Mineral dust particles can initiate the freezing of cloud droplets in the atmosphere. The freezing efficiency of these particles can, however, be strongly affected by solutes, such as inorganic acids, polyols, and carboxylic acids. Here, we report the effects of inorganic acids (HNO₃ and HCl), polyols, and carboxylic acids at low concentrations on the ice nucleating ability of potassium-rich feldspar (K-rich feldspar) using the droplet freezing technique. The inorganic acids and carboxylic acids decreased the median freezing temperature of droplets containing K-rich feldspar by up to 7 °C, while the polyols had no significant effect on the median freezing temperature. For the inorganic acids and carboxylic acids, the median freezing temperature was a strong function of the pH of the droplets, with the median freezing temperature decreasing as the pH decreased. By examining the surface properties of K-rich feldspar exposed to different concentrations of HCl with cryogenic X-ray photoelectron spectroscopy, we show that the decrease in the ice nucleating ability of K-rich feldspar by the inorganic acids and carboxylic acids was likely caused by ion exchange (H₃O⁺ with parent K⁺ in microcline) and the incongruent dissolution of Al with respect to Si at K-rich feldspar surfaces. The decrease in the ice nucleating ability of K-rich feldspar by the carboxylic acids only related to the pH of the droplets rather than the type of carboxylic acid and their expected binding mechanisms on K-rich feldspar. This study focuses on rare ice nucleating active sites (with an ice nucleating active site density of 10–600 cm^–2) of the K-rich feldspar and short exposure times between the solutes and the K-rich feldspar. Further studies are needed to investigate more abundant ice nucleating active sites and longer exposure times, as well as K-rich feldspar samples from different sources.

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无机酸和有机溶质对富钾长石冰成核能力和表面性质的影响

矿物尘埃颗粒可以引发大气中云滴的冻结。但是，这些颗粒的冷冻效率会受到诸如无机酸，多元醇和羧酸等溶质的强烈影响。在这里，我们报告了无机酸（HNO ₃和低浓度的HCl），多元醇和羧酸对采用滴滴冷冻技术的富钾长石（富钾长石）的冰成核能力的影响。无机酸和羧酸使含有富钾长石的液滴的中值冻结温度降低了7°C，而多元醇对中值冻结温度没有显着影响。对于无机酸和羧酸，中值冷冻温度是液滴pH的强函数，中值冷冻温度随着pH的降低而降低。通过用低温X射线光电子能谱检查暴露于不同浓度HCl的富钾长石的表面特性，₃ O ⁺和微晶中的母体K ⁺），并且在富钾长石表面Al相对于Si的溶解不均。羧酸对富钾长石冰成核能力的降低仅与液滴的pH有关，而与羧酸的类型及其与富钾长石的预期结合机理有关。这项研究的重点是富钾长石的稀有冰成核活性部位（冰成核活性部位密度为10–600 cm ^–2）以及溶质和富钾长石之间的暴露时间短。需要进行更多的研究来研究更丰富的冰成核活性位点和更长的暴露时间，以及来自不同来源的富含钾的长石样品。