Differential thermal analysis is a type of Thermal Analysis. This presentation includes definition of Thermal analysis, types of thermal analysis with focus on DTA, its principle, Instrumentation and applications.

1. Differential Thermal Analysis
(DTA)
SUBMITTED BY:
Vanshaj Raina
M. Pharmacy 1ST Yr
ROLL NO. 16000702005
SUBMITTED TO:
Dr. Aakashdeep
Asst. Professor

2. CONTENTS
Introduction to Thermal Analysis
Types of Thermal Analysis
Differential Thermal Analysis
Principle
Instrumentation
Applications

3. Thermal Analytical techniques
• When a material is heated its structural and chemical
composition can undergo changes such as fusion,
melting, crystallization, oxidation, decomposition,
transition, expansion and sintering. (1)
• Using Thermal Analysis such changes can be
monitored in every atmosphere of interest. The
obtained information is very useful in both quality
control and problem solving.
(2)

4. Types of thermal analysis
• TG (Thermogravimetric) analysis:
weight
• DTA (Differential Thermal Analysis): temperature
• DSC (Differential ScanningCalorimetry):
temperature (2) (3)

5. Differential Thermal Analysis
• In Differential Thermal Analysis, the temperature
difference that develops between a sample and an
inert reference material is measured, when both are
subjected to identical heat - treatments. (3)
• This is a comparison method
• Analytical method for recording the difference in
temperature (∆T) b/w a substance and an inert
reference material as a function of temperature or
time
• Any transformation – change in specific heat can be
detected by DTA. (4)

6. • In DTA both test sample & an inert reference material
(alumina) are controlled by heating or cooling
programming
• If zero temperature difference b/w sample &
reference material – sample does not undergo any
chemical or physical change.
• If any reaction takes place temperature difference
(∆T) will occur b/w sample & reference material
(4)

7. Principle
The basic principle involved in DTA is the
temperature difference (∆T) between the test sample
and an inert reference sample under controlled and
identical conditions of heating or cooling is recorded
continuously as a function of temperature or time,
thus the heat absorbed or emitted by a chemical
system is determined.
The shape and the size of the peak give information
about the nature of the test sample.
(5)

8. (1) Sharp endothermic peaks indicate phase changes or physical
changes (such as melting, fusion etc.) transition from one
crystalline form to another crystalline form.
(2) Broad endothermic peaks are obtained from dehydration
reactions
(3) Chemical reactions like oxidative reactions are exothermic
reactions. (3) (5)

9. Instrumentation
1. Sample holder comprising thermocouples, sample
containers and a ceramic or metallic
block.
2. Furnace.
3. Temperature programmer.
4. Recording system. (6)

10. -- Identical pair of cavities for the sample, ref. material
-- Whole unit is set in an oven- control pressure
-- Thermocouple is place directly in contact with the
sample and another in contact with the reference
-- Temp.of the block is raised, the temperature of the
sample & reference follow
--Zero temp. difference – no physical or chemical
change
-- If any reaction – difference in ∆T (6) (7)
Working

11. Applications
1. DTA curves for two substances are not identical. Hence they serve
as finger prints for various substances.
2. Used to study the characteristic of polymeric material.
3. This technique is used for testing the purity of the drug sample
and also to test the quality control of number of substances like
cement, soil, glass, etc.
4. Used for the determination of heat of reaction, specific heat and
energy change occurring during melting etc.
5. Trend in ligand stability (thermal stability of the ligands) gives the
information about the ligands in the coordination sphere. (7)

12. DTA APPARATUS

13. References
1. Pollock M H, Hammiche A. Micro-Thermal Analysis: te
chniques and applications, Journal Of Physics 2000; 34(
1): 21-53.
2. Ozawa T. Thermal analysis Review and Prospect, Journa
l of Chiba Institute of Technology 2000; 1(1): 35-42.
3. Pask A J, Warner F M. Differential Thermal Analysis me
thods and techniques, University of california 1953; 18(
5): 5-28.
4. Klancnik G, Medved Jozef. Differential Thermal analysi
sand Differential Scanning colorimetry, Materials and G
eo environment 2010; 57(1): 127-142.

14. 5. Vold J R. Differential thermal analysis, Analytical c
hemistry 1999;21(1): 684-688.
6. Ghaderi F, Monajjemzadeh F. Molecular pharmace
utics and Organic process research, Journal of mole
cular organic research 2015; 3(1): 5-18.
7. El-Naggar Y A. Thermal analysis of modified and u
nmodified silica gels, Scholarlink Research Institut
e Journals 2013; 4(1): 144-148.

15. THANK YOU…