Differential Scanning Calorimeter Instrumentation.(DSC)

In this slides contains principle and instrumentation of Differential Scanning Calorimeter (DSC).
Presented by: N Poojitha. (Department of pharmaceutics),
RIPER, anantapur.

1. 1 Differential Scanning Calorimeter Instrumentation A Seminar as a part of curricular requirement for I year M. Pharm I semester Presented by N. Poojitha (Reg. No. 20L81S0308) Under the guidance Dr. Nawaz Mahammad M. Pharm, Ph . D Associate Professor Dept. of Pharmaceutics

2. 2 Introduction of DSC Principle of DSC Instrumentation of DSC References Contents

3. 3 Introduction of DSC The technique was developed by E.S. Watson and M.J. O Neill in 1960, and introduced commercially at the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy in 1963. This technique is used to study what happens to polymers/samples upon heating. It is used to study thermal transitions of a polymer/sample (the changes that take place on heating) The differential scanning calorimeter does all of the above functions and heats the sample with the linear temperature. Both the sample and reference are maintained at nearly the same temperature through out the experiment in DSC

4. 4 Principle of DSC It is a technique in which the energy necessary to establish a zero temperature difference between the sample & reference material is measured as a function of temperature. Here, sample & reference material are heated by separate heaters in such a way that their temp are kept equal while these temp. are increased or decreased linearly. During heating two types of reactions can be take place one is the endothermic and the other is the exothermic.

5. 5 Endothermic reaction: If sample absorbs some amount of heat during phase transition then reaction is said to be endothermic. In endothermic reaction more energy needed to maintain zero temp difference between sample & reference. E.g. Melting, boiling, sublimation, vaporization

6. 6 Exothermic reaction: If sample released some amount of heat during phase transition, then reaction is said to be exothermic. In exothermic reaction, less energy needed to maintain zero temp difference between sample & reference. E.g crystallization, degradation, polymerization

7. 7 DSC Graph

8. 8 DSC Instrumentation

9. 9 Two basic types of DSC instruments: Heat flux DSC, Power compensated DSC Types of DSC Instuments

10. 10 1.Heat-flux DSC Sample Holder : PLATINUM, ALUMINIUM, STAINLESS STEEL SENSORS: Temperature Sensors Usually thermocouples, which are same for the sample are reference Furnace: One block for both sample and reference cells. Temperature: The temperature difference between the sample and reference is converted to differential thermal power, which is supplied to the heaters to maintain the temperature of the sample and reference at program value.

11. 11 2.Power Compensated DSC Sample Holder : PLATINUM, ALUMINIUM, STAINLESS STEEL PANS SENSORS: Pt resistance thermocouple Separate sensors and heaters for the sample and reference sample. Furnace: Separate blocks for sample and reference cells. Temperature: Differential thermal power is supplied to the heaters to maintain the temperature of the sample and reference at the program level.

12. 12 DSC attached to Computer

13. 13 P. J. Elving & I. M. Kolthoff, Chemical analysis, Vol. 19, P134, 1964. Wang L, Wang B, Lin Q. Demonstration of MEMS-based differential scanning calorimetry for determining thermodynamic properties of biomolecules. Sensor Actuat B-Chem 2008;134:953– 958 Masri MS, Reuter FW, Fiedman M. Interaction of wool with metal cations. J Appl Polym Sci 1974;18:675–681 Hohne G, Hemminger W, Flammersheim H-J. Differential Scanning Calimetry : An Introduction for Practitioners. Berlin, Germany: Springer-Verlag, 1996 . Instrumental methods of analysis- Willards,7th edition, CBS Publications ;237-332. 11/12/2019 References

14. 14 Thank you