Formation the Properties of Carbon Black Particles by Gas-Phase Thermochemical Modification

2019 ◽  
Vol 10 (2) ◽  
pp. 480-495 ◽  
Author(s):  
Yu. V. Surovikin ◽  
A. G. Shaitanov ◽  
I. V. Rezanov ◽  
A. V. Syrieva
Keyword(s):  
Carbon Black ◽  
Gas Phase ◽  
Thermochemical Modification

Formation of properties of carbon black particles in the conditions of the gas-phase thermochemical modification

2018 ◽  
pp. 53-73 ◽  
Author(s):  
Yu. V. Surovikin ◽  
◽  
A. G. Shaitanov ◽  
I. V. Rezanov ◽  
A. V. Syrieva ◽  
...  
Keyword(s):  
Carbon Black ◽  
Gas Phase ◽  
Thermochemical Modification

Gas phase hydrogenation of crotonaldehyde over platinum supported on oxidized carbon black

Carbon ◽  
1998 ◽  
Vol 36 (7-8) ◽  
pp. 1011-1019 ◽  
Author(s):  
F. Coloma ◽  
J. Narciso-Romero ◽  
A. Sepúlveda-Escribano ◽  
F. Rodríguez-Reinoso
Keyword(s):  
Carbon Black ◽  
Gas Phase ◽  
Oxidized Carbon

Mechanism of Silicon/Carbon Reaction for β-SiC Bonded SiC Materials

2011 ◽  
Vol 335-336 ◽  
pp. 12-17 ◽  
Author(s):  
Chun Jiang Lv ◽  
Yang Yang ◽  
Zhen Liu ◽  
Long Fei Li ◽  
Cheng Chang ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Carbon Black ◽  
Gas Phase ◽  
Reaction Sintering ◽  
In Situ Reaction ◽  
Sic Nanowires ◽  
Silicon Carbon ◽  
Mechanism Of Reaction

Based on industrial silicon and carbon black as starting materials,β-SiC bonded SiC materials were prepared. The microstructure of such material and the silicon/carbon reaction were analyzed and investigated by XRD, SEM and other tools. The results indicate that the synthesis of β-SiC at 1400°C can be achieved through gas-phase mass transfer, liquid dissolution as well as in-situ reaction. While gas-phase mass transfer is the dominant reaction during the sintering of the material, in which β-SiC exists mainly as nanowhisker. The formation of β-SiC nanowires is believed to be the mechanism of reaction sintering.

Isothermal and thermo-osmotic transport of sorbable gases in microporous carbon membranes

1973 ◽  
Vol 275 (1249) ◽  
pp. 255-307 ◽  
Keyword(s):  
Steady State ◽  
Carbon Black ◽  
Gas Phase ◽  
Diffusion Coefficients ◽  
Linear Relation ◽  
Microporous Carbon ◽  
Adsorbed Molecules ◽  
Carbon Membranes ◽  
Adsorbed Films ◽  
Absolute Adsorption

With the use of helium and a series of gases adsorbed to give dilute films, measurements have been made of thermo-osmotic steady-state pressure ratios established across microporous carbon membranes through which linear temperature gradients were maintained. Two contrasting adsorbents were employed: Carbolac I, a carbon black having an energetically heterogeneous high area surface and Graphon, a graphitized carbon black of one-tenth the surface area of Carbolac but energetically homogeneous. Complementary studies of isothermal transport of the gases through the membranes and determination of equilibrium adsorption isotherms at all temperatures employed for the flow experiments were required in order to analyse the non-isothermal experimental results. Part I is concerned with the equilibrium properties of the adsorbed films. Henry’s law constants, k, energies of adsorption, A E'and isosteric heats of adsorption, for the Gibbs excess adsorption were derived from the experimental isotherms. Taking the thickness of the adsorbed layer as one molecular diameter, the corresponding energies, A E,and heats qBt for absolute adsorption have been calculated. For the very dilute films the ratios AE'jAE and q'BtlqBt can differ appreciably from unity. Also in the Henry law range, values of the thermodynamic equilibrium constants and standard energies, AE&, and entropies, A for absolute adsorption have been evaluated. A linear relation between AS& and AE&, was observed. — A was considerably larger on Carbolac than on Graphon surfaces. This has been interpreted in terms of greater mobility of the adsorbed molecules on the more homogeneous Graphon surface. Good correlations have been found between K or A Eand properties, such as polarizability, a, related to the condensability of the sorbates. Part II is concerned with isothermal transport of the gases through the membranes. For the majority of systems studied the permeability, K and time-lag, L, were independent of pressure. For helium in both membranes the ratio K/^T was independent of temperature and pressure, indicating transport only in the gas phase and the absence of a viscous flow component. For an adsorbed gas the extra flux generated by the mobile adsorbed films per unit area of surface, JJA, were considerably greater for the more homogeneous Graphon membrane. Diffusion coefficients associated with the extra fluxes also indicated greater mobility of adsorbed molecules on the more homogeneous surface. Good correlations between K{MT)^ and ke have been demonstrated and, at constant temperature, a linear relation was observed between KM$ and the product, aTb, of polarizability and boiling-point TB. Gas-phase structure factors obtained by the procedure of Barrer & Gabor (1959) were considerably less than unity, indicating a dominant influence in each membrane of tortuosity and bottlenecks. For each membrane a linear relation has been demonstrated between the products KL and kB from which parameters associated with blind pore character have been obtained. Part III is concerned with the thermo-osmotic transport of the gases in the membranes. The nonisothermal flow is formulated in terms of the thermodynamics of irreversible processes and relations derived between the straight phenomenological coefficients of this treatment and the permeabilities and diffusion coefficients of part II. Equations are also presented relating the overall heat of transport, Q0, at temperature T0 to component heats of transport for the gas-phase flow (Qg, Q*) and extra flow (QB, Q*). In none of the systems studied did Q0 = — %RT0, the ideal value expected for a gas transported by molecular streaming (Knudsen flow). For He, H 2 and Ne in the Carbolac membranes, — ifiRT0 where /?, for a particular gas, is a constant < 1. With increasing sorbability of the flowing gas the temperature dependence of Q0 was progressively modified until, in the presence of substantial extra flow, — Q0 decreased strongly with increasing T0. Calculations of Qs and Q* are presented for the two limiting cases Q e— and Qg = 0. It is shown that Qs must always be negative and positive. A procedure for calculating isobaric permeabilities, utilizing a combination of thermo-osmotic steady-state and isothermal steady-state measurements, has been developed. For various pairs of gases, the ratios of isobaric permeabilities differed greatly from the corresponding ratios of isothermal permeabilities. Enhanced separations of sorbable mixtures by isobaric flow appear to be possible especially for the Graphon membrane.

On the gas-phase reforming of glycerol by Pt on carbon black: Effects of metal particle size and pH value of the glycerol stream

2016 ◽  
Vol 422 ◽  
pp. 142-147 ◽  
Author(s):  
Ricardo R. Soares ◽  
Douglas F. Martins ◽  
Douglas E.S. Pereira ◽  
Marlon B. Almeida ◽  
Yiu L. Lam
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Gas Phase ◽  
Metal Particle ◽  
Ph Value ◽  
Metal Particle Size

A Preparation of High Resolution Standards for Electron Microscopy. Part II

1971 ◽  
Vol 29 ◽  
pp. 160-161
Author(s):  
Akira Tanaka ◽  
David F. Harling
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Carbon Black ◽  
Single Crystal ◽  
Dark Field ◽  
Graphitized Carbon Black ◽  
Graphitized Carbon ◽  
Dark Field Imaging ◽  
Crystal Films ◽  
Micro Holes

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.

Residual Gas Reactions in the Electron Microscope: I. Qualitative Observations on the Water Gas Reaction

1968 ◽  
Vol 26 ◽  
pp. 292-293
Author(s):  
Richard E. Hartman ◽  
Roberta S. Hartman ◽  
Peter L. Ramos
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Gas Phase ◽  
Absolute Temperature ◽  
Residual Gas ◽  
Gas Reactions ◽  
Image Position ◽  
The Right ◽  
Water Gas ◽  
Thinning Rate

The action of water and the electron beam on organic specimens in the electron microscope results in the removal of oxidizable material (primarily hydrogen and carbon) by reactions similar to the water gas reaction .which has the form:The energy required to force the reaction to the right is supplied by the interaction of the electron beam with the specimen.The mass of water striking the specimen is given by:where u = gH2O/cm2 sec, PH2O = partial pressure of water in Torr, & T = absolute temperature of the gas phase. If it is assumed that mass is removed from the specimen by a reaction approximated by (1) and that the specimen is uniformly thinned by the reaction, then the thinning rate in A/ min iswhere x = thickness of the specimen in A, t = time in minutes, & E = efficiency (the fraction of the water striking the specimen which reacts with it).

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