roles of chemicals and the light source during the formation of silver nanoparticles have been studied. We have also developed a preparation route for the production size-controlled silver nanodecahedrons (LSPR range 420 ~ 660 nm) in high purity. Indeed our experiments indicate that both the chemicals and the light sources can affect the shape and purity of final products. Adjusting the molar ratio between sodium citrate and silver nitrate can help to control the crystal structure following rapid reduction from sodium borohydride. Light from a blue LED (465 nm) can efficiently transform the polyvinylpyrrolidone stabilized small silver nanoparticles into silver NDs through photo

  18. Design, fabrication, and characterization of metallic nanostructures for surface-enhanced Raman spectroscopy and plasmonic applications

    Science.gov (United States)

    Hao, Qingzhen

    Metal/dielectric nanostructures have the ability to sustain coherent electron oscillations known as surface plasmons. Due to their capability of localizing and guiding light in sub-wavelength metal nanostructures beyond diffraction limits, surface plasmon-based photonics, or “plasmonics” has opened new physical phenomena and lead to novel applications in metamaterials, optoelectronics, surface enhanced spectroscopy and biological sensing. This dissertation centers on design, fabrication, characterization of metallic nanostructures and their applications in surface-enhanced Raman spectroscopy (SERS) and actively tunable plasmonics. Metal-dielectric nanostructures are the building blocks for photonic metamaterials. One valuable design guideline for metamaterials is the Babinet’s principle, which governs the optical properties of complementary nanostructures. However, most complementary metamaterials are designed for the far infrared region or beyond, where the optical absorption of metal is small. We have developed a novel dual fabrication method, capable of simultaneously producing optically thin complementary structures. From experimental measurements and theoretical simulations, we showed that Babinet’s principle qualitatively holds in the visible region for the optically thin complements. The complementary structure is also a good platform to study subtle differences between nanoparticles and nanoholes in SERS (a surface sensitive technique, which can enhance the conventional Raman cross-section by 106˜108 fold, thus very useful for highly sensitive biochemical sensing). Through experimental measurement and theoretical analysis, we showed that the SERS enhancement spectrum (plot of SERS enhancement versus excitation wavelengths), dominated by local near-field, for nanoholes closely follows their far-field optical transmission spectrum. However, the enhancement spectrum for nanoparticles red-shifts significantly from their far-field optical extinction

  19. Focused-ion-beam nano-structuring of photonic cavities in dielectric materials

    NARCIS (Netherlands)

    Ay, F.; Pollnau, Markus

    Focused ion beam (FIB) milling is an emerging technology that enables fast, reliable and well-controlled nanometer-size feature definition. In this work we will discuss applications of the tool in the area of photonics. The FIB technique can be adapted and optimized almost for any material system

  20. In search of novel, high performance and intelligent materials for applications in severe and unconditioned environments

    International Nuclear Information System (INIS)

    Gyeabour Ayensu, A. I.; Normeshie, C. M. K.

    2007-01-01

    For extreme operating conditions in aerospace, nuclear power plants and medical applications, novel materials have become more competitive over traditional materials because of the unique characteristics. Extensive research programmes are being undertaken to develop high performance and knowledge-intensive new materials, since existing materials cannot meet the stringent technological requirements of advanced materials for emerging industries. The technologies of intermetallic compounds, nanostructural materials, advanced composites, and photonics materials are presented. In addition, medical biomaterial implants of high functional performance based on biocompatibility, resistance against corrosion and degradation, and for applications in hostile environment of human body are discussed. The opportunities for African researchers to collaborate in international research programmes to develop local raw materials into high performance materials are also highlighted. (au)

  1. Molecular materials for photovoltaic applications

    International Nuclear Information System (INIS)

    Gegout, A.

    2006-10-01

    This work deals with the elaboration of new C60 derivatives functionalized with p-conjugated oligomers in order to prepare organic materials for photovoltaic applications. In a first approach, the donating ability of different OPV-C60 systems has been enhanced to optimize the electron transfer. First, the length of the conjugated system has been increased and two heptamers bearing one and two C60 moieties respectively, have been synthesized. Electronic properties of these compounds have revealed an electron transfer dependant of the solvent's polarity. Then, three other systems combining the C60 with OPV subunits bearing one or two diethyl-amino groups have been prepared. In such systems, the electron transfer process is optimized as the photophysical studies have revealed an electron transfer from the OPV to the C60 subunit with formation of a charge-separated state even in apolar solvents. A dendritic approach has also been developed. Original isomeric branched conjugated systems based on the oligophenylene-ethynylene framework have been prepared. The excited-state properties have been investigated to understand the influence of the conjugation pathways within theses isomeric systems. The functionalization of the dendritic OPE branches with the C60 has allowed the preparation of the first and second generations of fullero-dendrimers. The peripheral OPE dendrons are able to transfer the absorbed energy to the central core. The preparation of photovoltaic cells which incorporate these systems shows that under light irradiation, the material is able to generate electrons and holes, and also transport them in the device, thus leading to a photocurrent. (author)

  2. Beam-induced magnetic property modifications: Basics, nanostructure fabrication and potential applications

    International Nuclear Information System (INIS)

    Devolder, T.; Bernas, H.; Ravelosona, D.; Chappert, C.; Pizzini, S.; Vogel, J.; Ferre, J.; Jamet, J.-P.; Chen, Y.; Mathet, V.

    2001-01-01

    We have developed an irradiation technique that allows us to tune the magnetic properties of thin films without affecting their roughness. We discuss the mechanisms involved and the applications. He + ion irradiation of Co/Pt multilayers lowers their magnetic anisotropy in a controlled way, reducing the coercive force and then leading to in-plane magnetization. By X-ray reflectometry, we study how irradiation-induced structural modifications correlate with magnetic properties. We also report the L1 0 chemical ordering of FePt by irradiation at 280 deg. C, and the consequent increase of magnetic anisotropy. Planar magnetic patterning at the sub 50 nm scale can be achieved when the irradiation is performed through a mask. New magnetic behaviors result from the fabrication process. They appear to arise from collateral damage. We model these effects in the case of SiO 2 and W masks. The planarity of irradiation-induced patterning and its ability to independently control nanostructure size and coercivity make it very appealing for magnetic recording on nanostructured media. Finally, possible applications to the granular media used in current hard disk drive storage technology are discussed

  3. Iron Oxide and Gold Based Magneto-Plasmonic Nanostructures for Medical Applications: A Review

    Directory of Open Access Journals (Sweden)

    Thi Thuy Nguyen

    2018-03-01

    Full Text Available Iron oxide and gold-based magneto-plasmonic nanostructures exhibit remarkable optical and superparamagnetic properties originating from their two different components. As a consequence, they have improved and broadened the application potential of nanomaterials in medicine. They can be used as multifunctional nanoprobes for magneto-plasmonic heating as well as for magnetic and optical imaging. They can also be used for magnetically assisted optical biosensing, to detect extreme traces of targeted bioanalytes. This review introduces the previous work on magneto-plasmonic hetero-nanostructures including: (i their synthesis from simple “one-step” to complex “multi-step” routes, including seed-mediated and non-seed-mediated methods; and (ii the characterization of their multifunctional features, with a special emphasis on the relationships between their synthesis conditions, their structures and their properties. It also focuses on the most important progress made with regard to their use in nanomedicine, keeping in mind the same aim, the correlation between their morphology—namely spherical and non-spherical, core-satellite and core-shell, and the desired applications.

  4. Electrochemical formation of InP porous nanostructures and its application to amperometric chemical sensors

    International Nuclear Information System (INIS)

    Sato, Taketomo; Mizohata, Akinori; Fujino, Toshiyuki; Hashizume, Tamotsu

    2008-01-01

    In this paper, we report the electrochemical formation of the InP porous nanostructures and their feasibility for the application to the amperometric chemical sensors. Our two step electrochemical process consists of the pore formation on a (001) n-type InP substrate and the subsequent etching of pore walls caused by changing the polarity of the InP electrode in a HCl-based electrolyte. By applying the anodic bias to the InP electrode, the high-density array of uniform nanopores was formed on the surface. Next, the cathodic bias was applied to the porous sample to reduce the wall thickness by cathodic decomposition of InP, where the thickness of InP nanowall decreased uniformly along the entire depth of the porous layer. From the amperometric measurements of the porous electrode, it was found that the electrocatalytic activity was much higher than that of the planar electrode. Furthermore, the current sensitivity for the H 2 O 2 detection was much enhanced after the cathodic decomposition process. The InP porous nanostructure formed by the present process is one of the promising structures for the application to the semiconductor-based bio/chemical sensors. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. ZnO thin films and nanostructures for emerging optoelectronic applications

    Science.gov (United States)

    Rogers, D. J.; Teherani, F. H.; Sandana, V. E.; Razeghi, M.

    2010-02-01

    ZnO-based thin films and nanostructures grown by PLD for various emerging optoelectronic applications. AZO thin films are currently displacing ITO for many TCO applications due to recent improvements in attainable AZO conductivity combined with processing, cost and toxicity advantages. Advances in the channel mobilities and Id on/off ratios in ZnO-based TTFTs have opened up the potential for use as a replacement for a-Si in AM-OLED and AM-LCD screens. Angular-dependent specular reflection measurements of self-forming, moth-eye-like, nanostructure arrays grown by PLD were seen to have green gap in InGaN-based LEDs was combated by substituting low Ts PLD n-ZnO for MOCVD n-GaN in inverted hybrid heterojunctions. This approach maintained the integrity of the InGaN MQWs and gave LEDs with green emission at just over 510 nm. Hybrid n-ZnO/p-GaN heterojunctions were also seen to have the potential for UV (375 nm) EL, characteristic of ZnO NBE emission. This suggests that there was significant hole injection into the ZnO and that such LEDs could profit from the relatively high exciton binding energy of ZnO.

  6. Nanostructured rare earth doped Nb2O5: Structural, optical properties and their correlation with photonic applications

    International Nuclear Information System (INIS)

    Pereira, Rafael Ramiro; Aquino, Felipe Thomaz; Ferrier, Alban; Goldner, Philippe; Gonçalves, Rogéria R.

    2016-01-01

    In the present work, we report on a systematic study on structural and spectroscopic properties Eu 3+ and Er 3+ -doped Nb 2 O 5 prepared by sol–gel method. The Eu 3+ ions were used as structural probe to determine the symmetry sites occupied by lanthanide ions. The Eu 3+ -doped Nb 2 O 5 nanocrystalline powders were annealed at different temperatures to verify how the different Nb 2 O 5 crystalline phases affect the structure and the luminescence properties. Er 3+ -doped Nb 2 O 5 was prepared showing an intense NIR luminescence, and, visible luminescence on the green and red, deriving from upconversion process. The synthetized materials can find widespread applicability in photonics as red luminophor for white LED (with tricolor), optical amplifiers and upconverter materials. - Highlights: • Vis and NIR emission from nanostructured lanthanide doped Nb 2 O 5 . • Eu 3+ -doped Nb 2 O 5 as Red luminophor. • Multicolor tunability of intense upconversion emission from lanthanide doped Nb 2 O 5 . • Potential application as biological markers. • Broad band NIR emission.

  7. Nanostructured Ti-Zr-Pd-Si-(Nb) bulk metallic composites: Novel biocompatible materials with superior mechanical strength and elastic recovery.

    Science.gov (United States)

    Hynowska, A; Blanquer, A; Pellicer, E; Fornell, J; Suriñach, S; Baró, M D; Gebert, A; Calin, M; Eckert, J; Nogués, C; Ibáñez, E; Barrios, L; Sort, J

    2015-11-01

    The microstructure, mechanical behaviour, and biocompatibility (cell culture, morphology, and cell adhesion) of nanostructured Ti45 Zr15 Pd35- x Si5 Nbx with x = 0, 5 (at. %) alloys, synthesized by arc melting and subsequent Cu mould suction casting, in the form of rods with 3 mm in diameter, are investigated. Both Ti-Zr-Pd-Si-(Nb) materials show a multi-phase (composite-like) microstructure. The main phase is cubic β-Ti phase (Im3m) but hexagonal α-Ti (P63/mmc), cubic TiPd (Pm3m), cubic PdZr (Fm3m), and hexagonal (Ti, Zr)5 Si3 (P63/mmc) phases are also present. Nanoindentation experiments show that the Ti45 Zr15 Pd30 Si5 Nb5 sample exhibits lower Young's modulus than Ti45 Zr15 Pd35 Si5 . Conversely, Ti45 Zr15 Pd35 Si5 is mechanically harder. Actually, both alloys exhibit larger values of hardness when compared with commercial Ti-40Nb, (HTi-Zr-Pd-Si ≈ 14 GPa, HTi-Zr-Pd-Si-Nb ≈ 10 GPa and HTi-40Nb ≈ 2.7 GPa). Concerning the biological behaviour, preliminary results of cell viability performed on several Ti-Zr-Pd-Si-(Nb) discs indicate that the number of live cells is superior to 94% in both cases. The studied Ti-Zr-Pd-Si-(Nb) bulk metallic system is thus interesting for biomedical applications because of the outstanding mechanical properties (relatively low Young's modulus combined with large hardness), together with the excellent biocompatibility. © 2014 Wiley Periodicals, Inc.

  8. One-dimensional nanostructured materials for lithium-ion battery and supercapacitor electrodes

    Science.gov (United States)

    Chan, Candace Kay

    cycling performance of the SiNWs in different electrolytes, with various surface modifications and coatings, and other experimental parameters were evaluated. The electrochemical reaction of GeNWs with lithium resulted in capacities of ˜1000 mAh/g for tens of cycles. The GeNWs were also observed to become amorphous after the first charge. Interestingly, very large irreversible capacities were observed in the GeNWs, indicating surface instabilities or reactivity with the electrolyte. To passivate the surface, a thin layer of amorphous Si was used to coat the GeNWs and make Ge-Si coreshell nanowires. This passivation helped to reduce the irreversibly capacity loss and gave reversible capacities typical for the GeNWs. Two positive electrode materials for Li-ion batteries were synthesized in nano-morphologies and characterized. Transformation of layered structured V2O5 nanoribbons into the fully lithiated o-Li 3V2O5 phase was found to depend not only on the width but also the thickness of the nanoribbons. For the first time, complete delithiation of o-Li3V2O5 back to the single-crystalline, pristine V2O5 nanoribbon was observed, indicating a 30% higher energy density. Nanostructured BiOCl, a conversion material, was also synthesized and characterized for its Li insertion properties. Networks of silver nanowires (AgNWs) and single-walled carbon nanotubes (SWNTs) were explored as highly conducting, high surface area, and printable materials for flexible, light-weight supercapacitors. Use of the solution-processible AgNWs and SWNTs, as well as a polymer electrolyte, facilitated the fabrication of an entirely printable device on plastic substrates. The devices showed promising results for high energy and power density supercapacitors, with energy and power densities reaching 24 Wh/kg and 42 kW/kg for the AgNW/SWNT composite.

  9. Silica supported TiO{sub 2} nanostructures for highly efficient photocatalytic application under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pal, A.; Jana, T.K.; Chatterjee, K., E-mail: kuntal2k@gmail.com

    2016-04-15

    Highlights: • Synthesis of silica–titania nanocomposite by simple and facile chemical route and characterization of the materials. • Excellent catalytic activity on organic pollutant methylene blue under the visible light irradiation. • Photocatalytic rate is much higher than commercial P25 TiO{sub 2} catalyst powder. • The higher activity is attributed to the special structure and synergistic effect of the materials which has immense application potential. - Abstract: Titanium dioxide decorated silica nanospheres have been synthesized by a simple wet chemical approach. X-ray diffraction, electron microscopy and energy dispersive X-ray analysis revealed that anatase phase of TiO{sub 2} nanostructures, with exposed {0 0 1} and {1 0 1} facets, are anchored onto the amorphous silica spheres of ∼60 nm diameter. The photocatalytic activity of the sample under visible light irradiation was examined. It is found that photocatalytic efficiency of the material is better than commercial P25 TiO{sub 2} photocatalyst and the result is attributed to the unique synergistic effect of SiO{sub 2}–TiO{sub 2} nanocomposite structure resulting enhanced charge separation and charge transfer.

  10. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Seth

    2012-09-12

    The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong

  11. Opportunities in chemistry and materials science for topological insulators and their nanostructures

    KAUST Repository

    Kong, Desheng

    2011-10-24

    Electrical charges on the boundaries of topological insulators favour forward motion over back-scattering at impurities, producing low-dissipation, metallic states that exist up to room temperature in ambient conditions. These states have the promise to impact a broad range of applications from electronics to the production of energy, which is one reason why topological insulators have become the rising star in condensed-matter physics. There are many challenges in the processing of these exotic materials to use the metallic states in functional devices, and they present great opportunities for the chemistry and materials science research communities. © 2011 Macmillan Publishers Limited. All rights reserved.

  12. Applications: Accelerators for new materials

    International Nuclear Information System (INIS)

    Andersen, H.H.

    1990-01-01

    Ion beams bring important benefits to material processing, and the Seventh International Conference on Ion Beam Modification of Materials (IBMM 90), held in Knoxville, Tennessee, in September showed the promising progress being made

  13. Applications: Accelerators for new materials

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, H. H. [Copenhagen (Denmark)

    1990-12-15

    Ion beams bring important benefits to material processing, and the Seventh International Conference on Ion Beam Modification of Materials (IBMM 90), held in Knoxville, Tennessee, in September showed the promising progress being made.

  14. Few molecule SERS detection using nanolens based plasmonic nanostructure: application to point mutation detection

    KAUST Repository

    Das, Gobind

    2016-10-27

    Advancements in nanotechnology fabrication techniques allow the possibility to design and fabricate a device with a minimum gap (<10 nm) between the composing nanostructures in order to obtain better control over the creation and spatial definition of plasmonic hot-spots. The present study is intended to show the fabrication of nanolens and their application to single/few molecules detection. Theoretical simulations were performed on different designs of real structures, including comparison of rough and smooth surfaces. Various molecules (rhodamine 6G, benzenethiol and BRCA1/BRCT peptides) were examined in this regard. Single molecule detection was possible for synthetic peptides, with a possible application in early detection of diseases. © The Royal Society of Chemistry.

  15. Few molecule SERS detection using nanolens based plasmonic nanostructure: application to point mutation detection

    KAUST Repository

    Das, Gobind; Alrasheed, Salma; Coluccio, Maria Laura; Gentile, Francesco; Nicastri, Annalisa; Candeloro, Patrizio; Cuda, Giovanni; Perozziello, Gerardo; Di Fabrizio, Enzo M.

    2016-01-01

    Advancements in nanotechnology fabrication techniques allow the possibility to design and fabricate a device with a minimum gap (<10 nm) between the composing nanostructures in order to obtain better control over the creation and spatial definition of plasmonic hot-spots. The present study is intended to show the fabrication of nanolens and their application to single/few molecules detection. Theoretical simulations were performed on different designs of real structures, including comparison of rough and smooth surfaces. Various molecules (rhodamine 6G, benzenethiol and BRCA1/BRCT peptides) were examined in this regard. Single molecule detection was possible for synthetic peptides, with a possible application in early detection of diseases. © The Royal Society of Chemistry.

  16. Nanostructured MnO2 as Electrode Materials for Energy Storage

    Science.gov (United States)

    Mauger, Alain

    2017-01-01

    Manganese dioxides, inorganic materials which have been used in industry for more than a century, now find great renewal of interest for storage and conversion of energy applications. In this review article, we report the properties of MnO2 nanomaterials with different morphologies. Techniques used for the synthesis, structural, physical properties, and electrochemical performances of periodic and aperiodic frameworks are discussed. The effect of the morphology of nanosized MnO2 particles on their fundamental features is evidenced. Applications as electrodes in lithium batteries and supercapacitors are examined. PMID:29149066

  17. Nanostructured MnO2 as Electrode Materials for Energy Storage

    Directory of Open Access Journals (Sweden)

    Christian M. Julien

    2017-11-01

    Full Text Available Manganese dioxides, inorganic materials which have been used in industry for more than a century, now find great renewal of interest for storage and conversion of energy applications. In this review article, we report the properties of MnO2 nanomaterials with different morphologies. Techniques used for the synthesis, structural, physical properties, and electrochemical performances of periodic and aperiodic frameworks are discussed. The effect of the morphology of nanosized MnO2 particles on their fundamental features is evidenced. Applications as electrodes in lithium batteries and supercapacitors are examined.

  18. Superconducting materials for large scale applications

    International Nuclear Information System (INIS)

    Dew-Hughes, D.

    1975-01-01

    Applications of superconductors capable of carrying large current densities in large-scale electrical devices are examined. Discussions are included on critical current density, superconducting materials available, and future prospects for improved superconducting materials. (JRD)

  19. Report of the results of the fiscal 1997 regional consortium R and D project. Regional consortium energy field / development of nano-structured materials for ceramic bearing application (first fiscal year); 1997 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium energy bun`ya / ceramic bearing yo nano seigyo zairyo no kenkyu kaihatsu (daiichi nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the purpose of developing high efficient ceramic bearing using nano-structured materials, technical development was proceeded with of raw material powder treatment, forming sintering, processing, structural analysis, property evaluation, etc. As to the study of manufacturing of ceramic balls, the following were conducted by the method developed at Osaka Prefectural Institute of Industrial Technology: coprecipitation laminate processing of ZrO2-Al2O3 system to alumina powder at Okumura Crucible Mfg. Co. Ltd., spherial press processing and sintering at Kyocera Co. Ltd., and precise machining at Nippon Pillow Block Mfg., Co. Ltd. The performance as bearing was measured of the ceramic balls obtained such as surface coarseness, sphericity, crush strength and fatigue life. Surface coarseness and sphericity were the same as those of bearing use silicon nitride, but crush strength was considerably low. In the experiment on rolling fatigue strength as bearing, separation occurred within 100 hours even at a load of 100kgf. It is thought that this is because of the pores remaining on the surface, and the measures to be taken for long life were studied. 12 refs., 64 figs., 27 tabs.

  20. Enzymatic electrodes nanostructured with functionalized carbon nanotubes for biofuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Nazaruk, E.; Bilewicz, R. [University of Warsaw, Faculty of Chemistry, Warsaw (Poland); Sadowska, K.; Biernat, J.F. [Gdansk University of Technology, Chemical Faculty, Gdansk (Poland); Rogalski, J. [Maria Curie Sklodowska University, Department of Biochemistry, Lublin (Poland); Ginalska, G. [Medical University of Lublin, Department of Biochemistry, Lublin (Poland)

    2010-10-15

    Nanostructured bioelectrodes were designed and assembled into a biofuel cell with no separating membrane. The glassy carbon electrodes were modified with mediator-functionalized carbon nanotubes. Ferrocene (Fc) and 2,2{sup '}-azino-bis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) bound chemically to the carbon nanotubes were found useful as mediators of the enzyme catalyzed electrode processes. Glucose oxidase from Aspergillus niger AM-11 and laccase from Cerrena unicolor C-139 were incorporated in a liquid-crystalline matrix-monoolein cubic phase. The carbon nanotubes-nanostructured electrode surface was covered with the cubic phase film containing the enzyme and acted as the catalytic surface for the oxidation of glucose and reduction of oxygen. Thanks to the mediating role of derivatized nanotubes the catalysis was almost ten times more efficient than on the GCE electrodes: catalytic current of glucose oxidation was 1 mA cm{sup -2} and oxygen reduction current exceeded 0.6 mA cm{sup -2}. The open circuit voltage of the biofuel cell was 0.43 V. Application of carbon nanotubes increased the maximum power output of the constructed biofuel cell to 100 {mu}W cm{sup -2} without stirring of the solution which was ca. 100 times more efficient than using the same bioelectrodes without nanotubes on the electrode surface. (orig.)

  1. Formation of titanate nanostructures under different NaOH concentration and their application in wastewater treatment

    International Nuclear Information System (INIS)

    Huang Jiquan; Cao Yongge; Deng Zhonghua; Tong Hao

    2011-01-01

    The effects of the concentration of NaOH on the formation and transformation of various titanate nanostructures were studied. With increasing NaOH concentration, three different formation mechanisms were proposed. Nanotubes can only be obtained under moderate NaOH conditions, and should transform into nanowires with prolonged hydrothermal treatment, and their formation rate is accelerated by increasing NaOH concentration. Low concentration of NaOH results in the direct formation of nanowires, while extra high concentration of NaOH leads to the formation of amorphous nanoparticles. Adsorption and photocatalysis studies show that titanate nanowires and nanotubes might be potential adsorbents for the removal of both heavy metal ions and dyes and photocatalysts for the removal of dyes from wastewater. -- Graphical abstract: The morphologies of the titanates depend deeply on the concentration of NaOH. With increasing NaOH concentration, three different formation mechanisms were proposed. The application of these titanate nanostructures in the wastewater treatment was studied. Display Omitted Research highlights: → Effect of NaOH concentration on the structures of various titanates was reported. → Three different formation mechanisms were presented with increasing NaOH concentration. → Various titanates were used as adsorbents/photocatalysts in wastewater treatment.

  2. Application of aqueous dispersions of silver nanostructures for treatment of pyoinflammatory diseases with a chronic component

    International Nuclear Information System (INIS)

    Rutberg, Ph; Kolikov, V; Snetov, V; Stogov, A; Moshkin, A; Khalilov, M

    2011-01-01

    Bactericidal properties of aqueous dispersions of oxide silver nanostructures (ADSN) produced by means of pulsed electric discharges (PED) in water can use in surgery for treatment of upper purulent wounds with a chronic component. The patients with such wounds are of large number and differ on etiology of diseases but their mutual feature is long treatment without marked positive changes. Thus long application of antibiotics leads to abnormality of immune processes and antibacterial resistance of microbial flora. Moreover, local antiseptics are frequently toxic and one can oppress processes of reparation in a wound. The investigation is addressed to finding out the opportunity of usage of an ADSN for treatment of purulent wounds with a chronic component and comparison of its efficiency with the sodium hypochlorite. At investigation, the ADSN formed at PED of 5 - 10 μs duration, with highest share of 'small' (hydrodynamic diameter ≤ 100 nm) nanostructures and greatest surface electric charge we used. It was found that the usage of ADSN during the first 5 days characterized by high active reparative processes with their maximum at 3rd - 4th days and subsequent moderate further healing. At local use of ADSN, there were no cellular atypia and preternatural representations about inflammatory reactions. It is possible to assume that usage of ADSN will allow in prospect to correct the practice of out-patient therapy of chronic and slow pyoinflammatory diseases.

  3. A facile route for 3D aerogels from nanostructured 1D and 2D materials

    Science.gov (United States)

    Jung, Sung Mi; Jung, Hyun Young; Dresselhaus, Mildred S.; Jung, Yung Joon; Kong, Jing

    2012-01-01

    Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO2, single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS2, graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications. PMID:23152940

  4. Glycopolymeric Materials for Advanced Applications

    Directory of Open Access Journals (Sweden)

    Alexandra Muñoz-Bonilla

    2015-04-01

    Full Text Available In recent years, glycopolymers have particularly revolutionized the world of macromolecular chemistry and materials in general. Nevertheless, it has been in this century when scientists realize that these materials present great versatility in biosensing, biorecognition, and biomedicine among other areas. This article highlights most relevant glycopolymeric materials, considering that they are only a small example of the research done in this emerging field. The examples described here are selected on the base of novelty, innovation and implementation of glycopolymeric materials. In addition, the future perspectives of this topic will be commented on.

  5. Nanostructural effect of acid-etching and fluoride application on human primary and permanent tooth enamels

    International Nuclear Information System (INIS)

    Cheong, Youjin; Choi, Samjin; Kim, So Jung; Park, Hun-Kuk

    2012-01-01

    This study examined the nanostructural effects of fluoride application and the acid-etching time with respect to the time elapsed after fluoride application on the primary and permanent tooth enamel layers using atomic force microscopy (AFM) and scanning electron microscopy (SEM). 192 non-carious teeth were assigned to sixteen experimental groups (n = 12) including primary (1 to 8) and permanent (9 to 16) teeth, based on the timing of acid-etching with 37% phosphoric acid after an acidulated phosphate fluoride (APF) pre-treatment. The APF pre-treatment led to a decrease in surface roughness in both the primary and permanent teeth. After the APF treatment, the roughness in both primary and permanent teeth increased with the time elapsed. An acid-etching time of 40 s led to increased nanostructural changes in the enamel surfaces compared to the conventional acid-etching time of 20 s. This acid-etching process led to a higher roughness changes in the primary teeth than in the permanent teeth. To obtain proper enamel adhesion of a sealant after APF pre-treatment, it is important to apply acid-etching two weeks after pre-treatment. In addition, the acid-etching time should be prolonged to apply etching more quickly than two weeks, regardless of the primary and permanent teeth. Highlights: ► APF pre-treatment led to decreased surface roughness in the enamel. ► After APF treatment, the more roughness increased with increasing time elapsed. ► Acid-etching should be performed two weeks after fluoride application.

  6. Nanostructural effect of acid-etching and fluoride application on human primary and permanent tooth enamels

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Youjin [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Choi, Samjin [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Department of Orthodontics, College of Dental Medicine, Kyung Hee University, Seoul (Korea, Republic of); Kim, So Jung [Department of Pediatric Dentistry, College of Dental Medicine, Kyung Hee University, Seoul (Korea, Republic of); Park, Hun-Kuk, E-mail: sigmoidus@khu.ac.kr [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Program of Medical Engineering, Kyung Hee University, Seoul (Korea, Republic of)

    2012-07-01

    This study examined the nanostructural effects of fluoride application and the acid-etching time with respect to the time elapsed after fluoride application on the primary and permanent tooth enamel layers using atomic force microscopy (AFM) and scanning electron microscopy (SEM). 192 non-carious teeth were assigned to sixteen experimental groups (n = 12) including primary (1 to 8) and permanent (9 to 16) teeth, based on the timing of acid-etching with 37% phosphoric acid after an acidulated phosphate fluoride (APF) pre-treatment. The APF pre-treatment led to a decrease in surface roughness in both the primary and permanent teeth. After the APF treatment, the roughness in both primary and permanent teeth increased with the time elapsed. An acid-etching time of 40 s led to increased nanostructural changes in the enamel surfaces compared to the conventional acid-etching time of 20 s. This acid-etching process led to a higher roughness changes in the primary teeth than in the permanent teeth. To obtain proper enamel adhesion of a sealant after APF pre-treatment, it is important to apply acid-etching two weeks after pre-treatment. In addition, the acid-etching time should be prolonged to apply etching more quickly than two weeks, regardless of the primary and permanent teeth. Highlights: Black-Right-Pointing-Pointer APF pre-treatment led to decreased surface roughness in the enamel. Black-Right-Pointing-Pointer After APF treatment, the more roughness increased with increasing time elapsed. Black-Right-Pointing-Pointer Acid-etching should be performed two weeks after fluoride application.

  7. Resolving the nanostructure of plasma-enhanced chemical vapor deposited nanocrystalline SiOx layers for application in solar cells

    Science.gov (United States)

    Klingsporn, M.; Kirner, S.; Villringer, C.; Abou-Ras, D.; Costina, I.; Lehmann, M.; Stannowski, B.

    2016-06-01

    Nanocrystalline silicon suboxides (nc-SiOx) have attracted attention during the past years for the use in thin-film silicon solar cells. We investigated the relationships between the nanostructure as well as the chemical, electrical, and optical properties of phosphorous, doped, nc-SiO0.8:H fabricated by plasma-enhanced chemical vapor deposition. The nanostructure was varied through the sample series by changing the deposition pressure from 533 to 1067 Pa. The samples were then characterized by X-ray photoelectron spectroscopy, spectroscopic ellipsometry, Raman spectroscopy, aberration-corrected high-resolution transmission electron microscopy, selected-area electron diffraction, and a specialized plasmon imaging method. We found that the material changed with increasing pressure from predominantly amorphous silicon monoxide to silicon dioxide containing nanocrystalline silicon. The nanostructure changed from amorphous silicon filaments to nanocrystalline silicon filaments, which were found to cause anisotropic electron transport.

  8. Characterization and Application of DNA-templated Silver Nanoclusters and Polarized Spectroscopy of Self-Assembled Nanostructures

    DEFF Research Database (Denmark)

    Carro-Temboury, Miguel R.

    In this thesis two different systems are investigated envisioning their potential applications: DNA-templated silver nanoclusters (DNA-AgNCs) and ionic self-assembled (ISA) nanostructures based on azo-dyes. Mainly Visible-NIR spectroscopy was used to probe electronic transitions with absorbance a...

  9. Novel functional magnetic materials fundamentals and applications

    CERN Document Server

    2016-01-01

    This book presents current research on advanced magnetic materials and multifunctional composites. Recent advances in technology and engineering have resulted from the development of advanced magnetic materials with improved functional magnetic and magneto-transport properties. Certain industrial sectors, such as magnetic sensors, microelectronics, and security, demand cost-effective materials with reduced dimensionality and desirable magnetic properties such as enhanced magnetic softness, giant magnetic field sensitivity, and large magnetocaloric effect.  Expert chapters present the most up-to-date information on the fabrication process, processing, tailoring of properties, and applications of different families of modern functional materials for advanced smart applications. Topics covered include novel magnetic materials and applications; amorphous and nanocrystalline magnetic materials and applications; hard magnetic materials; magnetic shape memory alloys; and magnetic oxides. The book's highly interdis...

  10. Highly ordered mesoporous cobalt oxide nanostructures: synthesis, characterisation, magnetic properties, and applications for electrochemical energy devices.

    Science.gov (United States)

    Wang, Guoxiu; Liu, Hao; Horvat, Josip; Wang, Bei; Qiao, Shizhang; Park, Jinsoo; Ahn, Hyojun

    2010-09-24

    Highly ordered mesoporous Co(3)O(4) nanostructures were prepared using KIT-6 and SBA-15 silica as hard templates. The structures were confirmed by small angle X-ray diffraction, high resolution transmission electron microscopy, and N(2) adsorption-desorption isotherm analysis. Both KIT-6 cubic and SBA-15 hexagonal mesoporous Co(3)O(4) samples exhibited a low Néel temperature and bulk antiferromagnetic coupling due to geometric confinement of antiferromagnetic order within the nanoparticles. Mesoporous Co(3)O(4) electrode materials have demonstrated the high lithium storage capacity of more than 1200 mAh g(-1) with an excellent cycle life. They also exhibited a high specific capacitance of 370 F g(-1) as electrodes in supercapacitors.

  11. Composite materials design and applications

    CERN Document Server

    Gay, Daniel; Tsai, Stephen W

    2002-01-01

    PART ONE. PRINCIPLES OF CONSTRUCTIONCOMPOSITE MATERIALS, INTEREST AND PROPERTIESWhat is Composite Material Fibers and MatrixWhat can be Made Using Composite Materials?Typical Examples of Interest on the Use of Composite MaterialsExamples on Replacing Conventional Solutions with CompositesPrincipal Physical PropertiesFABRICATION PROCESSESMolding ProcessesOther Forming ProcessesPractical Hints in the Manufacturing ProcessesPLY PROPERTIESIsotropy and AnisotropyCharacteristics of the Reinforcement-Matrix MixtureUnidirectional PlyWoven FabricsMats and Reinforced MatricesMultidimensional FabricsMetal Matrix CompositesTestsSANDWICH STRUCTURES:What is a Sandwich Structure?Simplified FlexureA Few Special AspectsFabrication and Design ProblemsNondestructive Quality ControlCONCEPTION AND DESIGNDesign of a Composite PieceThe LaminateFailure of LaminatesSizing of LaminatesJOINING AND ASSEMBLYRiveting and BoltingBondingInsertsCOMPOSITE MATERIALS AND AEROSPACE CONSTRUCTIONAircraftHelicoptersPropeller Blades for AirplanesTur...

  12. Structural properties of the nanostructured hydrogels containing nanoclay for application in agriculture

    International Nuclear Information System (INIS)

    Yonezawa, Uilian Gabaldi; Moura, Marcia Regina de; Aouada, Fauze Ahmad

    2016-01-01