Download or read book Micromechanics Modeling of the Electrical Conductivity of Carbon Nanotude CNT Polymer Nanocomposites written by Zhuang Feng and published by . This book was released on 2014 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: He addition of carbon nanotubes (CNTs) in polymers to form conductive composites has been attracting great interest from research and industry communities due to their potential applications. Experiments and simulations have demonstrated that the addition of a very small amount of CNTs into polymers can significantly improve the electrical conductivity of the composites. Such significant improvement in the electrical conductivity is attributed to two conductivity mechanisms: nanoscale electron hopping and microscale conductive networks. Understanding and prediction of the overall electrical conductivity of the composites with the incorporation of the conductivity mechanisms that underpin the macroscopic electrical properties are essential for their engineering applications. One of the most promising applications of the conductive composites is for stretchable electronics. For such an application, it is naturally necessary to investigate the stretching effects upon the overall electrical conductivity of the composites. Furthermore, CNTs dispersed in polymers are usually not straight but rather have a certain degree of waviness due to the CNTs' large aspect ratio and low bending stiffness. It has been suggested that the waviness can have considerable effect on the electrical conductivity of the composites. Therefore, the investigation of CNT waviness effect is of great importance for the prediction of the overall electrical conductivity of the composites. In this thesis, based on the micromechanics theory, a mixed micromechanics model with the incorporation of the nanoscale electron hopping and the microscale conductive networks is first developed to predict the electrical conductivity of the composites. The modeling results agree well with existing experimental data. It is found that both the electron hopping and the conductive networks contribute to the electrical conductivity of the composites while conductive networks become dominant to the electrical conductivity of the composites after percolation. It was also indicated that the sizes of CNTs have significant effects on the percolation threshold and the overall electrical conductivity of the nanocomposites. Based on the developed micromechanics model, stretching effects are then investigated by incorporating the stretching induced changes into the micromechanics model. The investigation found that the stretching, including uni-axial and bi-axial stretching, decreases the electrical conductivity of the composites in the stretching direction and the decrease is more evident for the bi-axial stretching compared to uni-axial stretching. It is also observed that the electrical conductivity is more sensitive to stretching for the composites with lower CNT volume fraction. Finally, we studied the CNT waviness effects upon the electrical conductivity of the composites under a uni-axial stretching. It is demonstrated that the waviness significantly decreases the electrical conductivity of the composites and the electrical conductivity is more sensitive to the waviness for the composites with lower CNT volume fraction and larger stretching strain. Reasons for the observed variations and phenomena are interpreted. The work in this thesis is expected to obtain increased understanding on the overall electrical conductivity of CNT-polymer composites from the theoretical perspective and provide useful guidelines for the design and optimization of the composites.

Download or read book Micromechanics Modeling of the Multifunctional Nature of Carbon Nanotube polymer Nanocomposites written by Gary Don Seidel and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present work provides a micromechanics approach based on the generalized self-consistent composite cylinders method as a non-Eshelby approach towards for assessing the impact of carbon nanotubes on the multi-functional nature of nanocom-posites in which they are a constituent. Emphasis is placed on the effective elastic properties as well as electrical and thermal conductivities of nanocomposites con-sisting of randomly oriented single walled carbon nanotubes in epoxy. The effective elastic properties of aligned, as well as clustered and well-dispersed nanotubes in epoxy are discussed in the context of nanotube bundles using both the generalized self-consistent composite cylinders method as well as using computational microme-chanics techniques. In addition, interphase regions are introduced into the composite cylinders assemblages to account for the varying degrees of load transfer between nanotubes and the epoxy as a result of functionalization or lack thereof. Model pre-dictions for randomly oriented nanotubes both with and without interphase regions are compared to measured data from the literature with emphasis placed on assessing the bounds of the effective nanocomposite properties based on the uncertainty in the model input parameters. The generalized self-consistent composite cylinders model is also applied to model the electrical and thermal conductivity of carbon nanotube-epoxy nanocomposites. Recent experimental observations of the electrical conductivity of carbon nanotube polymer composites have identifed extremely low percolation limits as well as a per-ceived double percolation behavior. Explanations for the extremely low percolation limit for the electrical conductivity of these nanocomposites have included both the creation of conductive networks of nanotubes within the matrix and quantum effects such as electron hopping or tunneling. Measurements of the thermal conductivity have also shown a strong dependence on nanoscale effects. However, in contrast, these nanoscale effects strongly limit the ability of the nanotubes to increase the thermal conductivity of the nanocomposite due to the formation of an interfacial thermal resistance layer between the nanotubes and the surrounding polymer. As such, emphasis is placed here on the incorporation of nanoscale effects, such as elec-tron hopping and interfacial thermal resistance, into the generalized self-consistent composite cylinder micromechanics model.

Download or read book Micromechanics and Nanomechanics of Composite Solids written by Shaker A. Meguid and published by Springer. This book was released on 2017-07-19 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book elucidates the most recent and highly original developments in the fields of micro- and nanomechanics and the corresponding homogenization techniques that can be reliably adopted and applied in determining the local properties, as well as the linear and nonlinear effective properties of the final architecture of these complex composite structures. Specifically, this volume, divided into three main sections—Fundamentals, Modeling, and Applications—provides recent developments in the mathematical framework of micro- and nanomechanics, including Green’s function and Eshelby’s inclusion problem, molecular mechanics, molecular dynamics, atomistic based continuum, multiscale modeling, and highly localized phenomena such as microcracks and plasticity. It is a compilation of the most recent efforts by a group of the world’s most talented and respected researchers. Ideal for graduate students in aerospace, mechanical, civil, material science, life sciences, and biomedical engineering, researchers, practicing engineers, and consultants, the book provides a unified approach in compiling micro- and nano-scale phenomena. · Elucidates recent and highly original developments in the fields of micromechanics and nanomechanics and the corresponding homogenization techniques; · Includes several new topics that are not covered in the current literature, such as micromechanics of metamaterials, electrical conductivity of CNT and graphene nanocomposites, ferroelectrics, piezoelectric, and electromagnetic materials; · Addresses highly localized phenomena such as coupled field problems, microcracks, inelasticity, dispersion of CNTs, synthesis, characterization and a number of interesting applications; · Maximizes readers’ ability to apply theories of micromechanics and nanomechanics to heterogeneous solids; · Illustrates application of micro- and nanomechanical theory to design novel composite and nanocomposite materials.

Download or read book Carbon Nanotube Polymer Nanocomposites written by Srikanta Moharana and published by Springer Nature. This book was released on with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Nanotube Reinforced Polymers written by Roham Rafiee and published by Elsevier. This book was released on 2017-10-06 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Nanotube-Reinforced Polymers: From Nanoscale to Macroscale addresses the advances in nanotechnology that have led to the development of a new class of composite materials known as CNT-reinforced polymers. The low density and high aspect ratio, together with their exceptional mechanical, electrical and thermal properties, render carbon nanotubes as a good reinforcing agent for composites. In addition, these simulation and modeling techniques play a significant role in characterizing their properties and understanding their mechanical behavior, and are thus discussed and demonstrated in this comprehensive book that presents the state-of-the-art research in the field of modeling, characterization and processing. The book separates the theoretical studies on the mechanical properties of CNTs and their composites into atomistic modeling and continuum mechanics-based approaches, including both analytical and numerical ones, along with multi-scale modeling techniques. Different efforts have been done in this field to address the mechanical behavior of isolated CNTs and their composites by numerous researchers, signaling that this area of study is ongoing. - Explains modeling approaches to carbon nanotubes, together with their application, strengths and limitations - Outlines the properties of different carbon nanotube-based composites, exploring how they are used in the mechanical and structural components - Analyzes the behavior of carbon nanotube-based composites in different conditions

Download or read book Modeling of Electrical Conductivity and Piezoresistivity of Carbon Nanotube Based Polymer Nanocomposites written by Weiqing Fang and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superior electrical, thermal, and mechanical properties of carbon nanotubes (CNTs) have made them effective filler for multifunctional polymer nanocomposites (PNCs). In this thesis work, an improved model has been developed to describe the CNT networks inside polymer matrix and thereby evaluated the PNCs c and . The new model accounts for the electrical conductance contributed by the continued CNT network across the boundary of adjacent representative volume elements. It more realistically represents the interconnectivity among CNTs and enhances the evaluation of the structure-to-property relationship of PNCs . Furthermore, comprehensive investigations on the piezoresistive behaviour of PNCs have been conducted using developed modeling framework. Quantitative analyses have revealed that piezoresistivity of PNCs is predominantly governed by the three mechanisms related to the strain-induced morphological evolution of the CNT network embedded in the polymer matrix.

Download or read book Carbon Nanotube polymer Composites written by Dimitrios Tasis and published by Royal Society of Chemistry. This book was released on 2013 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to summarize the basic chemical aspects for obtaining multifunctional carbon nanotube-based polymer composites, but also to highlight some of the most remarkable advances that occurred in the field during the last recent years.

Download or read book Carbon Nanotube Based Composites written by Antonio Pantano and published by Smithers Rapra. This book was released on 2012-09-28 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon nanotubes (CNTs) have amazing properties and a key way to take advantage of this is by incorporating nanotubes into a matrix to build composite materials. The best candidates for this task are undoubtedly polymers. Almost every characteristic of a polymer can be significantly enhanced by adding carbon nanotubes and as a result, new potential applications of carbon nanotube enhanced polymer composites are discovered every day. However, before carbon nanotube enhanced polymer composites become commonplace there are some tough challenges that need to be overcome. This book reviews the status of worldwide research in both single-walled and multi-walled carbon nanotube based composites. It serves as a practical guide on carbon nanotube based composites and a reference to students and researchers from the academia and industry.

Download or read book Carbon based Polymer Nanocomposites for Environmental and Energy Applications written by Ahmad Fauzi Ismail and published by Elsevier. This book was released on 2018-03-28 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-Based Polymer Nanocomposites for Environmental and Energy Applications provides the fundamental physico-chemical characterizations of recently explored carbon-based polymer nanocomposites, such as carbon nanotubes, graphene and its derivatives, nanodiamond, fullerenes and other nano-sized carbon allotropes. The book also covers the applications of carbon-based polymer nanocomposite in the environmental and energy fields. Topics range from the various approaches that have been explored and developed for the fabrication of carbon-based polymer nanocomposite, to their applications in tackling environmental and energy related issues. - Provides a clear picture of the current state-of-the-art and future trends in carbon-based polymer nanomaterials - Explains the interactions between nanofiller-polymer matrices and mechanisms related to applications in environmental pollution and energy shortage - Includes computational and experimental studies of the physical and chemical properties of carbon-based polymer nanocomposites - Features chapters written by world leading experts

Download or read book 2nd International Conference on Smart Sustainable Materials and Technologies ICSSMT 2023 written by M. Sumesh and published by Springer Nature. This book was released on with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Micromechanics Study on Carbon based and Multiferroic Composites written by Yang Wang and published by . This book was released on 2016 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, two physical properties of modern composites are studied. One is the electrical conductivity of carbon nanotube- and graphene-based polymer nanocomposites, and the other is the magnetoelectric coupling of highly anisotropic piezoelectric-piezomagnetic multiferroic composites. Along the way, several related issues have also been examined. These include percolation threshold, interfacial resistance, electron tunneling, and filler agglomeration in the first case, and, in the second one, the influence of aspect ratio of inclusions, imperfect interface, and phase connectivity. The studies of these two problems are linked by the common theme of micromechanics theory but cast in different settings. The effective electrical conductivity and percolation threshold of CNT-based nanocomposites are investigated with the effective-medium approach as the backbone. We then introduce of a diminishing layer of interface with an interfacial resistivity that is further modified by Cauchy's statistical distribution function to account for the additional tunneling-assisted interfacial conductivity. The issue of filler agglomeration is examined in details for graphene-based nanocomposites, in which a two-scale effective-medium approach with graphene-rich and graphene-poor regions is also developed. Our predictions are shown to be in close agreement with experimental data. For multiferroic composites, our focus is on the intriguing property of magnetoelectric coupling coefficient which is absent in either piezoelectric or piezomagnetic phase but owned by overall composites. We study this iconic effect in depth for BaTiO3-CoFe2O4 system with different types of connectivity, including 1-3, 0-3, 2-2, that display the inclusion-matrix morphology, and 1-1, 0-0 connectivity that are marked by their symmetric geometrical footing. These two classes of composites are analyzed by the Mori-Tanaka method and the effective-medium approach, respectively. We demonstrate how the magnetoelectric coupling coefficients are highly dependent on the phase volume concentration, inclusion aspect ratio, interface effect, and phase connectivity. Our results also reveal that the magnetoelectric coupling of 0-0 connectivity are substantially higher than that of 0-3 connectivity, but the difference between 1-1 and 1-3 connectivity is limited. In the end, we point to the need of exploring the physical mechanism of interfacial resistance for carbon-based nanocomposites and the nonlinear coupling behaviors for ferroelectric-ferromagnetic composites in our future work.

Download or read book Carbon Nanotube Reinforced Composites written by Marcio Loos and published by Elsevier. This book was released on 2014-09-11 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Nanotube Reinforced Composites introduces a wide audience of engineers, scientists and product designers to this important and rapidly expanding class of high performance composites. Dr Loos provides readers with the scientific fundamentals of carbon nanotubes (CNTs), CNT composites and nanotechnology in a way which will enable them to understand the performance, capability and potential of the materials under discussion. He also investigates how CNT reinforcement can be used to enhance the mechanical, electrical and thermal properties of polymer composites. Production methods, processing technologies and applications are fully examined, with reference to relevant patents. Finally, health and safety issues related to the use of CNTs are investigated. Dr. Loos compares the theoretical expectations of using CNTs to the results obtained in labs, and explains the reasons for the discrepancy between theoretical and experimental results. This approach makes the book an essential reference and practical guide for engineers and product developers working with reinforced polymers – as well as researchers and students in polymer science, materials and nanotechnology. A wealth of applications information is included, taken from the wide range of industry sectors utilizing CNT reinforced composites, such as energy, coatings, defense, electronics, medical devices, and high performance sports equipment. - Introduces a wide range of readers involved in plastics engineering, product design and manufacturing to the relevant topics in nano-science, nanotechnology, nanotubes and composites. - Assesses effects of CNTs as reinforcing agents, both in a materials context and an applications setting. - Focuses on applications aspects – performance, cost, health and safety, etc – for a wide range of industry sectors, e.g. energy, coatings, defense, electronics, medical devices, high performance sports equipment, etc.

Download or read book Nanocomposites written by Jinbo Bai and published by John Wiley & Sons. This book was released on 2022-06-24 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocomposites are one of the major advances in the field of materials. They have applications in sectors as varied as aeronautics, energy and the environment. However, the effective use of nanocomposites requires new knowledge and tools in order to overcome the difficulties and benefit from the advantages. Nanocomposites presents recent academic and industrial progress in this field, as well as the latest research on the effective use of nanoscale fillers and reinforcements to improve the performance of advanced nanocomposites. It also describes the techniques and tools used to prepare nanocomposites, including the latest techniques for synthesis and surface treatment of nanofillers for different applications. Finally, it details the role of nanoscience in the design, characterization and multi-scale modeling of these materials, with a focus on nanoscale phenomena.

Download or read book Electronic Composites written by Minoru Taya and published by Cambridge University Press. This book was released on 2008-04-24 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2005 book describes the processing, simulation and applications of electronic composites.

Download or read book Handbook of Polymers written by George Wypych and published by Elsevier. This book was released on 2022-03-19 with total page 751 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Polymers, Third Edition represents an update on available data, including new values for many commercially available products, verification of existing data, and removal of older data where it is no longer useful. Polymers selected for this edition include all primary polymeric materials used by the plastics and chemical industries and specialty polymers used in the electronics, pharmaceutical, medical and aerospace fields, with extensive information also provided on biopolymers. The book includes data on all polymeric materials used by the plastics industry and branches of the chemical industry, as well as specialty polymers in the electronics, pharmaceutical, medical and space fields. The entire scope of the data is divided into sections to make data comparison and search easy, including synthesis, physical, mechanical, and rheological properties, chemical resistance, toxicity, environmental impact, and more. - Provides key data on all primary polymeric materials used in a wide range of industries and applications - Presents easy-to-access data divided into sections, making comparisons and search simple and intuitive - Includes data on general properties, history, synthesis, structure, physical properties, mechanical properties, chemical resistance, flammability, weather stability, toxicity, and more

Download or read book Polymer Nanotubes Nanocomposites written by Vikas Mittal and published by John Wiley & Sons. This book was released on 2014-09-02 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the successful first edition of the book in 2010, the field has matured and a large number of advancements have been made to the science of polymer nanotube nanocomposites (PNT) in terms of synthesis, filler surface modification, as well as properties. Moreover, a number of commercial applications have been realized. The aim of this second volume of the book is, thus, to update the information presented in the first volume as well as to incorporate the recent research and industrial developments. This edited volume brings together contributions from a variety of senior scientists in the field of polymer nanotube composites technology to shed light on the recent advances in these commercially important areas of polymer technology. The book provides the following features: Reviews the various synthesis techniques, properties and applications of the polymer nanocomposite systems. Describes the functionalization strategies for single walled nanotubes in order to achieve their nanoscale dispersion in epoxy matrices. Provides insights into the multiscale modeling of the properties of PNT. Provides perspectives on the electron microscopy characterization of PNT. Presents an overview of the different methodologies to achieve micro-patterning of PNT. Describes the recent progress on hybridization modifications of CNTs with carbon nanomaterials and their further applications in polymer nanocomposites. Provides details on the foams generates with PNT. Provides information on synthesis and properties of polycarbonate nanocomposite. Describes the advanced microscopy techniques for understanding of the polymer/nanotube composite interfaces and properties.

Download or read book Electrical and Thermal Experimental Characterization and Modeling of Carbon Nanotube epoxy Composites written by Frank Gardea and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present work investigates the effect of carbon nanotube (CNT) inclusions on the electrical and thermal conductivity of a thermoset epoxy resin. The characterization of electrical and thermal conductivity of CNT/epoxy composites is presented. Pristine, oxidized, and fluorine-functionalized unpurified CNT mixtures ("XD grade") were dispersed in an epoxy matrix, and the effect of stirring rate and pre-curing of the epoxy on the dispersion of the CNTs was evaluated. In order to characterize the dispersion of the CNTs at different length scales, Optical Microscopy (OM), Raman Spectroscopy, and Scanning Electron Microscopy (SEM) was performed. Samples of varying CNT weight fractions were fabricated in order to find the effect of CNT weight fraction on thermal and electrical conductivity. Electrical conductivity was measured using a dielectric spectrometer, and thermal conductivity was determined by a transient plane source thermal analyzer. It was found that electrical conductivity increases by orders of magnitude for the pristine and oxidized XD CNT composites relative to the neat epoxy matrix, while fluorinated XD CNT composites remain electrically non-conductive. A small, but significant, increase in thermal conductivity was observed for pristine, oxidized, and fluorinated XD CNT composites, showing a linear increase in thermal conductivity with increasing CNT weight fraction. Pristine XD CNTs were ball-milled for different times in order to reduce the degree of agglomeration and entanglement of CNTs, and composites were fabricated using the same technique as with non-milled XD CNTs. Using ball-milled CNTs shows improved dispersion but results in an electrically non-conductive composite at the CNT weight fractions tested. The thermal conductivity of the ball-milled CNT samples shows an initial increase higher than that of non-milled pristine, oxidized, and fluorinated XD CNTs, but remains constant with increasing CNT weight fraction. A micromechanics model based on the composite cylinders method was implemented to model the electrical and thermal conductivity of the CNT/epoxy composites. Nanoscale effects in electrical and thermal conduction, such as electron hopping and interface thermal resistance, respectively, were incorporated into the model in order to accurately predict the acquired results. Modeling results show good agreement with acquired experimental results.