Thermal Analysis TA, TGA, DSC, DTA

Thermal Analysis (TA)

1. Advance Characterization Techniques Thermal Analysis (TA) Thermogravimetry Analysis (TGA), Differential thermal analysis (DTA), Differential Scanning Calorimetry (DSC) Kanhaya kumawat Ict mumbai 12-01-2020 1 Zahir Siddiqui C/0 Dr. S.P. More

2. Let’s activate by thermal analysis…… 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 2 I love Thermogram

3. Thermal Analysis=f(t) What is Thermal Analysis(TA) ? Study of physical property of a substance or its derivatives with respect to temperature while the substance is subjected to a controlled temperature Properties which can be observed or measured without changing the “ composition of matter ” It includes mass, volume, temperature, heat, pressure etc. 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 3

4. Thermal Analysis Instruments 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 4

5. Thermal Analysis methods 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 5

6. Thermal Analysis methods 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 6

7. 1-TGA Measure change in weight w.r.t. change in Temperature Weight loss curve reveals- Change in sample compositions Thermal stability Kinetic parameters for chemical reactions Note - derivative weight loss curve is utilised to find tempperature where weight loss is most prominent 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 7

8. How Useful Tool ? Method is useful for determining- Sample purity Water, carbonate, and organic content For studying decomposition reactions Composition of Multi-component Systems Estimated Lifetime of a Product (Related to thermal stability ) Moisture and Volatiles Content of Materials Oxidative Stability of Materials 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 8

9. Weight variation phenomenon in TGA Weight loss Decomposition, Evaporation, Reduction, Desorption Weight gain Oxidation,Absorption or Adsorption 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 9

10. Weight vs Temprature -TGA 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 10

11. How to Analyse TGA data? 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 11

12. Ca (CH3COO)2 TGA data TGA curve showing that the thermal decomposition of calcium acetate to CaO is completed by 800 oC. 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 12

13. Typical curve looks like for calcium oxalate monohydrate ( 128.1+ 18=146.1) 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 13

14. Effect of Heating Rate on TGA Curve of microfibril cellulose (MFC) Ultralight carbon aerogel from nanocellulose as a highly selective oil absorption material DOI 10.1007/s10570-014-0519-5 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 14

15. Effect of Heating rate on complete degardation 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 15

16. Effect of sample weight on nature of TGA curve 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 16

17. Differential Thermal analysis (DTA) “It is the measurement of the difference in temperature between a sample and a reference as heat is applied to the system ” 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 17

18. DTA Instrumentation 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 18

19. Typical DTA Curve 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 19

20. Combined TGA and DTA 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 20

21. TGA vs DTA TGA reflect the effect of mass loss only but DTA can reflect without any mass change like crystal structure change, glass transition etc 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 21

22. Phenomena causing changes in heat/temperature in DTA 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 22

23. Differential scanning calorimetry (DSC) DSC independently measures the rate of heat flow to a sample and a standard that are at the same temperature. Data is taken by monitoring the differential heat flow as a function of temperature. DSC is useful to make the same measurements as DTA and has the added capability to measure heat capacities. Thermodynamic equation , ( dH / dt )= Cp ( dT / dt ) Where dH / dt is DSC heat flow Signal, Cp is scpecific heat capacity of sample and dT / dt is change in temperature with time 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 23

24. DSC Instrumentation 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 24

25. Principle Of DSC 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 25

26. DSC Thermogram 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 26

27. DTA & DSC Chemical Reactions That Can Be Monitored 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 27

28. DSC vs TGA Combine the thermo/kinetic data of DSC with the stoichiometric data from TGA (Sodium Tungstate) 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 28

29. Example of phase transition 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 29

30. Thanku for your kind attention 12-01-2020 Zahir Siddiqui C/0 Dr. S.P. More 30