scholarly journals Anisotropic optical and conductive properties of oriented 1D-nanoparticle thin films made by spray-assisted self-assembly

2016 ◽  
Vol 191 ◽  
pp. 373-389 ◽  
Author(s):  
S. Sekar ◽  
V. Lemaire ◽  
H. Hu ◽  
G. Decher ◽  
M. Pauly
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Near Infrared ◽  
Energy Transport ◽  
Silver Nanowires ◽  
Grazing Incidence ◽  
Silver Nanowire ◽  
Metal Nanoparticle ◽  
Aspect Ratios ◽  
Uv Visible

We report on the fabrication of oriented anisotropic metal nanoparticle thin films made by Grazing Incidence Spraying (GIS) and on the anisotropic plasmonic properties of the resulting thin films. Gold nanorods of two different aspect ratios and silver nanowires were self-assembled as a uniaxially aligned monolayer with the GIS approach. In particular, we examine the influence of the nanowire/nanorod length and diameter on the degree of ordering determined by electron microscopy pictures. Furthermore, we show that the anisotropy of the optical properties (probed by polarized UV-visible-near infrared spectroscopy) strongly depend on the quality of alignment. The prepared monolayer thin films have an orientation order parameter of up to 0.83 for silver nanowires, which is reflected in an optical anisotropy of 0.57 in the UV-visible and 0.76 in the near infrared through the selective excitation of transverse and longitudinal surface plasmon resonance modes. The electronic transport in oriented silver nanowire monolayers is also shown to be highly directional, with the sheet resistance varying over almost an order of magnitude depending on the transport direction. Such anisotropic conductive plasmonic thin films may find applications in various fields like biochemical sensing, energy transport and harvesting or optoelectronic devices.

Enhanced Plasmonic Behavior of Metal Nanoparticles Surrounded With Dielectric Shell

2019 ◽  
Author(s):  
Anil Yuksel ◽  
Michael Cullinan ◽  
Edward T. Yu ◽  
Jayathi Murthy
Keyword(s):  
Metal Nanoparticles ◽  
Near Infrared ◽  
Energy Transport ◽  
Near Field ◽  
Metal Nanoparticle ◽  
Infrared Wavelength ◽  
Laser Illumination ◽  
Dielectric Media ◽  
Dielectric Shell ◽  
Laser Sources

Abstract Metal nanoparticles have attracted intense attention due to their unique optical and thermal properties in various next generation applications such as micro-nano electronics and photonics. The near-field confinement between closely packed metal nanoparticles, which is enhanced due to their plasmonic behavior, creates high thermal energy densities under visible to near-infrared wavelength laser irradiation. As metal nanoparticles tend to be oxidized or change shape under laser illumination, resulting in nonlinear optical and thermal behavior, surrounding each metal nanoparticle with a dielectric shell could be a potential way to prevent these effects as well as to engineer their plasmonic behavior. In this study, we investigate energy transport within dimer and 4 nanoparticle (chain) configurations of 50 nm radius Au nanoparticles surrounded by dielectric shells under illumination from various laser sources in different dielectric media.

Free-standing, anti-corrosion, super flexible graphene oxide/silver nanowire thin films for ultra-wideband electromagnetic interference shielding

2021 ◽  
Author(s):  
Hui Jia ◽  
Xiao Yang ◽  
Qing-Qiang Kong ◽  
Li-Jing Xie ◽  
Quan-Gui Guo ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Self Assembly ◽  
Electromagnetic Interference ◽  
Silver Nanowire ◽  
Ultra Wideband ◽  
Electromagnetic Interference Shielding ◽  
Free Standing ◽  
Emi Se ◽  
Ag Nanowire

A free-standing graphene oxide/Ag nanowire film with a dense sandwich-like structure was fabricated via vacuum-assisted self-assembly. The EMI SE is up to 62 dB when the thickness is merely 8 μm in 8–40 GHz. The corresponding specific SE (EMI SE/t) is up to 77 500 dB cm−1.

Preparation and optical properties of silver nanowires and silver-nanowire thin films

2011 ◽  
Vol 356 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Quocanh N. Luu ◽  
Joshua M. Doorn ◽  
Mary T. Berry ◽  
Chaoyang Jiang ◽  
Cuikun Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Silver Nanowires ◽  
Silver Nanowire

scholarly journals Polyol Silver Nanowire Synthesis and the Outlook for a Green Process

2020 ◽  
Vol 2020 ◽  
pp. 1-25 ◽  
Author(s):  
Shohreh Hemmati ◽  
Michael T. Harris ◽  
Dale P. Barkey
Keyword(s):  
Silver Nanowires ◽  
Synthesis Method ◽  
Polyol Process ◽  
Silver Nanowire ◽  
Polyol Synthesis ◽  
High Yield ◽  
Silver Nanostructures ◽  
Wearable Electronics ◽  
Aspect Ratios ◽  
Size And Morphology

Silver nanowires (AgNWs) have a broad range of applications including nanoelectronics, energy conversion, health care, solar cells, touch screens, sensors and biosensors, wearable electronics, and drug delivery systems. As their characteristics depend strongly on their size and morphology, it is essential to find the optimal and most cost-effective synthesis method with precise control over the size and morphology of the wires. Various methods for AgNW synthesis have been reported along with process optimization and novel techniques to increase the yield and aspect ratios of synthesized AgNWs. The most promising processes for synthesis of AgNWs are wet chemical techniques, in which the polyol process is low cost and simple and provides high yield compared to other chemical methods. Reaction mechanism is one of the most important factors in strategies to control the process. Our purpose here is to provide an overview on the main findings regarding synthesis, preparation, and characterization of AgNWs. Recent efforts in the polyol synthesis of AgNWs are summarized with respect to product morphology and size, reaction conditions, and characterization techniques. The effect of essential factors such as reagent concentration and preparation, temperature, and reaction atmosphere that control the size, morphology, and yield of synthesized AgNWs is reviewed. Moreover, a review on the novel modified polyol process and reactor design such as continuous millifluidic and flow reactors to increase the yield of synthesized AgNWs on large scales is provided. The most recent proposed growth mechanisms and kinetics behind the polyol process are addressed. Finally, comparatively few available studies in green and sustainable development of 1D silver nanostructures through the application of natural products with inherent growth termination, stabilization, and capping characteristics are reviewed to provide an avenue to natural synthesis pathways to AgNWs. Future directions in both chemical and green synthesis approaches of AgNWs are addressed.

Controllable self-assembly of a novel Bi2MoO6-based hybrid photocatalyst: excellent photocatalytic activity under UV, visible and near-infrared irradiation

2016 ◽  
Vol 52 (39) ◽  
pp. 6525-6528 ◽  
Author(s):  
Yuchen Hao ◽  
Xiaoli Dong ◽  
Shangru Zhai ◽  
Xiuying Wang ◽  
Hongchao Ma ◽  
...  
Keyword(s):  
Self Assembly ◽  
Near Infrared ◽  
Carbon Nanodots ◽  
Step Method ◽  
Excellent Photocatalytic Activity ◽  
One Step ◽  
Uv Visible ◽  
Nitrogen Doped Carbon ◽  
Bi Nanoparticles ◽  
Hybrid Photocatalyst

Herein, using a simple one-step method, a Bi2MoO6-based photocatalyst with novel ultrathin nanohollow structure and simultaneous sub-10 nm Bi nanoparticles and sub-1 nm graphitic nitrogen-doped carbon nanodots (NCDs) modification were successfully obtained.

scholarly journals Flexible transparent electrodes based on silver nanowires synthesized via a simple method

2017 ◽  
Vol 4 (9) ◽  
pp. 170756 ◽  
Author(s):  
De Li ◽  
Tao Han ◽  
Lei Zhang ◽  
Huai Zhang ◽  
Hui Chen
Keyword(s):  
Silver Nanowires ◽  
Cost Effective ◽  
Silver Nanowire ◽  
Vinyl Pyrrolidone ◽  
High Yield ◽  
Transparent Electrodes ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Uv Visible ◽  
Poly Vinyl Pyrrolidone

Silver nanowires (Ag NWs) with the length of approximately 60 µm and the diameter of approximately 300 nm are prepared via a simple, cost-effective, high-yield and eco-friendly procedure under a high molar concentration ratio of silver nitrate (AgNO 3 ) solution to poly(vinyl pyrrolidone) solution. The pre-synthesized Ag NWs were analysed by scanning electron microscopy, X-ray diffraction and UV–visible spectrophotometer. Furthermore, the as-prepared silver nanowires were roll-coated on the surfaces of the polyethylene terephthalate (PET) substrates. By optimizing the concentration of silver nanowire solution, the flexible Ag NW/PET transparent electrodes with a sheet resistance of 3.8 Ω sq −1 at a transmittance of 70% can be fabricated. The results reported in this paper provide a basis for optimizing the growth of silver nanowires and performances of transparent electrodes.

scholarly journals Investigating the effect of capping agent PVP on the synthesis of silver nanowires by polyol method and its application as flexible transparent conducting electrode

2013 ◽  
Vol 16 (4) ◽  
pp. 52-60
Author(s):  
Thu Thi Hoang ◽  
Trung Quang Tran
Keyword(s):  
Large Scale ◽  
Silver Nanowires ◽  
Silver Nanowire ◽  
Polyol Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Metal Nanostructures ◽  
Sem Images ◽  
Aspect Ratios ◽  
Transparent Conducting

In this report, we present a rapid and efficient polyol method - the solution-phase approach for the large scale synthesis of silver nanowires with diameters in the range of 40 - 50 nm, and lengths up to 20 μm. Although the polyol process is a popular method of preparing metal nanostructures, so far most of the published works mainly focused on the synthesis process regardless of amount of surfactants. In this article, we successfully synthesized large-scale uniform silver nanowires with high aspect ratios by introducing the long-chain PVP (MW = 58 000) and investigated the effect of the amount of PVP on the synthesis of Ag nanowires by studying their morphologies, structures and optical properties. The dependency of nanowire morphology and aspect ratio on synthesis parameters was shown via SEM images. The diameter of nanowires decreased when the molar ratio of PVP to silver nitrate was increased. Further more, the molar ratios decided the morphology (particle, rod or wire) of the Silve solution. Synthesized silver nanowires were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). This aqueous dispersions of silver nanowires were used to prepare thin, flexible, transparent, conducting films on polyethylene terephthalate substrate (PET) by spraying method. The prepared silver nanowire films on PET substrate had a transparency of 82% and sheet resistance of 10 Ω/□.

scholarly journals Self-Assembly in ultrahigh molecular weight sphere-forming diblock copolymer thin films under strong confinement

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wei Cao ◽  
Senlin Xia ◽  
Michael Appold ◽  
Nitin Saxena ◽  
Lorenz Bießmann ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Film Thickness ◽  
Self Assembly ◽  
Diblock Copolymers ◽  
Grazing Incidence ◽  
Structure Evolution ◽  
Solvent Vapor ◽  
Chain Mobility ◽  
Ultrahigh Molecular Weight

AbstractUltrahigh molecular weight (UHMW) diblock copolymers (DBCs) have emerged as a promising template for fabricating large-sized nanostructures. Therefore, it is of high significance to systematically study the influence of film thickness and solvent vapor annealing (SVA) on the structure evolution of UHMW DBC thin films. In this work, spin coating of an asymmetric linear UHMW polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) DBC is used to fabricate thin films, which are spherically structured with an inter-domain distance larger than 150 nm. To enhance the polymer chain mobility and facilitate approaching equilibrium nanostructures, SVA is utilized as a post-treatment of the spin coated films. With increasing film thickness, a local hexagonal packing of PMMA half-spheres on the surface can be obtained, and the order is improved at larger thickness, as determined by grazing incidence small angle X-ray scattering (GISAXS). Additionally, the films with locally hexagonal packed half-spherical morphology show a poor order-order-poor order transition upon SVA, indicating the realization of ordered structure using suitable SVA parameters.

Development of 3-D Magnetic Nano-Arrays by Electrodeposition into Mesoporous Silica Films

2006 ◽  
Vol 961 ◽  
Author(s):  
Jason Manning ◽  
Roger Campbell ◽  
Martin Gerard Bakker ◽  
Xuefa Li ◽  
Dong Ryeol Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Magnetic Nanostructures ◽  
Grazing Incidence ◽  
Nano Particles ◽  
Silica Films ◽  
Silica Thin Films ◽  
Current Path ◽  
Wide Range

ABSTRACTThe development of periodic nanostructures fabricated by self-assembly of surfactants and block co-polymers has opened up the possibility of generating periodic magnetic nanostructures of types not accessible by self-assembly of nano-particles. The fabrication of mesoporous silica thin films around self-assembled block co-polymers is well established. Common structures for such films are SBA-15 which consists of hexagonal arrays of cylindrical pores and SBA-16 which has face centered arrays of spherical voids. These pores are connected by 1-2 nm thick flaws in the continuous silica phase producing an effectively continuous porous phase. After removal of the block co-polymer template, electrodeposition into the mesoporous silica thin films produces arrays of 5-10 nm diameter nano-wires and nano-particles. We have demonstrated that such materials can be fabricated on a wide range of metal substrates. Characterization by Scanning Electron Microscopies shows that the mesoporous silica is well ordered over micron scale areas. Grazing Incidence Small Angle X-ray Scattering (GISAXS) studies shows diffraction spots, consistent with the entire film being well ordered. GISAXS also shows that the mesoporous silica films survive removal of the template and electrodeposition of nickel and cobalt into the mesoporous silica films. Such films are of interest for their magnetic properties, as the nanophase and scale can be independently varied. Further, the presence of nanowires inside an insulator suggests that these films might also be of interest as the current confining element for Confined Current Path-Current Perpendicular to Plane GMR sensors.

scholarly journals Ordered arrangement of F4TCNQ anions in three-dimensionally oriented P3HT thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shuichi Nagamatsu ◽  
Shyam S. Pandey
Keyword(s):  
Thin Films ◽  
Near Infrared ◽  
Optical Transition ◽  
Grazing Incidence ◽  
Acetonitrile Solution ◽  
P3ht Film ◽  
X Ray ◽  
Polymeric Chains ◽  
Axis Parallel ◽  
Ft Ir

AbstractAn ordered arrangement of electron-accepting molecular dopant, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), in three-dimensionally (3D) oriented poly(3-hexylthiophene) (P3HT) film was clarified. The 3D oriented P3HT thin films prepared by the friction-transfer technique were doped with F4TCNQ by dipping into an acetonitrile solution. The presence of F4TCNQ anions in the 3D oriented P3HT thin films was investigated by polarized ultraviolet/visible/near-infrared absorption spectroscopy, grazing incidence X-ray diffractometry, polarized Fourier transform infrared spectroscopy (FT-IR), and infrared p-polarized multiple-angle incidence resolution spectroscopy (pMAIRS). The F4TCNQ-doped 3D oriented P3HT films showed anisotropic properties in all characterizations. In particular, the anisotropic molecular vibrations from polarized FT-IR and pMAIRS have clearly revealed orientations of polymeric chains and molecular dopant molecules. Considering the results from several independent techniques indicated that F4TCNQ anions in the 3D oriented P3HT were orderly arranged in a 3D manner with respect to the 3D oriented P3HT such that their molecular long-axis parallel to the P3HT backbone, with in-plane molecular orientation. Additionally, the direction of the optical transition moment of the F4TCNQ anion was found to be parallel to the molecular short-axis.

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