Differential Scanning Calorimeter DSC

1. hassan-alnajem
Differential Scanning Calorimeter (DSC)
By : Hassan ALNAJEM
Alnajemhassan@gmail.com

2. Introduction
• A typical Differential Scanning Calorimeter(DSC) consists of two thermally separate compartments. The
pan with the sample is placed in one of the compartments, and a blank pan is placed in the other compa
rtment as a reference The two compartments are heated or cooled at the same temperature rate and th
en maintained at the same temperature. Both compartments are continuously purged with Nitrogen gas.
The heat flow difference between the two is monitored.
• Differential scanning calorimetry (DSC) belongs to the family of thermal analysis methods. In general ther
mal analysis is the determination of substance properties in dependence on temperature. The greatest ad
vantage of thermal analysis is the easy handling and the output of valuable information from small sampl
es of measured substance.

3. What is Differential Scanning Calorimeter (DSC)?
• The term DSC refers to both the technique of measuring calorimetric data while scanning as well as the specific
instrument design.
• A calorimeter measures the heat into or out of a sample
• A differential calorimeter measures the heat of a sample relative to a reference
• A differential scanning calorimeter does all the above and heats the sample with a linear temperature range
• DSC measures the temperature and heat flows associated with transitions in materials as a function of time and
temperature in a controlled atmosphere.
• These measurements provide quantitative and qualitative information about physical and chemical changes that involve
endothermic or exothermic processes or changes in heat capacity.
By : Hassan ALNAJEM

4. Information obtainable from DSC
• The DSC can be used to determine
1. Glass transition temperature (Tg)
2. Melting point and boiling point
3. Crystallization time and temperature
4. Percentage crystallimetry
5. Heat of fusion and reactions
6. Heat capacity
7. Oxidative/thermal stability
8. Reaction kinetics
9. Purity
10. Rate and degree of cure
By : Hassan ALNAJEM

5. Two types of DSC
1. Power Compensated DSC
2. Heat Flux DSC
By : Hassan ALNAJEM

6. Power Compensated DSC
The temperature of the sample and reference material are always kept the same by varying the heat flow to the sample and reference
during linear temperature scanning process.
By : Hassan ALNAJEM

7. Heat Flux DSC
The temperature is directly recorded during the same procedure. Together with the thermal resistance, the change in temperature can
be converted to heat flow difference. In heat flux DSC, the total heat flow dH/dt can be written as
By : Hassan ALNAJEM

8. How DSC Works:
1) Furnace Heaters
2) Cooling system
3) Gas Flow Controller
4) Computer
5) Platinum Lid
By : Hassan ALNAJEM

9. How DSC Works:
1) Furnace Heaters:
This is the main assembly where the sample pan and reference pan are heated as per the set temperature
program
By : Hassan ALNAJEM

10. How DSC Works:
2) Cooling system
This unit enables to cool the sample and assist in achieving the desired temperature program. Liquid nitro
gen can be used as coolant.
By : Hassan ALNAJEM

11. Parts Of DSC
3) Gas Flow Controller :Gas flow controller is used to control the sample atmosphere during DSC experim
ents by connecting purge gases to the system. Normally Nitrogen is equipped with flow controller to contr
ol the flow rate of the gas.
Nitrogen gas
By : Hassan ALNAJEM

12. How DSC Works:
4) Computer: This serves as an interface between the user and the instrument and enables automatic cont
rol of instrument as per the parameters set.
By : Hassan ALNAJEM

13. How DSC Works:
5) Platinum Lid : Platinum lids are used as furnace cover. Platinum lids are with two holes which provide to
enter the purge gas into the furnace.
By : Hassan ALNAJEM

14. hassan-alnajem
Thank you
By : Hassan ALNAJEM
Alnajemhassan@gmail.com