Download - Gerspacher Michel
Furnace Black Characterization
Sid Richardson Carbon CoFort Worth, TXDr. Michel Gerspacher
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DefinitionsParticle
Aggregate
= 20nm to 100nm "Diameter"= 200nm to 1,000nm "Length"= Set of Percolated Aggregates
Particle (?) Aggregate Agglomerate
Constituents Size = Tech/Scientific Challenge
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Furnace ProcessHigh Temperature
RefractoryFeedstock
OilAir
NaturalGas Reaction
ZoneQuench
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Specific Surface Area
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Structure
3-D Morphology Key Characteristic
Summary
of
Crystallographic Studies
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Methodologies
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Summary
• For all furnace carbon black12Å < LC < 17Å
• CrystalliteLa ≈ 25Å
• Amorphous Carbon• No micropores• Very few surface groups (hetero atoms)
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Effect of Heat Treatment on Amorphous CarbonRaman Study and Hydrogen Content
· Raman Spectrum of N299
1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800
Wave Number
0
50
100
150
200
250
I
Heat Treatment Temperature Amorphous Area / Total Area Hydrogen Content, (ppm)
Untreated 0.348 2407500°C 0.152 2502800°C 0.114 23931000°C 0.038 23252000°C 0.029 10
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Results (Cont’d)
T < 1000°C → “Reorganization” of graphitic planes on the surfaceT > 1000°C → Formation of microcrystallites
RT 500 800 1000 2000 3000 3200Temperature
1
1.08
1.16
1.24
1.32
I Ram
an
RT 500 800 1000 2000 3000 3200Temperature
1
1.3
1.6
1.9
2.2
I 002
Surface Unorganized Carbon Identified
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SRCC’s Model
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Carbon Black Surface Activity• Edges of crystallites → High concentrations of π electrons
Crystallites Amorphous
A A
B
CD
• Energy ScaleEA > EB > EC
• ED ? → Role of hydrogen atoms?
Active Site
Important Surface Energy Density
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Energetic Surface Structureof
Carbon Black(Summary)
A. Schroeder | R. Schuster DIK
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Polymer - Filler “Bonding”
( ) ( ) ( )0
, , ,
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G H T S
H Enthalpy of Adsorption
Adsorption Isotherm
T T Q f Q dQρ θ ρ∞
∆ = ∆ − ∆
∆ =
⇓
Θ = ∫
( )f Q Distribution of Energetic Sites=
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Energetic Surface Structure of Carbon Black
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Role of Active SitesActive sites → High density of π electrons
A Sites for Van der Waals bonding with neighbor aggregates → carbon black network
B Sites for weak (Van der Waals …)bonding with polymer chains
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Carbon Black Surface Groups* As per Professor Bertrand (Belgium) ACS Rubber Division, Spring
1998
• Heterogroup → Very few
• Hydrogen atoms → Significant amount
Hydrogen Most Relevant Surface Group
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Surface Hydrogen Group
• Study to be started with Professor Bertrand (Belgium)• SIMS T.O.F.• E.S.C.A. / Auger
• Surface hydrogen proportional to total hydrogenTotal Hydrogen → Leco Technique
Amorphous Carbon Hydrogen Content
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• Carbon black of - same “particle” diameter (TEM)- different Nitrogen adsorption
• Special process to increase the amorphous carbon
2 2.5 3 3.5 4
ppm Hydrogen (10-3)
6
6.5
7
7.5
8
8.5
9
9.5
10
G'm
ax (M
Pa)
Hydrogen Directly Linked to Amorphous Carbon
Hydrogen Content of Amorphous Carbon