What is a modulated DSC?
Modulated DSC is a technique which also measures the difference in heat flow between a sample and an inert. reference as a function of time and temperature. In addition, the same “heat flux” cell design is used. However, in MDSC a different heating profile (temperature regime) is applied to the sample and reference.
How does power compensated DSC differ from temperature modulated DSC?
Power compensated DSC has lower sensitivities than the heat flux DSC, however power compensated DSC are faster than their heat flux counterparts. Thus, power compensated DSC are often used in studying kinetics wherein very fast equilibrium to a desired temperature is reached.
What is modulated differential scanning calorimetry?
Temperature-modulated differential scanning calorimetry (TMDSC) is an upgraded thermoanalytical technique over conventional methods which includes superimposition of modulation on the linear heating, cooling, or isothermal temperature program.
What is difference between heat flux and power compensation in DSC?
Power compensated DSC has lower sensitivity than heat flux DSC, but its response time is more rapid. This makes power compensated DSC well suited for kinetics studies in which fast equilibrations to new temperature settings are needed. it is also capable of higher resolution then heat flux DSC [4].
How is a glass transition observed in DSC?
In DSC measurements, the glass transition can be observed by a step in the baseline of the measurement curve (Fig. 1). It is characterized by its onset, midpoint, inflection and endset temperature. The step height corresponds to Δcp and is given in J/(g⋅K).
What is difference between heat flux and heat rate?
Heat rate is a scalar quantity, while heat flux is a vectorial quantity. To define the heat flux at a certain point in space, one takes the limiting case where the size of the surface becomes infinitesimally small.
What is modulated DSC™?
The separation of the total heat flow into its reversing and nonreversing components Modulated DSC™, which is based on the proven technique of DSC, offers a number of benefits over conventional DSC. It can measure both heat flow and heat capacity by performing two simultaneous experiments.
Is modulated heat flow signal equal to conventional DSC signal?
An analysis of the three transitions reveals that the average value of the modulated heat flow signal is equal to the heat flow signal from conventional DSC both qualitatively and quantitatively, at the same average heating rate.
What are the raw signals in an MDSC experiment?
The modulated heat flow and modulated heating rate signals are the raw signals created in an MDSC experiment. MDSC uses the amplitude of these two signals to calculate heat capacity.
How does MDSC calculate heat capacity in a single experiment?
However, MDSC calculates heat capacity in a single experiment using a single sample once the instrument has been calibrated. Figure 5. The modulated heat flow and modulated heating rate signals are the raw signals created in an MDSC experiment.