Chemical Morphology of Frozen Mixed Nitrate-Salt Solutions.
Chemical Morphology of Frozen Mixed Nitrate-Salt Solutions.
复制标题
冷冻混合硝酸盐溶液的化学形态。
DOI：
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发表时间：
2017
影响因子：
2.9
通讯作者：
D. Donaldson
中科院分区：
文献类型：
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作者：
Karen J. Morenz;D. Donaldson
冰上的表面化学可以在大气组成中发挥重要作用，但冰样中化学分配的不确定性阻碍了这些系统准确模型的发展。使用拉曼显微镜，我们检查了冰和含有与环境相关的氯化钠、溴化钠和海盐类似物Instant Ocean的液体样品中硝酸盐的分布。在所有冷冻样品中，硝酸盐在表面比在整体中都有所增加，但程度取决于添加的盐。冰冻样品水平方向上硝酸盐的巨大变化提供了直接证据，表明它聚集在晶体内的口袋或晶界内。在这些口袋里，硝酸盐经历了一个类似溶液的环境，而在表面，硝酸盐有时会形成固体晶体。
Surface chemistry on ice can play an important role in atmospheric composition, but uncertainties in the chemical partitioning within ice samples has hindered the development of accurate models of these systems. Using Raman microscopy, we examine the nitrate distribution in ice and liquid samples containing environmentally relevant concentrations of sodium chloride, sodium bromide, and sea salt analogue Instant Ocean. Nitrate is enhanced at the surface compared to in the bulk in all frozen samples but to different degrees depending on the added salt. A large variation of nitrate in the horizontal dimension of frozen samples provides direct evidence that it congregates in pockets or grain boundaries within the crystal. In these pockets, nitrate experiences a solution-like environment, whereas at the surface nitrate sometimes forms solid crystals.