scholarly journals Preparation and Microwave Absorption Properties of Polyaniline and Magnetite Core-Shell-Structured Hybrid

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Xuan Zhang
Keyword(s):  
Microwave Absorption ◽  
Photoelectron Spectroscopy ◽  
Microwave Absorption Property ◽  
Absorption Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared Spectrophotometer ◽  
Aniline Polymerization

In this study, polyaniline and Fe3O4 (PAN@Fe3O4) hybrids are fabricated and their microwave absorption property is studied. PAN@Fe3O4 hybrids are fabricated by the in situ aniline polymerization at spherical of Fe3O4 which is prepared by the solvothermal process. Fourier-transform infrared spectrophotometer (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) are applied to confirm the composition of the fabricated PAN@Fe3O4 hybrids. The morphologies of PAN@Fe3O4 hybrids are studied by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The content of polyaniline in the PAN@Fe3O4 hybrids is calculated by thermogravimetric analysis (TGA). The magnetic properties of PAN@Fe3O4 hybrids are characterized by vibrating sample magnetometer (VSM). The microwave absorption property of PAN@Fe3O4 hybrids are measured on a vector network analyzer. The research show that the microwave absorptions property of the obtained PAN@Fe3O4 hybrids can be adjusted by controlling the in situ aniline polymerization at spherical of Fe3O4.

Synthesis and Excellent Microwave Absorption Properties of ZnO/Fe3O4/MWCNTs Composites

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650139 ◽  
Author(s):  
Lei Wang ◽  
Honglong Xing ◽  
Zhenfeng Liu ◽  
Ziyao Shen ◽  
Xiang Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Microwave Absorption ◽  
Photoelectron Spectroscopy ◽  
Wave Attenuation ◽  
Impedance Matching ◽  
Interfacial Polarization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Transmission Electron

ZnO nanocrystals were introduced into Fe3O4/MWCNTs composites to improve the impedance matching and electromagnetic (EM) wave attenuation of the system. The as-synthesized ZnO/Fe3O4/MWCNTs composites were characterized by X-ray diffraction, vibrating sample magnetometer, field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy. SEM and TEM images showed that Fe3O4 microspheres 100–200[Formula: see text]nm in size connected MWCNTs. Analysis of EM parameters revealed that the impedance matching of the ZnO/Fe3O4/MWCNTs composites was considerably improved after ZnO nanocrystals were introduced. The ZnO/Fe3O4/MWCNTs composites exhibited a highly efficient microwave absorption (MA) capacity within the tested frequency range of 2–18[Formula: see text]GHz. The optimal reflection loss of EM waves was [Formula: see text][Formula: see text]dB at 6.08[Formula: see text]GHz with an absorber thickness of 3.5[Formula: see text]mm. The excellent MA properties of the composites could be attributed to the improved impedance matching, interfacial polarization, and combined effects of dielectric and magnetic losses.

Surface nitridation of Ta powder by molten-salt electrolysis of Ta2O5 under N2 atmosphere

2020 ◽  
Vol 13 (07) ◽  
pp. 2050032
Author(s):  
Qing Huang ◽  
Guojin Zheng ◽  
Tian Wu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Cell Voltage ◽  
X Ray Diffraction ◽  
Molten Salt Electrolysis ◽  
X Ray ◽  
Structured Catalysts ◽  
Transmission Electron ◽  
N2 Atmosphere

The electro-deoxidation of Ta2O5 in molten CaCl2 under N2 atmosphere is a facile way for the in situ surface nitridation of Ta particles. The cell voltage and electrolysis time of Ta2O5 are rationalized to realize the in situ surface nitridation of Ta. All the characterization results including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elements mapping as well as X-ray photoelectron spectroscopy (XPS) confirm the formation of Ta2N layers on the surface of Ta particles, with the thickness of 3–4[Formula: see text]nm. This method provides a strategy for the facile in situ surface nitridation with N2 as the nitrogen source for the fabrication of core-shell structured catalysts.

Synthesis and characterization of organic–inorganic poly(3,4-ethylenedioxythiophene)/MoS2 nanocomposite via in situ oxidative polymerization

2006 ◽  
Vol 21 (1) ◽  
pp. 112-118 ◽  
Author(s):  
A. Vadivel Murugan ◽  
Mathieu Quintin ◽  
Marie-Helene Delville ◽  
Guy Campet ◽  
Annamraju Kasi Viswanath ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Rechargeable Lithium Batteries ◽  
X Ray ◽  
Transmission Electron ◽  
Basal Distance ◽  
New Type

Here we demonstrate the synthesis of a new type of layered poly(3,4-ethylenedioxy- thiophene) (PEDOT)/MoS2 nanocomposite via flocculation of delaminated MoS2 with subsequent in situ oxidative polymerization of 3,4-ethylenedioxythiophene. The resulting nanocomposite was characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction, x-ray photoelectron spectroscopy, thermal analysis, transmission electron microscopy, and four-probe electrical conductivity measurements with respect to temperature. X-ray diffraction results indicated that the exfoliated MoS2 and PEDOT are restacked to produce a novel nanoscale composite material containing alternate nanoribbons of PEDOT in between MoS2 with a basal distance of ∼1.38 nm. The nanocomposite, which could be used as a cathode material for small power rechargeable lithium batteries, has also been demonstrated by the electrochemical insertion of lithium into the PEDOT/MoS2 nanocomposite, where a significant enhancement in the discharge capacity is observed, compared to that of respective pristine molybdenum disulfide.

scholarly journals Plasmon Sensitized Heterojunction 2D Ultrathin Ag/AgI-δ-Bi2O3 for Enhanced Photocatalytic Nitrogen Fixation

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 781 ◽  
Author(s):  
Xiaoming Gao ◽  
Yanyan Shang ◽  
Kailong Gao ◽  
Feng Fu
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Fixation ◽  
Photoelectron Spectroscopy ◽  
Separation Efficiency ◽  
Average Height ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sacrificial Agent

A novel 2D ultrathin Ag/AgI-δ-Bi2O3 photocatalyst was constructed by a facile hydrothermal and in situ photodeposition method, which presented a uniform nanosheet structure with an average height of 6 nm. Its composition, morphology and light-harvesting properties were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis spectrophotometer (UV–vis) and photoluminescence (PL) measurements in detail. The Ag/AgI-δ-Bi2O3 nanocomposites showed an excellent photocatalytic nitrogen fixation performance of 420 μmol L−1 g−1 h−1 in water without any sacrificial agent. The introduction of Ag/AgI nanoparticles caused the morphology modification of δ-Bi2O3, a higher concentration of oxygen vacancy, and the construction of a plasmon sensitized heterojunction, resulting in enhanced light absorption, improved separation efficiency of charge carriers and strong N2 absorption and activation ability, which are responsible for the superior photocatalytic performance of Ag/AgI-δ-Bi2O3.

Preparation and characterization of a copper@polyimide core–shell structure via an in situ induction/imidization route

2016 ◽  
Vol 29 (5) ◽  
pp. 569-574
Author(s):  
Haoran Zhou ◽  
Dexin Wang ◽  
Chunyan Qu ◽  
Changwei Liu ◽  
Shanshan Mao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Amic Acid ◽  
Core Shell ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Cu

Based on the combination of an in situ induction and imidization method for improving the interface bonding of an inorganic material and a polymer, copper@polyimide (Cu@PI) core–shell composite particles have been successfully prepared from poly(amic acid) ammonium salts (PAAS) and a Cu complex via a simple solvothermal process. The structures and the morphologies of the samples were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM), respectively. It was found that PAAS formed PI via a thermal imidization and subsequently precipitated in the solvent. Through crystallization induction, it then successfully coated on the surface of the formed Cu particles. Based on thermo gravimetric analyses curves and due to no Cu oxidation reactions taking place in the core coated with high-temperature-resistant PI, the weight increase was determined to be 106.4%, instead of up to 124.0% in samples consisting of pure Cu.

Thermoelectric behavior of PEDOT:PSS/CNT/graphene composites

2018 ◽  
Vol 38 (4) ◽  
pp. 381-389 ◽  
Author(s):  
Yan-Xin Liu ◽  
Hai-Hui Liu ◽  
Jian-Ping Wang ◽  
Xing-Xiang Zhang
Keyword(s):  
Power Factor ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Hybrid Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Styrene Sulfonate ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotube

AbstractHybrids of poly(3,4-ethylenedioxythiophene) (PEDOT):poly(4-styrene sulfonate) (PSS)/multi-walled carbon nanotube (MWCNT)/graphene (P/M/G), which have high electrical conductivity and low thermal conductivity, were successfully prepared in aqueous solution throughin situpolymerization of 3,4-ethylenedioxythiophene (EDOT) monomers in the presence of poly(sodium 4-styrene sulfonate) (PSSNa). Meanwhile, the composites were characterized by Raman spectroscopy, infrared (IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy. Thermoelectric properties of the samples were measured at room temperature and 50°C. Compared with pristine PEDOT:PSS (P), PEDOT:PSS/MWCNT (P/M) and PEDOT:PSS/graphene (P/G), the power factor of P/M/G composites was significantly improved, whatever the temperature. It increased from 0.061 μW/mK2to 0.105 μW/mK2at room temperature and from 0.070 μW/mK2to 0.142 μW/mK2at 50°C, meaning 72% and 103% enhancement, respectively. The increased power factor is attributed to the synergic effects of MWCNT and graphene, a hybrid structure with excellent electronic coupling and more electric channels.

scholarly journals Aqueous Medium Synthesis Route for Randomly Stacked Molybdenum Disulfide

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Pravas Kumar Panigrahi ◽  
Amita Pathak
Keyword(s):  
Molybdenum Disulfide ◽  
Photoelectron Spectroscopy ◽  
Sodium Dodecyl ◽  
Ammonium Molybdate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Cold Pressed

Synthesis of poorly crystalline, randomly oriented rag-like structures of molybdenum disulfide has been reported starting from aqueous solutions of ammonium molybdate, and thioacetamide in presence of sodium dodecyl sulfate via calcination of the amorphous precipitates, obtained through acidification of the in situ generated intermediate of ammonium tetrathiomolybdate. X-ray photoelectron spectroscopy, UV-visible spectroscopy, and X-ray diffraction of the calcined samples reveal the formation of single-phase MoS2, while the amorphous precipitates have been found to be a mixture of Mo2S5, MoS3, and a trace amount of H2MoS4. Highly folded and disordered layers of rag-like MoS2 have been confirmed through high-resolution transmission electron microscopy. The electrical conductivity for the cold pressed pellet of the MoS2 sample is found to be significantly higher than that of 2H-MoS2 and increases further on annealing.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

scholarly journals α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Photoelectron Spectroscopy ◽  
Cellulose Fibers ◽  
Relative Activity ◽  
Significant Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Laccase Immobilization ◽  
Surface Modified

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

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