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 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 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 Aqueous Phase Adsorption written by Jayant K Singh and published by CRC Press. This book was released on 2018-10-25 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers theoretical aspects of adsorption, followed by an introduction to molecular simulations and other numerical techniques that have become extremely useful as an engineering tool in recent times to understand the interplay of different mechanistic steps of adsorption. Further, the book provides brief experimental methodologies to use, test, and evaluate different types of adsorbents for water pollutants. Through different chapters contributed by accomplished researchers working in the broad area of adsorption, this book provides the necessary fundamental background required for an academician, industrial scientist or engineer to initiate studies in this area. Key Features Explores fundamentals of adsorption-based separation Provides physical insight into aqueous phase adsorption Includes theory, molecular and mesoscopic level simulation techniques and experiments Describes molecular simulations and lattice-Boltzmann method based models for aqueous phase adsorption Presents state-of-art experimental works particularly addressing removal of "emerging pollutants" from aqueous phase
Download or read book Handbook of Nanophysics written by Klaus D. Sattler and published by CRC Press. This book was released on 2010-09-17 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Nanophysics: Functional Nanomaterials illustrates the importance of tailoring nanomaterials to achieve desired functions in applications. Each peer-reviewed chapter contains a broad-based introduction and enhances understanding of the state-of-the-art scientific content through fundamental equations and illustrations, some in color.This
Download or read book Self assembled Monolayers of Thiols written by Abraham Ulman and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work looks at thin films and self-assembled monolayers of thiols. It is aimed at researchers in chemistry, materials science, electrical engineering, biology and condensed matter physics.
Download or read book Nanoscale Materials written by Luis M. Liz-Marzán and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organized nanoassemblies of inorganic nanoparticles and organic molecules are building blocks of nanodevices, whether they are designed to perform molecular level computing, sense the environment or improve the catalytic properties of a material. The key to creation of these hybrid nanostructures lies in understanding the chemistry at a fundamental level. This book serves as a reference book for researchers by providing fundamental understanding of many nanoscopic materials.
Download or read book Control of the Self assembly of Alkanethiol coated Gold Nanoparticles in the Solid State written by Vladimir S. Tarasov and published by . This book was released on 2008 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the behavior of nanoparticles in the presence of solvent vapors is presented. Millimeter-scale films of gold nanoparticles, one nanometer thick, are treated with solvent vapors at various temperatures and the behavior of the nanoparticles is tracked over time using transmission electron microscopy. The ultimate goal of this processing is to repair defects such as grains, dislocations, and vacancies in the original superlattice. Additionally, Langmuir-Schaeffer films of gold nanoparticles on water surfaces are subjected to thermal and ultrasonic treatment in an attempt to correct defects in the films, which are then transferred to solid substrates for observation. Unfortunately, none of these approaches is able to reduce the defect concentration in a lattice, although thermal treatment and sonication of Langmuir-Schaeffer nanoparticle films are found to provide a controllable approach to depositing exact double layers of nanoparticles.
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 The Formation Structural Dynamics and Surface Properties of Thiol gold Self Assembled Monolayers written by David Stephen Karpovich and published by . This book was released on 1996 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Establishing the Quality of Molecular Coatings on Gold Nanoparticles written by Idah C. Pekcevik and published by . This book was released on 2014 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surface chemistry of nanoparticles imparts colloidal stability to nanoparticles by acting as barriers between their surrounding environment and the nanoparticles. Gold nanoparticles (AuNPs) are an ideal platform for many studies because of localized surface plasmon resonant properties, chemical stability, and the relative ease of modifying their surfaces with a wide variety of molecular coatings (e.g., alkanethiolates). Understanding and improving the physicochemical stability of these surface-modified nanoparticles is essential for their reproducible use in each application. The long-term colloidal stability of AuNPs relies on the resistance of their surface modifications to thermal degradation, chemical attack and oxidizing conditions. For this purpose, my research has been focused on determining the quality of molecular coatings on gold nanoparticles, and developing techniques, which are complementary to each other, to assess the quality factor of these coatings. Gold nanoparticles with varied qualities of molecular coatings were prepared and tested for their relative stabilities under various physical (e.g., temperature, time, laser irradiation) and chemical (e.g., in presence of metal etchants) conditions. We found that the quality of molecular coatings on AuNPs depends on the process conditions such as solution composition (e.g., the presence of co-surfactants, concentration of excess surfactants), density of capping molecules, and process time, used to form these coatings. We found that higher quality molecular coatings on the gold colloids increased the chances that the particles would remain stable over the over the duration of their intended use. Those colloids modified with relatively higher quality self-assembled monolayers were also more resistant to cyanide etching. These results highlight the importance of methodology for preparing high quality monolayers on nanoparticles and testing their ability to remain stable over the duration of their intended use, for example, during photothermal processes. In addition, the loading of DNA molecules onto AuNPs was tuned to achieve varying densities of DNA, and through this work, achieved the highest reported loading of single-stranded DNA (ss-DNA) molecules on gold nanorods. These high loadings of DNA oligonucleotides could enable a high loading of therapeutics onto the nanorods, which could translate into a higher or more prolonged delivery of therapeutic doses when actived by photothermal or other processes.
Download or read book DFT Study of Alkanethiol Self assembled Monolayers on Gold 111 Surfaces written by Edmanuel Torres and published by . This book was released on 2009 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Complex Magnetic Nanostructures written by Surender Kumar Sharma and published by Springer. This book was released on 2017-04-04 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a detailed discussion of the complex magnetic behavior of magnetic nanosystems, with its myriad of geometries (e.g. core-shell, heterodimer and dumbbell) and its different applications. It provides a broad overview of the numerous current studies concerned with magnetic nanoparticles, presenting key examples and an in-depth examination of the cutting-edge developments in this field. This contributed volume shares the latest developments in nanomagnetism with a wide audience: from upper undergraduate and graduate students to advanced specialists in both academia and industry. The first three chapters serve as a primer to the more advanced content found later in the book, making it an ideal introductory text for researchers starting in this field. It provides a forum for the critical evaluation of many aspects of complex nanomagnetism that are at the forefront of nanoscience today. It also presents highlights from the extensive literature on the topic, including the latest research in this field.
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 Thermal and Rheological Measurement Techniques for Nanomaterials Characterization written by Sabu Thomas and published by Elsevier. This book was released on 2017-05-23 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal and Rheological Measurement Techniques for Nanomaterials Characterization, Second Edition covers thermal and rheological measurement techniques, including their principle working methods, sample preparation and interpretation of results. This important reference is an ideal source for materials scientists and industrial engineers who are working with nanomaterials and need to know how to determine their properties and behaviors. - Outlines key characterization techniques to determine the thermal and rheological behavior of different nanomaterials - Explains how the thermal and rheological behavior of nanomaterials affect their usage - Provides a method-orientated approach that explains how to successfully use each technique
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 Chemically Modified Electrodes written by and published by John Wiley & Sons. This book was released on 2009-07-10 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from an international group of expert authors, this book includes the latest trends in tailoring interfacial properties electrochemically. The chapters cover various organic and inorganic compounds, with applications ranging from electrochemistry to nanotechnology and biology. Of interest to physical, surface and electrochemists, materials scientists and physicists.
