Download or read book Interaction entre les nanotubes de carbone et leur environnement physico chimique written by Fabien Vialla and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse est consacrée à l'étude expérimentale par spectroscopie de photoluminescence de nanotubes de carbone nus et fonctionnalisés. Les nanotubes étant formés exclusivement d'atomes de surface, leurs propriétés optiques peuvent être grandement altérées, mais aussi contrôlées, par interaction avec l'environnement physico-chimique. Un dispositif de microscopie confocale à l'échelle de l'objet unique et à température cryogénique est développé pour l'étude de la luminescence de nanotubes déposés sur substrat. La variété des profils spectraux observés est interprétée en terme d'un couplage entre excitons localisés et phonons acoustiques unidimensionnels dont le spectre peut être altéré aux basses énergies. Ce mécanisme explique notamment l'observation originale de raies très fines, de largeur inférieure à 500 μeV. La fonctionnalisation non-covalente des nanotubes par des molécules de colorants (porphyrines) introduit une nouvelle voie d'excitation optique par un transfert d'énergie très efficace. Le suivi physico-chimique de la réaction d'adsorption nous informe sur la couverture et l'affinité des molécules sur les nanotubes. Une étude de photoluminescence sur composés uniques résolue en polarisation montre une forte anisotropie du transfert d'énergie gouvernée par des effets d'antenne à proximité du nanotube. Enfin, le colorant peut être utilisé comme cellule d'absorption de référence pour évaluer la section efficace d'absorption des nanotubes. Une nette évolution avec l'angle chiral de l'espèce est notamment observée pour l'absorption à la résonance optique S22.
Download or read book Carbon Nanotubes written by Stephanie Reich and published by John Wiley & Sons. This book was released on 2004-03-12 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoröhrchen aus Kohlenstoff werden hervorragende Eigenschaften nachgesagt: sie sind chemisch sehr stabil, mechanisch sehr fest und elektrisch leitend. Aufgrund dieses Charakters eröffnen sich Perspektiven für verschiedene Anwendungen: als Nanotransistoren in Schaltkreisen, als Wasserstoff-Speicher für Brennstoffzellen, als künstliche Muskeln oder als Zusatz zur Verstärkung von Verbundwerkstoffen. Vor allem in der Elektronik werden die fadenförmigen Makromolekülen aus Kohlenstoff eines Tages das Silizium verdrängen. Das vorliegende Buch ist eine Einführung in die Konzepte zur Behandlung und Untersuchung von Carbon Nanotubes für eine breite wissenschaftliche Leserschaft. Jedes Kapitel besteht aus einer edukativen Hinführung auf die Problematik sowie aus nachhaltigen Lösungskonzepten. Zum ersten Mal werden ab initio Rechnungen zur physikalischen Beschreibung von CNT vorgestellt und Ergebnisse aus neuen experimentellen Untersuchungsmethoden (STM, Raman) präsentiert.
Download or read book Etude optique de la dynamique des interactions lectroniques dans des nanotubes de carbone written by Sébastien Berger and published by . This book was released on 2007 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse est consacrée à l'étude expérimentale des propriétés électroniques des nanotubes de carbone par des techniques de spectroscopie de photoluminescence. Le travail a d'abord consisté en la préparation et la caractérisation d'échantillons de nanotubes de carbone isolés les uns des autres dans une suspension de surfactant. Ils présentent alors de la luminescence. Intégrés ensuite dans un gel, ils sont adaptés aux températures entre 10 et 300 K. le premier volet d'expériences a concerné la spectroscopie de luminescence en régime stationnaire. Les mesures sur des ensembles macroscopiques permettent d'identifier les classes de chiralité présentes et mettent en évidence divers phénomènes de couplage des nanotubes entre eux et à leur environnement. Grâce à un montage de microscopie confocale, on a en outre étudié la luminescence d'un nanotube unique. On s'affranchit ainsi de l'inhomogénéité de l'échantillon, comme le montrent les faibles largeurs de raies (moins de 1 meV à 10 K) et les phénomènes de diffusion spectrale et de clignotement observés à l'échelle de la seconde. Le second volet d'expériences est consacré à la spectroscopie de photoluminescence résolue en temps à l'échelle picoseconde, sur des ensembles de nanotubes. On mesure la dynamique de recombinaison des excitations élémentaires (excitons), sur 3 ordres de grandeur de variation, dans les chiralités (9,4) et (10,2). L'évolution du temps de vie (300 ps à 10 K, 50 ps à 300 K) et de l'intensité de la luminescence (présentant un maximum à 50 K) donne des informations sur la structure des états excitoniques. On estime en particulier qu'il existe un niveau noir 4 meV en dessous de l'état luminescent.
Download or read book Influence de l tat de dispersion de nanotubes de carbone sur leur relargage et a rosolisation lors de la sollicitation tribologique de nanocomposites MWNT polym re written by Maxime Pras and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les composites renforcés avec des nanotubes de carbone présentent un réel potentiel en terme de renforcement mécanique, d'amélioration de conductivités électrique et thermique des matériaux cependant les effets toxicologiques des nanotubes de carbone sur la santé humaine sont toujours à l'étude, et tout laisse à penser que ceux-ci feront prochainement l'objet de normes et autres législation. C'est pourquoi les fabricants de composites renforcés nanotubes de carbone ont tout intérêt à prendre les devants sur de futures législations en contrôlant le relargage de nanotubes isolés lors de différentes sollicitations de ces matériaux telles que la casse ou l'abrasion. Un bon état de dispersion des nanotubes au sein de la matrice est un paramètre qui améliore les performances du composite et que l'on suppose faire baisser le relargage de nanotubes de carbone isolé dans l'environnement. Le but final de cette étude est donc ici de savoir si la qualité de l'état de dispersion des nanotubes influe sur la nature des particules relarguées suite à une dégradation d'un composites. Il faut savoir si l'on a relargué des nanotubes isolés, ou bien des particules de polymère dans lesquelles des nanotubes seraient complètement enrobés, d'où l'intérêt de bien maitriser cette étape de dispersion. Pour contrôler la dispersion des nanotubes de carbone dans un système polymère, différentes méthode peuvent être utilisées, notamment la microscopie électronique (MEB et MET), mais également des méthodes telles que la caractérisation des propriétés mécaniques, la conductivité électrique, thermique ou encore la rhéologie des suspensions. Ces différentes méthodes étant plus ou moins efficaces et simple à mettre en œuvre pour indiquer si les nanotubes sont individuellement dispersés, en fagots, voire en agglomérats. Une fois l'état de dispersion des composites biens caractérisés, il s'agit de le corréler avec une prédisposition plus ou moins prononcée de ce nanocomposite au relargage. La théorie prédit que l'interface entre un nanotube et le polymère est supposé bien plus forte que celle entre un nanotube entouré par d'autres nanotubes au sein d'un agrégat. Des observations microscopiques de fractures ainsi que la caractérisation des particules relarguées lors des tests en abrasion standardisés (mesures granulométriques combinées à des observations par microscopie électronique) menées sur ces matériaux modèles permettent alors de confirmer les prédictions théoriques et de caractériser les particules relarguées en termes de taille, nombre et nature. Les résultats ne permettent pas d'affirmer que des nanotubes de carbone isolés sont relargués pendant la sollicitation mécanique des nanocomposites, quel que soit l'état de dispersion des nanotubes de carbone. En revanche, les interactions entre les particules de matrice polymère et les nanotubes de carbone observés sur celles-ci, apparaissent extrêmement dépendantes de cet état de dispersion.
Download or read book Carbon Nanotubes and Graphene written by Kazuyoshi Tanaka and published by Newnes. This book was released on 2014-07-10 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Nanotubes and Graphene is a timely second edition of the original Science and Technology of Carbon Nanotubes. Updated to include expanded coverage of the preparation, purification, structural characterization, and common application areas of single- and multi-walled CNT structures, this work compares, contrasts, and, where appropriate, unitizes CNT to graphene. This much expanded second edition reference supports knowledge discovery, production of impactful carbon research, encourages transition between research fields, and aids the formation of emergent applications. New chapters encompass recent developments in the theoretical treatments of electronic and vibrational structures, and magnetic, optical, and electrical solid-state properties, providing a vital base to research. Current and potential applications of both materials, including the prospect for large-scale synthesis of graphene, biological structures, and flexible electronics, are also critically discussed. - Updated discussion of properties, structure, and morphology of biological and flexible electronic applications aids fundamental knowledge discovery - Innovative parallel focus on nanotubes and graphene enables you to learn from the successes and failures of, respectively, mature and emergent partner research disciplines - High-quality figures and tables on physical and mathematical applications expertly summarize key information – essential if you need quick, critically relevant data
Download or read book Advanced 2D Materials written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2016-07-12 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together innovative methodologies and strategies adopted in the research and developments of Advanced 2D Materials. Well-known worldwide researchers deliberate subjects on (1) Synthesis, characterizations, modeling and properties, (2) State-of-the-art design and (3) innovative uses of 2D materials including: Two-dimensional layered gallium selenide Synthesis of 2D boron nitride nanosheets The effects of substrates on 2-D crystals Electrical conductivity and reflectivity of models of some 2D materials Graphene derivatives in semicrystalline polymer composites Graphene oxide based multifunctional composites Covalent and non-covalent polymer grafting of graphene oxide Graphene-semiconductor hybrid photocatalysts for solar fuels Graphene based sensors Graphene composites from bench to clinic Photocatalytic ZnO-graphene hybrids Hydroxyapatite-graphene bioceramics in orthopaedic applications
Download or read book Mechanical Behaviors of Carbon Nanotubes written by K.M. Liew and published by William Andrew. This book was released on 2016-12-25 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical Behaviors of Carbon Nanotubes: Theoretical and Numerical Approaches presents various theoretical and numerical studies on mechanical behaviors of carbon nanotubes. The main theoretical aspects included in the book contain classical molecular dynamics simulation, atomistic-continuum theory, atomic finite element method, continuum plate, nonlocal continuum plate, and shell models. Detailed coverage is also given to structural and elastic properties, trace of large deformation, buckling and post-buckling behaviors, fracture, vibration characteristics, wave propagation, and the most promising engineering applications. This book not only illustrates the theoretical and numerical methods for analyzing the mechanical behavior of carbon nanotubes, but also contains computational results from experiments that have already taken place. - Covers various theoretical and numerical studies, giving readers a greater understanding of the mechanical behavior of carbon nanotubes - Includes multiscale methods that provide the advantages of atomistic and continuum approaches, helping readers solve complex, large-system engineering problems - Allows engineers to create more efficient carbon nanotube structures and devices
Download or read book 2D Nanoelectronics written by Mircea Dragoman and published by Springer. This book was released on 2016-12-01 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to the new two-dimensional one-atomic-layer-thick materials such as graphene, metallic chalcogenides, silicene and other 2D materials. The book describes their main physical properties and applications in nanoelctronics, photonics, sensing and computing. A large part of the book deals with graphene and its amazing physical properties. Another important part of the book deals with semiconductor monolayers such as MoS2 with impressive applications in photonics, and electronics. Silicene and germanene are the atom-thick counterparts of silicon and germanium with impressive applications in electronics and photonics which are still unexplored. Consideration of two-dimensional electron gas devices conclude the treatment. The physics of 2DEG is explained in detail and the applications in THz and IR region are discussed. Both authors are working currently on these 2D materials developing theory and applications.
Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Download or read book Earthworm Management in Tropical Agroecosystems written by Patrick Lavelle and published by Oxford University Press, USA. This book was released on 1999 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers all aspects of the ecology of tropical earthworm communities and their effects on soil properties and plant growth. It examines the latest methods and technologies for their management and includes work from leading experts in Europe, South and Central America, Africa, and Asia.
Download or read book Magnetism and Superconductivity written by Laurent-Patrick Levy and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date work presents a modern vision of magnetism and superconductivity covering both microscopic and phenomenological aspects. The basic information is illustrated with the help of current research topics such as the quantum Hall effect or mesoscopic aspects of superconductivity.
Download or read book Activated Carbon written by Harry Marsh and published by Elsevier. This book was released on 2006-07-12 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent years have seen an expansion in speciality uses of activated carbons including medicine, filtration, and the purification of liquids and gaseous media. Much of current research and information surrounding the nature and use of activated carbon is scattered throughout various literature, which has created the need for an up-to-date comprehensive and integrated review reference. In this book, special attention is paid to porosities in all forms of carbon, and to the modern-day materials which use activated carbons - including fibres, clothes, felts and monoliths. In addition, the use of activated carbon in its granular and powder forms to facilitate usage in liquid and gaseous media is explored. Activated Carbon will make essential reading for Material Scientists, Chemists and Engineers in academia and industry. - Characterization of porosity - The surface chemistry of the carbons - Methods of activation and mechanisms of adsorptio - Computer modelling of structure and porosity within carbons - Modern instrumental analytical methods
Download or read book N Heterocyclic Carbenes written by Silvia Diez-Gonzalez and published by Royal Society of Chemistry. This book was released on 2016-11-04 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: In less than 20 years N-heterocyclic carbenes (NHCs) have become well-established ancillary ligands for the preparation of transition metal-based catalysts. This is mainly due to the fact that NHCs tend to bind strongly to metal centres, avoiding the need of excess ligand in catalytic reactions. Also, NHC‒metal complexes are often insensitive to air and moisture, and have proven remarkably resistant to oxidation. This book showcases the wide variety of applications of NHCs in different chemistry fields beyond being simple phosphine mimics. This second edition has been updated throughout, and now includes a new chapter on NHC‒main group element complexes. It covers the synthesis of NHC ligands and their corresponding metal complexes, as well as their bonding and stereoelectronic properties and applications in catalysis. This is complemented by related topics such as organocatalysis and biologically active complexes. Written for organic and inorganic chemists, this book is ideal for postgraduates, researchers and industrialists.
Download or read book A Political Theology of Climate Change written by Michael S. Northcott and published by Wm. B. Eerdmans Publishing. This book was released on 2013-11-30 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover -- Dedication -- Contents -- Acknowledgements -- 1. The Geopolitics of a Slow Catastrophe -- 2. Coal, Cosmos, and Creation -- 3. Engineering the Air -- 4. Carbon Indulgences, Ecological Debt, and Metabolic Rift -- 5. The Crisis of Cosmopolitan Reason -- 6. The Nomos of the Earth and Governing the Anthropocene -- 7. Revolutionary Messianism and the End of Empire -- Index
Download or read book Modern Styrenic Polymers written by John Scheirs and published by John Wiley & Sons. This book was released on 2003-03-28 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title addresses the latest developments in the field, covering the major advances that have occurred over the past five years in the polymerization and structure of new generation polystyrenes that are broadening its scope of application. It covers the advent of branched polystyrenes, syndiotactic polystyrene, high-molecular weight general purpose PS, styrenic interpolymers, and clear SBS copolymers Presents voluminous research previously only reported at conferences in one reference Unique coverage of a topic not found in the field
Download or read book Nanomaterials For Energy Conversion And Storage written by Dunwei Wang and published by World Scientific. This book was released on 2017-11-10 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of nanomaterials in energy conversion and storage represents an opportunity to improve the performance, density and ease of transportation in renewable resources. This book looks at the most recent research on the topic, with particular focus on artificial photosynthesis and lithium-ion batteries as the most promising technologies to date. Research on the broad subject of energy conversion and storage calls for expertise from a wide range of backgrounds, from the most fundamental perspectives of the key catalytic processes at the molecular level to device scale engineering and optimization. Although the nature of the processes dictates that electrochemistry is a primary characterization tool, due attention is given to advanced techniques such as synchrotron studies in operando. These studies look at the gap between the performance of current technology and what is needed for the future, for example how to improve on the lithium-ion battery and to go beyond its capabilities.Suitable for students and practitioners in the chemical, electrochemical, and environmental sciences, Nanomaterials for Energy Conversion and Storage provides the information needed to find scalable, economically viable and safe solutions for sustainable energy.
Download or read book Risk Assessment in the Process Industries written by Robin Turney and published by IChemE. This book was released on 1996 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this updated and amplified edition, Dr Pitblado answers the crucial questions of risk analysis: what can go wrong?; what are the effects and consequences?; and how often will it happen'.
