Differential scanning calorimetry (DSC) is a thermal analysis technique that measures the heat flow into or out of a sample as it is heated, cooled, or held at constant temperature. DSC was developed in 1962 and measures the difference in heat flow between a sample and an inert reference as they are subjected to a controlled temperature program. DSC can be used to analyze physical and chemical changes in materials by measuring the heat effects associated with phase transitions, crystallization, melting, and chemical reactions as a function of temperature.

1. DIFFERENTIAL SCANNING CALORIMETRY (DSC)
PCH 803 ASSIGNMENT
By
OGOH, ADAKOLE AUGUSTINE
Group 1
M.Sc. Students
Department of Pharmaceutical chemistry
University of Jos, Jos
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2. OUTLINE
 INTRODUCTION
 Thermal analysis
 History
 Method of thermal analysis
 BACKGROUND THEORY
 REFERENCES
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3. INTRODUCTION
THERMAL ANALYSIS
 During the past few years, the methods of thermal analysis have been widely
accepted in analytical chemistry.
 The term thermal analysis incorporates those techniques in which some
physical parameter of the system is determined and/or recorded as a function
of temperature (Willard et al, 2012)
 Thermal analysis has been used to determine the physical and chemical
properties of polymers, electronic circuit board, geological materials and
coals (Willard et al, 2012)
 A number of physical and chemical effects can be produced by temperature
changes , and method for characterizing these alteration upon heating or
cooling a sample material are referred as thermal analysis.
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4. THERMAL ANALYSIS cont’d
 A physical and chemical changes a sample undergoes when heated are
characteristic of the material being examine.
 By measuring the temperature at which such reactions occur and the heat
involved in the reaction, the compounds present in such material can be
characterized
 The physical and chemical changes that take place when unknown sample is
heated provide the information that enables identification of the material
 The majority of the known inorganic compounds have been so
characterized.
 Common method of thermal analysis are DSC, DTA and TMA.
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5. METHOD OF THERMALANALYSIS
S/N NAME OF
TECHNIQUE
INSTRUMENT
EMPLOY
PARAMETER
MEASURED
GRAPH
1 Thermogravimetry Thermobalance Mass Mass vs Temperature
2 Differential Thermal
Analysis (DTA)
DTA apparatus ∆T ∆T VS Temperature
3 Dilatometry (TMA) Dilatometer Volume or
length
Volume or length vs
Temperature
4 Emanation Thermal
Analysis (ETA)
ETA apparatus Radioactivity
(E)
E vs Temperature
5 Differential Scanning
Calorimetry (DSC)
Differential
scanning
calorimeter
dH/dt dH/dt vs Temperature
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6. DIFFERENTIAL SCANNING CALORIMETRY (DSC)-
HISTORY
 This technique is developed by E.S Watson and M. J. O’Neill in 1962
 It was introduced commercially at the Pittsburgh conference on Analytical
Chemistry and Apply Spectroscopy
 First adiabatic differential scanning calorimeter that could be used in
biochemistry was developed by P.L. Privalov in 1964
 The term DSC was coined to describe this instrument, which measures
energy directly and allows precise measurements of heat capacity
(Wunderlich, 1990)
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7. DIFFERENTIAL SCANNING CALORIMETRY (DSC)
 Differential scanning calorimetry (DSC) is one of the thermo-analytical
techniques
 A calorimeter measures the heat into or out of a sample
 A differential calorimeter measures the heat of sample relative to a reference.
 A differential scanning calorimeter does all of the above and heats the sample
with a linear temperature ramp (Freire, 1995)
 DSC is a technique in which the difference in the amount of heat required to
increase the temperature of a sample and reference are measured as function
of temperature
 Both the sample and reference are maintained at nearly the same temperature
throughout the experiment
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8. PICTURAL REPRESENTATION
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9. INTRODUCTION CONT’D
 Generally, the temperature program for a DSC analysis is designed such that
the sample holder temperature increases linearly as a function of time
 Only a few mg of material are required to run the analysis
 DSC is the most often used thermal analysis method, primarily because of its
speed, simplicity, and availability
 It is mostly used for quantitative analysis
 The reference is an inert material material such as alumina or just an empty
aluminium pan
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10. BACKGROUND THEORY
 Since the Differential Scanning Calorimeter is at constant pressure, the heat
flow is equivalent to enthalpy changes:
(dq/dt)p=dH/dt
 Here dH/dt is the heat flow measure in mcalsec.
 The heat flow difference between the sample and reference is:
∆dH/dt= ( dH/dt)sample – (dH/dt)reference
 The heat change can be either positive or negative.
 In an endothermic process, such as most phase transition, heat is absorbed
and therefore, the heat that flow to the sample is higher than that to the
reference.
 In an exothermic process,such as crystallization,oxidation reactions and
some decomposition reactions,the opposite is true and dH/dt is negative
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11. REFERENCES
 Thermal Methods. In: Chatwal GR, Anand SK. Instrumental Methods of
Chemical Analysis. Fifth Edition: Himalaya Publication House, 2002.
P.2.701 2.749-2.751
 Thermal Analysis. In:Willard HH, Merritt LL, Dean JA, Settle FA.
Instrumental Methods of Analysis. Seventh edition: CBS publishers,2012.p.
761.
 Freire E. Differential scanning calorimetry. Methods Mol Biol. 1995; 40:
191-218.
 Thermal Methods. In: Skoog DA, Holler FJ, Crouch SR. Instrumental
Analysis. India edition: Cengage Learning, 2011.p. 982,983,984
 Wunderlich, B. (1990). Thermal Analysis. New York: Academic Press.
pp. 137–140.ISBN 0-12-765605-7.
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12. THANK YOU
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