Tag Archives: chelator

Rare-earth recycling (new method) can strengthen raw material independence

I wasn’t planning on celebrating my 7500th [March 9, 2026 correction: 7499th] post by publishing something from last July. Ah well. Here it is: a July 1, 2025 Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) press release (also on EurekAlert) announced research into recycling that could provide more critical minerals, in this case, rare earths, Note: Link have been removed,

The scientific team of Dr. Miloslav Polášek at IOCB Prague has developed a new method of separating the rare earth elements, or lanthanides, which are widely used in the electronic, medical, automotive, and defense industries. The unique method allows metals such as neodymium or dysprosium to be purified from used neodymium magnets. The environmentally friendly process precipitates the rare earths from water without organic solvents or toxic substances. The results were published in the Journal of the American Chemical Society (JACS) at the end of June [2025].

Global demand for rare earths is driven primarily by their use in extremely strong neodymium magnets, which enable efficient conversion of motion into electrical energy and vice versa. They are essential to manufacturers of electric cars, wind power plants, mobile phones, computers, and data centers. As these industries develop, demand for rare earths will continue to grow. However, the process of mining and purifying these elements is highly energy intensive and produces large amounts of toxic and radioactive waste.

The rare-earth market is dominated by China, giving it leverage over Europe and North America. It is therefore strategically advantageous to focus on so-called urban mining, i.e. the recycling, renewal, and reuse of materials from discarded equipment, such as electric vehicles, as a significant domestic source of rare earths.

“In the future, we won’t be able to cover the growing consumption of rare earths with primary mining. We know that within ten years at the latest, it will be necessary to manage these materials more carefully. In order to achieve this, the development of new technologies must start now,” explains Miloslav Polášek, head of the Coordination Chemistry group. “Our method solves the fundamental problems of recycling neodymium magnets. We can separate the right elements so that new magnets can be produced. Our process is environmentally friendly, and we believe that it will work on an industrial scale. Fortunately, unlike plastics, chemical elements don’t lose their properties through repeated processing, so their recycling is sustainable and can compensate for traditional mining.”

The topic, which Polášek’s group has been working on for a long time, is part of Kelsea G. Jones’s doctoral thesis. “We’ve developed a new type of chelator, which is a molecule that binds metal ions. This chelator specifically precipitates neodymium from dissolved magnets, while dysprosium remains in solution, and the elements are easily separated from each other. The method is also adaptable for the other rare earths found in neodymium magnets,” says Jones. “The separation is done in water and generates no hazardous waste. We achieve the same or better results than current industrial methods that rely on organic solvents and toxic reagents.”

The new technology is patented and responds to a fundamental global problem at the right time. “We’re impatiently awaiting the results of a feasibility study, which will help us direct this research from the laboratory into practice. I believe that in cooperation with the investors and business partners we’re approaching, this new technology from IOCB Prague has the potential to influence a wide range of industrial sectors,” says Milan Prášil, director of the transfer company IOCB Tech.

This research has also yielded another important finding: namely, that the element holmium is used in neodymium magnets of newer electric cars. Scientists from Polášek’s team discovered this by analyzing samples from the electric motors of European and Chinese cars. However, professional publications have not yet mentioned this fact, and most recycling projects do not take it into account when processing waste from electric cars. These findings will undoubtedly influence other development and recycling projects, even beyond the automotive industry.

….

Here’s a link to and a citation for the paper,

Macrocyclic Chelators for Aqueous Lanthanide Separations via Precipitation: Toward Sustainable Recycling of Rare-Earths from NdFeB Magnets by Kelsea G. Jones, Tomáš David, Martin Loula, Stanislava Matějková, Jan Blahut, Anatolij Filimoněnko, Miroslava Litecká, Jan Rohlíček, Jiří Böserle, Miloslav Polasek. Journal of the American Chemical Society (J. Am. Chem. Soc.) 2025, 147, 26, 22666–22676 DOI: https://doi.org/10.1021/jacs.5c04150 Published June 19, 2025 Copyright © 2025 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 .

This paper is open access.

Better bioimaging accuracy with direct radiolabeling of nanomaterials

Even I can tell the image is improved when the chelator is omitted,

Courtesy: Wiley

A Feb. 9, 2017 news item on phys.org describes a new, chelator-free technique for increased bioimaging accuracy,

Positron emission tomography (PET) plays a pivotal role for monitoring the distribution and accumulation of radiolabeled nanomaterials in living subjects. The radioactive metals are usually connected to the nanomaterial through an anchor, a so-called chelator, but this chemical binding can be omitted if nanographene is used, as American scientists report in the journal Angewandte Chemie. The replacement of chelator-based labeling by intrinsic labeling significantly enhances the bioimaging accuracy and reduces biases.

A Feb 9, 2017Wiley press release (also on EurekAlert), which originated the news item, provides more detail,

Nanoparticles are very promising substances for biodiagnostics (e.g., detecting cancerous tissue) and biotherapy (e.g., destroying tumors by molecular agents), because they are not as fast [sic] metabolized as normal pharmaceuticals and they particularly enrich [sic] in tumors through an effect called enhanced permeability and retention (EPR). Chelators, which have a macrocyclic structure, are used to anchor the radioactive element (e.g., copper-64) onto the nanoparticles’ surface. The tracers are then detected and localized in the body with the help of a positron emission tomography (PET) scanner. However, the use of a chelator can also be problematic, because it can detach from the nanoparticles or bias the imaging. Therefore, the group of Weibo Cai at University of Wisconsin-Madison, USA, sought for chelator-free solutions—and found it in nanographene, one of the most promising substances in nanotechnology.

Nanographene offers the electronic system to provide special binding electrons for some transition metal ions. “π bonds of nanographene are able to provide the additional electron to stably incorporate the 64Cu2+ acceptor ions onto the surface of graphene,” the authors wrote. Thus, it was possible to directly and stably attach the copper isotope to reduced graphene oxide nanomaterials stabilized by poly(ethylene glycol) (PEG), and this system was used for several bioimaging tests including the detection of tumors in mice.

After injection in the mouse model, the scientists observed long blood circulation and high tumor uptake. “Prolonged blood circulation of 64Cu-RGO-PEG […] induced a prompt and persistent tumor uptake via EPR effect,” they wrote. Moreover, the directly radiolabeled nanographene was readily prepared by simply mixing both components and heating them. This simple chelator-free, intrinsically labeled system may provide an attractive alternative to the chelator-based radiolabeling, which is still the “gold standard” in bioimaging.

Here’s a link to and a citation for the paper,

Chelator-Free Radiolabeling of Nanographene: Breaking the Stereotype of Chelation by Sixiang Shi, Cheng Xu, Dr. Kai Yang, Shreya Goel, Hector F. Valdovinos, Dr. Haiming Luo, Emily B. Ehlerding, Dr. Christopher G. England, Dr. Liang Cheng, Dr. Feng Chen, Prof. Robert J. Nickles, Prof. Zhuang Liu, and Prof. Weibo Cai. Angewandte Chemie International Edition DOI: 10.1002/anie.201610649 Version of Record online: 7 FEB 2017

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.