Hydrolytic Lignin: It’s Activated and Fluorinated Forms

2019 ◽  
Vol 806 ◽  
pp. 100-105 ◽  
Author(s):  
Yury M. Nikolenko ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Vladimir E. Silant'ev ◽  
Valery G. Kuryavyi ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Energy Intensity ◽  
Electronic Conductivity ◽  
High Vacuum ◽  
Electrochemical Process ◽  
Physical Activation ◽  
Operating Voltage ◽  
Thermally Activated ◽  
Hydrolytic Lignin ◽  
Structural Blocks

The hydrolytic lignin (HL) derivatives have been prepared via its physical activation (high-temperature annealing in vacuum) followed by chemical modification (fluorination). It was found that the graphitized product of thermal activation up to 1000 °C at a low temperature gain rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes it potentially useful as sorbent, catalytic substrate, or electrode material. It was revealed from the experimental data the manufactured graphitized material consists of nanometric structural blocks, possibly nanographites and/or few-layer nanographenes. The edges of graphenes in agglomerates in activated hydrolytic lignin (AHL) have armchair and zigzag shapes. The nontrivial electronic structure of the zigzag edges, along with the electronic conductivity and the ability of AHL to absorb oxygen, can cause an increase in the energy intensity of lithium battery (LB) manufactured using AHL.The carbon-fluorine bond of semi-ionic type was detected in HL and AHL fluorinated in the temperature range of synthesize 60 – 300 oC. The fluorinated forms of both HL and its thermally activated product show increased values of operating voltage due to the participation of fluorine bound to carbon in the electrochemical process.

New Energy-Consuming Carbon Materials Derived from Hydrolytic Lignin

2020 ◽  
Vol 992 ◽  
pp. 814-820
Author(s):  
Yury M. Nikolenko ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
A. Sokolov ◽  
Albert M. Ziatdinov
Keyword(s):  
Lithium Battery ◽  
Specific Capacity ◽  
Electrochemical Process ◽  
Physical Activation ◽  
Operating Voltage ◽  
Thermally Activated ◽  
New Energy ◽  
Hydrolytic Lignin ◽  
Different Temperatures ◽  
Energy Consuming

Hydrolytic lignin (HL) has been used in manufacturing of graphitized carbon via HL one-step physical activation. It was found that the layered carbon products of pyrolysis of hydrolytic lignin (AHL) at different temperatures may be used as cathode materials in primary current sources. The galvanostatic discharge of lithium battery at a current density of 100 μA/cm2 between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of lithium battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process. Some fluorinated AHL samples show the promise of their use as supercapacitor electrodes.

High-Capacity Derivatives Produced from Hydrolytic Lignin as Electrode Materials for Energy Storage and Conversion

2018 ◽  
Vol 386 ◽  
pp. 359-364
Author(s):  
Yury M. Nikolenko ◽  
Denis P. Opra ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Valery G. Kuryavyi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Energy Storage ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Energy Storage And Conversion ◽  
Operating Voltage ◽  
X Ray ◽  
Thermally Activated ◽  
Hydrolytic Lignin

The hydrolytic lignin derivatives have been prepared via its physical activation (high-temperature heating in vacuum) followed by chemical modification (fluorination). The obtained products were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the graphitized product of thermal activation up to 1000 °C at a low rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes its potentially useful as sorbent, catalytic substrate or electrode material. To clarify the potentialities of hydrolytic lignin derivatives for energy storage and conversion, the electrochemical system with metallic lithium anode was applied. The galvanostatic discharge of battery at a current density of 100 μA/cm2between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The improve of the electrochemical performance of product originates from its graphitization, increasing electronic conductivity, and, possibly, enhanced ability to adsorb of oxygen. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process.

Modeling of Dislocation Mobility in Metals: Effect of Obstacles and Thermal Processes

2001 ◽  
Vol 683 ◽  
Author(s):  
Masato Hiratani ◽  
Hussein M. Zbib
Keyword(s):  
Thermal Activation ◽  
Dislocation Dynamics ◽  
Thermal Processes ◽  
Weak Point ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Discrete Dislocation Dynamics ◽  
Discrete Dislocation ◽  
Activation Rate ◽  
Activation Event

ABSTRACTThermally activated dislocation glide velocity through weak point obstacle arrays is studied analytically and computationally. Thermal activation rate is estimated using the modified Friedel relations under the weak obstacle approximation. The average flight velocity after an activation event as a function of stress and temperature is obtained by the discrete dislocation dynamics (DD). This numerical calculation includes the effect of self-stress, interaction with electrons and phonons, and the inertial effect. These results are implemented into a phenomenological model to study the dislocation velocity under various conditions. The model can reproduce both obstacle control and drag control motion in low and high velocity regions, and a flow stress anomaly at transient regions.

Spectroscopic Identification of the Acceptor-Hydrogen Complex in Mg-Doped GaN Grown by MOCVD

1997 ◽  
Vol 468 ◽  
Author(s):  
W. Götz ◽  
M. D. McCluskey ◽  
N. M. Johnson ◽  
D. P. Bour ◽  
E. E. Haller
Keyword(s):  
Hall Effect ◽  
Absorption Spectra ◽  
Thermal Activation ◽  
Variable Temperature ◽  
Chemical Vapor ◽  
Thermally Activated ◽  
Local Vibrational Mode ◽  
Hall Effect Measurements ◽  
Spectroscopic Identification ◽  
Mg Doped

ABSTRACTMg-doped GaN films grown by metalorganic chemical vapor deposition were characterized by variable-temperature Hall-effect measurements and Fourier-transform infrared absorption spectroscopy. As-grown, thermally activated, and deuterated Mg-doped GaN samples were investigated. The existence of Mg-H complexes in GaN is demonstrated with the observation of a local vibrational mode (LVM) at 3125 cm-1 (8 K). At 300 K this absorption line shifts to 3122 cm-1. The intensity of the LVM line is strongest in absorption spectra of as-grown GaN. Mg which is semi-insulating. Upon thermal activation, the intensity of the LVM line significantly decreases and an acceptor concentration of 2×1019cm-3 is derived from the Hall-effect data. After deuteration at 600°C the resistivity of the Mg-doped GaN increased by four orders of magnitude. A LVM line at 2321 cm-1 (8 K) appears in the absorption spectra which is consistent with the isotopie shift of the vibrational frequency when D is substituted for H.

Stable and metallic two-dimensional TaC2as an anode material for lithium-ion battery

2017 ◽  
Vol 5 (35) ◽  
pp. 18698-18706 ◽  
Author(s):  
Tong Yu ◽  
Shoutao Zhang ◽  
Fei Li ◽  
Ziyuan Zhao ◽  
Lulu Liu ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Anode Material ◽  
Diffusion Rate ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Operating Voltage ◽  
Two Dimensional ◽  
High Specific Capacity

Two dimensional TaC2is a promising anode material from the standpoint of a high specific capacity, fast Li diffusion rate, low operating voltage, and good electronic conductivity.

scholarly journals Molecular-scale thermally activated fractures in methane hydrates: a molecular dynamics study

2019 ◽  
Vol 21 (25) ◽  
pp. 13539-13544 ◽  
Author(s):  
Henrik Andersen Sveinsson ◽  
Anders Malthe-Sørenssen
Keyword(s):  
Molecular Dynamics ◽  
Thermal Activation ◽  
Fracture Initiation ◽  
Methane Hydrates ◽  
Activation Model ◽  
Thermally Activated ◽  
Molecular Scale

Cage by cage slow fracture initiation in methane hydrates is consistent with a thermal activation model.

Electrochemical Performances of Li4Ti5-xAlxO12 (x=0.03, 0.05, 0.10) as Anode Materials for Lithium Ion Battery

2013 ◽  
Vol 750-752 ◽  
pp. 1791-1794
Author(s):  
Fang Gu
Keyword(s):  
Anode Materials ◽  
Solution Method ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
Negative Influence ◽  
Electrochemical Process ◽  
Electrochemical Performances ◽  
X Ray Diffraction

Li4Ti5-xAlxO12(x=0.03, 0.05, 0.10) were prepared by a solution method. The electrochemical performances including charge-discharge and AC impedance were investigated. The structure of the samples were characterized by X-ray diffraction. The results revealed that proper Al doped into Li4Ti5O12would not change or destroy the crystal structure. Li4Ti5-xAlxO12(x=0.03, 0.05) had better capacity than Li4Ti5O12, because of the decrease of electric resistance. But when the quality percent of Al was too big, it will bring negative influence to Li4Ti5O12. Al3+doping did not change the electrochemical process, instead enhanced the electronic conductivity and ionic conductivity. The reversible capacity and cycling performance were effectively improved.

Hydrogen Production from Ethanol. Comparing Thermal Catalytic Reactions to Photo-catalytic Reactions.

2011 ◽  
Vol 1326 ◽  
Author(s):  
M. Scott ◽  
A.M. Nadeem ◽  
G.I.W. Waterhouse ◽  
H. Idriss
Keyword(s):  
Hydrogen Production ◽  
Thermal Activation ◽  
Room Temperature ◽  
Complete Removal ◽  
Catalytic Reactions ◽  
Hydrogen Yield ◽  
Hydrogen Atoms ◽  
Catalytic Systems ◽  
Thermally Activated ◽  
Sustainable System

ABSTRACTHydrogen production from renewables such as bio-ethanol is one of the most promising processes for energy carriers in a sustainable way. In this work we review and compare two catalytic systems: one based on thermal activation over bimetallic catalysts (Rh-Pd/CeO2) and the other over photo-excited semiconductor catalysts (Au/TiO2 anatine, rutile and anatase/rutile). It is found that the hydrogen yield is far higher on the thermally activated catalysts (at 773K) when compared to that of the photo-exited catalysts (at room temperature); about 60 times. However, the photo-excited catalysts are a promising way to create a fully sustainable system for future applications if the complete removal of hydrogen atoms from water and ethanol are obtained at room temperature.

scholarly journals Fast and Slow Magnetization Processes in Magnetic Recording Media

2005 ◽  
Vol 887 ◽  
Author(s):  
J. Zhou ◽  
R. Skomski ◽  
S. Michalski ◽  
R. D. Kirby ◽  
D. J. Sellmyer
Keyword(s):  
Magnetic Recording ◽  
Remanent Magnetization ◽  
Thermal Activation ◽  
Information Loss ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Local Anisotropy ◽  
Thermally Activated ◽  
Ultrahigh Density ◽  
Magnetization Processes

ABSTRACTInformation loss due to thermal activation is a major concern in ultrahigh-density magnetic recording media. The usually considered mechanism is thermally activated magnetization reversal over micromagnetic energy barriers. However, micromagnetic approaches ignore local anisotropy fluctuations, which translate into a time-dependent reduction of the remanent magnetization. The effect is negligibly small in macroscopic magnets but becomes important on a scale of a few nanometers.

Mechanical Properties of Nanocrystalline Cu and Cu-Zn Using Tensile and Shear Punch Tests

2009 ◽  
Vol 633-634 ◽  
pp. 373-382 ◽  
Author(s):  
J.M. Tao ◽  
Xin Kun Zhu ◽  
P.Z. Wong ◽  
Ron O. Scattergood ◽  
Carl C. Koch
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Rate Sensitivity ◽  
Physical Activation ◽  
Thermally Activated ◽  
Punch Test ◽  
Shear Punch Test ◽  
Average Grain Size ◽  
Shear Punch ◽  
Zn Alloys

Shear punch test (SPT) has been used to study the mechanical properties of Cu, Cu–10 wt.% Zn, Cu–20 wt.% Zn and Cu–30 wt.% Zn after ball milling with an average grain size in the range of 33-12nm. The strain rate sensitivity (SRS) and physical activation volume have been determined. The magnitude observed for these characteristic deformation parameters is very different from their course-grained (cg) counterpart. This suggests that the thermally activated process in nanocrystalline (nc) metal/alloys is different from the conventional forest dislocation cutting mechanism. The stacking fault energy (SFE) of Cu-Zn alloys decreased with the adding of Zn, and deformation twins are anticipated to introduce into the nc Cu-Zn alloys during process of ball milling. Dislocations could accumulate along the TBs and carry the plastic strain, so the ductility of nc Cu-Zn alloys could be improved.

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