scholarly journals Corrosion Resistance of Modified Hexagonal Boron Nitride (h-BN) Nanosheets Doped Acrylic Acid Coating on Hot-Dip Galvanized Steel

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2340 ◽  
Author(s):  
Yongzhe Fan ◽  
Huazhen Yang ◽  
Haisheng Fan ◽  
Qi Liu ◽  
Chuang Lv ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Boron Nitride ◽  
Acrylic Acid ◽  
Hexagonal Boron Nitride ◽  
Corrosion Current ◽  
Galvanized Steel ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Acid Coating

The hexagonal boron nitride (h-BN) nanosheets modified by silane coupling agent (KH560) were doped into acrylic acid coating on the surface of galvanized steel to improve its corrosion resistance. H-BN nanosheets modified by KH560 were prepared and characterised by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The corrosion resistance of the acrylic acid coatings was measured by electrochemical testing. The results show that the corrosion current density of the coating with modified h-BN nanosheets was reduced from 2.2 × 10−5 A/cm2 to 2.3 × 10−7 A/cm2 compared with the acrylic acid coating. The impedance of the composite coating with modified h-BN is 4435 Ω·cm2, higher than the BNNS coating (2500 Ω·cm2) and the acrylic acid coating (1500 Ω·cm2). This is due to the physical barrier and electrical insulation properties of the hexagonal boron nitride (h-BN) nanosheets.

Microstructure and Electrochemical Properties of Ce-Containing 7072 Al Alloy

2013 ◽  
Vol 704 ◽  
pp. 114-119
Author(s):  
Jing Feng ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Al Alloy ◽  
Nacl Solution ◽  
Tafel Polarization ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Positive Effect

The microstructure and electrochemical properties of Ce-containing 7072 Al alloy were investigated through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Tafel polarization analysis. It was found that Ce alloying could result in a formation of finer grains in the simulated brazing alloys. The 7072 Al alloy with 0.15% Ce had desirable distribution of precipitates. The electrochemical testing results indicated that Ce element had a great impact on the corrosion potential of the alloy tested in 0.5% NaCl solution. Alloying with 0.15% Ce element could make the corrosion potential shift to inert direction and reduce the corrosion current density. An excessive Ce addition could weaken its positive effect on the corrosion resistance of the Ce-containing alloy.

scholarly journals Catalyst-Free Bottom-Up Synthesis of Few-Layer Hexagonal Boron Nitride Nanosheets

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shena M. Stanley ◽  
Amartya Chakrabarti ◽  
Joshua J. DeMuth ◽  
Vanessa E. Tempel ◽  
Narayan S. Hosmane
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
X Ray Diffraction ◽  
Bottom Up ◽  
X Ray ◽  
Boron Nitride Nanosheets ◽  
Catalyst Free ◽  
Transmission Electron ◽  
Novel Catalyst

A novel catalyst-free methodology has been developed to prepare few-layer hexagonal boron nitride nanosheets using a bottom-up process. Scanning electron microscopy and transmission electron microscopy (both high and low resolution) exhibit evidence of less than ten layers of nanosheets with uniform dimension. X-ray diffraction pattern and other additional characterization techniques prove crystallinity and purity of the product.

scholarly journals Atomic-scale dynamics of triangular hole growth in monolayer hexagonal boron nitride under electron irradiation

Nanoscale ◽  
2015 ◽  
Vol 7 (24) ◽  
pp. 10600-10605 ◽  
Author(s):  
Gyeong Hee Ryu ◽  
Hyo Ju Park ◽  
Junga Ryou ◽  
Jinwoo Park ◽  
Jongyeong Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Electron Beam Irradiation ◽  
Hexagonal Boron Nitride ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Beam Irradiation ◽  
Transmission Electron ◽  
Hole Growth ◽  
Over Time

The production of holes by electron beam irradiation in hexagonal boron nitride is monitored over time using atomic resolution transmission electron microscopy.

Microcrystalline Cubic Boron Nitride/Amorphous Hydrogenated Boron Nitride Mixed Phase Thin Films

1994 ◽  
Vol 358 ◽  
Author(s):  
Shu-Han Lin ◽  
Bernard J. Feldman
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Cubic Boron Nitride ◽  
Mixed Phase ◽  
Good Adhesion ◽  
Transmission Electron ◽  
Plasma Decomposition ◽  
Absorption Measurements

ABSTRACTTransparent and insulating thin films have been grown by the plasma decomposition of B2H6, NH3, and H2, at a substrate temperature of 250°C. From chemical composition, transmission electron microscopy, infrared absorption, and optical absorption measurements, the thin films are determined to be a mixed phase of crystalline cubic boron nitride and amorphous hydrogenated boron nitride. Also, the films have significantly more boron than nitrogen, a large concentration of hydrogen, a very large bandgap, strong infrared aborption due to both hexagonal boron nitride and boron icosahedra, and good adhesion to various substrates.

scholarly journals Synthesis of Three-Dimensionally Interconnected Hexagonal Boron Nitride Networked Cu-Ni Composite

2021 ◽  
Vol 59 (7) ◽  
pp. 505-513
Author(s):  
Zahid Hussain ◽  
Hye-Won Yang ◽  
Byung-Sang Choi
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Compaction Pressure ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Composite Energy

A three-dimensionally interconnected hexagonal boron nitride (3Di-hBN) networked Cu-Ni (3DihBN-Cu-Ni) composite was successfully synthesized in situ using a simple two-step process which involved the compaction of mixed Cu-Ni powders (70 wt.% Cu and 30 wt.% Ni) into a disc followed by metal-organic chemical vapor deposition (MOCVD) at 1000 oC. During MOCVD, the Cu-Ni alloy grains acted as a template for the growth of hexagonal boron nitride (hBN) while decaborane and ammonia were used as precursors for boron and nitrogen, respectively. Boron and nitrogen atoms diffused into the Cu-Ni solution during the MOCVD process and precipitated out along the Cu-Ni interfaces upon cooling, resulting in the formation of the 3Di hBN-Cu-Ni composite. Energy-dispersive spectroscopic analysis confirmed the presence of boron and nitrogen atoms at the interfaces of Cu-Ni alloy grains. Optical microscopy examination indicated that there was a minimum amount of bulk hBN at a certain compaction pressure (280 MPa) and sintering time (30 min). Scanning electron microscopy and transmission electron microscopy revealed that an interconnected network of hBN layers surrounding the Cu-Ni grains developed in the 3Di-hBN-Cu-Ni composite. This 3Di-hBN network is expected to enhance the mechanical, thermal, and chemical properties of the 3Di-hBN-Cu-Ni composite. Moreover, the foam-like 3Di-hBN extracted from 3Di-hBN-Cu-Ni composite could have further applications in the fields of biomedicine and energy storage.

scholarly journals High-Yield Synthesis of Cubic and Hexagonal Boron Nitride Nanoparticles by Laser Chemical Vapor Decomposition of Borazine

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
A. Hidalgo ◽  
V. Makarov ◽  
G. Morell ◽  
B. R. Weiner
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
High Yield ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Chemical Vapor Decomposition ◽  
Electron Energy Loss ◽  
Bn Nanostructures

We report a new method for the synthesis of boron nitride nanostructures (nBN) using laser chemical vapor decomposition (LCVD). Borazine was used as precursor and excited with two simultaneous radiations, the fundamental and second YAG laser harmonics. If only one of the two radiations is employed, no reaction takes place. Abundant BN powder is obtained after one hour of laser radiation. The BN yield obtained with the LCVD technique is about 83% by weight. The BN material was characterized using scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. They all indicate that the BN powder consists of a mixture of hexagonal and cubic BN nanostructures. No other BN phases or stoichiometries were found. The size of the resulting BN nanostructures is in the range of 20–100 nm and their B : N composition is 1 : 1. A simplified mechanism involving laser-excited states followed by photoinduced removal of hydrogen is proposed to understand the synthesis of BN nanopowder by LCVD of borazine.

Atomically thin hexagonal boron nitride probed by ultrahigh-resolution transmission electron microscopy

2009 ◽  
Vol 80 (15) ◽  
Author(s):  
Nasim Alem ◽  
Rolf Erni ◽  
Christian Kisielowski ◽  
Marta D. Rossell ◽  
Will Gannett ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Ultrahigh Resolution ◽  
Transmission Electron
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