Immersion and Contact Efflorescence Induced by Mineral Dust Particles.
Immersion and Contact Efflorescence Induced by Mineral Dust Particles.
复制标题
矿物粉尘颗粒引起的浸泡和接触风化。
DOI：
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发表时间：
2018
影响因子：
2.9
通讯作者：
M. Tolbert
中科院分区：
文献类型：
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作者：
S. Ushijima;R. Davis;M. Tolbert
无机盐气溶胶的相态影响其性质，包括经历吸湿生长、催化非均相反应和充当云凝结核的能力。在这里，我们报告的矿物粉尘气溶胶接触风化的第一次观察。利用光学悬浮箱研究了硫酸铵（（NH4）2SO4）和氯化钠（NaCl）水溶液液滴与三种矿物粉尘颗粒（伊利石、蒙脱石和NX伊利石）接触后的风化现象。浸没模式风化也进行了研究比较。我们发现，在矿物粉尘颗粒的存在下，结晶发生在一个较高的相对湿度（RH）相比，均匀的相变。此外，结晶接触模式风化发生在一个较高的RH比相应的浸没模式。接触模式下的结晶效率表现出与Hoffmeister系列一致的离子特异性趋势。对盐滴与尘埃粒子碰撞的寿命的估计表明，两种气溶胶类型之间的碰撞可能发生在盐气溶胶被其他大气过程清除之前。这样的碰撞可能会导致原本保持液态的盐滴结晶，从而改变盐气溶胶对大气化学和气候的整体影响。
The phase state of inorganic salt aerosols impacts their properties, including the ability to undergo hygroscopic growth, catalyze heterogeneous reactions, and act as cloud condensation nuclei. Here, we report the first observation of contact efflorescence by mineral dust aerosol. The efflorescence of aqueous ammonium sulfate ((NH4)2SO4) and sodium chloride (NaCl) droplets by contact with three types of mineral dust particles (illite, montmorillonite, and NX illite), were examined using an optical levitation chamber. Immersion mode efflorescence was also studied for comparison. We find that in the presence of mineral dust particles, crystallization occurred at a higher relative humidity (RH) when compared to the homogeneous phase transition. Additionally, crystallization by contact mode efflorescence occurred at a higher RH than the corresponding immersion mode. Crystallization efficiencies in the contact mode exhibited an ion-specific trend consistent with the Hoffmeister series. Estimates for lifetimes of a salt droplet to collide with dust particles suggests that collisions between the two aerosol types are likely to occur before the salt aerosol is removed by other atmospheric processes. Such collisions could then lead to the crystallization of salt droplets that would otherwise have remained liquid, changing the overall impact that salt aerosols have on atmospheric chemistry and climate.