Concentrated Ionic Fluids: Is There a Difference Between Chloride-Based Brines and Deep Eutectic Solvents?
Concentrated Ionic Fluids: Is There a Difference Between Chloride-Based Brines and Deep Eutectic Solvents?
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浓离子液体：氯化物盐水和低共熔溶剂之间有区别吗？
DOI：
10.1002/anie.202311140
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Zante G
中科院分区：
文献类型：
--
作者：
Zante G
深度共晶溶剂(DESS)被誉为新型溶剂，但它们与浓盐水真的有区别吗？它们提供了一种调节水和氯离子活性的方法，可以影响质量传输、形态形成和反应活性。这项研究提出了一种跨浓缩离子液体的性质的连续体，并以金属加工为例。电荷输运受流动性控制，摩尔电导率和流动性之间不存在间断，与阳离子、电荷密度或离子半径无关。铁(III)和氯化铜(II)在众多浓离子液体中的扩散系数与流动性呈线性关系。这些氧化剂被用来腐蚀铜、银和镍，虽然铜的腐蚀速率随着铜的流动性的增加而增加，但银和镍的腐蚀只在高氯和低水活度时发生，因为随着水活度的增加而发生钝化。总体而言，与DESS相比，盐水的含氯量高，粘度低，但与DESS不同的是，由于其高水分，盐水无法防止钝化。结果表明，如何通过调节氯化物和水的活度来实现对混合金属废流的选择性刻蚀。
Deep Eutectic Solvents (DESs) have been lauded as novel solvents, but is there really a difference between them and concentrated aqueous brines? They provide a method of adjusting the activity of water and chloride ions which can affect mass transport, speciation and reactivity. This study proposes a continuum of properties across concentrated ionic fluids and uses metal processing as an example. Charge transport is shown to be governed by fluidity and there is no discontinuity between molar conductivity and fluidity irrespective of cation, charge density or ionic radius. Diffusion coefficients of iron(III) and copper(II) chloride in numerous concentrated ionic fluids show the same linear correlation between diffusion coefficient and fluidity. These oxidising agents were used to etch copper, silver and nickel and while the etching rate increased with fluidity for copper, etching of silver and nickel only occurred at high chloride and low water activity as passivation occurred when water activity increased. Overall, brines provide a high chloride content at a lower viscosity than DESs, but unlike DESs, brines are unable to prevent passivation due to their high water content. The results show how selective etching of mixed metal waste streams can be achieved by tuning chloride and water activity.