EAGER: Adsorptive separation of rare-earth elements in DNA grafted mesoporous carbons

用于电子产品、阴极射线管、光学设备、永磁体、电源和各种军事应用的特殊金属来自一组被称为稀土元素的金属。稀土元素不是大量开采、加工或交易的。世界上90%以上的这些金属供应由外国控制。最近的出口限制中断了这些金属对美国的供应，并引发了人们对它们在军事和能源领域继续使用的担忧。因此，这些稀土元素的回收、分离、循环和再利用至关重要。然而，这些金属经常紧密地混合在一起--因此很难从其他类似的金属中分离出来。使用溶剂可以从废弃的铁磁铁中回收两种稀土元素--钕和镝。溶剂提取可能是危险的、昂贵的、时间和劳动力密集型的，而且当发现金属浓度较低时，效果不佳。该项目将开发一种新的材料，可以在不使用溶剂的情况下选择性地从铁中回收低浓度的钕和镝。该项目将开发DNA接枝介孔碳，以选择性地从铁中回收钕和镝。DNA分子上高浓度的氧和磷将增加对这些金属的选择性亲和力，使它们集中在固体基质上。介孔碳将为每克材料提供大量的表面位，以促进回收。该探索性项目将在中孔碳表面共价嫁接特定的核苷酸单元，探索核苷酸对孔的渗透，确定材料的稳定性，并测试材料对钕、镝和铁的非竞争和竞争吸附。预期的结果是一系列高度可调和稳定的DNA接枝碳，与目前可用的材料相比，可以显著提高对钕和镝的吸收和回收。可以预期，DNA接枝碳的可调磷和氧含量将在化学分离、传感、荧光或分子电子学中有更多的应用。该项目将支持本科生和硕士研究生，将研究纳入本科工程课程，并在工程夏令营向高中生介绍概念。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The specialty metals used in electronics, cathode ray tubes, optical devices, permanent magnets, power sources and various military applications are from a group of metals known as 'rare earth elements'. Rare earth elements are not mined, processed or traded in large quantities. Over 90% of the world's supply of these metals is controlled by foreign countries. Recent export restrictions have interrupted the supply of these metals to the United States, and raised concerns about their continued use in military and energy sectors. Recovery, separation, recycle, and reuse of these rare earth elements is thus critical. However, these metals are often found closely intermingled - and thus difficult to separate from - other 'like' metals. Two rare earth elements, neodymium and dysprosium, can be recovered from discarded iron magnets using solvents. Solvent extraction can be hazardous, expensive, time and labor intensive, and ineffective when the metals are found in low concentration. This project will develop a novel material that will selectively recover low concentrations of neodymium and dysprosium from iron without the use of solvents. This project will develop DNA-grafted mesoporous carbon to selectively recover neodymium and dysprosium from iron. The high concentration of oxygen and phosphorous on the DNA molecules will increase the selective affinity for these metals, concentrating them on the solid substrate. The mesoporous carbon will provide a high number of surface sites per gram of material to facilitate the recovery. The exploratory project will covalently graft specific nucleotide units on the mesopore carbon surface, explore the penetration of the nucleotides into the pores, determine material stability, and test the materials for both non-competitive and competitive adsorption of neodymium, dysprosium, and iron. The anticipated outcome is a series of highly tunable and stable DNA grafted carbons that can substantially enhance the uptake and recovery of neodymium and dysprosium compared to currently available materials. It is anticipated that the tunable phosphorous and oxygen content of DNA grafted carbon will have additional applications in chemical separations, sensing, fluoresce, or molecular electronics. The project will support both undergraduate and masters-level research students, incorporate the research into the undergraduate engineering curriculum, and presented the concepts to high school students at an engineering summer camp.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.