Dynamic DSC

Temperature modulated DSC

The conventional method of applying a constant heating rate is modified by adding temperature modulation using a sine wave. This technique allows for the separation of overlapping reactions and facilitates the straightforward determination of specific heat capacity.

• Separate observation is achievable
  Even when enthalpy relaxation, glass transition, and recrystallization overlap, they can be distinguished from each other.
• Your current DSC can be upgraded
  Upgrades are available for your DSCvesta2, DSCvesta and DSC8231.
• Modulation period as low as five seconds is supported!
  Frequency-resolved analysis and more can be done with higher accuracy (maximum period of 200 seconds).
• Easy specific heat capacity measurement
  Specific heat capacity measurement is made easier compared to conventional DSC measurements.
• Easy-to-read data
  By utilizing the Non-reversible DSC zero sift function, the analyzed data can be easily visualized and separated.

Dynamic DSC Measurement Example

Sample: Pharmaceutical substance

Heating rate: 3°C/min., Cycle: 36 sec., Amplitude: 0.43°C

Dynamic DSC measures with a sinusoidal temperature amplitude in addition to the constant heating/cooling rate. The obtained measurement results (left figure) can be separated into three DSC curves: the average of one cycle (DSC total), the component that follows the sinusoidal wave (DSC rev.), and the component that does not follow the sinusoidal wave (DSC non-rev.). In the analyzed results (right figure), the DSC total shows an endothermic peak at 61°C, and exothermic peaks at 77°C and 110°C, indicating no glass transition. However, the DSC rev. shows a shift in glass transition at 60°C. Since the glass transition is a change in heat capacity, it appears in the reversible component, DSC rev. Through dynamic DSC measurement, it is possible to separate and confirm the glass transition, which may overlap with non-reversible reactions such as enthalpy relaxation or crystallization in constant heating rate measurements.

Dynamic DSC Heat Capacity Analysis

With Dynamic DSC, it is possible to calculate the heat capacity of a sample through analysis. By measuring a reference material, such as sapphire (Al₂O₃), under the same conditions as the sample, and calibrating the results with DSC rev., the heat capacity of the sample can be determined.