Download or read book Metal Nanoparticle Synthesis by Photochemical Reduction with a High intensity Focused Laser Beam written by Victoria Kathryn Meader and published by . This book was released on 2019 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal, metallic nanoparticles have myriad applications, but they are most ideal when they are monodisperse, and demonstrate maximum catalytic utility when they are small (

Download or read book SIZE CONTROLLED SYNTHESIS OF TRANSITION METAL NANOPARTICLES THROUGH CHEMICAL AND PHOTO CHEMICAL ROUTES written by Behzad Tangeysh and published by . This book was released on 2015 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central objective of this work is developing convenient general procedures for controlling the formation and stabilization of nanoscale transition metal particles. Contemporary interest in developing alternative synthetic approaches for producing nanoparticles arises in large part from expanding applications of the nanomaterials in areas such as catalysis, electronics and medicine. This research focuses on advancing the existing nanoparticle synthetic routes by using a new class of polymer colloid materials as a chemical approach, and the laser irradiation of metal salt solution as a photo-chemical method to attain size and shape selectivity. Controlled synthesis of small metal nanoparticles with sizes ranging from 1 to 5nm is still a continuing challenge in nanomaterial synthesis. This research utilizes a new class of polymer colloid materials as nano-reactors and protective agents for controlling the formation of small transition metal nanoparticles. The polymer colloid particles were formed from cross-linking of dinegatively charged metal precursors with partially protonated poly dimethylaminoethylmethacrylate (PDMAEMA). Incorporation of [PtCl6]2- species into the colloidal particles prior to the chemical reduction was effectively employed as a new strategy for synthesis of unusually small platinum nanoparticles with narrow size distributions (1.12 ± 0.25nm). To explore the generality of this approach, in a series of proof-of-concept studies, this method was successfully employed for the synthesis of small palladium (1.4 ±0.2nm) and copper nanoparticles (1.5 ±0.6nm). The polymer colloid materials developed in this research are pH responsive, and are designed to self-assemble and/or disassemble by varying the levels of protonation of the polymer chains. This unique feature was used to tune the size of palladium nanoparticles in a small range from 1nm to 5nm. The procedure presented in this work is a new convenient room temperature route for synthesis of small nanoparticles, and its application can be extended to the formation of other transition metals and alloy nanoparticles. This research also focuses on developing new photo-chemical routes for controlling the size and shape of the nanoparticles through high-intensity ultra-fast laser irradiation of metal salt solution. One of the core objectives of this work is to explore the special capabilities of shaped laser pulses in formation of metal nanoparticles through irradiation of the solutions by using simultaneous spatial and temporal focusing (SSTF). Femtosecond laser irradiation has not yet been widely applied for nanoparticle synthesis, and offers new regimes of energy deposition for synthesis of nanomaterials. Photo-reduction of aqueous [AuCl4]- solution to the gold nanoparticles (AuNPs) has been applied as a model process for optimizing the experimental procedures, and evaluating the potential of shaped laser pulses in the synthesis of AuNPs. Systematic manipulation of the laser parameters and experimental conditions provided effective strategies to control the size of Au nanoparticles in strong laser fields. Varying the concentration of polyethylene glycol (PEG45) as a surfactant effectively tuned the size of AuNPs from 3.9 ±0.7nm to 11.0 ±2.4nm, and significantly increased the rate of Au(III) reduction during irradiation. Comparative studies revealed the capability of shaped laser pulses in the generation of smaller and more uniform AuNPs (5.8 ±1.1nm) relative to the other conventional laser irradiation methods (7.2 ±2.9nm). Furthermore, a new laser-assisted approach has been developed for selective formation of triangular Au nanoplates in the absence of any surfactant molecule. This method relies on rapid energy deposition by using shaped, ultra-intense laser pulses to generate Au seeds in aqueous [AuCl4]- solution, and the slow post-irradiation reduction of un-reacted [AuCl4]- species by using H2O2 as a mild reducing agent. Variation of the laser irradiation-time was found as an effective strategy to tune the morphology of Au nanomaterials from nanospheres to triangular nanoplates. The surfactant-free Au nanoplates produced in this research can be readily functionalized with a variety of target molecules or surfactants for desirable applications such as biomedicine. The concept of rapid laser processing followed by in situ chemical reduction can be expanded as a general methodology for high-yield production of nanomaterials, and provides a series of new laser dependent parameters for controlling the nanoparticle formation.

Download or read book Laser Ablation in Liquids written by Guowei Yang and published by CRC Press. This book was released on 2012-02-22 with total page 1166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the fundamental concepts and physical and chemical aspects of pulsed laser ablation of solid targets in liquid environments and its applications in the preparation of nanomaterials and fabrication of nanostructures. The areas of focus include basic thermodynamic and kinetic processes of laser ablation in liquids, and its applic

Download or read book Metal oxide Nanostructures Fabricated from Reactive Laser Ablation in Liquid written by Mallory G. John and published by . This book was released on 2020 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of metal-oxide nanostructures is a growing area due to their applications in diverse fields spanning energy conversion and storage, chemical manufacturing, and en- vironmental technology. This interest in catalytically active nanomaterials has prompted the synthesis and investigation of highly functionalized nanoparticles (NPs), including core- shell, silicate-stabilized, and bi- and multi-metallic nanocomposites. While wet-chemical synthesis methods of metal-oxide nanostructures have led to several morphologies, compositions, and shapes, these syntheses often require high temperatures, toxic solvents or reducing agents, and long reaction times. Laser synthesis and processing of colloids (LSPC) encompasses both 'top down' and 'bottom up' approaches to synthesize metal-oxide nanostructures. Pulsed laser ablation in liquid (PLAL) involves focusing laser pulses onto a solid target immersed in a liquid in which target atoms coalesce to form nanostructured materials once ejected into solution. Laser reduction in liquid (LRL) is a second laser-assisted approach to synthesizing nanomaterials, where photochemical reduction of metal salts is achieved by focusing the laser beam into solution. Both PLAL and LRL are able to generate metal and semiconductor NPs at room temperature in aqueous solutions without added surfactants or stabilizers, giving them an advantage over conventional wet-chemical methods. Recently, these two approaches have been combined into a single step- referred to as reactive laser ablation in liquid (RLAL), in which laser ablation of a solid target is carried out in a metal salt solution. This work goes through the synthesis and characterization of femtosecond-RLAL (fs-RLAL)-generated silica-metal nanostructures, and discusses the relationship between the precursor solution composition, the product morphology, and the catalytic activity toward a model para-nitrophenol (PNP) reduction reaction. First, silica-Au NPs were synthesized, exhibiting two populations of product nanoparticles which resulted from reaction dynamics occurring on two distinct timescales. Next, silica-Cu NPs were synthesized under different pH conditions, yielding pH-dependent product morphology. The different morphologies resulted from the surface charge of ablated silica species, which repelled the Cu2 ions in solution at low pH yielding core/shell morphology, and attracted the Cu2+ ions at high pH, forming well-dispersed

Download or read book Au Nanoparticle Synthesis Via Femtosecond Laser Induced Photochemical Reduction of AuCl4 written by Mallory G. John and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-assisted metallic nanoparticle synthesis is a versatile "green" method that has become a topic of active research. This chapter discusses the photochemical reaction mechanisms driving AuCl4− reduction using femtosecond-laser irradiation, and reviews recent advances in Au nanoparticle size-control. We begin by describing the physical processes underlying the interactions between laser pulses and the condensed media, including optical breakdown and supercontinuum emission. These processes produce a highly reactive plasma containing free electrons, which reduce AuCl4−, and radical species producing H2O2 that cause autocatalytic growth of Au nanoparticles. Then, we discuss the reduction kinetics of AuCl4−, which follow an autocatalytic rate law in which the first- and second-order rate constants depend on free electrons and H2O2 availability. Finally, we explain strategies to control the size of gold nanoparticles as they are synthesized; including modifications of laser parameters and solution compositions.

Download or read book Metal Nanoparticles for Drug Delivery and Diagnostic Applications written by Muhammad Raza Shah and published by Elsevier. This book was released on 2019-11-05 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Nanoparticles for Drug Delivery and Diagnostic Applications addresses the lifecycle of metal nanoparticles, from synthesis and characterization, to applications in drug delivery and targeting. It is an important resource for those in biomaterials, nanomedicine and pharmaceutical sciences, exploring gold, silver and iron-based drug delivery systems for controlled and targeted delivery of potential drugs and genes for enhanced clinical efficacy. Nanotechnology is widely used in drug delivery due to its ability to reduce plasma fluctuation of drugs, high solubility, and efficiency, the relatively low cost of nanoscale products, and enhancement of patient comfort, hence this resource is a welcome edition to the science. Illustrates the progression of nanoparticle therapeutics from basic research to applications Explores new opportunities and ideas for developing and improving technologies in nanomedicine and nanobiology Discusses the toxicity of different types of metal nanoparticles and how to ensure their safe use

Download or read book Synthesis of Uncapped Noble Metal Nanoparticles by Laser Reduction in Liquid written by Katharine Tibbetts and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncapped, or u201cnakedu201d metal nanoparticles have pure metal/oxide surfaces that are amenable to subsequent conjugation with biocompatible ligands and provide active surface sites for catalysis. This presentation will highlight my groupu2019s recent work on the synthesis of uncapped u201cnakedu201d Au, Pd, and Ag nanoparticles by femtosecond laser-induced reduction of salt precursors in aqueous solution. Focusing femtosecond laser pulses into a condensed medium produces a dense plasma containing electrons and radicals that can reduce metal ions to neutral metal atoms, which coalesce into nanoparticles. For Au, Pd, and Ag salts, distinct reduction mechanisms operate that depend on one or more of the following reactive species: hydrated electrons, hydroxyl radicals, hydrogen peroxide, and hydrogen molecules. Following a discussion of these mechanisms, I will present chemical strategies for controlling the plasma composition by changing the solution pH and adding radical scavengers. Each metal requires distinct solution chemistry to effectively manipulate the nanoparticle sizes and morphologies. For instance, adding hydroxyl radical scavengers during reduction of KAuCl4 enables control over Au nanoparticle size distributions, while the choice of Pd salt determines the morphologies of Pd nanoparticles.

Download or read book Photochemical Strategies for the Synthesis of Gold Nanoparticles written by Katherine McGilvray and published by . This book was released on 2010 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Laser Ablation written by Dongfang Yang and published by BoD – Books on Demand. This book was released on 2016-12-21 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser ablation refers to the phenomenon in which a low wavelength and short pulse (ns-fs) duration of laser beam irradiates the surface of a target to induce instant local vaporization of the target material generating a plasma plume consisting of photons, electrons, ions, atoms, molecules, clusters, and liquid or solid particles. This book covers various aspects of using laser ablation phenomenon for material processing including laser ablation applied for the deposition of thin films, for the synthesis of nanomaterials, and for the chemical compositional analysis and surface modification of materials. Through the 18 chapters written by experts from international scientific community, the reader will have access to the most recent research and development findings on laser ablation through original research studies and literature reviews.

Download or read book Synthesis of Inorganic Nanomaterials written by Sneha Bhagyaraj and published by Woodhead Publishing. This book was released on 2018-06-29 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis of Inorganic Nanomaterials: Advances and Key Technologies discusses the latest advancements in the synthesis of various types of nanomaterials. The book's main objective is to provide a comprehensive review regarding the latest advances in synthesis protocols that includes up-to-date data records on the synthesis of all kinds of inorganic nanostructures using various physical and chemical methods. The synthesis of all important nanomaterials, such as carbon nanostructures, Core-shell Quantum dots, Metal and metal oxide nanostructures, Nanoferrites, polymer nanostructures, nanofibers, and smart nanomaterials are discussed, making this a one-stop reference resource on research accomplishments in this area. Leading researchers from industry, academia, government and private research institutions across the globe have contributed to the book. Academics, researchers, scientists, engineers and students working in the field of polymer nanocomposites will benefit from its solutions for material problems. Provides an up-to-date data record on the synthesis of all kinds of organic and inorganic nanostructures using various physical and chemical methods Presents the latest advances in synthesis protocols Includes the latest techniques used in the physical and chemical characterization of nanomaterials Covers the characterization of all the important materials groups, such as carbon nanostructures, core-shell quantum dots, metal and metal oxide nanostructures, Nano ferrites, polymer nanostructures and nanofibers

Download or read book Metal Nanoparticles written by Daniel L. Fedlheim and published by CRC Press. This book was released on 2001-10-26 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: A state-of-the-art reference, Metal Nanoparticles offers the latest research on the synthesis, characterization, and applications of nanoparticles. Following an introduction of structural, optical, electronic, and electrochemical properties of nanoparticles, the book elaborates on nanoclusters, hyper-Raleigh scattering, nanoarrays, and several applications including single electron devices, chemical sensors, biomolecule sensors, and DNA detection. The text emphasizes how size, shape, and surface chemistry affect particle performance throughout. Topics include synthesis and formation of nanoclusters, nanosphere lithography, modeling of nanoparticle optical properties, and biomolecule sensors.

Download or read book Laser Ablation Technique for Synthesis of Metal Nanoparticle in Liquid written by Amir Reza Sadrolhosseini and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, the synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as silver, gold, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this technique, the high-power laser ablates the metal plate and the nanoparticles are formed in the liquid. The properties of nanoparticles using laser ablation are unique, and they are not reproducible by any other method such as chemical methods. The important parameters to produce the metal nanoparticles are energy, wavelength, repetition rate of laser, ablation time, and absorption of an aqueous solution. Laser ablation is a simple method for fabricating the metal nanoparticles without surfactant or chemical addition. In this chapter, the mechanism of formation of metal nanoparticles in liquid, significant parameters for using the laser ablation technique to prepare the metal nanoparticles, and the preparation of silver, gold and copper nanoparticles will be reviewed.

Download or read book Laser Synthesis of Nanomaterials Incorporated Within High Surface Area Materials written by Julian A. Bobb and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical methods are generally used for the synthesis of active nanoparticles (metals, semi-metals, metal oxides, and etc) supported on high surface area materials. Chemical methods involve using strong solvents, harmful gases (H2 & CO), and high temperature techniques such as high boiling solvents, calcination and pyrolysis. The main drawbacks of using this approach, is the prevalence of chemical agents on nanomaterials which tends to negate its applications. Alternatively, photochemical and photothermal methods are widely being considered for the synthesis and design of nanomaterials. For these studies, the active nanomaterials incorporated within high surface area materials were prepared by the laser vaporization-controlled condensation (LVCC) technique or by the laser irradiation in solution (LIS) technique. The LVCC technique involves the irradiation of a solid target at the focal point of a laser beam (532 nm, 30 Hz) by the Nd: YAG laser inside a chamber that is sandwiched between two steel plates in the presence of high purity He. Whereas, the LIS technique involves the laser irradiation of chemical precursors in aqueous solvents using an unfocused beam. The LVCC technique was used for the preparation of carbonaceous and N-doped carbonaceous TiO2 support materials from MIL-125(Ti) and NH2-MIL-125(Ti) metal organic frameworks, Ge and GeO2 nanostructures, GeOx/PRGO nanocomposite, and the Fe3O4/PRGO nanocomposite. On the other hand, Pd supported on MIL-125(Ti) and NH2-MIL-125(Ti) nanocatalysts, GeO2/RGO, and the poly(ethylene glycol methacrylate-co-bisacrylamide) hydrogels were all prepared by the LIS technique.

Download or read book Graphene Oxide written by Ayrat M. Dimiev and published by John Wiley & Sons. This book was released on 2016-11-14 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to its unique properties, graphene oxide has become one of the most studied materials of the last decade and a great variety of applications have been reported in areas such as sensors, catalysis and biomedical applications. This comprehensive volume systematically describes the fundamental aspects and applications of graphene oxide. The book is designed as an introduction to the topic, so each chapter begins with a discussion on fundamental concepts, then proceeds to review and summarize recent advances in the field. Divided into two parts, the first part covers fundamental aspects of graphene oxide and includes chapters on formation and chemical structure, characterization methods, reduction methods, rheology and optical properties of graphene oxide solutions. Part Two covers numerous graphene oxide applications including field effect transistors, transparent conductive films, sensors, energy harvesting and storage, membranes, composite materials, catalysis and biomedical applications. In each case the differences and advantages of graphene oxide over its non-oxidised counterpart are discussed. The book concludes with a chapter on the challenges of industrial-scale graphene oxide production. Graphene Oxide: Fundamentals and Applications is a valuable reference for academic researchers, and industry scientists interested in graphene oxide, graphene and other carbon materials.

Download or read book Design of Elemental Nanoparticles and Their Application in Catalysis Lithography and Biochemistry written by Chiara Fasciani and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interest in metal nanoparticles has seen an exponential growth in the last twenty years, due to the astonishing properties these materials possess on the nanometer size scale. Compared to the bulk metal, nanoparticles present different optical and physical properties, which can be tuned according to their size or shape. As an example, colloidal solutions of 15 nm gold nanoparticles appear red, a very different tint as compare to the typical gold color of a gold brick. The reason for this variation is due to the fact that visible light wavelengths are bigger than the nanoparticles sizes. Therefore, after excitation, part of the light is absorbed and produces a coherent oscillation of the surface electrons, resulting in a phenomenon known as surface plasmon resonance. At this point the system tends to return to the initial state, following different pathways. One of the processes occurring is the local release of heat around the nanoparticle surface. The aim of this thesis is to gain more insight into the actual temperature values achievable after plasmon irradiation and to explore the possible applications of the localized heat release. Synthetic procedures developed in the Scaiano group were used to synthesize and modify the nanoparticles. The applicability of these photochemical procedures was extended to the synthesis of bimetallic silver-gold (Ag/Au) core-shell materials via a controlled and facile synthesis method. Ag/Au core-shells combine the optical and physical properties of gold and silver together and they have shown promise as potential antimicrobial agents. Information regarding the temperatures achievable after plasmon excitation has been obtained using dicumyl peroxide as a molecular thermometer and has indicated temperatures close to 500oC near the nanoparticle surface. This finding was a precious guideline for the selection of thermal processes that can be performed after plasmon excitation. The catalytic reduction of resazurin to resorufin was one of the reactions chosen. This process, indeed, appears significantly faster (nanoseconds) when performed using AuNP irradiated at 530 nm. The use of laser and LED irradiations has been a constant throughout this work with both systems being to suite the experimental needs. The high temperature reached irradiating metal nanoparticles has also been used to trigger the caprolactam polymerization, in such a way that only in the light exposed position AgNP favored nylon formation, presenting promising applications in lithography. Moreover, DNA melting processes have been successfully studied, by employing a switch On/Off controllable irradiation of AuNP, aiming for eventual application in the polymerase chain reaction (PCR) process. Finally, considerable work has been done in the functionalization and modification of carbon-based materials. Functionalization with silver and gold nanoparticles has been performed using a photochemical procedure, during which a different behavior was observed for the two metals. In addition, modification of the reduced graphene oxide morphology was obtained by laser irradiation without the use of any external template. The spherical reduced graphene oxide, thus obtained, has shown promising potential in water splitting catalysis. In this system, the evolution of hydrogen was observed by employing only spherical reduced graphene oxide and visible light (532 nm laser or LED irradiation). In summary, this thesis describes how light can not only be used to synthesize and modify nanomaterials, but also to perform high energetic processes at room temperature, taking advantage of the nanoscale properties of the materials being used.

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 Sustainable Preparation of Metal Nanoparticles written by Rafael Luque and published by Royal Society of Chemistry. This book was released on 2013 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely publication bridges and presents the latest trends and updates in three hot topics of current and future society: nanomaterials, energy and environment. It provides the state-of-the-art as well as current challenges and advances in the sustainable preparation of metal nanoparticles and their applications. The book fills a critical gap in a multidisciplinary area of high economic, social and environmental importance. Currently, there are no books published that deal with these ever increasing important topics, as most books in this area focus on a particular topic (eg. nanomaterials or catalysis or energy or environment). This is the first multidisciplinary edited book covering the very basics to the more advanced, trendy developments, containing a unique blend of nano, green, renewable and bio.