Thermogravimetric analysis Presentation.pptx

TGA and its details

1. Topic Thermogravimetric Analysis & Differential Thermal Analysis Name Ata Ur Rahman

2. Outline Thermo gravimetric Analysis (TGA) 1 TGA Application 2 Instrumentation of TGA/DTA 4 TGA & DTA Differential thermal analysis 3 Comparison Between TGA & DTA 5

3. Thermogravimetric Analysis Thermo Gravy Weight Metry Measurement Heat

4. Thermogravimetric Analysis Thermogravimetric Analysis is a technique in which the mass of a substance is monitored as a function of temperature or time as the sample specimen is subjected to a controlled temperature program in a controlled atmosphere . An Alternate Definition : TGA is a technique in which, upon heating a material, its weight increases or decreases. Definition

5. The plot of mass or %age of mass against temperature or time at constant temperature . Thermogram

6. TGA Curve For complex compound % m Temp T onset ∆ m

7. Example of TGA

8. TGA Application Corrosion study Gasification process Kinetic Process Examination of Thermal Stability Material Purity Determination of Humidity Characterization B urning point Ash content Analysis Accurate drying temperature Determination TGA

9. Factor Affecting TGA 1 2 3 4 5

10. DTA A technique in which the difference in temperature between the sample and a reference material is monitored against time or temperature while the temperature of the sample, in a specified atmosphere, is programmed. ∆T= T R - Ts

11. DTA Curve

12. Phenomena that Cause changes in Temperature in DTA Adsorption ( Exo ) Desorption (Endo) Crystallization ( Exo ) Melting (Endo) Vaporization (Endo) Sublimation (Endo) Physical Changes Oxidation ( Exo ) Reduction (Endo) Breakdown (Endo/ exo ) Chemisorption ( Exo ) Solid State Reaction ( Exo /Endo) Chemical Changes

13. Instrumentation of TGA/DTA TGA

14. DTA Instrument

15. TGA DTA Weight loss as a function temperature or time Stair case thermal curve with horezental and vertical lines. Upper temp is up to 1000 c” Quantitative analysis by change in mass The temp difference between reference and sample is measured as a function of time. Thermal curve show upword and downward peaks. Upper temp is up to 1600 C” Quantitative analysis by peak height and area. COMPARISON BETWEEN TGA AND DTA