To treat data from temperature modulated differential scanning calorimetry (TMDSC) in terms of complex or reversing heat capacity
firstly one should pay attention that the response is linear and stationary because this is a prerequisite for data evaluation.
The reason for non-linear and non-stationary thermal response is discussed and its influence on complex (reversing) heat capacity
determination is shown. The criterion for linear and stationary response is proposed. This allows to choose correct experimental
conditions for any complex heat capacity measurement. In the case when these conditions can not be fulfilled because of experimental
restrictions one can estimate the influence of non-linearity and non-stationarity on measured value of complex or reversing
Authors:Robert A. Shanks and L. M. Wasantha K. Gunaratne
-DSC scans were then used to calculate the total ( C p,total ), storage or reversing ( C p ′), loss ( C p ″), and non-reversingheatcapacity ( C p,NR ) curves, more correctly C p measured under DSC conditions is the apparent heat capacity since
allows a material to relax at a given temperature, which should allow further differentiation. In MDSC a sinusoidal modulation is overlaid on a linear ramp. By doing this the reversingheatcapacity can be separated. The reversingheatcapacity is
Authors:C. A. Gracia-Fernández, P. Davies, S. Gómez-Barreiro, Beceiro J. López, J. Tarrío-Saavedra, and R. Artiaga
the application of a modulated temperature ramp is also sinusoidal in shape, with an amplitude A HF .
The reversingheatcapacity, Cp rev, can be then defined as
where K Cp is a calibration constant, A T is the temperature
Authors:A. Boller, I. Okazaki, K. Ishikiriyama, G. Zhang, and B. Wunderlich
The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on the symmetry of the twin
calorimeters. This symmetry is of particular importance for the temperature-modulated DSC (TMDSC) since positive and negative
deviations from symmetry cannot be distinguished in the most popular analysis methods. Three different DSC instruments capable
of modulation have been calibrated for asymmetry using standard non-modulated measurements and a simple method is described
that avoids potentially large errors when using the reversing heat capacity as the measured quantity. It consists of overcompensating
the temperature-dependent asymmetry by increasing the mass of the sample pan.
flow or isobaric apparent heat capacity curve ( C p,total ), the same as a conventional DSC curve), the in-phase curve (reversing or storage C p ) and out-of-phase curve (loss C p ) [ 11 ]. In addition, a non-reversingheatcapacity (kinetic) curve
Total and reversingheatcapacity for a sapphire disc, no pan, was measured using either a 40, 60, or 80 s period for overall heating rate of 5 °C min −1 and 10 °C min −1 . The total range in heat capacity values measured under these
]. Previous study based on the specific reversingheatcapacity of PET/silica, electrospun nanocomposite fibers [ 15 ] demonstrated the existence of the rigid amorphous phase in the absence of PET crystallinity. Experimental results show that the rigid