First SIM² - WORKSHOP Thermal analysis (TGA/DSC): practical aspects TGA – Thermogravimetric Analysis DSC – Differential Scanning Calorimetry Jacek Chwast jacek.chwast@ees.kuleuven.be Geo-Instituut 23.01.2013 Measurement conditions furnace 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 microbalance 2 Measurement conditions furnace 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 sample + reference microbalance 3 Thermal analysis (TGA/DSC) in a nutshell TG analysis – mass (T) DSC analysis – heat flow (T) TG /mg DTG /(mg/min) 0.000 [1] 0.0 -0.500 [1] cemI 1A 4d.dsv TG DTG -1.000 -0.1 -0.1 -1.500 Onset*: 429.2 °C -0.2 -2.000 -0.2 -2.500 [1] 100.0 200.0 300.0 400.0 500.0 600.0 700.0 Temperature /°C 800.0 900.0 -0.3 1000.0 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 in heat flow, measured by DSC analysis: - crystallization - melting - glass transitions DSC applications: - thermodynamic characterization of pure substances - quality control: sample purity 4 - thermal stability studies Sample compatibility 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 5 Evaluation of new materials 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 6 Sample preparation 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) 7 Analysis of results Software: NETZSCH Proteus® (Marsh procedure) Quantification of portlandite (Ca(OH)2) content in cement ~430°C: Ca(OH)2 -> CaO + H2O↑ TG /mg 0.000 DTG /(mg/min) [1] 0.0 -0.500 [1] cemI 1A 4d.dsv TG DTG -1.000 -0.1 -0.1 -1.500 Onset*: 429.2 °C -0.2 -2.000 -0.2 -2.500 [1] 100.0 200.0 300.0 400.0 700.0 600.0 500.0 Temperature /°C 800.0 900.0 -0.3 1000.0 8 Analysis of results Software: NETZSCH Proteus® (Marsh procedure) Quantification of portlandite (Ca(OH)2) content in cement ~430°C: Ca(OH)2 -> CaO + H2O↑ TG /mg [1] cemI 1A 4d.dsv TG -1.700 -1.800 mass loss -1.900 -2.000 [1] -2.100 400.0 420.0 440.0 460.0 Temperature /°C 480.0 500.0 9 Analysis of results Software: NETZSCH Proteus® (Marsh procedure) Quantification of portlandite (Ca(OH)2) content in cement ~430°C: Ca(OH)2 -> CaO + H2O↑ TG /mg [1] cemI 1A 4d.dsv TG -1.700 -1.800 -1.900 -2.000 [1] -2.100 400.0 420.0 440.0 460.0 Temperature /°C 480.0 500.0 10 Analysis of results Software: NETZSCH Proteus® (Marsh procedure) Quantification of portlandite (Ca(OH)2) content in cement ~430°C: Ca(OH)2 -> CaO + H2O↑ TG /mg [1] cemI 1A 4d.dsv TG -1.700 Mass Loss (Marsh): 431.7 °C Onset: 440.4 °C Inflection: Mass Change: -0.258 mg -1.800 -1.900 -2.000 [1] -2.100 400.0 420.0 440.0 460.0 Temperature /°C 480.0 500.0 11 Contact information and reservations Contact / Training: Jacek Chwast jacek.chwast@ees.kuleuven.be 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 12 Thank you for your attention Questions? 13