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Nanostructured Materials (nanostructured + material)
Selected AbstractsNanostructured Materials: Microstructural and Biochemical Characterization of the Nanoporous Sucker Rings from Dosidicus gigas (Adv. Mater.ADVANCED MATERIALS, Issue 4 20094/2009) The cover image shows an SEM image of a squid tentacle, revealing the individual sucker rings. These toothed ringlike structures within the suckers provide additional gripping power during prey capture and handling. The background image depicts the nanoscale network of parallel tubular elements from which the rings are constructed. The structural, mechanical and biochemical properties of this wholly organic material is discussed in detail by David Kisailus, Henrik Birkedal, and co-workers on p. 401. [source] Nanostructured Materials for Skeletal RepairMACROMOLECULAR SYMPOSIA, Issue 1 2010Joerg Brandt Abstract The treatment of bone and cartilage defects with bioengineered constructs of artificial scaffolds and autogenous cells became the main challenge of contemporary regenerative medicine. Early defect repair may prevent secondary injury. Recent studies could prove that bone and cartilage cells are sensitive to microscale and nanoscale patterns of surface topography and chemical structure. Nanostructured materials provide an environment for tissue regeneration mimicking the physiological range of extracellular matrix. The article reviews several studies substantiating the superiority of nanostructured materials for bone and cartilage repair along with own results on cell attachment. [source] Mechanical activation of precursors for nanocrystalline materialsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2003H. Heegn Abstract Nanostructured materials win big scientific interest and increasingly economic meaning through their specific exceptional properties. Precursors that were compacted by pressing and sintering are normally used preparation of materials. In present work, the influence of mechanical activation by grinding on the structure as well as on compacting and sintering behavior of oxides from magnesium, aluminium and silicon has been investigated. Starting materials for each metal oxide differ in microstructure, dispersity, and porosity. The influence of mechanical activation on the destruction of crystalline structure to nanocrystalline, as well as to the amorphous stage and the compaction of powders with nano-particles, as well as structures with nanoscale pores have been compared. The possibilities of the consolidation of nanostructured materials were investigated. The mechanical activation took place in a disc vibration mill. The mechanical activated materials as well as their pressing and their sintering products were characterized by density, particle-sizedistribution, specific surface, pore-structure, microstructure, and crystallite size by X-ray powder diffraction (XRD). The mechanical activation of the model-substances led, in most cases, to an improvement of the compaction properties; thus, this improvement can be achieved with subsequent sintering densities up to 98% of the theoretical density. From these experiments, generalizations transferable to other materials can be made. [source] Nanoporous Copper with Tunable Nanoporosity for SERS ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 8 2009Lu-Yang Chen Abstract Nanostructured materials with designable microstructure and controllable physical and chemical properties are highly desired for practical applications in nanotechnology. In this article, it is reported that nanoporous copper with a tunable nanopore size can be fabricated by controlling the dealloying process. The influence of acid concentration and etching potential on the formation of nanoprosity is systematically investigated. With optimal etching conditions, the nanopore sizes can be tailored from ,15 to ,120,nm by controlling the dealloying time. It is found that the tunable nanoporosity leads to significant improvements in surface-enhanced Raman scattering (SERS) of nanoporous copper and peak values of SERS enhancements for both rhodamine 6G and crystal violet 10B molecules are observed at a pore size of ,30,50,nm. This study underscores the effect of complex three-dimensional nanostructures on physical and chemical properties and is helpful in developing inexpensive SERS substrates for sensitive instrumentations in molecular diagnostics. [source] Gold Nanocages for Biomedical Applications,ADVANCED MATERIALS, Issue 20 2007E. Skrabalak Abstract Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis and use of Au nanocages for such biomedical applications. Gold nanocages represent a novel class of nanostructures, which can be prepared via a remarkably simple route based on the galvanic replacement reaction between Ag nanocubes and HAuCl4. The Au nanocages have a tunable surface plasmon resonance peak that extends into the near-infrared, where the optical attenuation caused by blood and soft tissue is essentially negligible. They are also biocompatible and present a well-established surface for easy functionalization. We have tailored the scattering and absorption cross-sections of Au nanocages for use in optical coherence tomography and photothermal treatment, respectively. Our preliminary studies show greatly improved spectroscopic image contrast for tissue phantoms containing Au nanocages. Our most recent results also demonstrate the photothermal destruction of breast cancer cells in vitro by using immuno-targeted Au nanocages as an effective photo-thermal transducer. These experiments suggest that Au nanocages may be a new class of nanometer-sized agents for cancer diagnosis and therapy. [source] Nanostructured Materials for Skeletal RepairMACROMOLECULAR SYMPOSIA, Issue 1 2010Joerg Brandt Abstract The treatment of bone and cartilage defects with bioengineered constructs of artificial scaffolds and autogenous cells became the main challenge of contemporary regenerative medicine. Early defect repair may prevent secondary injury. Recent studies could prove that bone and cartilage cells are sensitive to microscale and nanoscale patterns of surface topography and chemical structure. Nanostructured materials provide an environment for tissue regeneration mimicking the physiological range of extracellular matrix. The article reviews several studies substantiating the superiority of nanostructured materials for bone and cartilage repair along with own results on cell attachment. [source] Raman spectroscopy of optical phonon confinement in nanostructured materialsJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2007Akhilesh K. Arora Abstract If the medium surrounding a nano-grain does not support the vibrational wavenumbers of a material, the optical and acoustic phonons get confined within the grain of the nanostructured material. This leads to interesting changes in the vibrational spectrum of the nanostructured material as compared to that of the bulk. Absence of periodicity beyond the particle dimension relaxes the zone-centre optical phonon selection rule, causing the Raman spectrum to have contributions also from phonons away from the Brillouin-zone centre. Theoretical models and calculations suggest that the confinement results in asymmetric broadening and shift of the optical phonon Raman line, the magnitude of which depends on the widths of the corresponding phonon dispersion curves. This has been confirmed for zinc oxide nanoparticles. Microscopic lattice dynamical calculations of the phonon amplitude and Raman spectra using the bond-polarizability model suggest a power-law dependence of the peak-shift on the particle size. This article reviews recent results on the Raman spectroscopic investigations of optical phonon confinement in several nanocrystalline semiconductor and ceramic/dielectric materials, including those in selenium, cadmium sulphide, zinc oxide, thorium oxide, and nano-diamond. Resonance Raman scattering from confined optical phonons is also discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mechanical activation of precursors for nanocrystalline materialsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2003H. Heegn Abstract Nanostructured materials win big scientific interest and increasingly economic meaning through their specific exceptional properties. Precursors that were compacted by pressing and sintering are normally used preparation of materials. In present work, the influence of mechanical activation by grinding on the structure as well as on compacting and sintering behavior of oxides from magnesium, aluminium and silicon has been investigated. Starting materials for each metal oxide differ in microstructure, dispersity, and porosity. The influence of mechanical activation on the destruction of crystalline structure to nanocrystalline, as well as to the amorphous stage and the compaction of powders with nano-particles, as well as structures with nanoscale pores have been compared. The possibilities of the consolidation of nanostructured materials were investigated. The mechanical activation took place in a disc vibration mill. The mechanical activated materials as well as their pressing and their sintering products were characterized by density, particle-sizedistribution, specific surface, pore-structure, microstructure, and crystallite size by X-ray powder diffraction (XRD). The mechanical activation of the model-substances led, in most cases, to an improvement of the compaction properties; thus, this improvement can be achieved with subsequent sintering densities up to 98% of the theoretical density. From these experiments, generalizations transferable to other materials can be made. [source] Nanoparticle-Structured Ligand Framework as Electrode InterfacesELECTROANALYSIS, Issue 1-2 2004Nancy Abstract Nanostructured thin film assemblies derived from metal or oxide nanocrystal cores and functionalized molecular shells provide large surface-to-volume ratio and three-dimensional ligand frameworks. In this article, we report results of an investigation of the nanostructured materials for electroanalysis. Monolayer-capped gold nanoparticles of 2-nm core diameter and carboxylic acid-functionalized alkyl thiols were assembled on electrode surfaces via an exchange-crosslinking-precipitation reaction route, and were studied as a model system. The network assemblies exhibit open frameworks in which the void space forms channels with the nanometer sized cores defining its size and the shell structures defining its chemical specificity. Such nanostructures were exploited to demonstrate the viability of responsive materials for interfacial incorporation and fluxes of ionic species. The nanomaterials were characterized by an array of techniques, including cyclic voltammetry, electrochemical quartz-crystal nanobalance, flow injection analysis, and surface infrared reflection spectroscopy. The current responses and mass loading as a result of the incorporation of ionic species into the nanostructure have been analyzed. The potential application of the nanostructured thin films for electrochemical detection in microfluidic systems is also discussed. [source] Sol,Gel Derived Nanocomposites for Optical ApplicationsADVANCED ENGINEERING MATERIALS, Issue 5 2010Peter W. de Oliveira This paper provides a selective description of the development of nanostructured materials and the fabrication of the devices for optical applications. Examples are interference coatings, refractive and diffractive lenses, and macro- and micro-GRIN (graded refractive index) optical elements. Hybrid materials containing nanoparticles are of particular interest for the production of optical elements because, by exploiting the intrinsic solid state properties of the nanoparticles, nanocomposites can be tailored to exhibit the desired properties. A particular advantage of wet chemical processing lies in its great flexibility for depositing functional coatings. [source] Phase Reversion-Induced Nanograined/Ultrafine-Grained Structures in Austenitic Stainless Steel and their Significance in Modulating Cellular Response: Biochemical and Morphological Study with Fibroblasts,ADVANCED ENGINEERING MATERIALS, Issue 12 2009R. Devesh Kumar Misra Materials science, engineering, and biological sciences have been combined to improve the tissue compatibility of medical devices. In this regard, nano/ultrafine structuring of austenitic stainless steel obtained using an innovative approach of "phase-reversion" has been evaluated for modulation of cellular activity. The biochemical and morphology study with fibroblasts point toward the improvement of tissue compatibility on comparison with coarse-grained structures, strengthening the foundation of nanostructured materials for bio-medical applications. [source] Technical Cost Modeling for the Mechanical Milling at Cryogenic Temperature (Cryomilling),ADVANCED ENGINEERING MATERIALS, Issue 8 2004J. Ye Cryomilling is one of the few technologies available to fabricate a large quantity of nanostructured materials. No matter how exciting and promising a technology is, its ultimate realization is invariably dependent on economic success. Technical cost modeling was employed in this paper to analyze the processing cost of cryomilling. The results demonstrated that cryomilling has the potential to be commercially economical to fabricate nanostructured materials. [source] Enhancement of Thermoelectric Figure-of-Merit by a Bulk Nanostructuring ApproachADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Yucheng Lan Abstract Recently a significant figure-of-merit (ZT) improvement in the most-studied existing thermoelectric materials has been achieved by creating nanograins and nanostructures in the grains using the combination of high-energy ball milling and a direct-current-induced hot-press process. Thermoelectric transport measurements, coupled with microstructure studies and theoretical modeling, show that the ZT improvement is the result of low lattice thermal conductivity due to the increased phonon scattering by grain boundaries and structural defects. In this article, the synthesis process and the relationship between the microstructures and the thermoelectric properties of the nanostructured thermoelectric bulk materials with an enhanced ZT value are reviewed. It is expected that the nanostructured materials described here will be useful for a variety of applications such as waste heat recovery, solar energy conversion, and environmentally friendly refrigeration. [source] Protein-Enabled Synthesis of Monodisperse Titania Nanoparticles On and Within Polyelectrolyte MatricesADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Eugenia Kharlampieva Abstract Here, the results of a study of the mechanism of bio-enabled surface-mediated titania nanoparticle synthesis with assistance of polyelectrolyte surfaces are reported. By applying atomic force microscopy, surface force spectroscopy, circular dichroism, and in situ attenuated total reflection Fourier-transform infrared spectroscopy, structural changes of rSilC-silaffin upon its adsorption to polyelectrolyte surfaces prior to and during titania nanoparticle growth are revealed. It is demonstrated that the adhesion of rSilC-silaffin onto polyelectrolyte surfaces results in its reorganization from a random-coil conformation in solution into a mixed secondary structure with both random coil and , -sheet structures presented. Moreover, the protein forms a continuous molecularly thin layer with well-defined monodisperse nanodomains of lateral dimensions below 20,nm. It is also shown that rSilC embedded inside the polylelectrolyte matrix preserves its titania formation activity. It is suggested that the surface-mediated, bio-enabled synthesis of nanostructured materials might be useful to develop general procedures for controlled growth of inorganic nanomaterials on reactive organic surfaces, which opens new perspectives in the design of tailored, in situ grown, hybrid inorganic,organic nanomaterials. [source] Encapsulation and Ostwald Ripening of Au and Au,Cl Complex Nanostructures in Silica Shells,ADVANCED FUNCTIONAL MATERIALS, Issue 13 2006W. Lou Abstract We report a general template strategy for rational fabrication of a new class of nanostructured materials consisting of multicore shell particles. Our approach is demonstrated by encapsulating Au or Pt nanoparticles in silica shells. Other superstructures of these hollow shells, like dimers, trimers, and tetramers can also be formed by nanoparticle-mediated self-assembly. We have also used the as-prepared multicore Au,silica hollow particles to perform the first studies of Ostwald ripening in confined microspace, in which chloride was found to be an efficient mediating ligand. After treatment with aqua regia, Au,Cl complex is formed inside the shell, and is found to be very active under in,situ transmission electron microscopy observations while confined in a microcell. This aspect of the work is expected to motivate further in,situ studies of confined crystal growth. [source] Cover Picture: Synthesis of Gadolinium-Labeled Shell-Crosslinked Nanoparticles for Magnetic Resonance Imaging Applications (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 8 2005Mater. Abstract Robust, amphiphilic core,shell nanoparticles that are selectively labeled with gadolinium in the hydrophilic and water-swollen shell layer are depicted in the cover picture. These well-defined nanostructured materials exhibit high relaxivity, a large loading capacity, and are based upon a biocompatible platform for ultimate function in magnetic resonance imaging (MRI) applications, as reported by Wooley and co-workers on p.,1248. Shell-crosslinked knedel-like nanoparticles (SCKs; "knedel" is a Polish term for dumplings) were derivatized with gadolinium chelates and studied as robust magnetic-resonance-imaging-active structures with hydrodynamic diameters of 40,±,3,nm. SCKs possessing an amphiphilic core,shell morphology were produced from the aqueous assembly of diblock copolymers of poly-(acrylic acid) (PAA) and poly(methyl acrylate) (PMA), PAA52,b,PMA128, and subsequent covalent crosslinking by amidation upon reaction with 2,2,-(ethylenedioxy)bis(ethylamine) throughout the shell layer. The properties of these materials, including non-toxicity towards mammalian cells, non-immunogenicity within mice, and capability for polyvalent targeting, make them ideal candidates for utilization within biological systems. The synthesis of SCKs derivatized with GdIII and designed for potential use as a unique nanometer-scale contrast agent for MRI applications is described herein. Utilization of an amino-functionalized diethylenetriaminepentaacetic acid,Gd analogue allowed for direct covalent conjugation throughout the hydrophilic shell layer of the SCKs and served to increase the rotational correlation lifetime of the Gd. In addition, the highly hydrated nature of the shell layer in which the Gd was located allowed for rapid water exchange; thus, the resulting material demonstrated large ionic relaxivities (39,s,1,mM,1) in an applied magnetic field of 0.47,T at 40,°C and, as a result of the large loading capacity of the material, also demonstrated high molecular relaxivities (20,000,s,1,mM,1). [source] Nanoelectronic Biosensing of Dynamic Cellular Activities Based on Nanostructured MaterialsADVANCED MATERIALS, Issue 25 2010Yinxi Huang Abstract Detecting subtle cellular activities that occur dynamically as regulated temporally and spatially by molecular machinery is of obvious importance in fundamental biology as well as in drug discovery. Additionally, it demands fast and sensitive detection modality. The emerging nanoelectronic biosensors based on nanostructured materials have shown promising potential to resolve the dynamic biological processes of living cells with high sensitivity and high temporal and spatial resolution. Here, the recent advances in the nanoelectronic biosensing of regulated secretion of biomolecules and bioelectrical activities of ion channels using carbon nanotubes and silicon nanowires are briefly reviewed. The perspectives and key issues of future development are also discussed. [source] Block Copolymer Nanolithography: Translation of Molecular Level Control to Nanoscale PatternsADVANCED MATERIALS, Issue 47 2009Joona Bang Abstract The self-asembly of block copolymers is a promising platform for the "bottom-up" fabrication of nanostructured materials and devices. This review covers some of the advances made in this field from the laboratory setting to applications where block copolymers are in use. [source] Nanostructured Organic,Inorganic Composite Materials by Twin Polymerization of Hybrid MonomersADVANCED MATERIALS, Issue 20 2009Stefan Spange Abstract Forming two structurally different but associated polymer structures in a single step is a possible route for the production of nanostructured materials. By means of twin polymerization of specially constructed monomers consisting of two different covalently bonded building blocks (hybrid monomers), this route is realized. What is important is that two different macromolecular structures are formed from one monomer in a single process. The two polymers formed can be linear, branched, or cross-linked structures. The molecular composition of the hybrid monomer defines the degree of cross-linking of the corresponding macromolecular structures that is theoretically possible. [source] Biomedical Applications of Layer-by-Layer Assembly: From Biomimetics to Tissue Engineering,ADVANCED MATERIALS, Issue 24 2006Z. Tang Abstract The design of advanced, nanostructured materials at the molecular level is of tremendous interest for the scientific and engineering communities because of the broad application of these materials in the biomedical field. Among the available techniques, the layer-by-layer assembly method introduced by Decher and co-workers in 1992 has attracted extensive attention because it possesses extraordinary advantages for biomedical applications: ease of preparation, versatility, capability of incorporating high loadings of different types of biomolecules in the films, fine control over the materials' structure, and robustness of the products under ambient and physiological conditions. In this context, a systematic review of current research on biomedical applications of layer-by-layer assembly is presented. The structure and bioactivity of biomolecules in thin films fabricated by layer-by-layer assembly are introduced. The applications of layer-by-layer assembly in biomimetics, biosensors, drug delivery, protein and cell adhesion, mediation of cellular functions, and implantable materials are addressed. Future developments in the field of biomedical applications of layer-by-layer assembly are also discussed. [source] Oxide-Assisted Growth of Semiconducting Nanowires,ADVANCED MATERIALS, Issue 7-8 2003R.-Q. Zhang Abstract In this contribution, we outline oxide-assisted growth (OAG) (distinct from the conventional metal-catalytic vapor,liquid,solid (VLS) process) for the growth of nanostructured materials. This synthesis technique, in which oxides instead of metals play an important role in inducing the nucleation and growth of nanowires, is capable of producing large quantities of high-purity silicon nanowires with a preferential growth direction, uniform size, and long length, without the need for a metal catalyst. The OAG 1D nanomaterials synthesis is complementary to, and coexistent with, the conventional metal-catalyst VLS approach, and can be utilized to produce nanowires from a host of materials other than Si including Ge nanowires, carbon nanowires, silicon and SnO2 nanoribbons, and Group III,V and II,VI compound semiconductor nanowires. [source] Analysis of scattering from polydisperse structure using Mellin convolutionJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2006Norbert Stribeck This study extends a mathematical concept for the description of heterogeneity and polydispersity in the structure of materials to multiple dimensions. In one dimension, the description of heterogeneity by means of Mellin convolution is well known. In several papers by the author, the method has been applied to the analysis of data from materials with one-dimensional structure (layer stacks or fibrils along their principal axis). According to this concept, heterogeneous structures built from polydisperse ensembles of structural units are advantageously described by the Mellin convolution of a representative template structure with the size distribution of the templates. Hence, the polydisperse ensemble of similar structural units is generated by superposition of dilated templates. This approach is particularly attractive considering the advantageous mathematical properties enjoyed by the Mellin convolution. Thus, average particle size, and width and skewness of the particle size distribution can be determined from scattering data without the need to model the size distributions themselves. The present theoretical treatment demonstrates that the concept is generally extensible to dilation in multiple dimensions. Moreover, in an analogous manner, a representative cluster of correlated particles (e.g. layer stacks or microfibrils) can be considered as a template on a higher level. Polydispersity of such clusters is, again, described by subjecting the template structure to the generalized Mellin convolution. The proposed theory leads to a simple pathway for the quantitative determination of polydispersity and heterogeneity parameters. Consistency with the established theoretical approach of polydispersity in scattering theory is demonstrated. The method is applied to the best advantage in the field of soft condensed matter when anisotropic nanostructured materials are to be characterized by means of small-angle scattering (SAXS, USAXS, SANS). [source] Raman spectroscopy of optical phonon confinement in nanostructured materialsJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2007Akhilesh K. Arora Abstract If the medium surrounding a nano-grain does not support the vibrational wavenumbers of a material, the optical and acoustic phonons get confined within the grain of the nanostructured material. This leads to interesting changes in the vibrational spectrum of the nanostructured material as compared to that of the bulk. Absence of periodicity beyond the particle dimension relaxes the zone-centre optical phonon selection rule, causing the Raman spectrum to have contributions also from phonons away from the Brillouin-zone centre. Theoretical models and calculations suggest that the confinement results in asymmetric broadening and shift of the optical phonon Raman line, the magnitude of which depends on the widths of the corresponding phonon dispersion curves. This has been confirmed for zinc oxide nanoparticles. Microscopic lattice dynamical calculations of the phonon amplitude and Raman spectra using the bond-polarizability model suggest a power-law dependence of the peak-shift on the particle size. This article reviews recent results on the Raman spectroscopic investigations of optical phonon confinement in several nanocrystalline semiconductor and ceramic/dielectric materials, including those in selenium, cadmium sulphide, zinc oxide, thorium oxide, and nano-diamond. Resonance Raman scattering from confined optical phonons is also discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Raman spectroscopy and molecular simulation investigations of adsorption on the surface of single-walled carbon nanotubes and nanospheresJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2007Maher S. Amer Abstract Raman spectroscopy has, for long, been utilized to investigate material systems on the micro and mesoscales. Recently, the technique has proven its ability in exploring systems on the nanoscale. In this paper, we review our recent work on the Raman investigation of molecular adsorption from liquid mixtures on surfaces of single-walled carbon nanotubes and fullerene nanospheres, emphasizing the following major research findings: the development of a Raman-based technique capable of sensing local chemical interactions on the surface of carbon nanotubes and spheres; the molecular simulation results supporting the Raman investigation; the possibility of creating mesostructures based upon mixtures of carbon nanotubes and nanospheres that are crucial for selective adsorption. The current findings represent a major new thrust for the development of new nanostructured materials with superior adsorption capabilities and unique applications. Copyright © 2007 John Wiley & Sons, Ltd. [source] Surface Enthalpy, Enthalpy of Water Adsorption, and Phase Stability in Nanocrystalline Monoclinic ZirconiaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2009A. V. Radha A fundamental issue that remains to be solved when approaching the nanoscale is how the size induces transformation among different polymorphic structures. Understanding the size-induced transformation among the different polymorphic structures is essential for widespread use of nanostructured materials in technological applications. Herein, we report water adsorption and high-temperature solution calorimetry experiments on a set of samples of single-phase monoclinic zirconia with different surface areas. Essential to the success of the study has been the use of a new ternary water-in-oil/water liquid solvothermal method that allows the preparation of monoclinic zirconia nanoparticles with a broad range of (BET) Brunauer,Emmett,Teller surface area values. Thus, the surface enthalpy for anhydrous monoclinic zirconia is reported for the first time, while that for the hydrous surface is a significant improvement over the previously reported value. Combining these data with previously published surface enthalpy for nanocrystalline tetragonal zirconia, we have calculated the stability crossovers between monoclinic and tetragonal phases to take place at a particle size of 28 ± 6 nm for hydrous zirconia and 34 ± 5 nm for anhydrous zirconia. Below these particle sizes, tetragonal hydrous and anhydrous phases of zirconia become thermodynamically stable. These results are within the margin of the theoretical estimation and confirm the importance of the presence of water vapor on the transformation of nanostructured materials. [source] Nanostructured Materials for Skeletal RepairMACROMOLECULAR SYMPOSIA, Issue 1 2010Joerg Brandt Abstract The treatment of bone and cartilage defects with bioengineered constructs of artificial scaffolds and autogenous cells became the main challenge of contemporary regenerative medicine. Early defect repair may prevent secondary injury. Recent studies could prove that bone and cartilage cells are sensitive to microscale and nanoscale patterns of surface topography and chemical structure. Nanostructured materials provide an environment for tissue regeneration mimicking the physiological range of extracellular matrix. The article reviews several studies substantiating the superiority of nanostructured materials for bone and cartilage repair along with own results on cell attachment. [source] Preface: phys. stat. sol. (c) 1/12PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004Chair person Mohammad Ghafari The Second Seeheim Conference on Magnetism (SCM2004) was the second conference in the tri-annual series of this conference series on magnetism, organized under the auspices of Darmstadt University of Technology, Forschungszentrum Karlsruhe and Ulm University. SCM2004 was held from 27 June to 1 July 2004. The location was the Lufthansa Training Center in Seeheim located conveniently in central Germany and easily accessible by air, train and car. The purpose of the meeting was to provide an opportunity to present and discuss recent developments in the field of magnetic nanomaterials. SCM2004 was focused on the latest developments in specific areas of magnetism (nanostructured materials, surfaces, interfaces and nanoparticles) and covered fundamental aspects of magnetism as well as applications. The most recent results were presented in the form of invited and contributed talks as well as posters. The topical areas were: ,,hard and soft magnetic materials ,,magnetic interactions ,,magnetization processes ,,spin dependent transport properties ,,nanostructured materials ,,applications. The first conference of this series was held in Seeheim in 2001. The papers from the 2001 conference were published in a regular issue of physica status solidi (a) 189, Nos. 2, 3 (2002), and since their publication they have been downloaded from the Web more than 14,000 times. This cleary demonstrates both the interest in and the need for this conference series. Our second meeting was attended by participants from 36 countries. A total number of 271 papers correlating nanostructure and magnetic properties were selected for presentation. Throughout the meeting a total of 51 talks was given; the remaining 220 papers were selected for poster presentation. The conference proceeded in an informal and very friendly atmosphere among the researchers from various parts of the world. We are grateful to the Deutsche Forschungsgemeinschaft, Forschungszentrum Karlsruhe and Darmstadt University of Technology for their kind financial support. We are looking forward to welcoming again participants of SCM2004 at the Third Seeheim Conference on Magnetism, planned for 2007 in Seeheim. [source] Composite aqueous microgels: an overview of recent advances in synthesis, characterization and applicationPOLYMER INTERNATIONAL, Issue 3 2007Andrij Z Pich Abstract In the last decade there has been a steady increase in the number of publications describing the synthesis, characterization and applications of hybrid particles. Colloidal aqueous microgels form an important subdivision of polymer colloids used for the deposition of different functional materials. Due to their numerous attractive properties, microgel particles have been used as templates for the synthesis, storage and transportation of nanostructured materials. This paper reviews the important developments in the area of composite microgels over the last decade, and is limited to microgel particles operating in aqueous media. The patent literature is not included in the review. Different synthetic approaches as well as some properties and applications of composite microgels are discussed. Copyright © 2006 Society of Chemical Industry [source] Production of Inorganic Nanoparticles by MicroorganismsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2009N. Krumov Abstract A promising new dimension in the field of biotechnology is the use of microorganisms for the production of inorganic nanoscale particles. The interest in nanotechnology is provoked by the unique properties of nanostructured materials and their potential fields of application ranging from medicine to electronics. This review article presents a systematic overview of the microorganisms capable of producing nanoparticles, and describes cellular mechanisms and outlines cultivation conditions that turn this process into a successful synthetic pathway. [source] Self-Assembling of Er2O3,TiO2 Mixed Oxide Nanoplatelets by a Template-Free Solvothermal RouteCHEMISTRY - A EUROPEAN JOURNAL, Issue 45 2009Beatriz Julián-López Dr. Abstract An easy solvothermal route has been developed to synthesize the first mesoporous Er2O3,TiO2 mixed oxide spherical particles composed of crystalline nanoplatelets, with high surface area and narrow pore size distribution. This synthetic strategy allows the preparation of materials at low temperature with interesting textural properties without the use of surfactants, as well as the control of particle size and shape. TEM and Raman analysis confirm the formation of nanocrystalline Er2O3,TiO2 mixed oxide. Mesoscopic ordered porosity is reached through the thermal decomposition of organic moieties during the synthetic process, thus leading to a template-free methodology that can be extended to other nanostructured materials. High specific surface areas (up to 313,m2,g,1) and narrow pore size distributions are achieved in comparison to the micrometric material synthesized by the traditional sol,gel route. This study opens new perspectives in the development, by solvothermal methodologies, of multifunctional materials for advanced applications by improving the classical pyrochlore properties (magnetization, heat capacity, catalysis, conductivity, etc.). In particular, since catalytic reactions take place on the surface of catalysts, the high surface area of these materials makes them promising candidates for catalysts. Furthermore, their spherical morphology makes them appropriate for advanced technologies in, for instance, ceramic inkjet printers. [source] | ||||||||||||||||||||||||||||