A review on differential scanning calorimetry technique and its importance in the field of energetic materials

Differential scanning calorimetry (DSC) helps to follow processing conditions, since it is relatively easy to fingerprint the thermal behavior of materials. DSC instrument nowadays became a routine technique, which can be found virtually in every chemical characterization laboratory. The sample can be analyzed over a wide temperature range using various temperature programs under isothermal and non-isothermal conditions. It is appropriate to determine the kinetic parameters under non-isothermal conditions. The sample can be in many different physical forms and in various shapes (powder, granules, fiber, etc.). A lot of characterization (step/glass transition, melting, and decomposition temperature, etc.) data can be obtained by easy way and within short time. DSC is very helpful in analysis of energetic materials due to very small amount of material is enough to run the experiment.

Photopyroelectric Calorimeter for Phase Transitions Monitoring: Application to Chocolate

ABSTRACTIn this work we report about the design and construction of a simple and cheap calorimeter for phase transitions monitoring using Peltier elements and based in the well known inverse (front) photopyroelectric method for thermophysical characterization of materials. We describe its application for the detection of phase transitions in chocolate samples, as an alternative, for example, to the most widely used and more expensive Differential Scanning Calorimetry technique. The manufacture of chocolate requires an understanding of the chemistry and the physical properties of the product. Thus the involved problems during the confection process are those of the so-called materials science. Among them, those related with tempering are of particular importance. Because the fats in cocoa butter experience the so-called polymorphous crystallization, the primary purpose of tempering is to assure that only the best form is present in the final product. One way to characterize this is by measurement of the temperature dependence of the thermal properties of the chocolate and the monitoring of the temperature at which phase transitions take place. We show that the photopyroelectric method, aided with Peltier cells temperature control, can be a useful choice for this purpose.