Download or read book Promising Methods for Improving the Thermoelectric Properties of Carbon Nanotube Insulating Polymer Composites written by Jiang Li and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelectric technology has been treated as a candidate to convert heat into electricity and reuse the waste heat. By using the body heat, the thermoelectric generator is promising to apply to wearable devices as the power source. The organic thermoelectric materials have drawn more and more attention in such applications due to their good flexibility, low density, low toxicity, low cost, low thermal conductivity, and good processability. In contrast to conductive polymers, the thermoelectric performance of insulating polymers with better processability and lower cost is limited by the low electrical conductivity. In this dissertation, two methods, including polymer pyrolysis and transition metal-polymer coordination, which were reported to improve the electrical conductivity of some insulting polymers were studied in their effects on thermoelectric properties of insulting polymer composites. The results indicate that both these methods effectively enhance the power factor of MWCNT/PAN composites and the thermoelectric performance is comparable to that of conductive polymer composites. Through pyrolysis, a maximum power factor of 18.6 μW/mK2 was obtained from the stabilized MWCNT/PAN, which was almost 3 times higher than that of the MWCNT/PAN. Moreover, both p- and n-type properties were obtained from the pyrolyzed MWCNT/PAN. The power factor of MWCNT/PAN was also improved to 22.3 μW/mK2 through transition metal coordination. The feasibility of these methods on some other insulating polymers has been proved. With the contribution of these methods, more options are provided for the studies of flexible thermoelectric materials with better processability and lower cost.
Download or read book Organic Thermoelectric Materials written by Zhiqun Lin and published by Royal Society of Chemistry. This book was released on 2019-10-18 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarises the significant progress made in organic thermoelectric materials, focusing on effective routes to minimize thermal conductivity and maximize power factor.
Download or read book Fundamentals of Conjugated Polymer Blends Copolymers and Composites written by Parveen Saini and published by John Wiley & Sons. This book was released on 2015-04-30 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since their discovery in 1977, the evolution of conducting polymers has revolutionized modern science and technology. These polymers enjoy a special status in the area of materials science yet they are not as popular among young readers or common people when compared to other materials like metals, paper, plastics, rubber, textiles, ceramics and composites like concrete. Most importantly, much of the available literature in the form of papers, specific review articles and books is targeted either at advanced readers (scientists / technologists / engineers / senior academicians) or for those who are already familiar with the topic (doctoral / postdoctoral scholars). For a beginner or even school / college students, such compilations are bit difficult to access / digest. In fact, they need proper introduction to the topic of conducting polymers including their discovery, preparation, properties, applications and societal impact, using suitable examples and already known principles/knowledge/phenomenon. Further, active participation of readers in terms of "question & answers", "fill-in-the-blanks", "numerical" along with suitable answer key is necessary to maintain the interest and to initiate the "thought process". The readers also need to know about the drawbacks and any hazards of such materials. Therefore, I believe that a comprehensive source on the science / technology of conducting polymers which maintains a link between grass root fundamentals and state-of-the-art R&D is still missing from the open literature.
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 Development and Thermal Properties of Carbon Nanotube polymer Composites written by Enrique Monte Jackson and published by . This book was released on 2014 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Dimensional Solids written by Duncan W. Bruce and published by John Wiley & Sons. This book was released on 2011-03-29 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: With physical properties that often may not be described by the transposition of physical laws from 3D space across to 2D or even 1D space, low-dimensional solids exhibit a high degree of anisotropy in the spatial distribution of their chemical bonds. This means that they can demonstrate new phenomena such as charge-density waves and can display nanoparticulate (0D), fibrous (1D) and lamellar (2D) morphologies. This text presents some of the most recent research into the synthesis and properties of these solids and covers: Metal Oxide Nanoparticles Inorganic Nanotubes and Nanowires Biomedical Applications of Layered Double Hydroxides Carbon Nanotubes and Related Structures Superconducting Borides Introducing topics such as novel layered superconductors, inorganic-DNA delivery systems and the chemistry and physics of inorganic nanotubes and nanosheets, this book discusses some of the most exciting concepts in this developing field. Additional volumes in the Inorganic Materials Book Series: Molecular Materials Functional Oxides Porous Materials Energy Materials All volumes are sold individually or as comprehensive 5 Volume Set.
Download or read book Electrical and Thermal Transport Properties of Polymer carbonaceous Nanostructured Composites written by Rakibul Islam and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conducting polymer nanocomposites exhibit for instance interesting thermoelectric properties which make them a promising, inexpensive, clean and efficient solution for heat waste harvesting. This thesis reports on properties of polyaniline (PANI) nanostructured composites as a function of various carbonaceous nano-fillers content such as carbon nanotubes (1-D), and 2-D reduced graphene oxide (RGO). SEM, TEM, X-ray diffraction, and Raman spectroscopy have been employed to investigate their structure and morphology. Electrical and thermal conductivity, Seebeck coefficient, and thermoelectric figure of merit (ZT) have been systematically performed. An important increase of electrical conductivity has been observed with increasing filler fraction whereas thermal conductivity only slightly increases, which enhances ZT of several orders of magnitude. Fillers dimension effect is evidenced, but, whatever this dimension, it is shown that, in contrast with thermal conductivity, electrical conductivity follows a percolation behavior through 2D conduction process. This behavior is also observed in the case of the volumetric heat capacity of PANI/RGO nanohybrids which make them potential candidates as high heat capacitive materials. For the first time their heat storage factor is assessed with a new analytical model proposed in this study. The PANI/RGO samples have also been investigated by Dielectric Spectroscopy at different temperatures. Results evidence an interesting charge trapping phenomenon occurring at the PANI/RGO interface which might find promising applications in supercapacitors or gate memory devices.
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 Polymer Carbon Nanotube Composites written by Cor Koning and published by CRC Press. This book was released on 2012-04-11 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a comprehensive toolbox for dispersing single-walled and multiwalled carbon nanotubes in thermoplastic polymer matrices. The book starts with an overview of all known techniques for dispersing CNTs in thermoplastic polymers and then concentrates on one of the most versatile techniques known nowadays: the so-called latex technology. Also discussed are the basic principles of this latex technology, the role of the matrix viscosity on percolation threshold, the importance of the intrinsic CNT quality, the use of "smart" surfactants facilitating electron transport in the final composite, the preparation of highly loaded master-batches, which can be diluted with virgin polymer by melt-extrusion, and some promising potential applications.
Download or read book Doping of Carbon Nanotubes written by Sergey Bulyarskiy and published by Springer. This book was released on 2017-07-01 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the control of electronic properties of carbon nanotubes. It presents thermodynamic calculations of the formation of impurities and defects in the interaction of nanotubes with hydrogen, oxygen, nitrogen and boron, based on theoretical models of the formation of defects in carbon nanotubes. It is shown that doping and adsorption lead to changes in the electronic structure of the tubes as well as to the appearance of impurity states in the HOMO-LUMO gap. The book presents examples of specific calculations for doping of carbon nanotubes with oxygen, hydrogen, nitrogen and boron, together with numerous experimental results and a comparison with the author’s thermodynamic calculations. Possible directions of the technological processes of optimization are pointed out, as well as the perspectives of p-n-transition creation with the help of carbon nanotube arrays. The results presented were derived from the physics of the processes and a theoretical model of the technological processes. Though a wealth of empirical information on doping nanotubes has been accumulated in the scientific literature, what is lacking is a theoretical model for their analysis. As such, the book develops a thermodynamic model of the self-organization of structural elements in multicomponent systems – including carbon nanotubes, clusters and precipitates in condensed matter – and subsequently adapts it to the doping of carbon nanotubes. This approach allows readers to gain a far deeper understanding of the processes of doping carbon nanotubes.
Download or read book Thermoelectricity written by D. K. C. MacDonald and published by Courier Corporation. This book was released on 2013-02-21 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This introductory treatment provides an understanding of the fundamental concepts and principles involved in the study of thermoelectricity in solids and of conduction in general. Aimed at graduate-level students and those interested in basic theory, it will be especially valuable to experimental physicists working in fields connected with electron transport and to theoreticians seeking a survey of thermoelectricity and related questions. Chronicling the early history of thermoelectricity from its discovery to modern times, this text features a considerable amount of experimental data and discusses these findings at length wherever they bear a particular relevance to theory. The author, a well-known authority in this field, draws heavily from his own work on thermoelectrical phenomena as they are observed in the study of metals. Numerous illustrative figures appear throughout the text.
Download or read book Manipulation of Carbon Nanoparticles in Composites for Improved Electrical Properties written by Manuel Maria Vilão Cruz Gião Morais and published by Fraunhofer Verlag. This book was released on 2021-01-27 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the electrical properties of epoxy nanocomposites with carbon nanoparticles as conductive filler are investigated for different processing conditions. Compared to a classical shaping process for epoxy materials, the application of electric fields during the curing process is used as an additional process parameter. Electric fields are applied to the nanocomposites during curing, influencing the electrical properties of the final material by inducing polarization and dipole interactions between the conductive particles (dielectrophoresis), leading to a new micro- and nanostructure of the conductive network. This phenomenon is studied for a system of single-wall carbon nanotube and the impact of processing parameters on the electrical response of the system is evaluated. A scalable process based on resin transfer moulding for producing nanocomposites under electric fields is developed. This processing technique presents promising results for enhancing and tailoring the electrical conductivity of polymer nanocomposites.
Download or read book Tailored Semiconducting Carbon Nanotube Networks with Enhanced Thermoelectric Properties written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelectric power generation, allowing recovery of part of the energy wasted as heat, is emerging as an important component of renewable energy and energy efficiency portfolios. Although inorganic semiconductors have traditionally been employed in thermoelectric applications, organic semiconductors garner increasing attention as versatile thermoelectric materials. Here we present a combined theoretical and experimental study suggesting that semiconducting single-walled carbon nanotubes with carefully controlled chirality distribution and carrier density are capable of large thermoelectric power factors, higher than 340 [mu]W m-1 K-2, comparable to the best-performing conducting polymers and larger than previously observed for carbon nanotube films. Furthermore, we demonstrate that phonons are the dominant source of thermal conductivity in the networks, and that our carrier doping process significantly reduces the thermal conductivity relative to undoped networks. As a result, these findings provide the scientific underpinning for improved functional organic thermoelectric composites with carbon nanotube inclusions.
Download or read book Electrical and Thermal Percolation in Carbon Nanotube polymer Composites written by Byung-Wook Kim and published by . This book was released on 2014 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrical and thermal properties of carbon-nanotube (CNT)/polymer composites were investigated through percolating behavior of conducting fillers in insulating matrix. Synthesis methodology has been found using a blend of solution processing, which was adapted to facilitate uniformly distributed CNTs in polymer matrix and consequently to contribute to percolation. The onset of percolation thresholds depending on aspect ratio of fillers were theoretically estimated by the excluded volume method as well as experimentally examined with a power relation of the both electrical and thermal conductivities. Consistent modeling of the both electrical and thermal conductivity anisotropy, in addition to the incorporation of interfacial resistance between connected conducting CNT fillers, was used to understand the underlying transport mechanisms and variations. Furthermore, we report a decrease in the specific heat capacity of the composites at a particular nanotube filler fraction, corresponding to the electrical and thermal conductivity percolation threshold. Extensive calibration and characterization of two different methods were accomplished for the specific heat capacity measurement, and degree of crystallinity through x-ray diffraction implied how degree of disorder would alter depending on arranging nanotubes in the polymer matrix. We explained such change in terms of the entropic configuration determined by number of isolated or connected nanotube fillers. Our investigations could yield better insight into percolation phenomena, of wide importance in the theory of networks, and the optimal conditions of CNT connectivity and dispersion for various applications.
Download or read book PEDOT written by Andreas Elschner and published by CRC Press. This book was released on 2010-11-02 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: While there is information available in handbooks on polythiophene chemistry and physics, until now, few if any books have focused exclusively on the most forwardly developed electrically conductive polymer, Poly (3,4-ethylenedioxythiophene)-otherwise known as PEDOT. This resource provides full chemical, physical, and technical information about this important conducting polymer, discussing basic knowledge and exploring its technical applications. Presented information is based on information generated at universities and through academic research, as well as by industrial scientists, providing a complete picture of the experimental and the practical aspects of this important polymer.
Download or read book Low Dimensional Carbon Based Organic Thermoelectric Composites written by Corey Alan Hewitt and published by . This book was released on 2013 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the most commonly used room temperature thermoelectric material bismuth telluride nearly sixty years ago, the performance of thermoelectrics has seen little improvement. In recent years, slight improvements through the use of complex crystalline structures and nano arrays have renewed interest in thermoelectrics, however, their performance is still orders of magnitude below that required to replace current heat engine power sources. Alternatively, one potential solution is to consider using thermoelectrics in low powered applications where their efficiencies are comparable to those of standard heat engines, and where the use of heat engines is physically impractical. The use of nonorganic crystalline thermoelectrics like bismuth telluride are also somewhat impractical despite their high performance at lower power output levels due to their fragile and rigid physical structure which limits their application. Carbon nanotube based polymer composites possess several properties that make them ideal for use in low powered waste heat recovery applications not suitable to nonorganic crystalline materials. The favorable thermoelectric properties of the carbon nanotubes with moderate Seebeck coefficients and potentially large electrical conductivities result in modest power factors, while the low thermal conductivity of the polymer host aids in maintaining a temperature gradient across the composite, thus improving the figure of merit. Although the thermoelectric performance of these composites is lower than that of standard crystalline thermoelectrics, their light weight and flexible physical structure makes them more ideal for use in personal and portable electronics that utilize waste heat to maintain a temperature gradient. In order to effectively utilize a thermoelectric material in a practical application, they must be combined in a device structure consisting of alternating p-type and n-type elements that are connected electrically in series and thermally in parallel. Here, we introduce a novel device architecture suited to using the thin film carbon nanotube based polymer composites. The device performance is then dictated by the intrinsic thermoelectric properties of the individual layers composing the device. Therefore, the majority of the work presented here focuses on understanding the thermoelectric properties of the individual layers. Effects on these properties are quantified including the chemical vapor deposition growth temperature, sonication, acid reflux treatment, temperature, n-type doping through the use of polyethylenimine, and composite composition including carbon nanotube, polymer, and solvent type and concentrations. By quantifying these effects, the thermoelectric performance of the individual layers can be optimized in order to increase the total power output of the device. Ultimately however, the total power output is limited by the specific application; therefore, power output measurements are performed versus several application parameters including the temperature difference, load resistance, dimensions of the device, and the number of repeatable thermocouple elements contained within the device. Finally, the power output of an interconnected device array is measured to exemplify the potential performance of an application appropriate design.
Download or read book Carbon Nanotubes for Polymer Reinforcement written by Peng-Cheng Ma and published by CRC Press. This book was released on 2011-03-22 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discovered in the twentieth century, carbon nanotubes (CNT) were an integral part of science and industry by the beginning of the twenty first century, revolutionizing chemistry, physics, and materials science. More recent advances in carbon nanotube production methods have resulted in a tremendous push to incorporate CNTs into polymer matrices. Although many advances have been made, two major obstacles continue unresolved: the enhancement of interfacial adhesion between CNTs and polymer matrix, and the improvement of dispersion of CNTs in polymers. Both substantial original contributors to the field, the authors present Carbon Nanotubes for Polymer Reinforcement, the first monograph on various conventional and innovative techniques to disperse and functionalize carbon nanotubes for polymer reinforcement, elegantly explaining the basic sciences and technologies involved in those processes. Topics covered include: Use of CNTs in fabricating novel polymer composites Principles and mechanisms behind CNT dispersion and functionalization Methods for the functionalization and dispersion of CNTs in polymer matrices Effects of CNTs on functional and mechanical properties of polymer composites Optimization of CNT/polymer nanocomposite fabrication Carbon Nanotubes for Polymer Reinforcement is a comprehensive treatment and critical review of the new class of polymer nanocomposites, and points to areas of future developments. Composites engineers, scientists, researchers, and students will find the basic knowledge and technical results contained herein informative and useful references for their work, whether for advanced research or for design and manufacture of such composites.
