Design and functionality of a high-sensitivity bomb calorimeter specialized for reactive metallic foils

摘要

We have designed and built a unique non-adiabatic bomb calorimeter to measure heat generated from intermetallic formation reactions and the subsequent partial combustion of nanocomposite metallic foils. Reactions are initiated with a low-energy electrical spark and can be performed in 1 atm of air, oxygen, nitrogen, or argon, in order to investigate reaction and burning characteristics in various environments. The bomb was designed to hold the foil samples with minimal thermal contact in order to mitigate heat losses and maximize surface area available for oxidation and nitridation. Samples are limited to the milligram range, and are much less energetic than an equivalent mass of organic material such as benzoic acid. Therefore, to maximize instrument sensitivity, heat capacity was minimized by designing the bomb to be as small as possible and by using low-viscosity silicone oil for the bath instead of water. The calorimeter has an energy equivalent of epsilon ((calor)) = 279 +/- A 6 J K-1, allowing us to measure heat generation on the order of tens of Joules. Calibrations were performed in argon using Al:Ni nanocomposite foils with well-known heats of reaction, which were measured using differential scanning calorimetry.