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First SIM² - WORKSHOP
Thermal analysis (TGA/DSC):practical aspects
TGA – Thermogravimetric Analysis DSC – Differential Scanning Calorimetry
Jacek [email protected]
23.01.2013
Measurement conditions
2
Netzsch STA 409 PC Luxx®:- T [25 – 1000 °C]- heating rate 10 °C/min
- N2 atmosphere (60 ml/min)
- alumina crucibles - simultaneous measurement of mass
change (TG) and heat flow (DSC)- 1 analysis (25100025 °C) = 3 hrs
furnace
microbalance
Measurement conditions
3
Netzsch STA 409 PC Luxx®:- T [25 – 1000 °C]- heating rate 10 °C/min
- N2 atmosphere (60 ml/min)
- alumina crucibles - simultaneous measurement of mass
change (TG) and heat flow (DSC)- 1 analysis (25100025 °C) = 3 hrs
furnace
microbalance
sample + reference
Thermal analysis (TGA/DSC) in a nutshell
4
Examples of thermal reactions resulting in mass change, measured by TG analysis:-loss of free water-loss of bound water-decomposition
TG applications:-identification and quantification of sample components-thermal stability studies
Examples of thermal reactions resulting inheat flow, measured by DSC analysis:-crystallization-melting-glass transitions
DSC applications:-thermodynamic characterization of pure substances-quality control: sample purity-thermal stability studies
100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0Temperature /°C
-2.500
-2.000
-1.500
-1.000
-0.500
0.000
TG /mg
-0.3
-0.2
-0.2
-0.1
-0.1
0.0
DTG /(mg/min)
[1] cemI 1A 4d.dsv TG
DTG
Onset*: 429.2 °C
[1]
[1]
TG analysis – mass (T) DSC analysis – heat flow (T)
Sample compatibility
5
Requirements:- no reaction with alumina crucible- no expansion or creep during thermal decomposition
Compatible materials (KUL expertise):- clays and other geological materials- cements- slags
Limitations:- polymers can be hazardous, as they can foam at high
temperatures,- compatibility assessment is necessary for new materials
Evaluation of new materials
6
Compatibility assessment:
•by providing a reference to a thermal analysis
or•by burning the sample in a furnace
at the conditions foreseen for the measurement:– sample composition– temperature range (max. 1000 °C)– inert atmosphere– alumina crucible
Sample preparation
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1) Sample form: – fine powders – compact solids– films, fibers
2) Ensure good thermal contact between sample and heat flux-sensor:– powders: evenly distributed at the bottom
of the sample crucible, gently tamped
3) Always use the same sample mass (~ 10-30 mg)
Software: NETZSCH Proteus® (Marsh procedure)
Quantification of portlandite (Ca(OH)2) content in cement
100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0Temperature /°C
-2.500
-2.000
-1.500
-1.000
-0.500
0.000
TG /mg
-0.3
-0.2
-0.2
-0.1
-0.1
0.0
DTG /(mg/min)
[1] cemI 1A 4d.dsv TG
DTG
Onset*: 429.2 °C
[1]
[1]
Analysis of results
8
~430°C: Ca(OH)2 -> CaO + H2O↑
400.0 420.0 440.0 460.0 480.0 500.0Temperature /°C
-2.100
-2.000
-1.900
-1.800
-1.700
TG /mg
[1] cemI 1A 4d.dsv TG
[1]
Software: NETZSCH Proteus® (Marsh procedure)
Quantification of portlandite (Ca(OH)2) content in cement
Analysis of results
9
~430°C: Ca(OH)2 -> CaO + H2O↑
mass loss
400.0 420.0 440.0 460.0 480.0 500.0Temperature /°C
-2.100
-2.000
-1.900
-1.800
-1.700
TG /mg
[1] cemI 1A 4d.dsv TG
[1]
Software: NETZSCH Proteus® (Marsh procedure)
Quantification of portlandite (Ca(OH)2) content in cement
Analysis of results
10
~430°C: Ca(OH)2 -> CaO + H2O↑
400.0 420.0 440.0 460.0 480.0 500.0Temperature /°C
-2.100
-2.000
-1.900
-1.800
-1.700
TG /mg
[1] cemI 1A 4d.dsv TG
Mass Loss (Marsh): Onset:Inflection:Mass Change:
431.7 °C440.4 °C
-0.258 mg
[1]
Software: NETZSCH Proteus® (Marsh procedure)
Quantification of portlandite (Ca(OH)2) content in cement
Analysis of results
11
~430°C: Ca(OH)2 -> CaO + H2O↑
Contact information and reservations
12
Contact / Training:
Jacek Chwast
tel. +32 16 3 27593 or +32 16 3 27580
Responsible professor: Jan Elsen
TG /DSC instrument:
Geo-Instituut
Celestijnenlaan 200c
Room 01.83
Reservations:
- fill in the reservation list in the room 01.83
Thank you for your attention
Questions?
13
