Differential Scanning Calorimetry (DSC)

Features

Differential scanning calorimetry is an important technique in determining the phase transitions such as melting, crystallization, crystal-to-crystal transitions, crystal-to-liquid crystal transitions, vice versa, glass transitions in polymers, etc. It gives valuable information on heat absorbed or released during phase change.

Applications

• Differential scanning calorimetry can be used to measure a number of characteristic properties of a sample. Using this technique, it is possible to observe fusion and crystallization events as well as glass transition temperatures.
• DSC can also be used to study oxidation, as well as other chemical reactions
• Glass transitions may occur as the temperature of an amorphous solid is increased. These transitions appear as a step in the baseline of the recorded DSC signal. This is due to the sample undergoing a change in heat capacity; no formal phase change occurs.
• As the temperature increases, an amorphous solid will become less viscous. At some point, the molecules may obtain enough freedom of motion to spontaneously arrange themselves into a crystalline form. This is known as the crystallization temperature (Tc). This transition from amorphous solid to crystalline solid is an exothermic process and results in a peak in the DSC signal. As the temperature increases, the sample eventually reaches its melting temperature (T_m). The melting process results in an endothermic peak in the DSC curve. The ability to determine transition temperatures and enthalpies makes DSC a valuable tool in producing phase diagrams for various chemical systems.

Handled By Er. Atul Singh

atul.singh@iiti.ac.in