Download or read book Molecular Dynamics Simulations of Dodecanethiol Coated Gold Nanoparticles on Organic Liquid Toluene written by Nitun Nirjhar Poddar and published by . This book was released on 2013 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal gold nanoparticles may be used in a variety of applications ranging from solar cells to sensors to catalysis and drug delivery. In particular, ordered gold nanoparticle thin-films have been proposed as efficient coupling layers which may be used to maximize the efficiency of photovoltaic solar cells. In addition, recently a drop-drying method to self-assemble a well-ordered monolayer of Au nanoparticles has been developed. In this method, a monodisperse solution of gold nanoparticles whose size has been selected via chemical synthesis, and which are coated with organic ligands to prevent aggregation and precipitation is used. Using this method a monolayer of Au nanoparticles can be made that covers the full area of a 2" silicon wafer. However, the interaction between the gold nanoparticles and the interface, which plays a key role in determining the film-quality, is not well understood. One of the main objectives of the work presented in this thesis is to obtain a better fundamental understanding of the structure and interactions of ligand-coated Au nanoparticles at a solvent-vapor interface. In particular, motivated by experimental and simulation results, we have carried out extensive molecular dynamics simulations of dodecanethiol (DDT)-coated Au nanoparticles in both bulk toluene and at the toluene-vapor interface. Our simulations were carried out using the public domain software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) along with the OPLS (Optimized Potential for Liquid Simulation) force field which is a force-field which has been specifically developed for simulating organic liquids. Our simulations indicate that, in contrast to previous simulations of decanethiol and octadecanethiol coated Au nanoparticles in water, the dodecanethiol-coated nanoparticle (NP) sits relatively low in the toluene, such that the Au core never penetrates above the interface, while the thiols only partially stick out above the interface. Somewhat surprisingly, we also found that the nanoparticle is not spherical at the interface, but instead the nanoparticle width is larger than the nanoparticle height. Both of these results may be explained by the fact that the nanoparticle ligands are attracted to toluene. Due to this attraction, the ligands above the NP core, which stick out above the interface, are more compressed than those on the side or bottom which extend into liquid toluene. These results also indicate that the nanoparticle rolling mechanism, which has been observed in other experiments and which may greatly enhance the diffusivity of Au nanoparticles during the island self-assembly process, does not apply in this case. In addition to determining the nanoparticle position and shape at the interface, we have also determined the interfacial adsorption energy for a nanoparticle at the interface. The resulting relatively large value for the binding energy was found to be consistent with experimental results for nanoparticle island-growth with high excess thiol concentration, for which a diffusion length (corresponding to the distance a nanoparticle can diffuse before leaving the interface and returning to solution due to thermal fluctuations) much larger than the inter-island spacing was observed. By comparing the radial toluene density near the nanoparticle at the interface with that near the nanoparticle in bulk, and also taking into account the particle position with respect to the interface, the van der Waals corrections to the binding energy were also calculated. Since diffusion plays an important role in in drop-drying, we have also calculated the diffusion coefficient for DDT-coated Au NP at the toluene-vapor interface. Somewhat surprisingly, we find that - perhaps due to the fact that the nanoparticle is almost fully submerged - the two-dimensional diffusion coefficient at the toluene-vapor interface is in good agreement with the Stokes-Einstein prediction for 3D bulk diffusion.

Download or read book Molecular Dynamics Study of Alkanethiolate Self Assembled Monolayer Coated Gold Nanoparticle written by and published by . This book was released on 2007 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through molecular simulations we have observed that the surface of gold nanoparticles become highly corrugated by the adsorption of alkanethiolate self assembled monolayers (SAMs). Furthermore, as the temperature is increased, the SAMs dissolve into the gold nanoparticle, creating a liquid mixture at temperatures much lower than the melting temperature of the gold nanoparticle. By analyzing the mechanical and chemical properties of gold nanoparticles at temperatures below the melting point of gold, with different SAM chain lengths and surface coverage properties, we have determined that the system is metastable. The model and computational results that provide support for this hypothesis are presented in this paper.

Download or read book Understanding Shape Control in Gold Nanoparticles from Molecular Dynamics Simulations written by Santosh Kumar Meena and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frontiers of Multifunctional Nanosystems written by Eugenia V. Buzaneva and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Research Workshop on Frontiers in Molecular-Scale Science and Technology of Fullerence, Nanotube, Nanosilicon, Biopolymer (DNA, Protein) Multifunctional Nanosystems, Kyiv, Ukraine, 9-12 September 2001

Download or read book Molecular Simulations of Gold Nanoparticles Coated With Self Assembled Alkanethiolate Monolayers written by and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to utilize the novel electrical, magnetic, optical, and physical properties of coated metal nanoparticles, one must be able to efficiently predict the nanoparticle size-dependent properties and to fabricate consistently sized nanoparticles. Both of these goals can be obtained through the use of numerical simulation. In this work the gold nanoparticle and nanoparticle/self-assembled monolayer systems have been analyzed with a physically accurate and computationally efficient numerical simulation. The simulation model and method are described in the following paper.

Download or read book Brownian Dynamics Study of the Self assembly of Ligated Gold Nanoparticles and Other Colloidal Systems written by Siddique J. Khan and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We carry out Brownian Dynamics Simulations to study the self-assembly of ligated gold nanoparticles for various ligand chain lengths. First, we develop a phenomenological model for an effective nanoparticle-nanoparticle pair potential by treating the ligands as flexible polymer chains. Besides van der Waals interactions, we incorporate both the free energy of mixing and elastic contributions from compression of the ligands in our effective pair potentials. The separation of the nanoparticles at the potential minimum compares well with experimental results of gold nanoparticle superlattice constants for various ligand lengths. Next, we use the calculated pair potentials as input to Brownian dynamics simulations for studying the formation of nanoparticle assembly in three dimensions. For dodecanethiol ligated nanoparticles in toluene, our model gives a relatively shallower well depth and the clusters formed after a temperature quench are compact in morphology. Simulation results for the kinetics of cluster growth in this case are compared with phase separations in binary mixtures. For decanethiol ligated nanoparticles, the model well depth is found to be deeper, and simulations show hybrid, fractal-like morphology for the clusters. Cluster morphology in this case shows a compact structure at short length scales and a fractal structure at large length scales. Growth kinetics for this deeper potential depth is compared with the diffusion-limited cluster-cluster aggregation (DLCA) model. We also did simulation studies of nanoparticle supercluster (NPSC) nucleation from a temperature quenched system. Induction periods are observed with times that yield a reasonable supercluster interfacial tension via classical nucleation theory (CNT). However, only the largest pre-nucleating clusters are dense and the cluster size can occasionally range greater than the critical size in the pre-nucleation regime until a cluster with low enough energy occurs, then nucleation ensues. Late in the nucleation process the clusters display a crystalline structure that is a random mix of fcc and hcp lattices and indistinguishable from a randomized icosahedra structure. Next, we present results from detailed three-dimensional Brownian dynamics simulations of the self-assembly process in quenched short-range attractive colloids. Clusters obtained in the simulations range from dense faceted crystals to fractal aggregates which show ramified morphology on large length scales but close-packed crystalline morphology on short length scales. For low volume fractions of the colloids, the morphology and crystal structure of a nucleating cluster are studied at various times after the quench. As the volume fraction of the colloids is increased, growth of clusters is controlled by cluster diffusion and cluster-cluster interactions. For shallower quenches and low volume fractions, clusters are compact and the growth-law exponent agrees well with BinderStauffer predictions and with recent experimental results. As the volume fraction is increased, clusters do not completely coalesce when they meet each other and the kinetics crosses over to diffusion-limited cluster-cluster aggregation (DLCA) limit. For deeper quenches, clusters are fractals even at low volume fractions and the growth kinetics asymptotically reaches the irreversible DLCA case.

Download or read book Nanotechnology in Catalysis 3 written by Bing Zhou and published by Springer Science & Business Media. This book was released on 2007-09-05 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume continues the tradition formed in Nanotechnology in Catalysis 1 and 2. As with those books, this one is based upon an ACS symposium. Some of the most illustrious names in heterogeneous catalysis are among the contributors. The book covers: Design, synthesis, and control of catalysts at nanoscale; understanding of catalytic reaction at nanometer scale; characterization of nanomaterials as catalysts; nanoparticle metal or metal oxides catalysts; nanomaterials as catalyst supports; new catalytic applications of nanomaterials.

Download or read book Nanoelectronic Materials written by Loutfy H. Madkour and published by Springer. This book was released on 2019-06-27 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents synthesis techniques for the preparation of low-dimensional nanomaterials including 0D (quantum dots), 1D (nanowires, nanotubes) and 2D (thin films, few layers), as well as their potential applications in nanoelectronic systems. It focuses on the size effects involved in the transition from bulk materials to nanomaterials; the electronic properties of nanoscale devices; and different classes of nanomaterials from microelectronics to nanoelectronics, to molecular electronics. Furthermore, it demonstrates the structural stability, physical, chemical, magnetic, optical, electrical, thermal, electronic and mechanical properties of the nanomaterials. Subsequent chapters address their characterization, fabrication techniques from lab-scale to mass production, and functionality. In turn, the book considers the environmental impact of nanotechnology and novel applications in the mechanical industries, energy harvesting, clean energy, manufacturing materials, electronics, transistors, health and medical therapy. In closing, it addresses the combination of biological systems with nanoelectronics and highlights examples of nanoelectronic–cell interfaces and other advanced medical applications. The book answers the following questions: • What is different at the nanoscale? • What is new about nanoscience? • What are nanomaterials (NMs)? • What are the fundamental issues in nanomaterials? • Where are nanomaterials found? • What nanomaterials exist in nature? • What is the importance of NMs in our lives? • Why so much interest in nanomaterials? • What is at nanoscale in nanomaterials? • What is graphene? • Are pure low-dimensional systems interesting and worth pursuing? • Are nanotechnology products currently available? • What are sensors? • How can Artificial Intelligence (AI) and nanotechnology work together? • What are the recent advances in nanoelectronic materials? • What are the latest applications of NMs?

Download or read book Experimental Relations of Gold and Other Metals to Light written by Michael Faraday and published by . This book was released on 1857 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Molecule Metal Interface written by Norbert Koch and published by John Wiley & Sons. This book was released on 2013-02-08 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviewing recent progress in the fundamental understanding of the molecule-metal interface, this useful addition to the literature focuses on experimental studies and introduces the latest analytical techniques as applied to this interface. The first part covers basic theory and initial principle studies, while the second part introduces readers to photoemission, STM, and synchrotron techniques to examine the atomic structure of the interfaces. The third part presents photoelectron spectroscopy, high-resolution UV photoelectron spectroscopy and electron spin resonance to study the electronic structure of the molecule-metal interface. In the closing chapter the editors discuss future perspectives. Written as a senior graduate or senior undergraduate textbook for students in physics, chemistry, materials science or engineering, the book's interdisciplinary approach makes it equally relevant for researchers working in the field of organic and molecular electronics.

Download or read book Metal Nanoparticles in Microbiology written by Mahendra Rai and published by Springer Science & Business Media. This book was released on 2011-04-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following an introduction to biogenic metal nanoparticles, this book presents how they can be biosynthesized using bacteria, fungi and yeast, as well as their potential applications in biomedicine. It is shown that the synthesis of nanoparticles using microbes is eco-friendly and results in reproducible metal nanoparticles of well-defined sizes, shapes and structures. This biotechnological approach based on the process of biomineralization exploits the effectiveness and flexibility of biological systems. Chapters include practical protocols for microbial synthesis of nanoparticles and microbial screening methods for isolating a specific nanoparticle producer as well as reviews on process optimization, industrial scale production, biomolecule-nanoparticle interactions, magnetosomes, silver nanoparticles and their numerous applications in medicine, and the application of gold nanoparticles in developing sensitive biosensors.

Download or read book Nanomaterials and Their Applications written by Zishan Husain Khan and published by Springer. This book was released on 2017-10-20 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the latest advances in the field of nanomaterials and their applications, and provides a comprehensive overview of the state-of-the-art of research in this rapidly developing field. The book comprises chapters exploring various aspects of nanomaterials. Given the depth and breadth of coverage, the book offers a valuable guide for researchers and students working in the area of nanomaterials.

Download or read book Reversed Micelles written by Willie L. Hinze and published by JAI Press(NY). This book was released on 1994 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combinatorial Methods for Chemical and Biological Sensors written by Radislav A. Potyrailo and published by Springer Science & Business Media. This book was released on 2009-03-21 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical sensors are in high demand for applications as varied as water pollution detection, medical diagnostics, and battlefield air analysis. Designing the next generation of sensors requires an interdisciplinary approach. The book provides a critical analysis of new opportunities in sensor materials research that have been opened up with the use of combinatorial and high-throughput technologies, with emphasis on experimental techniques. For a view of component selection with a more computational perspective, readers may refer to the complementary volume of Integrated Analytical Systems edited by M. Ryan et al., entitled “Computational Methods for Sensor Material Selection”.

Download or read book Inorganic Nanoparticles written by Claudia Altavilla and published by CRC Press. This book was released on 2017-12-19 with total page 885 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the various nanomaterials, inorganic nanoparticles are extremely important in modern technologies. They can be easily and cheaply synthesized and mass produced, and for this reason, they can also be more readily integrated into applications. Inorganic Nanoparticles: Synthesis, Applications, and Perspectives presents an overview of these special materials and explores the myriad ways in which they are used. It addresses a wide range of topics, including: Application of nanoparticles in magnetic storage media Use of metal and oxide nanoparticles to improve performance of oxide thin films as conducting media in commercial gas and vapor sensors Advances in semiconductors for light-emitting devices and other areas related to the energy sector, such as solar energy and energy storage devices (fuel cells, rechargeable batteries, etc.) The expanding role of nanosized particles in the field of catalysis, art conservation, and biomedicine The book’s contributors address the growing global interest in the application of inorganic nanoparticles in various technological sectors. Discussing advances in materials, device fabrication, and large-scale production—all of which are urgently required to reduce global energy demands—they cover innovations in areas such as solid-state lighting, detailing how it still offers higher efficiency but higher costs, compared to conventional lighting. They also address the impact of nanotechnology in the biomedical field, focusing on topics such as quantum dots for bioimaging, nanoparticle-based cancer therapy, drug delivery, antibacterial agents, and more. Fills the informational gap on the wide range of applications for inorganic nanoparticles in areas including biomedicine, electronics, storage media, conservation of cultural heritage, optics, textiles, and cosmetics Assembling work from an array of experts at the top of their respective fields, this book delivers a useful analysis of the vast scope of existing and potential applications for inorganic nanoparticles. Versatile as either a professional research resource or textbook, this effective tool elucidates fundamentals and current advances associated with design, characterization, and application development of this promising and ever-evolving device.

Download or read book Nanoparticulate Materials written by Kathy Lu and published by John Wiley & Sons. This book was released on 2012-09-25 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Serving as the only systematic and comprehensive treatment on the topic of nanoparticle-based materials, this book covers synthesis, characterization, assembly, shaping and sintering of all types of nanoparticles including metals, ceramics, and semiconductors. A single-authored work, it is suitable as a graduate-level text in nanomaterials courses.

Download or read book Metal Nanoclusters in Catalysis and Materials Science The Issue of Size Control written by Benedetto Corain and published by Elsevier. This book was released on 2011-08-11 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Nanoclusters in Catalysis and Materials Science: The Issue of Size Control deals with the synthesis of metal nanoclusters along all known methodologies. Physical and chemical properties of metal nanoclusters relevant to their applications in chemical processing and materials science are covered thoroughly. Special attention is given to the role of metal nanoclusters size and shape in catalytic processes and catalytic applications relevant to industrial chemical processing.An excellent text for expanding the knowledge on the chemistry and physics of metal nanoclusters. Divided in two parts; Part I deals with general aspects of the matter and Part II has to be considered a useful handbook dealing with the production of metal nanoclusters, especially from their size-control point of view.* Divided into two parts for ease of reference: general and operational * Separation of synthetic aspects, physical properties and applications* Specific attention is given to the task of metal nanoclusters size-control