Immobilized β-cyclodextrin on surface-modified carbon-coated cobalt nanomagnets: reversible organic contaminant adsorption and enrichment from water.
Immobilized β-cyclodextrin on surface-modified carbon-coated cobalt nanomagnets: reversible organic contaminant adsorption and enrichment from water.
复制标题
DOI：
10.1021/la103873v
复制
发表时间：
2011-01
期刊：
影响因子：
--
通讯作者：
R. Fuhrer;I. Herrmann;E. K. Athanassiou;R. Grass;W. Stark
中科院分区：
文献类型：
--
作者：
R. Fuhrer;I. Herrmann;E. K. Athanassiou;R. Grass;W. Stark
表面改性的磁性纳米粒子可用于提取过程，因为它们易于分散在常见溶剂中，并且结合了高饱和磁化强度和优异的可及性。通过溶剂变化和磁分离实现可逆且可回收的吸附和解吸，为传统溶剂萃取提供了技术上有吸引力的替代方案。薄聚合物层状碳包覆钴纳米颗粒用 β-环糊精进行标记。所得材料在几分钟内可逆地吸附水中的有机污染物。由于纳米磁体（金属核而不是迄今为止使用的氧化铁）的强磁化作用，通过磁分离可以在几秒钟内轻松地进行固定的包合物的分离。通过用微生物学上广泛接受的替代品（例如苯甲醇）填充环糊精空腔，捕获的分子被完全且快速地回收。酚酞被用作有机污染物（例如多氯二苯并二恶英 (PCDD) 或双酚 A (BPA)）的模型化合物。纳米磁体在温和条件下快速再生（与类似的基于环糊精的系统相比），可实现全效率的 16 次重复循环（吸附/解吸）。在化学平衡条件下和快速循环（5 分钟）下通过 UV-vis 测量检查了高去除和再生效率。超低浓度（160 ppb）的实验强调了环糊精改性纳米磁体作为大水流中有机污染物的快速、可回收提取方法或作为分析富集工具的巨大潜力。
Surface-modified magnetic nanoparticles can be used in extraction processes as they readily disperse in common solvents and combine high saturation magnetization with excellent accessibility. Reversible and recyclable adsorption and desorption through solvent changes and magnetic separation provide technically attractive alternatives to classical solvent extraction. Thin polymer layered carbon-coated cobalt nanoparticles were tagged with β-cyclodextrin. The resulting material reversibly adsorbed organic contaminants in water within minutes. Isolation of the immobilized inclusion complex was easily carried out within seconds by magnetic separation due to the strong magnetization of the nanomagnets (metal core instead of hitherto used iron oxide). The trapped molecules were fully and rapidly recovered by filling the cyclodextrin cavity with a microbiologically well accepted substitute, e.g., benzyl alcohol. Phenolphthalein was used as a model compound for organic contaminants such as polychlorinated dibenzodioxins (PCDDs) or bisphenol A (BPA). Fast regeneration of nanomagnets (compared to similar cyclodextrin-based systems) under mild conditions resulted in 16 repetitive cycles (adsorption/desorption) at full efficiency. The high removal and regeneration efficiency was examined by UV-vis measurements at chemical equilibrium conditions and under rapid cycling (5 min). Experiments at ultralow concentrations (160 ppb) underline the high potential of cyclodextrin modified nanomagnets as a fast, recyclable extraction method for organic contaminants in large water streams or as an enrichment tool for analytics.