Differential scanning calorimetry (DSC) provides an easy way of screening to evaluate thermal hazards. As some chemical substances react with metals, the use of metal vessels in DSC often results in an overestimation of the thermal hazard. In the study reported here, a commercially available DSC vessel was coated with SiO2 (thickness = 125, 140, 150, or 200 nm) using atomic layer deposition (ALD). The thermal behavior using the coated vessels was compared with the results for glass and uncoated vessels. The samples measured for the evaluation were ammonium perchlorate (AP) and 2-amino-4-chloro-nitrophenol (ACNP), which react with stainless steel vessels. Regarding the ability of the SiO2 coating to withstand the decomposition induced by AP and ACNP, the optimal film thickness was estimated to be within the range of 140–150 nm. This durability may be reduced when internal pressure is applied to the vessel by corrosive gases generated at low temperature. The heating and cooling rates under the measurement conditions were also found to affect the durability of the coating. Furthermore, it was suggested that, when coating a vessel with SiO2 using the ALD method, better coating effects could be expected upon using Hastelloy C as the vessel material.
Akiyoshi et al. (Fri,) studied this question.