Insights into the effect of temperature () and relative humidity (RH) as well as structure and polarisation on ion mobility help the comparison and interpretation of mobility and mass-based data. We measured alkylammonium ions in air under different (14 °C, 24 °C, 34 °C and 41 °C) and RH (0 %, 20 %, 40 %) conditions using two individual setups (in both cases a planar differential mobility analyser coupled with a time-of-flight mass spectrometer) and the results are in excellent agreement. Mobility increases with rising and decreases with water vapour loading. When separating the measurement mobility by structures, clear mass dependence was observed. The measured mobilities exhibited large deviations from theoretically calculated results in dry conditions, which are possibly caused by adduct formation on the monomer ions via clustering (or reactions). This phenomenon seems to be unavoidably associated with light ions under atmospheric pressures, which is worth further exploration and bearing in mind when comparing measurements to calculations. Both methanol and oxygen (occasionally nitrogen or alkyl chain elongation) are possible candidates of the adduct. Under spherical assumption, we used the modified Mason–Schamp's approximation to link the measured mobility to the mobility equivalent diameter. The drag enhancement factor and the effective gas-molecule collision diameter derived from our measurement data are comparable to literature values. Our data also exposed a non-linear dependence on the polarisation parameter . Polarisation, and were parameterised using linear models against ion structures, , and RH for primary, secondary and tertiary alkylammonium ions with identical alkyl groups. Our model parametrisations predict mobilities within ±10 % deviation from the measured data. The model also has satisfying predicting power for alkylammonium ions with unidentical alkyl structures.

中文翻译：

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电迁移率对温度、湿度和烷基铵离子结构的依赖性

深入了解温度 (T) 和相对湿度 (RH) 以及结构和极化对离子淌度的影响，有助于比较和解释淌度和基于质量的数据。我们使用两种单独的设置（在两种情况下均采用平面微分迁移率）在不同（14 °C、24 °C、34 °C 和 41 °C）和 RH（0 %、20 %、40 %）条件下测量了空气中的烷基铵离子分析仪与飞行时间质谱仪相结合），结果非常一致。流动性随着水蒸气负载的升高而增加，并随着水蒸气负载的增加而降低。当按结构分离测量迁移率时，观察到明显的质量依赖性。在干燥条件下，测量的迁移率与理论计算结果存在较大偏差，这可能是由于单体离子通过聚类（或反应）形成加合物造成的。这种现象似乎不可避免地与大气压下的轻离子有关，在将测量结果与计算结果进行比较时，值得进一步探索和牢记这一点。甲醇和氧（偶尔是氮或烷基链延长）都是加合物的可能候选者。在球形假设下，我们使用修改后的 Mason-Schamp 近似将测量的迁移率与迁移率当量直径联系起来。从我们的测量数据得出的阻力增强系数和有效气体分子碰撞直径与文献值相当。我们的数据还揭示了对偏振参数的非线性依赖性。极化，并使用线性模型对具有相同烷基的伯、仲和叔烷基铵离子的离子结构、 和 RH 进行参数化。我们的模型参数化预测迁移率与测量数据的偏差在 ±10% 以内。该模型对于具有不同烷基结构的烷基铵离子也具有令人满意的预测能力。