The Effects of Heating and Cooling Rates on the Structure of Carbon Black Particles

1998 ◽  
Vol 71 (1) ◽  
pp. 26-37 ◽  
Author(s):  
T. W. Zerda ◽  
W. Xu ◽  
H. Yang ◽  
M. Gerspacher
Keyword(s):  
Surface Roughness ◽  
Carbon Black ◽  
Amorphous Carbon ◽  
Cooling Rates ◽  
Carbon Blacks ◽  
Carbon Particles ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Crystallite Sizes ◽  
Bet Technique

Abstract The effects of heating and cooling rates on the structure of N660 and N299 carbon black particles have been investigated using Raman spectroscopy, X-ray scattering, and the BET technique. Carbon blacks were kept at 2700 K for various lengths of time and next cooled down at different rates. The size of crystallites and the surface roughness of the particles have been determined for these different treatment schedules. The fractal dimension decreases from 2.2 for untreated samples to 2.0 for samples heat treated to 1300 K. Cooling rates do not affect the surface roughness. However, rapid cooling reduces crystallite sizes. We postulate that the surface of carbon particles is composed of crystallites and amorphous carbon. The amount of amorphous carbon depends on the thermal treatment. The role of amorphous carbon in determining reinforcing properties of carbon blacks in tires is discussed.

INVESTIGATION OF THE ELECTROCHEMICAL BEHAVIOR OF HEAT-TREATED CARBON BLACKS AND Pt/C CATALYSTS

2002 ◽  
Vol 09 (03n04) ◽  
pp. 1443-1452 ◽  
Author(s):  
C. D. HUANG ◽  
Z. T. XIONG ◽  
J. Y. LIN ◽  
K. L. TAN
Keyword(s):  
Carbon Black ◽  
Electrochemical Behavior ◽  
Catalyst Support ◽  
Carbon Surface ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Platinum Particles ◽  
Electro Oxidation ◽  
Treated Carbon ◽  
Xps Study

In this paper we report the electrochemical behavior of heat-treated carbon blacks and Pt/C catalysts. Cyclic voltammetry indicates that the heat-treated carbon black as catalyst support does not improve the Pt/C catalyst's activity for methanol oxidation. An XPS study of a Pt-loaded carbon black indicates that the amounts of oxidized platinum and oxygen-functional groups on catalysts are decreased when the platinum particles are deposited on the heat-treated carbon surface. These changes in the surface and crystalline structural properties of carbon materials lead to the catalytic activity change in methanol electro-oxidation.

ADSORPTION STUDIES ON A SERIES OF HEAT TREATED SHAWINIGAN ACETYLENE CARBON BLACKS

1957 ◽  
Vol 35 (12) ◽  
pp. 1542-1554 ◽  
Author(s):  
J. M. Holmes ◽  
R. A. Beebe
Keyword(s):  
Heat Treatment ◽  
Carbon Black ◽  
Low Oxygen ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Treated Carbon ◽  
Derivatives Of ◽  
Graphitic Material ◽  
Acetylene Carbon ◽  
Acetylene Carbon Black

An experimental study has been made of the adsorption of a nitrogen, sulphur dioxide, carbon dioxide, and ammonia on Shawinigan acetylene carbon black and several derivatives of this material produced by heat treatment up to temperatures of 3000°. The effect of the heat treatment of the Shawinigan carbon black on its adsorption of the polar and non-polar gases studied is compared with the behavior of other heat treated carbon blacks. In particular, the effect of the low oxygen content of the Shawinigan black is considered. The isosteric heats of adsorption for ammonia on the most highly graphitized material (Shawinigan 3000) have been calculated. The results are in general agreement with previous calorimetric work of this laboratory. A special type of hysteresis for the system ammonia – Shawinigan black has been observed. This may be due to a reversible swelling of the graphitic material.

A Method for Evaluation of Carbon Blacks and Correlation with Road Wear Ratings

1974 ◽  
Vol 2 (3) ◽  
pp. 211-228 ◽  
Author(s):  
G. R. Cotten ◽  
E. M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Abrasion Resistance ◽  
Laboratory Tests ◽  
The Other ◽  
Rubber Content ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Bound Rubber ◽  
Normal Production

Abstract Prediction of tread wear from laboratory tests can be a valuable guide in the development of improved carbon blacks and controlling the quality of normal production. We have developed two tests which give good correlation with actual road wear data on over 100 experimental blacks. One test involves running Akron angle abrasion on a compound with only 30 phr of carbon black where differences in abrasion resistance are magnified. The other test measures surface activity towards the polymer by determining bound rubber content of a heat-treated nonproductive mix. By using both tests together, tread wear ratings of blacks used in this study could be predicted almost as well as by a single, controlled, multisectional road test with five tires run for 8000–10,000 miles.

Carbon Black Structure Effects in Synthetic Rubbers

1961 ◽  
Vol 34 (4) ◽  
pp. 1141-1161
Author(s):  
T. D. Bolt ◽  
E. M. Dannenberg ◽  
R. E. Dobbin ◽  
R. P. Rossman
Keyword(s):  
Carbon Black ◽  
Term Structure ◽  
Primary Structure ◽  
Mechanical Strain ◽  
Secondary Structures ◽  
Spherical Particles ◽  
Carbon Blacks ◽  
Carbon Particles ◽  
Particle Association ◽  
High Degree

Abstract Carbon blacks are composed of spherical particles which are to varying degrees arranged in chainlike structures. This type of particle association, which is readily seen in electron photomicrographs of most carbon blacks, can be termed “primary structure”. The use of the term “structure” to describe interparticle association must not be confused with the basic intraparticle structure of an atomic crystallographic nature. There is strong evidence that primary structure units, and possibly individual particles, can further associate or flocculate in fluid or elastomeric systems. This is a secondary type of structure formation which can be readily disrupted under the influence of mechanical strain. Some investigators have used the term “structure” to describe this strain-sensitive flocculation behavior. It is suggested here that carbon blacks possess both primary structure features and the ability to form secondary structures by flocculation in dispersed systems. The tendency to form secondary structures is probably greater with carbon blacks possessing a high degree of primary structure. Unless otherwise specified, the term “structure” in this paper will be used in the sense of primary structure. The structure of carbon blacks is thought to originate in the flame by the agglomeration of growing carbon nuclei and particles. The appearance of electron micrographs of carbon blacks lends some support to the assumption of simultaneous agglomeration and growth processes. Carbon blacks having a broad particle size distribution are characterized by carbon black chains, where each chain is composed of particles of the same size, rather than a randomized distribution of various sized carbon black particles. Thus, these chainlike structures must result from the continued growth of agglomerates formed from neighboring carbon particles at the same stage of their growth history. This process results in a chemical fusing of these particles as layers of new carbon are deposited on the surfaces of actively growing agglomerates.

The Effect of Thermal Processing in Vacuum on the Water Adsorption Characteristics of Carbon Black

1992 ◽  
Vol 270 ◽  
Author(s):  
Kurt D. Schachner ◽  
Paul E. Thoma
Keyword(s):  
Heat Treatment ◽  
Relative Humidity ◽  
Carbon Black ◽  
Thermal Processing ◽  
Heat Treatment Temperature ◽  
Water Adsorption ◽  
Treatment Temperature ◽  
Carbon Particles ◽  
Heat Treated ◽  
Oxygen Complexes

ABSTRACTCommercially available carbon black contains oxygen complexes on its surface that affect the surface properties of the carbon. Water adsorption on the surface of carbon black is influenced by the amount and type of oxygen complexes present. When carbon black is heated in vacuum at sufficiently high temperatures, removal of the oxygen complexes occurs and the surface of the carbon particles is modified. The amount of water adsorbed by the carbon is dependent on the vacuum heat treatment temperature. As the heat treatment temperature increases, water adsorption on the carbon decreases.Commercially available electrically conductive carbon black adsorbs from 1.25% to 2.50% water when exposed to 50% relative humidity for 24 hours at 25°C. This variation in water adsorption is due to a difference in the amount of oxygen complexes on the surface of the carbon. The carbon with more oxygen complexes adsorbs more water. However, when this carbon black is heat treated at 1200°C for 4 hours in a vacuum of 1 × 10−5 torr or better, the water adsorbed by the carbon is 0.4% when exposed to 50% relative humidity. Data showing the dependence of water adsorption on vacuum thermal processing are presented and discussed.

INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL

2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Surface Roughness ◽  
Carbon Steel ◽  
Cold Water ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Heating And Cooling ◽  
Treatment Processes ◽  
Quenching And Tempering

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling

scholarly journals Reproduction of melting behavior for vitrified hillforts based on amphibolite, granite, and basalt lithologies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
John S. McCloy ◽  
José Marcial ◽  
Jack S. Clarke ◽  
Mostafa Ahmadzadeh ◽  
John A. Wolff ◽  
...  
Keyword(s):  
Iron Age ◽  
Glass Production ◽  
Melting Behavior ◽  
Source Rocks ◽  
Ex Situ ◽  
Maximum Temperature ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Granitoid Rocks ◽  
Dark Glass

AbstractEuropean Bronze and Iron Age vitrified hillforts have been known since the 1700s, but archaeological interpretations regarding their function and use are still debated. We carried out a series of experiments to constrain conditions that led to the vitrification of the inner wall rocks in the hillfort at Broborg, Sweden. Potential source rocks were collected locally and heat treated in the laboratory, varying maximum temperature, cooling rate, and starting particle size. Crystalline and amorphous phases were quantified using X-ray diffraction both in situ, during heating and cooling, and ex situ, after heating and quenching. Textures, phases, and glass compositions obtained were compared with those for rock samples from the vitrified part of the wall, as well as with equilibrium crystallization calculations. ‘Dark glass’ and its associated minerals formed from amphibolite or dolerite rocks melted at 1000–1200 °C under reducing atmosphere then slow cooled. ‘Clear glass’ formed from non-equilibrium partial melting of feldspar in granitoid rocks. This study aids archaeological forensic investigation of vitrified hillforts and interpretation of source rock material by mapping mineralogical changes and glass production under various heating conditions.

scholarly journals Nanostructured LiFe5O8 by a Biogenic Method for Applications from Electronics to Medicine

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 193
Author(s):  
Silvia Soreto Teixeira ◽  
Manuel P. F. Graça ◽  
José Lucas ◽  
Manuel Almeida Valente ◽  
Paula I. P. Soares ◽  
...  
Keyword(s):  
Spinel Ferrite ◽  
Sol Gel ◽  
Reaction Medium ◽  
Magnetic Hyperthermia ◽  
Magnetic Characteristics ◽  
Secondary Phases ◽  
Heat Treated ◽  
Structure Morphology ◽  
Sol Gel Process ◽  
Crystallite Sizes

The physical properties of the cubic and ferrimagnetic spinel ferrite LiFe5O8 has made it an attractive material for electronic and medical applications. In this work, LiFe5O8 nanosized crystallites were synthesized by a novel and eco-friendly sol-gel process, by using powder coconut water as a mediated reaction medium. The dried powders were heat-treated (HT) at temperatures between 400 and 1000 °C, and their structure, morphology, electrical and magnetic characteristics, cytotoxicity, and magnetic hyperthermia assays were performed. The heat treatment of the LiFe5O8 powder tunes the crystallite sizes between 50 nm and 200 nm. When increasing the temperature of the HT, secondary phases start to form. The dielectric analysis revealed, at 300 K and 10 kHz, an increase of ε′ (≈10 up to ≈14) with a tanδ almost constant (≈0.3) with the increase of the HT temperature. The cytotoxicity results reveal, for concentrations below 2.5 mg/mL, that all samples have a non-cytotoxicity property. The sample heat-treated at 1000 °C, which revealed hysteresis and magnetic saturation of 73 emu g−1 at 300 K, showed a heating profile adequate for magnetic hyperthermia applications, showing the potential for biomedical applications.

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