scholarly journals New Insights into the Reactivity of Detonation Nanodiamonds during the First Stages of Graphitization

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2671
Author(s):  
Florent Ducrozet ◽  
Hugues A. Girard ◽  
Jocelyne Leroy ◽  
Eric Larquet ◽  
Ileana Florea ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Surface Chemistry ◽  
Atmospheric Pressure ◽  
Outer Shell ◽  
Detonation Nanodiamonds ◽  
Annealing Atmosphere ◽  
Xps Analysis ◽  
Extreme Surface ◽  
Complementary Techniques ◽  
Set Up

The present study aims to compare the early stages of graphitization of the same DND source for two annealing atmospheres (primary vacuum, argon at atmospheric pressure) in an identical set-up. DND samples are finely characterized by a combination of complementary techniques (FTIR, Raman, XPS, HR-TEM) to highlight the induced modifications for temperature up to 1100 °C. The annealing atmosphere has a significant impact on the graphitization kinetics with a higher fraction of sp2-C formed under vacuum compared to argon for the same temperature. Whatever the annealing atmosphere, carbon hydrogen bonds are created at the DND surface during annealing according to FTIR. A “nano effect”, specific to the < 10 nm size of DND, exalts the extreme surface chemistry in XPS analysis. According to HR-TEM images, the graphitization is limited to the first outer shell even for DND annealed at 1100 °C under vacuum

scholarly journals Laser-Induced Modification of Hydrogenated Detonation Nanodiamonds in Ethanol

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2251
Author(s):  
Irena Bydzovska ◽  
Ekaterina Shagieva ◽  
Ivan Gordeev ◽  
Oleksandr Romanyuk ◽  
Zuzana Nemeckova ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Laser Irradiation ◽  
Structural Changes ◽  
Irradiation Time ◽  
Detonation Nanodiamonds ◽  
High Temperature Annealing ◽  
Inert Environment ◽  
Transmission Electron ◽  
Gradual Loss ◽  
532 Nm

Apart from the frequently used high-temperature annealing of detonation nanodiamonds (DNDs) in an inert environment, laser irradiation of DNDs in a liquid can be effectively used for onion-like carbon (OLC) formation. Here, we used fully de-aggregated hydrogenated DNDs (H-DNDs) dispersed in ethanol, which were irradiated for up to 60 min using a 532 nm NdYAG laser with an energy of 150 mJ in a pulse (5 J/cm2) at a pulse duration of 10 ns and a repetition rate of 10 Hz. We investigated the DND surface chemistry, zeta potential, and structure as a function of laser irradiation time. Infrared spectroscopy revealed a monotonical decrease in the C–Hx band intensities and an increase of the C–O and C=O features. Transmission electron microscopy (TEM) revealed the formation of OLC, as well as a gradual loss of nanoparticle character, with increasing irradiation time. Surprisingly, for samples irradiated up to 40 min, the typical and unchanged DND Raman spectrum was recovered after their annealing in air at 450 °C for 300 min. This finding indicates the inhomogeneous sp3 to sp2 carbon transformation during laser irradiation, as well as the insensitivity of DND Raman spectra to surface chemistry, size, and transient structural changes.

Surface Chemistry and Properties of Ozone-Purified Detonation Nanodiamonds

2011 ◽  
Vol 115 (20) ◽  
pp. 9827-9837 ◽  
Author(s):  
O. Shenderova ◽  
A. Koscheev ◽  
N. Zaripov ◽  
I. Petrov ◽  
Y. Skryabin ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Detonation Nanodiamonds

Influence of hydrogen bonds on the colloidal and fluorescent properties of detonation nanodiamonds in water, methanol and ethanol

2017 ◽  
Vol 25 (10) ◽  
pp. 602-606 ◽  
Author(s):  
S. A. Burikov ◽  
A. M. Vervald ◽  
K. A. Laptinskiy ◽  
T. V. Laptinskaya ◽  
O. A. Shenderova ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Detonation Nanodiamonds ◽  
Fluorescent Properties

Use BP Neural Network Set up the Corrosion Prediction Model of Low Temperature Parts of Atmospheric Pressure Device

2012 ◽  
Vol 152-154 ◽  
pp. 1138-1142 ◽  
Author(s):  
Yu Guang Fan ◽  
Zai Dong Piao ◽  
Bing Chen ◽  
Hong Xian Lin ◽  
Yang Yang
Keyword(s):  
Neural Network ◽  
Low Temperature ◽  
Prediction Model ◽  
Corrosion Protection ◽  
Bp Neural Network ◽  
Atmospheric Pressure ◽  
Ph Value ◽  
Set Up

In research of the low temperature parts of atmospheric pressure device, by using BP neural network, the connection of PH value, Cl-, H2S and Fe+2 was setup which can predict Fe+2 content accurately, and obtain the requirement accuracy, hence more accurate corrosion can be predicted and providing more suggests for corrosion protection.

scholarly journals Crystal structure of [Co(NH3)6][Co(CO)4]2

2015 ◽  
Vol 71 (11) ◽  
pp. 1418-1420 ◽  
Author(s):  
Thomas G. Müller ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Hydrogen Bonds ◽  
Liquid Ammonia ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Distorted Tetrahedron ◽  
Carbonyl Ligands ◽  
Set Up

Hexaamminecobalt(II) bis[tetracarbonylcobaltate(-I)], [Co(NH3)6][Co(CO)4]2, was synthesized by reaction of liquid ammonia with Co2(CO)8. The CoIIatom is coordinated by six ammine ligands. The resulting polyhedron, the hexaamminecobalt(II) cation, exhibits point group symmetry -3. The Co-Iatom is coordinated by four carbonyl ligands, leading to a tetracarbonylcobaltate(−I) anion in the shape of a slightly distorted tetrahedron, with point group symmetry 3. The crystal structure is related to that of high-pressure BaC2(space groupR-3m), with the [Co(NH3)6]2+cations replacing the Ba sites and the [Co(CO)4]−anions replacing the C sites. N—H...O hydrogen bonds between cations and anions stabilize the structural set-up in the title compound.

scholarly journals Influence of chemosynthetic substrates availability on symbiont densities, carbon assimilation and transfer in the dual symbiotic vent mussel <I>Bathymodiolus azoricus</I>

2008 ◽  
Vol 5 (3) ◽  
pp. 2279-2304 ◽  
Author(s):  
V. Riou ◽  
S. Halary ◽  
S. Duperron ◽  
S. Bouillon ◽  
M. Elskens ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Hydrothermal Vents ◽  
Inorganic Carbon ◽  
Carbon Assimilation ◽  
Gill Tissue ◽  
Mid Atlantic Ridge ◽  
Set Up ◽  
High Level ◽  
Substrate Concentrations

Abstract. High densities of mussels of the genus Bathymodiolus are present at hydrothermal vents of the Mid-Atlantic Ridge. It was already proposed that the chemistry at vent sites would affect their sulphide- and methane-oxidizing endosymbionts' abundance. In this study, we confirmed the latter assumption using fluorescence in situ hybridization on Bathymodiolus azoricus specimens maintained in a controlled laboratory environment at atmospheric pressure with one, both or none of the chemical substrates. A high level of symbiosis plasticity was observed, methane-oxidizers occupying between 4 and 39% of total bacterial area and both symbionts developing accordingly to the presence or absence of their substrates. Using H13CO3− in the presence of sulphide, 13CH4 or 13CH3OH, we monitored carbon assimilation by the endosymbionts and its translocation to symbiont-free mussel tissues. Although no significant carbon assimilation could be evidenced with methanol, carbon was incorporated from methane and sulphide-oxidized inorganic carbon at rates 3 to 10 times slower in the host muscle tissue than in the symbiont-containing gill tissue. Both symbionts thus contribute actively to B. azoricus nutrition and adapt to the availability of their substrates. Further experiments with varying substrate concentrations using the same set-up should provide useful tools to study and even model the effects of changes in hydrothermal fluids on B. azoricus' chemosynthetic nutrition.

scholarly journals Dutch Skies, Global Laws

2016 ◽  
Vol 46 (1) ◽  
pp. 1-43 ◽  
Author(s):  
A. Achbari ◽  
F. van Lunteren
Keyword(s):  
Wind Direction ◽  
Atmospheric Pressure ◽  
Royal Society ◽  
Warning System ◽  
Scientific Basis ◽  
Local Rule ◽  
Rule Of Thumb ◽  
The World ◽  
Set Up ◽  
A Current

This essay examines the transformation of a local rule of thumb into a widely acknowledged meteorological law, generally known as Buys Ballot’s law. This law relates wind direction to atmospheric pressure. From 1857 to 1867, Christophorus Buys Ballot (1817–1890) actively lobbied in the international arena for his wind rule, which he regarded as a promising basis for a system of storm warnings. At the same time he was reluctant to generalize his rule beyond the Dutch boundaries or to make strong claims about its predictive nature. Initially he failed to interest foreign meteorologists in his work, partly because of a widespread scepticism with regard to meteorological predictions, and partly because some of his foreign colleagues favored competing theories. One of his main rivals in this respect was Robert Fitzroy, director of the British Meteorological Office, who had set up his own warning system. This practice provoked the wrath of the Royal Society, as its members regarded Fitzroy’s theories and the resulting predictions as unscientific. After his death the Society took the British Meteorological Office under its control and abolished the practice of storm warnings. The resulting wave of protests from people who felt they had benefitted from the warnings landed the Society in an awkward predicament. The warnings could only be reintroduced without losing face if they had a “scientific” basis, and therefore finding a sound basis for storm predictions became a matter of urgency. At last Buys Ballot found a willing ear for his campaign. A rapid verification of his wind rule in Britain sufficed for the introduction of the unprecedented expression “Buys Ballot’s law” in the Royal Society reports. From these authoritative reports the designation rapidly spread all over the world, thus becoming a current expression.

SHADE3server: a streamlined approach to estimate H-atom anisotropic displacement parameters using periodicab initiocalculations or experimental information

2014 ◽  
Vol 47 (6) ◽  
pp. 2100-2104 ◽  
Author(s):  
Anders Østergaard Madsen ◽  
Anna A. Hoser
Keyword(s):  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Ab Initio ◽  
Experimental Information ◽  
Neutron Diffraction Data ◽  
New Methods ◽  
Anisotropic Displacement Parameters ◽  
Proton Sponges ◽  
Set Up ◽  
Better Than

A major update of theSHADEserver (http://shade.ki.ku.dk) is presented. In addition to all of the previous options for estimating H-atom anisotropic displacement parameters (ADPs) that were offered bySHADE2, the newest version offers two new methods. The first method combines the original translation–libration–screw analysis with input from periodicab initiocalculations. The second method allows the user to input experimental information from spectroscopic measurements or from neutron diffraction experiments on related structures and utilize this information to evaluate ADPs of H atoms. Tools are provided to set up theab initiocalculations and to derive the internal motion from the calculations. The new server was tested on a range of compounds where neutron diffraction data were available. In most cases, the results are significantly better than previous estimates, and for strong hydrogen bonds in proton sponges, theab initiocalculations become crucial.

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