Carbon Nanotubes and Carbon Nanofibers in Concrete—Advantages and Potential Risks PDF Download

Author: Andrzej Cwirzen
Publisher: Elsevier
ISBN: 0323855725
Category : Technology & Engineering
Languages : en
Pages : 382

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Book Description
This book focuses on the application of carbon nanotubes and carbon nanofibers in traditional concretes based on Portland cement. Fundamental information is given related to the production technologies of carbon nanotubes and carbon nanofibers, as well as concretes and methods of incorporation. It also contains a section focusing on the possible negative effects of carbon nanotubes and carbon nanofibers on animals and humans. The book indicates benefits and possible problems related to the application of carbon nanotubes and carbon nanofibers in concrete. It is designed to be easy to access and digest for the reader, aiming to reach an audience, not only from academia, but also from the construction industry, materials producers, and contractors who might work with nanomaterials. Outlines the major properties and synthesis methods for carbon nanomaterials in concrete engineering; Explains the role of carbon nanotubes and nanofibers in creating high-performance concrete; Assesses the major challenges of integrating carbon nanomaterials into concrete manufacture on an industrial scale.

Author: Siva Yellampalli
Publisher: BoD – Books on Demand
ISBN: 9533074981
Category : Science
Languages : en
Pages : 414

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Book Description
Polymer nanocomposites are a class of material with a great deal of promise for potential applications in various industries ranging from construction to aerospace. The main difference between polymeric nanocomposites and conventional composites is the filler that is being used for reinforcement. In the nanocomposites the reinforcement is on the order of nanometer that leads to a very different final macroscopic property. Due to this unique feature polymeric nanocomposites have been studied exclusively in the last decade using various nanofillers such as minerals, sheets or fibers. This books focuses on the preparation and property analysis of polymer nanocomposites with CNTs (fibers) as nano fillers. The book has been divided into three sections. The first section deals with fabrication and property analysis of new carbon nanotube structures. The second section deals with preparation and characterization of polymer composites with CNTs followed by the various applications of polymers with CNTs in the third section.

Author: Miriam A. Summerfield
Publisher: Nova Science Publishers
ISBN: 9781631176296
Category : Carbon nanofibers
Languages : en
Pages : 0

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Book Description
Results from recent animal studies indicate that carbon nanotubes (CNT) and carbon nanofibres (CNF) may pose a respiratory hazard. CNTs and CNFs are tiny, cylindrical, large aspect ratio, manufactured forms of carbon. There is no single type of carbon nanotube or nanofibre; one type can differ from another in shape, size, chemical composition (from residual metal catalysts or functionalisation of the CNT and CNF) and other physical and chemical characteristics. Such variations in composition and size have added to the complexity of understanding their hazard potential. Occupational exposure to CNTs and CNFs can occur not only in the process of manufacturing them, but also at the point of incorporating these materials into other products and applications. This book reviews the animal and other toxicological data relevant to assessing the potential non-malignant adverse respiratory effects of CNT and CNF; provides a quantitative risk assessment based on animal dose-response data; proposes a recommended exposure limit (REL) of 1 μg/m3 elemental carbon as a respirable mass 8-hour time-weighted average (TWA) concentration; and describes strategies for controlling workplace exposures and implementing a medical surveillance program.

Author: Rashid Kamel Abu Al-Rub
Publisher:
ISBN:
Category : Portland cement
Languages : en
Pages : 135

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Book Description
The focus of this study was on exploring the use of nanotechnology-based nano-filaments, such as carbon nanotubes (CNTs) and nanofibers (CNFs), as reinforcement in improving the mechanical properties of Portland cement paste as a construction material. Due to their ultra-high strength and very high aspect ratios, CNTs and CNFs have been used as excellent reinforcements in enhancing the physical and mechanical properties of polymer, metallic, and ceramic composites. Very little attention has been devoted to explore the use of nanofilaments in the transportation industry. Therefore, this study aimed to bridge the gap between nano-filaments and transportation materials. This was achieved by testing the integration of CNTs and CNFs in ordinary Portland cement paste through state-of-the-art techniques. Different mixes in fixed proportions (e.g. water-to-cement ratio, air content, admixtures) along with varying concentrations of CNTs or CNFs were prepared. Different techniques commonly used for other materials (like polymers) were used in achieving uniform dispersion of nano-filaments in the cement paste matrix and strong nano-filaments/cement bonding. Small-scale specimens were prepared for mechanical testing in order to measure the modified mechanical properties as a function of nano-filaments concentration, type, and distribution. With 0.1% CNFs, the ultimate strain capacity increased by 142%, the flexural strength increased by 79%, and the fracture toughness increased by 242%. A scanning electron microscope was used to discern the difference between crack bridging and fiber pullout. Test results showed that the strength, ductility, and fracture toughness can be improved with the addition of low concentrations of either CNTs or CNFs.

Author: Arvind Agarwal
Publisher: CRC Press
ISBN: 9781439811498
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
From the Foreword, written by legendary nano pioneer M. Meyyappan, Chief Scientist for Exploration Technology NASA Ames Research Center, Moffett Field, California, USA: "...there is critical need for a book to summarize the status of the field but more importantly to lay out the principles behind the technology. This is what Professor Arvind Agarwal and his co-workers ... have done here." Carbon Nanotubes: Reinforced Metal Matrix Composites reflects the authors’ desire to share the benefits of nanotechnology with the masses by developing metal matrix carbon nanotube (MM-CNT) composites for large-scale applications. Multiwall carbon nanotubes can now be produced on a large scale and at a significantly reduced cost. The book explores potential applications and applies the author’s own research to highlight critical developmental issues for different MM-CNT composites—and then outline novel solutions. With this problem-solving approach, the book explores: Advantages, limitations, and the evolution of processing techniques used for MM-CNT composites Characterization techniques unique to the study of MM-CNT composites—and the limitations of these methods Existing research on different MM-CNT composites, presented in useful tables that include composition, processing method, quality of CNT dispersion, and properties The micro-mechanical strengthening that results from adding CNT The applicability of micro-mechanics models in MM-CNT composites Significance of chemical stability for carbon nanotubes in the metal matrix as a function of processing, and its impact on CNT/metal interface and mechanical properties Computational studies that have not been sufficiently covered although they are essential to research and development The critical issue of CNT dispersion in the metal matrix, as well as a unique way to quantify CNT distribution and subsequently improve control of the processing parameters for obtaining improved properties Carbon Nanotubes: Reinforced Metal Matrix Composites paints a vivid picture of scientific and application achievements in this field. Exploring the mechanisms through which CNTs are enhancing the properties of different metal-based composites, the authors provide a roadmap to help researchers develop MM-CNT composites and choose potential materials for use in emerging areas of technology.

Author: Ardavan Yazdanbakhsh
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Carbon nanotubes (CNTs) and carbon nanofirbers (CNFs) have excellent properties (mechanical, electrical, magnetic, etc.), which can make them effective nanoreinforcements for improving the properties of materials. The incorporation of CNT/Fs in a wide variety of materials has been researched extensively in the past decade. However, the past study on the reinforcement of cementitious materials with these nanofilaments has been limited. The findings from those studies indicate that CNT/Fs did not significantly improve the mechanical properties of cementitious materials. Two major parameters influence the effectiveness of any discrete inclusion in composite material: The dispersion quality of the inclusions and the interfacial bond between the inclusions and matrix. The main focus of this dissertation is on the dispersion factor, and consists of three main tasks: First a novel thermodynamic-based method for dispersion quantification was developed. Second, a new method, incorporating the utilization of silica fume, was devised to improve and stabilize the dispersion of CNFs in cement paste. And third, the dispersion quantification method and mechanical testing were employed to measure, compare, and correlate the dispersion and mechanical properties of CNF-incorporated cement paste produced with the conventional and new methods. Finally, the main benefits, including the increase in strength and resistance to shrinkage cracking, obtained from the utilization of CNFs in cement paste will be presented. The investigations and the corresponding results show that the novel dispersion quantification method can be implemented easily to perform a wide variety of tasks ranging from measuring dispersion of nanofilaments in composites using their optical/SEM micrographs as input, to measuring the effect of cement particle/clump size on the dispersion of nano inclusions in cement paste. It was found that cement particles do not affect the dispersion of nano inclusions in cement paste significantly while the dispersion of nano inclusions can notably degenerates if the cement particles are agglomerated. The novel dispersion quantification method shows that, the dispersion of CNFs in cement paste significantly improves by utilizing silica fume. However, it was found that the dispersion of silica fume particles is an important parameter and poorly dispersed silica fume cannot enhance the overall dispersion of nano inclusions in cementitious materials. Finally, the mechanical testing and experimentations showed that CNFs, in absence of moist curing, even if poorly dispersed, can provide important benefits in terms of strength and crack resistance.

Author: Agnieszka Jędrzejewska
Publisher: Springer Nature
ISBN: 3031332113
Category : Technology & Engineering
Languages : en
Pages : 1363

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Book Description
This book highlights the latest advances, innovations, and applications in cement-based materials (CBM) and concrete structures, as presented by leading international researchers and engineers at the International RILEM Conference on synergizing expertise toward sustainability and robustness of CBM and concrete structures (SynerCrete), held in Milos Island, Greece, on June 14-16, 2023. The aim of the conference was to discuss and arouse progress in research, development, and application of CBM and structural concrete through combination of expertise from distinct fields of knowledge, such as performance-based design, 3D modeling for analysis/design, building information modeling, and even robotics, while keeping focus on multiscale approaches at time and spatial levels. It covers a diverse range of topics concerning alternative concrete formulations for adaptation to climate change, performance-based and multiphysics/multiscale design and innovative testing, structural health monitoring and maintenance management, integral BIM-based planning, and resource-responsible building. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster new multidisciplinary collaborations. The two volumes encompass more than 200 original contributions in the field.

Author: Fabian Ifeanyichukwu Ezema
Publisher: CRC Press
ISBN: 1000894118
Category : Science
Languages : en
Pages : 505

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Book Description
The book Materials for Sustainable Energy Storage Devices at the Nanoscale anticipates covering all electrochemical energy storage devices such as supercapacitors, lithium-ion batteries (LIBs), and fuel cells, transformation and enhancement materials for solar cells, photocatalysis, etc. The focal objective of the book is to deliver stunning and current information to the materials application at nanoscale to researchers and scientists in our contemporary time towardthe enhancement of energy conversion and storage devices. However, the contents of the proposed book, Materials for Sustainable Energy Storage at the Nanoscale, will cover various fundamental principles and wide knowledge of different energy conversion and storage devices with respect to their advancement due to the emergence of nanoscale materials for sustainable storage devices. This book is targeted to be award-winning as well as a reference book for researchers and scientists working on different types of nanoscale materials-based energy storage and conversion devices. Features Comprehensive overview of energy storage devices, an important field of interest for researchers worldwide Explores the importance and growing impact of batteries and supercapacitors Emphasizes the fundamental theories, electrochemical mechanism, and its computational view point and discusses recent developments in electrode designing based on nanomaterials, separators, and fabrication of advanced devices and their performances

Author: Michael J. O’Connell
Publisher: CRC Press
ISBN: 1420004212
Category : Technology & Engineering
Languages : en
Pages : 339

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Book Description
Since their discovery more than a decade ago, carbon nanotubes (CNTs) have held scientists and engineers in captive fascination, seated on the verge of enormous breakthroughs in areas such as medicine, electronics, and materials science, to name but a few. Taking a broad look at CNTs and the tools used to study them, Carbon Nanotubes: Properties and Applications comprises the efforts of leading nanotube researchers led by Michael O’Connell, protégé of the late father of nanotechnology, Richard Smalley. Each chapter is a self-contained treatise on various aspects of CNT synthesis, characterization, modification, and applications. The book opens with a general introduction to the basic characteristics and the history of CNTs, followed by discussions on synthesis methods and the growth of “peapod” structures. Coverage then moves to electronic properties and band structures of single-wall nanotubes (SWNTs), magnetic properties, Raman spectroscopy of electronic and chemical behavior, and electromechanical properties and applications in NEMS (nanoelectromechanical systems). Turning to applications, the final sections of the book explore mechanical properties of SWNTs spun into fibers, sidewall functionalization in composites, and using SWNTs as tips for scanning probe microscopes. Taking a fresh look at this burgeoning field, Carbon Nanotubes: Properties and Applications points the way toward making CNTs commercially viable.

Author: Hosam El-Din M. Saleh
Publisher: BoD – Books on Demand
ISBN: 1789841534
Category : Technology & Engineering
Languages : en
Pages : 276

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Book Description
Cement-based materials have been used by humans nearly since the dawn of civilization. The Egyptians used lime and gypsum cement to bind their aggregate materials, mud and straw, resulting in bricks that are used for building their famous Egyptian pyramids (between 3000 and 2500 BC). Hydrated cement is a cement material bonded together with water and used for building construction; it is characterized by acceptable chemical, physical, thermal, mechanical, and structural stability. It plays a main role in the creation of vessels for storage, roads to travel on, weather-resistant structure for protection, inert hard stabilizer for hazardous wastes, and so on. Due to the composition of these materials and their advantages, it has been practiced in different applications. Cement is an essential component of making concrete, the single most prevalent building material used worldwide for construction, skyscrapers, highways, tunnels, bridges, hydraulic dams, and railway ties. Besides their numerous desired properties, there are some undesirable features. To overcome these disadvantages, several studies were established to prepare, improve, and evaluate innovative cement-based materials. Despite its oldness and deep research, every year several methods and materials evolve and so do cement technology. This book intends to provide a comprehensive overview on recent advances in the evaluation of these materials.