Departamento de Física, Facultade de Ciencias, Campus da Zapateira, Universidade da Coruña, 15071 A Coruña, Spain.
Grupo de Nanomateriais, Fotónica e Materia Branda, Departamento de Física de Partículas y Departamento de Física Aplicada, Universidade de Santiago de Compostela, Campus Vida s/n, 15782 Santiago de Compostela, Spain.
Int J Mol Sci. 2021 Jul 8;22(14):7334. doi: 10.3390/ijms22147334.
This paper presents a comprehensive study of two alkylammonium nitrate ionic liquids. As part of this family of materials, mainly ethylammonium nitrate (EAN) and also propylammonium nitrate (PAN) have attracted a great deal of attention during the last decades due to their potential applications in many fields. Although there have been numerous publications focused on the measurement of their physical properties, a great dispersion can be observed in the results obtained for the same magnitude. One of the critical points to be taken into account in their physical characterization is their water content. Thus, the main objective of this work was to determine the degree of influence of the presence of small quantities of water in EAN and PAN on the measurement of density, viscosity, electrical conductivity, refractive index and surface tension. For this purpose, the first three properties were determined in samples of EAN and PAN with water contents below 30,000 ppm in a wide range of temperatures, between 5 and 95 °C, while the last two were obtained at 25 °C. As a result of this study, it has been concluded that the presence of water is critical in those physical properties that involve mass or charge transport processes, resulting in the finding that the absolute value of the average percentage change in both viscosity and electrical conductivity is above 40%. Meanwhile, refractive index (≤0.3%), density (≤0.5%) and surface tension (≤2%) present much less significant changes.
本文对两种烷基硝酸铵离子液体进行了全面研究。作为这类材料的一部分，硝酸乙酯（EAN）和硝酸丙酯（PAN）在过去几十年中由于其在许多领域的潜在应用而受到了极大的关注。尽管有许多出版物专注于测量它们的物理性质，但对于同一物理性质，所得到的结果存在很大的差异。在对其物理特性进行表征时，需要考虑的一个关键点是它们的含水量。因此，这项工作的主要目的是确定 EAN 和 PAN 中少量水的存在对密度、粘度、电导率、折射率和表面张力测量的影响程度。为此，在 5 至 95°C 的宽温度范围内，确定了含水量低于 30,000ppm 的 EAN 和 PAN 样品的前三个性质，而最后两个性质则在 25°C 下获得。通过这项研究得出的结论是，水的存在对涉及质量或电荷传输过程的那些物理性质至关重要，结果发现粘度和电导率的平均百分比变化绝对值均超过 40%。而折射率（≤0.3%）、密度（≤0.5%）和表面张力（≤2%）的变化则小得多。
