Self-Assembly of Cobalt/Bipyridine Multilayers Modeled After Hofmann Clathrate Compounds

1994 ◽  
Vol 351 ◽  
Author(s):  
Michael A. Ansell ◽  
Astrid C. Zeppenfeld ◽  
William K. Ham ◽  
Catherine J. Page
Keyword(s):  
Self Assembly ◽  
Grazing Angle ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Grown Layer ◽  
Multilayered Films ◽  
X Ray ◽  
Clathrate Compounds ◽  
Micro Analysis ◽  
Ordered Layers

ABSTRACTProgress has been made towards the development of inorganic-organic multilayered films modeled after Hofmann clathrate compounds. Cobalt-bipyridine multilayers were grown layer by layer on a silicon substrate. The resulting films were characterized using ellipsometry, grazing angle X-ray diffraction, Auger electron spectroscopy and EPMA (Electron Probe Micro- Analysis). Results indicate that moderately well ordered layers have been synthesized, but cross-linking with M(CN)42(M = Ni, Pd, or Pt) to simulate the model structure does not significantly occur.

scholarly journals Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiwoong Heo ◽  
Daheui Choi ◽  
Jinkee Hong
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Precursor Solution ◽  
Ferrite Nanoparticles ◽  
Energy Dispersive ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Scanning Electron

We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4) nanoparticles, using layer-by-layer (LbL) self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1) a blended three-component LbL film consisting of a sequential poly(acrylic acid)/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride) layer and (2) a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride), poly(sodium-4-sulfonate), bPEI-ferrite, and poly(sodium-4-sulfonate) layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4) were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

Self-Assembly of Inorganic/Organic Multilayer Films

1994 ◽  
Vol 351 ◽  
Author(s):  
Astrid C. Zeppenfeld ◽  
Catherine J. Page
Keyword(s):  
Self Assembly ◽  
Grazing Angle ◽  
Multilayer Films ◽  
Silicon Wafers ◽  
Initial Surface ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Influence Of Substrate ◽  
The Individual

ABSTRACTIn order to investigate the influence of substrate functionalization on the subsequent selfassembly of multilayer films, multilayers composed of alternating hafnium and 1,10-decanediylbis(phosphonic) acid (DBPA) have been grown on three different substrates. Substrates studied include gold wafers functionalized with 4-mercaptobutylphosphonic acid, silicon wafers functionalized using a hafnium oxychloride solution, and silicon wafers coated with an octadecylphosphonate LB-template layer. The nature of these films is probed using ellipsometry and grazing angle x-ray diffraction. These studies indicate that the overall order and the individual layer thickness can vary substantially from sample to sample and depend strongly on the initial surface functionalization prior to multilayer growth.

Fire retardancy of graphene oxide/wood composite (GOW) prepared by a vacuum-pulse dipping technique

Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 375-378 ◽  
Author(s):  
Xiaoshuai Han ◽  
Qinqin Zhang ◽  
Yihui Yin ◽  
Junwen Pu
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Degree Of Crystallinity ◽  
Multilayer Graphene ◽  
Layer By Layer ◽  
Fire Retardancy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Natural Wood ◽  
Thermal Stability Of

AbstractGraphene oxide/wood (GOW) composite was fabricated by a vacuum-pulse dipping technique, and the resulting composites were characterized by scanning electron microscope (SEM), Raman spectroscopy and thermogravimetric analysis (TGA). As demonstrated, the wood matrix became filled by the dense multilayer graphene oxide (GO) membrane structure, which was formed by the layer-by-layer self-assembly of GO nano-sheets. X-ray diffraction (XRD) revealed that the amorphous GO decreased the composite’s relative degree of crystallinity. Additionally, the filled GO generated improvement in the thermal stability of GOW composites in comparison with that of the natural wood (NW).

A nanocomposite constructed by intercalating iron porphyrin into layered tantalotungstate with exfoliation/self-assembly method utilized for electrocatalytic oxidation of nitrite

2019 ◽  
Vol 12 (05) ◽  
pp. 1950069 ◽  
Author(s):  
Mengjun Wang ◽  
Jinpeng Li ◽  
Zichun Fan ◽  
Shining Wu ◽  
Juanjuan Ma ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electrocatalytic Oxidation ◽  
Colloidal Suspension ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Electrochemical Behaviors ◽  
X Ray ◽  
Assembly Method ◽  
Cyclic Voltammetry Method ◽  
Pulse Voltammetry

Exfoliation/restacking route was utilized to investigate layer-by-layer self-assembly of FeTMPyP/TaWO6 [5, 10, 15, 20-tetrakis (N-methylpyridinium-4-yl) porphyrinato iron (III)] nanocomposite in this paper. The colloidal suspension of [Formula: see text] nanosheet was tested by Zeta potential and proved to be in a well-dispersed statement. Analysis technologies such as X-ray diffraction Scanning electron microscope (SEM) infrared UV-Vis were used to characterize the final product. The results showed that FeTMPyP molecules were introduced into the lamellar space of host material successfully. The electrochemical behaviors of FeTMPyP-TaWO6 nanocomposite were tested by cyclic voltammetry method, and the nanocomposite showed excellent electrocatalytic properties to the oxidation of nitrite with the anodic peak shifts from 0.122 to 0.860[Formula: see text]V. Besides, the detection limit of nitrite can be calculated to be [Formula: see text][Formula: see text]M with the concentration of nitrite ranging from 0.1 to 3.61[Formula: see text]mM by different pulse voltammetry (DPV) analyzation.

scholarly journals Synthesis of Magnetic Nanocomposite Fe3O4@ZIF-8@ZIF-67 and Removal of Tetracycline in Water

2021 ◽  
Author(s):  
Xu Song ◽  
Jingqian Mo ◽  
Yuting Fang ◽  
Shumin Luo ◽  
Jingjing Xu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Environmental Remediation ◽  
Advanced Characterization ◽  
Magnetic Nanocomposite ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
X Ray ◽  
Before And After ◽  
High Adsorption Capacity

Abstract We prepared a double-layer magnetic nanocomposite Fe3O4@ZIF-8@ZIF-67 by layer-by-layer self-assembly. Fe3O4@ZIF-8@ZIF-67 was used to remove tetracycline from aqueous solution via a combination of adsorption and Fenton-like oxidation. Depending on the outstanding porous structure of the Fe3O4@ZIF-8@ZIF-67, a high adsorption capacity for tetracycline was 356.25 mg g− 1, with > 95.47% removal efficiency within 100 min based on Fenton-like oxidation. To better understand the mechanisms involved in integrated adsorption and Fenton-like oxidation, various advanced characterization techniques were used to monitor the changes in morphology and composition of Fe3O4@ZIF-8@ZIF-67 before and after removal of tetracycline. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) all supported adsorption and Fenton oxidation of tetracycline. This study extends the application of Fe3O4@ZIF-8@ZIF-67 for environmental remediation.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Crystal structures of (S)- and (R,S)-2,2′-bipyridine-3,3′-dicarboxylic acid 1,1′-dioxides and of their barium salts: absolute configuration and molecular distortion enforced by supramolecular self-assembly

1997 ◽  
Vol 212 (3) ◽  
Author(s):  
P. Vojtíšek ◽  
I. Císařová ◽  
J. Podlaha ◽  
Z. Žák ◽  
S. Böhm ◽  
...  
Keyword(s):  
Single Crystal ◽  
Dicarboxylic Acid ◽  
Crystal Structures ◽  
Absolute Configuration ◽  
Self Assembly ◽  
Barium Salt ◽  
X Ray Diffraction ◽  
X Ray

AbstractCrystal structures of the title compounds were determined by single crystal X-ray diffraction. Absolute configuration of the barium salt of (+)-(

AIN/GaN and AIGaN/GaN Heterostructures Grown by HVPE on SiC Substrates

1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  
Keyword(s):  
Growth Rate ◽  
Electron Beam ◽  
Vapor Phase ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Hydride Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Micro Analysis

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.

The Evaluation of TiTe2 as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi2Te3 and Sb2Te3

2010 ◽  
Vol 74 ◽  
pp. 38-47
Author(s):  
Clay Mortensen ◽  
Paul Zschack ◽  
David C. Johnson
Keyword(s):  
Thermal Conductivity ◽  
Diffusion Barrier ◽  
Self Assembly ◽  
Low Temperatures ◽  
Annealing Temperature ◽  
The Self ◽  
High Angle ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.

Preparation and Characterization of Polyaniline Nanotubes Doped with Different Acid

2013 ◽  
Vol 401-403 ◽  
pp. 663-666
Author(s):  
Xue Lian Bai ◽  
Jian Ting Mei ◽  
Zhong Guo Mu ◽  
Yun Bai
Keyword(s):  
Acetic Acid ◽  
Self Assembly ◽  
Ammonium Persulfate ◽  
Tetraacetic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Assembly Method ◽  
Polyaniline Nanotubes

Polyaniline (PANI) nanotubes were synthesized separately using amino acetic acid (AA), ethylenediamine tetraacetic acid (EDTA), oxalic acid (OA) as dopant and ammonium persulfate (APS) as oxidant by a self-assembly method. SEM, TEM,FTIR and X-ray diffraction (XRD) and applying the 4 probes method characterized the morphology, structure and property of the product. It was found that nanotubes morphology were synthesized when the [Aci/[A ratio is 1:2.The room template conductivity of the products were studied.

Sign in / Sign up

Export Citation Format

Share Document