, Module III
INSTRUMENTAL METHODS AND
NANOMATERIALS
Downloaded from Ktunotes.in
, Module III
PART I:Instrumental Methods and Nanomaterials
Instrumental Methods include Thermal Analysis and Chromatography
Thermal Analysis: This method is based on the dynamic relationship between temperature
and any of the physical properties such as mass change (Δ m) and heat change ( Δ H)
The most important methods are
1) TGA (Thermo gravimetric Analysis)
2) DTA (Differential Thermal Analysis)
1. TGA (Thermogravimetric Analysis)
Principle
It involves recording the mass of the sample continuously as a function of temperature.
As the T of the sample is increased linearly from room T to a temperature of 1200 oC, the
sample undergoes physical or chemical change which is accompanied by mass loss.
The measurement is normally carried out in an inert atmosphere such as N2, He or Ar
and weight is recorded as a function of increasing T
Thermogram: A plot of mass Vs T.
Region I:
The horizontal portion indicates the region where there is no mass change.
From this we can identify thermally stable compounds.
Region II:
The slanting down portion indicates the weight loss.
This can be due to dehydration, decomposition and evaporation.
From the % weight loss, the number of hydrated water molecules lost with T range can
be determined.
Thermobalance: The instrument used for TGA.
Instrumentation
Downloaded from Ktunotes.in
INSTRUMENTAL METHODS AND
NANOMATERIALS
Downloaded from Ktunotes.in
, Module III
PART I:Instrumental Methods and Nanomaterials
Instrumental Methods include Thermal Analysis and Chromatography
Thermal Analysis: This method is based on the dynamic relationship between temperature
and any of the physical properties such as mass change (Δ m) and heat change ( Δ H)
The most important methods are
1) TGA (Thermo gravimetric Analysis)
2) DTA (Differential Thermal Analysis)
1. TGA (Thermogravimetric Analysis)
Principle
It involves recording the mass of the sample continuously as a function of temperature.
As the T of the sample is increased linearly from room T to a temperature of 1200 oC, the
sample undergoes physical or chemical change which is accompanied by mass loss.
The measurement is normally carried out in an inert atmosphere such as N2, He or Ar
and weight is recorded as a function of increasing T
Thermogram: A plot of mass Vs T.
Region I:
The horizontal portion indicates the region where there is no mass change.
From this we can identify thermally stable compounds.
Region II:
The slanting down portion indicates the weight loss.
This can be due to dehydration, decomposition and evaporation.
From the % weight loss, the number of hydrated water molecules lost with T range can
be determined.
Thermobalance: The instrument used for TGA.
Instrumentation
Downloaded from Ktunotes.in
