Author: Edward J. SwansonPublisher:
ISBN:
Category : Metal clusters
Languages : en
Pages : 0
Book Description
Dual-plasma Synthesis of Coated Metal Nanoparticles with Controlled Surface Properties
Author: Edward J. SwansonPublisher:
ISBN:
Category : Metal clusters
Languages : en
Pages : 0
Book Description
Dual Plasma Synthesis of Functionalized Metal Nanoparticles
Author: Jason TavaresSynthesis of Organic Layer-coated Metal Nanoparticles in a Dual-plasma Process
Author: Cao QinPublisher:
ISBN:
Category : Metal clusters
Languages : en
Pages : 226
Book Description
"The effects of operating conditions such as reactor pressure and inert gas flow rate on the average size of the produced bare copper nanoparticles were studied. It was demonstrated that the metal nanoparticle size tends to decrease with decreasing reactor pressure, while inert gas flow rate has little influence on the mean nanoparticle size." --
Plasma Synthesis and Self-Assembly of Magnetic Nanoparticles
Author: Sebastian EkerothPublisher: Linköping University Electronic Press
ISBN: 9176850099
Category :
Languages : en
Pages : 58
Book Description
Nanomaterials are important tools for enabling technological progress as they can provide dramatically different properties as compared to the bulk counterparts. The field of nanoparticles is one of the most investigated within nanomaterials, thanks to the existing, relatively simple, means of manufacturing. In this thesis, high-power pulsed hollow cathode sputtering is used to nucleate and grow magnetic nanoparticles in a plasma. This sputtering technique provides a high degree of ionization of the sputtered material, which has previously been shown to aid in the growth of the nanoparticles. The magnetic properties of the particles are utilized and makes it possible for the grown particles to act as building blocks for self-assembly into more sophisticated nano structures, particularly when an external magnetic field is applied. These structures created are termed “nanowires” or “nanotrusses”, depending on the level of branching and inter-linking that occurs. Several different elements have been investigated in this thesis. In a novel approach, it is shown how nanoparticles with more advanced structures, and containing material from two hollow cathodes, can be fabricated using high-power pulses. The dual-element particles are achieved by using two distinct and individual elemental cathodes, and a pulse process that allows tuning of individual pulses separately to them. Nanoparticles grown and investigated are Fe, Ni, Pt, Fe-Ni and Ni-Pt. Alternatively, the addition of oxygen to the process allows the formation of oxide or hybrid metal oxide – metal particles. For all nanoparticles containing several elements, it is demonstrated that the stoichiometry can be easily varied, either by the amount of reactive gas let into the process or by tuning the amount of sputtered material through adjusting the electric power supplied to the different cathodes. One aim of the presented work is to find a suitable material for the use as a catalyst in the production of H2 gas through the process of water splitting. H2 is a good candidate to replace fossil fuels as an energy carrier. However, rare elements (such as Ir or Pt) needs to be used as the catalyst, otherwise a high overpotential is required for the splitting to occur, leading to a low efficiency. This work demonstrates a possible route to avoid this, by using nanomaterials to increase the surface-to-volume ratio, as well as optimizing the elemental ratio between different materials to lower the amount of noble elements required.
Plasma for Energy and Catalytic Nanomaterials
Author: Lanbo Di Publisher: MDPI
ISBN: 3039286544
Category : Science
Languages : en
Pages : 234
Book Description
The Special Issue “Plasma for Energy and Catalytic Nanomaterials” highlights the recent progress and advancements in the synthesis and applications of energy and catalytic nanomaterials by plasma. Compared with conventional preparation methods, plasma provides a fast, facile, and environmentally friendly method for synthesizing highly efficient nanomaterials. The synthesized nanomaterials generally show enhanced metal–support interactions, small-sized metal nanoparticles, specific metal structures, and abundant oxygen vacancies. The plasma method allows thermodynamically and dynamically difficult reactions to proceed at low temperatures due to the activation of energetic electrons. Despite the growing interest in plasma for energy and catalytic nanomaterials, the synthesis mechanisms of nanomaterials using plasma still remain obscure due to the complicated physical and chemical reactions that occur during plasma preparation. The Guest Editors and the MDPI staff are therefore pleased to offer this Special Issue to interested reader, including graduate and Ph.D. students, postdoctoral researchers, and the entire community interested in the field of nanomaterials. We share the conviction that the Issue can serve as a useful tool for updating the literature and to aid with the conception of new production and/or research programs. Further dedicated R&D advances are possible based on new instruments and materials under development.
Controlled Assembly of Metal Nanoparticles with Enhanced Optical Properties
Author: Zhaoxia QianPublisher:
ISBN:
Category :
Languages : en
Pages : 584
Book Description
Controlled synthesis of metal nanoparticles is an important area of study because of the unique size and shape dependent properties of such nanoparticles. For example, gold and silver nanoparticles show distinct surface Plasmon resonance (SPR) bands varying with the size, shape and surface morphology of the nanoparticles. The assembly of these nanoparticles usually exhibit interesting collective optical properties different from their individual components. However, controlled synthesis and assembly of metal nanoparticles with high yield and enhanced optical properties is still challenging. In this thesis, I presented the synthesis of ultrathin gold/silver nanowires and sub-50 nm gold triangular nanoprisms by adopting silver seeds and benzyl dimethyl hexadecyl ammonium chloride (BDAC) in a seed-mediated growth method. Furthermore, I developed a templated surfactant-assisted seed growth method to synthesize gold nanoshells with varying surface morphologies by changing the type of surfactants and ions in the growth solution. The optical properties of the nanoshells could be controlled over a wide wavelength range by varying the surface morphology. By using a combination of BDAC surfactant and template surfactant-assisted seed growth method, isotropic shell-type gold nanoparticle clusters, or raspberry-like meta-molecules (raspberry-MMs), were successfully synthesized. The raspberry-MMs exhibited interesting far field and near field optical properties. The raspberry-MMs showed unusually strong magnetic resonances, yielding broad SPR bands in the visible and near-IR region. Both experimental data and finite-difference time-domain (FDTD) simulations showed that the magnetic dipole can be even larger than that of the electric dipole resonance in large raspberry-MMs. Moreover, I utilized Raman spectroscopy as a tool to probe the near field optical properties of the raspberry-MMs. Due to the existence of a large number of hotspots at the gaps among gold beads within individual raspberry-MMs, individual raspberry-MMs proved to be efficient Raman substrate. Importantly, the contribution from hotspots created at the gap between two adjacent raspberry-MMs is negligible compared to that from a large number of hotspots on individual raspberry-MMs. Consequently, the Raman signal intensity of the analyte molecules on the raspberry-MM dimers exhibited quite narrow distribution and is weakly dependent on the distance between the two raspberry-MMs. This paved the way for fabricating large-area raspberry-MM films which can serve as macroscopic efficient and reproducible Raman substrate. The robustness and tunability of the synthetic method presented in this thesis, the strong magnetic responses of the raspberry-MMs and the efficient Raman enhancement from single raspberry-MM, raspberry-MM dimer and films can lead to large-scale manufacture and wide applications of magnetic metamaterials as well as commercialization of uniform Raman substrate.
Nanoparticles
Author: American Chemical Society. MeetingPublisher:
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 474
Book Description
The book summarizes recent advances in methods to synthesize, stabilize, passivate and functionalize diverse nanoparticles from metals, metal oxides, semiconductors, polymers, organics and biomolecules. A wide range of potential appplications with nanoparticles as building blocks are described.
Plasma-Aided Nanofabrication
Author: Ken OstrikovPublisher: John Wiley & Sons
ISBN: 3527611568
Category : Technology & Engineering
Languages : en
Pages : 315
Book Description
In this single work to cover the use of plasma as nanofabrication tool in sufficient depth internationally renowned authors with much experience in this important method of nanofabrication look at reactive plasma as a nanofabrication tool, plasma production and development of plasma sources, as well as such applications as carbon-based nanostructures, low-dimensional quantum confinement structures and hydroxyapatite bioceramics. Written principally for solid state physicists and chemists, materials scientists, and plasma physicists, the book concludes with the outlook for such applications.
Nanoparticles
Author: Vincent RotelloPublisher: Springer Science & Business Media
ISBN: 1441990429
Category : Science
Languages : en
Pages : 291
Book Description
The integration of top-down lithographic techniques with synthetic organic and inorganic technologies is a key challenge for the development of effective nanosca1e devices. In terms of assembly, nanoparticles provide an excellent tool for bridging the gap between the resolution of electron beam lithography (-60 nm) and the molecular level. Nanoparticles possess an array of unique properties associated with their core materials, including distinctive magnetic, photonic and electronic behavior. This behavior can be controlled and applied through monolayer functionalization and assembly strategies, making nanoparticles both scaffolds and building blocks for nanotechnology. The diverse structures and properties of nanoparticles makes them useful tools for both fundamental studies and pragmatic applications in a range of disciplines. This volume is intended to provide an integrated overview of the synthesis and assembly of nanoparticles, and their applications in chemistry, biology, and materials science. The first three chapters focus on the creation and intrinsic properties of nanoparticles, covering some of the myriad core materials and shapes that have been created. The remaining chapters of the book discuss the assembly of nanoparticles, and applications of both discrete particles and particle assemblies in a wide range of fields, including device and sensor fabrication, catalysis, biology, and nanosca1e electronic and magnetic systems.
Author: Bin Zhang