溶剂对提取液液提取过程中提取剂构造能量的作用:对分子溶剂和离子液体的模拟研究
Xiaoyu Wang1, Srikanth Nayak1, Richard E Wilson1
1Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA. xiaoyu.wang@anl.gov.
Physical chemistry chemical physics : PCCP
|December 4, 2023
概括
纳米结构溶剂通过重塑提取剂的能量来增强金属离子分离. 离子液体显著降低了能量障碍,改善了金属复合物相互作用,以实现有效的分离.
科学领域:
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
- 计算化学计算化学
背景情况:
- 用于金属离子分离的液体-液体提取 (LLE) 主要集中在直接的提取剂-金属相互作用上.
- 除了金属协调之外的能量驱动因素以及溶剂在提取剂阶段的作用往往被忽视.
- 了解这些因素对于设计高效的分离工艺至关重要.
研究的目的:
- 提出和研究一种用于利用纳米结构溶剂增强金属复合物能量的新机制.
- 阐明不同有机溶剂对提取剂的形状景观和结合能量的影响.
- 探索离子液 (ILs) 在促进金属离子分离方面的潜力.
主要方法:
- 利用分子动力学模拟与雨采样来计算自由能量概况.
- 在各种溶剂中研究了双酸提取剂CMPO (碳甲基氧化物) 的构造变化.
- 采用化学自由能计算来评估具有明确阴离子存在的溶剂效应.
主要成果:
- 有机溶剂可以重塑提取剂形状的能量景观.
- 特定的溶剂,特别是离子液体 (ILs),促进提取剂重组成结合性构成.
- 在ILs中的电荷交替纳米域大大降低了提取剂重组的自由能量罚款.
- 这种稳定效应即使在提取的离子存在时也会持续下去.
结论:
- 溶剂的选择对LLE中金属复合物相互作用的能量有重大影响.
- 纳米结构溶剂,特别是ILs,为提高金属离子分离效率提供了一个有希望的策略.
- 对溶剂效应的分子层次理解可以指导下一代分离剂的设计.
相关概念视频
Extraction: Effects of pH
498
Consider a neutral form of an amine, B, with a partition coefficient, K, in a liquid mixture containing organic and aqueous phases. The pH of the aqueous phase affects the charge on acidic and basic solutes, and the charged form is usually more soluble in the aqueous phase. Suppose the conjugate acid form of the amine is soluble only in the aqueous phase while the base form is soluble in both phases. Then the distribution coefficient, D, can be given as the ratio of amine concentration in the...
498
Entropy and Solvation
7.1K
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ...
7.1K
Energetics of Solution Formation
6.7K
The formation of a solution is an example of a spontaneous process, which is a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Formation of the solution requires the solute–solute and solvent–solvent...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Formation of the solution requires the solute–solute and solvent–solvent...
6.7K
Extraction: Advanced Methods
450
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
450
Ideal Solutions
19.6K
According to Raoult’s law, the partial vapor pressure of a solvent in a solution is equal or identical to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution. However, Raoult's Law is only valid for ideal solutions. For a solution to be ideal, the solvent-solute interaction must be just as strong as a solvent-solvent or solute-solute interaction. This suggests that both the solute and the solvent would use the same amount of energy to escape to the...
19.6K
Chemical and Solubility Equilibria
4.1K
The free energy change associated with dissolving a solute in a liter of solvent is called the free energy of a solution, ΔGsolution. The overall ΔGsolution is expressed as the balance of ΔGinteraction against the always-favorable free-energy of mixing, ΔGmixing. Solution formation is favorable if ΔGsolution is less than zero, whereas it is unfavorable if ΔGsolution is greater than zero. In short, for a solution to form and complete dissolution to take place,...
4.1K


