Hypothesis

Nanoparticles functionalized with ligands which can on-demand and remotely be detached have recently attracted interest as stimuli-responsive materials. Research is now focused on multi-responsive systems, with applications in environmental science and biomedicine. The possibility to covalently couple two different ligands on a single nanoparticles, and to release them independently is investigated. This concept of nanoparticles functionalized with dual on-demand cleavable ligands is exploited in ground water decontamination and radionuclides separation. Efficient separation of contaminants in a single step is expected, simplifying partitioning process and decreasing generation of secondary waste by nuclear industry.

Experiments

Sub−10 nm Janus superparamagnetic nanoparticles are functionalized by click-chemistry (thiol and Diels-Alder) with two different Actinide-specific chelators. The reversible covalent bonds allow to detach chelators independently by either pH- or thermo-stimulation. The nanoparticles decorated with diethylenetriamine-pentaacetic acid (DTPA) and [(2-furan-2-yl-2-hydroxy-ethylcarbamoyl)-methoxy]-acetic acid (FHECMAA) are incubated with UO₂²⁺ and La³⁺ (as substitute for Pu³⁺) at pH = 3 and 7 before chelator-metal complexes are released. Metal contents are measured to determine separation efficiency.

Findings

Chelators can be detached from Janus nanoparticles with perfect selectivity. The nanoparticles are highly efficient for extraction of metals in acidic medium and show good ability for separation of U and La at neutral pH.

中文翻译：

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Janus多响应超顺磁性纳米粒子功能化，具有两个按需且可独立裂解的配体，可用于separation系元素的分离

假设

最近，作为刺激响应材料，用可以按需和远程分离的配体功能化的纳米颗粒引起了人们的兴趣。现在的研究重点是多响应系统，并在环境科学和生物医学中得到应用。研究了在单个纳米颗粒上共价偶联两个不同配体并独立释放的可能性。这种具有双重按需可裂解配体功能的纳米颗粒的概念被用于地下水净化和放射性核素分离中。期望在单个步骤中有效分离污染物，从而简化了分配过程并减少了核工业产生的二次废物。

实验

低于10 nm的Janus超顺磁性纳米颗粒通过点击化学（硫醇和Diels-Alder）与两种不同的Act系元素特异性螯合剂进行官能化。可逆的共价键允许通过pH刺激或热刺激独立地分离螯合剂。将装饰有二亚乙基三胺五乙酸（DTPA）和[（2-呋喃-2-基-2-羟基-乙基氨基甲酰基）-甲氧基]-乙酸（FHECMAA）的纳米颗粒与UO ₂ ²⁺和La ³⁺（如在释放螯合金属络合物之前，在pH = 3和7时代替Pu ³⁺）。测量金属含量以确定分离效率。

发现

螯合剂可以完美的选择性从Janus纳米颗粒中分离出来。纳米颗粒对于在酸性介质中萃取金属非常有效，并且在中性pH值下具有良好的分离U和La的能力。