Hygroscopicity of ultrafine particles containing ammonium/alkylaminium sulfates: A Köhler model investigation with correction of surface tension

A new advance in the pollution profile, transformation process, and contribution to aerosol formation and aging of atmospheric amines

“…Recently, Liu et al incorporated surface tension into the conventional Köhler model, and found that the critical supersaturation follows a consistent order of AS > MMAS > DMAS > TMAS over 10 nm and MMAS > DMAS > AS > TMAS for ultra-small particles with ∼3 nm. 204 According to their results, the value of AS is higher at large size and contributes more to CCN activity, but MMAS and DMAS would show higher hygroscopic capacity in primary nanoparticles. Clearly, the potential hydrate formation, unknown phase-state, and particle-shape effect represent fundamental limitations in measurements of the hygroscopic growth and CCN activity of alkylaminium aerosols.…”

Molecular dynamics study on the surface tension of succinic acid-water nano-aerosol droplets

“…可知，液滴周围水蒸气的平衡蒸气压只和液滴的粒径和组分相关，因此添加 n 个水蒸 气分子可以抑制液滴中水分蒸发，从而使液滴中的水分子个数近似保持在 1000 个。不 从图 2 中可以看出，随着温度的升高，纯水液滴和丁二酸-水液滴的表面张力均减 小。这与文献中水平液面表面张力的实验结果一致 [27] ，原因主要包含以下两个方面。首 先，从图 此外，表面张力和丁二酸浓度的关系呈现近似对数曲线函数。在已有研究中通常将液滴 表面张力与溶质的浓度近似为线性关系 [22,30] ， 本文的研究结果表明这种处理方法在液滴 粒径较大时(近似大于等于 6.12 nm，对应水分子数大于等于 4000)是合理的，但是在 液滴粒径较小时(近似小于 6.12 nm)将带来较大的误差。基于 Szyszkowski 公式 [31] (公 式( 7))对表面张力和丁二酸浓度间的函数关系进行拟合，获得的拟合参数列于表 1。…”