Download or read book Interactions of Trivalent Lanthanides and Actinides with Solid Phase Extractants written by Jennifer Anne Shusterman and published by . This book was released on 2015 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to successfully sequester and separate trivalent lanthanides and actinides has applications to the nuclear fuel cycle, processing of irradiated target materials, and nuclear forensics. The challenge in separating the trivalent lanthanides and actinides is their similar size and charge. As a result of this, standard size exclusion or ion exchange techniques become much more challenging. Instead of focusing on size or charge for separation, their differences in interactions with complexing ligands can be utilized. Another challenge in trivalent lanthanide and actinide separations is that these metals are often dissolved in highly acidic matrices. Thus, the stability of the extractant ligand used to complex the metal is at risk of degradation. The most common sequestration and separation routes based on complex formation for lanthanides and actinides use liquid-liquid separations, which can generate large volumes of hazardous organic waste. By moving to solid-liquid separations, in which the organic phase is replaced by a solid-phase extractant (SPE), the production of large volumes of waste can be minimized. The most common method of making SPEs for lanthanide and actinide separations is coating an organic extractant ligand on either a silica or polymer support. As a result of only coating the ligand rather than bonding it to the solid support, these materials can suffer from ligand degradation and detachment. Chapter 5 focuses on trivalent lanthanide and actinide interactions with a commercially available SPE. While those materials were found to have use for certain applications, their limitations motivated the organically-modified mesoporous silica (OMMS) development presented in Chapter 7. The work presented here is a study on solid-phase extractants for lanthanide and actinide separations, particularly focused on OMMS. The OMMS materials are made by covalently binding the extractant ligand to the mesoporous silica, to increase the stability of these SPEs in the presence of acidic media. Chapters 6 and 7 discuss the synthesis and characterization of two types of OMMS materials as well as macroscopic and molecular level studies of these materials with trivalent lanthanides and actinides. Additionally, the stability of the OMMS materials in the presence of acid was probed using nuclear magnetic resonance (NMR) spectroscopy. The first OMMS material discussed is a caprolactam (CA)-modified mesoporous silica. The behavior of Eu(III), Sc(III), and Al(III) was studied with the CA-modified mesoporous silica. Al and Sc were studied as comparative trivalent metals that had smaller ionic radii than Eu. The results of batch sorption experiments and mainly solid-state NMR spectroscopy studies are presented. The acid stability studies showed that the CA-modified mesoporous silica degraded in two ways in the presence of acid: 1) the 7-membered ring of the ligand opened, and 2) a portion of the isolated ligands on the surface were cleaved at the silane anchor. It was determined that while the CA materials were not effective sorbents for Eu(III) from acidic matrices, they did bind Al(III) and Sc(III). Through the NMR studies, both Al and Sc were found to complex to the CA ligand and the surface silanols simultaneously. This work was the first time solid-state NMR had been used to study the surface, ligand, and metals directly of OMMS materials via their NMR active nuclei (29Si, 13C, 1H, 27Al, and 45Sc). The second OMMS material studied was a diglycolamide (DGA)-modified mesoporous silica. The main focus of this work was the interactions of the DGA-modified mesoporous silica with Eu(III) and Am(III), but also touched on other trivalent species such as La(III), Lu(III), and Y(III). Again, the stability of this material in the presence of acid was investigated using NMR spectroscopy and while the DGA ligand was found to withstand acid treatment, the isolated ligand cleavage at the silane anchor still occurred. The DGA-modified mesoporous silica was found to efficiently bind the trivalent species at high acid concentrations, particularly below pH 1. As a result of the mesoporous substrate and subsequently high ligand loading for the associated mass, the sorption capacity for Eu(III) (379 umol/g) was found to be higher than other diglycolamide SPEs. Through infrared spectroscopy and NMR spectroscopy experiments, the trivalent metals were found to bind to the carbonyl and ether oxygens of the DGA ligand. Fluorescence spectroscopy of Eu(III) and X-ray absorption spectroscopy studies elucidated that the trivalent metals are complexing as three ligands per metal center. Proof-of-concept column experiments demonstrate the use of DGA-modified mesoporous silica as a stationary phase to which Eu was both sorbed and then eluted. A major focus of this work was the interplay of macroscopic and molecular level studies to best characterize metal interactions with OMMS materials. While both the bulk and molecular level investigations can provide information about these systems, neither gives the full picture in itself. In designing materials for separations, knowledge of the complete picture is necessary in order to best optimize methodologies and predict separation behavior.

Download or read book Mixed Monofunctional Extractants for Trivalent Actinide lanthanide Separations written by and published by . This book was released on 2015 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic features of an f-element extraction process based on a solvent composed of equimolar mixtures of Cyanex-923 (a mixed trialkyl phosphine oxide) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) extractants in n-dodecane are investigated in this report. This system, which combines features of the TRPO and TALSPEAK processes, is based on co-extraction of trivalent lanthanides and actinides from 0.1 to 1.0 M HNO3 followed by application of a buffered aminopolycarboxylate solution strip to accomplish a Reverse TALSPEAK selective removal of actinides. This mixed-extractant medium could enable a simplified approach to selective trivalent f-element extraction and actinide partitioning in a single process. As compared with other combined process applications in development for more compact actinide partitioning processes (DIAMEX-SANEX, GANEX, TRUSPEAK, ALSEP), this combination features only monofunctional extractants with high solubility limits and comparatively low molar mass. Selective actinide stripping from the loaded extractant phase is done using a glycine-buffered solution containing N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) or triethylenetetramine-N, N, N', N'', N''', N'''-hexaacetic acid (TTHA). Lastly, the results reported provide evidence for simplified interactions between the two extractants and demonstrate a pathway toward using mixed monofunctional extractants to separate trivalent actinides (An) from fission product lanthanides (Ln).

Download or read book Synthesis of Lanthanide and Actinide Compounds written by G. Meyer and published by Springer Science & Business Media. This book was released on 1990-12-31 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of the rare earths has entered its third century; trans uranium elements are now a half century old. Both the lanthanide and actinide ele­ ments, 30 elements altogether, are f elements, meaninj that their metallic 2 1 1 electronic configurations are typically 6s 5d 4f" and 7s 6d 5f" respectively. To an elementary approximation as summarized in the 'average inorganic chemistry textbook, these configurations cause their chemistry to be described by the trivalent state accompanied by less interesting effects such as the lanthanide contraction. However, the discovery of divalent and tetravalent lanthanides and di- to seven-valent actinides hinted at the existence of more interesting although still classic solid-state and coor­ dination chemistry. Metallic halides and chalcogenides and electron-poor cluster compounds have been the outgrowth of many synthetic efforts during the past 25 years or so. These days, one can say that the lan­ thanides and actinides are not at all boring; the fascination arises from every element being an individual, having its own chemistry.

Download or read book Lanthanides And Actinides The Synthesis Reactivity Properties And Applications written by Stephen T Liddle and published by World Scientific. This book was released on 2021-12-30 with total page 727 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lanthanides and Actinides: Synthesis, Reactivity, Properties and Applications constitutes an introduction to and comprehensive coverage of f-block chemistry encompassing the following areas: periodicity, natural occurrence and extraction, separations, electronic structure, coordination chemistry, organometallic chemistry, small molecule activation, catalysis, organic synthesis applications, magnetism, spectroscopy, computation, materials, photonics, solar cell technology, biological imaging, and technological applications. Under these subject areas the book provides a broad but deep coverage, providing basic overviews as well as detailed chapters on specific areas.This book, targeted at academics, postgraduates and advanced undergraduates, will serve as an ideal introductory text and key reference work to the Lanthanides and Actinides.

Download or read book Separation of Trivalent Lanthanides and Actinides by Solvent Extraction Without Aqueous Complexing Agents written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of separating the trivalent actinides, mainly Am and Cm, from trivalent lanthanides is presented. This method embodies the sequential use of two different solvent extractants; the first extractant would remove the heavy lanthanides from the lighter lanthanides and Am--Cm, while the second would extract Am--Cm in preference to the lighter lanthanides. In this scheme, no additional complexing agents are required. Thus, waste disposal and corrosion problems are minimized. Overall separation factors for Am--Cm from lanthanide fission products in reactor wastes may be as high as several thousand. (auth).

Download or read book Experimental and Theoretical Approaches to Actinide Chemistry written by John K. Gibson and published by John Wiley & Sons. This book was released on 2018-03-19 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of contemporary actinide research that focuses on new advances in experiment and theory, and the interplay between these two realms Experimental and Theoretical Approaches to Actinide Chemistry offers a comprehensive review of the key aspects of actinide research. Written by noted experts in the field, the text includes information on new advances in experiment and theory and reveals the interplay between these two realms. The authors offer a multidisciplinary and multimodal approach to the nature of actinide chemistry, and explore the interplay between multiple experiments and theory, as well as between basic and applied actinide chemistry. The text covers the basic science used in contemporary studies of the actinide systems, from basic synthesis to state-of-the-art spectroscopic and computational techniques. The authors provide contemporary overviews of each topic area presented and describe the current and anticipated experimental approaches for the field, as well as the current and future computational chemistry and materials techniques. In addition, the authors explore the combination of experiment and theory. This important resource: Provides an essential resource the reviews the key aspects of contemporary actinide research Includes information on new advances in experiment and theory, and the interplay between the two Covers the basic science used in contemporary studies of the actinide systems, from basic synthesis to state-of-the-art spectroscopic and computational techniques Focuses on the interplay between multiple experiments and theory, as well as between basic and applied actinide chemistry Written for academics, students, professionals and researchers, this vital text contains a thorough review of the key aspects of actinide research and explores the most recent advances in experiment and theory.

Download or read book The Chemistry of the Actinide and Transactinide Elements 3rd ed Volumes 1 5 written by L.R. Morss and published by Springer Science & Business Media. This book was released on 2007-12-31 with total page 4059 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Chemistry of the Actinide and Transactinide Elements is a contemporary and definitive compilation of chemical properties of all of the actinide elements, especially of the technologically important elements uranium and plutonium, as well as the transactinide elements. In addition to the comprehensive treatment of the chemical properties of each element, ion, and compound from atomic number 89 (actinium) through to 109 (meitnerium), this multi-volume work has specialized and definitive chapters on electronic theory, optical and laser fluorescence spectroscopy, X-ray absorption spectroscopy, organoactinide chemistry, thermodynamics, magnetic properties, the metals, coordination chemistry, separations, and trace analysis. Several chapters deal with environmental science, safe handling, and biological interactions of the actinide elements. The Editors invited teams of authors, who are active practitioners and recognized experts in their specialty, to write each chapter and have endeavoured to provide a balanced and insightful treatment of these fascinating elements at the frontier of the periodic table. Because the field has expanded with new spectroscopic techniques and environmental focus, the work encompasses five volumes, each of which groups chapters on related topics. All chapters represent the current state of research in the chemistry of these elements and related fields.

Download or read book Lanthanides and Actinides written by K. W. Bagnall and published by . This book was released on 1972 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solvent Extraction Separation of Trivalent Lanthanide and Actinide Ions Using an Aqueous Aminomethanediphosphonic Acid written by and published by . This book was released on 1998 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The possibility of separating the trivalent lanthanides, represented by EU{sup 3+}, and actinides, represented by Cf{sup 3+}, using HDEHP in toluene and an aqueous phase containing N-piperidinomethane-1,1-diphosphotic acid, PMDPA, has been investigated. This modified aqueous phase offers potential advantages over the diethylenetriaminepentaacetic acid based TALSPEAK process because of the improved complexation properties of PMDPA in acidic solutions, and the ability to decompose PMDPA before disposal. Extraction experiments were conducted at 25 C in 2 M NaClO4 between -log [H] 1 and 2. The studies enabled us to derive the aqueous phase speciation, the stability constants of the aqueous complexes, and the Cf/Eu separation factors. Despite the presence of an amino group in PMDPA that should favor the retention of the actinides in the aqueous phase, the Cf/Eu separation factors are near unity under the conditions studied.

Download or read book Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am and Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their academic experience. New information has been developed to qualify the extraction potential of a class of pyridine-functionalized tetraaza complexants indicating potential single contact Am-Nd separation factors of about 40. The methodology developed for characterization will find further application in our continuing efforts to synthesize and characterize new reagents for this separation. Significant new insights into the performance envelope and supporting information on the TALSPEAK process has also been developed.

Download or read book Ion Exchange Chromatography and Related Techniques written by Pavel Nesterenko and published by Elsevier. This book was released on 2023-11-15 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion-Exchange Chromatography and Related Techniques defines the current state-of-the-art in ion-exchange chromatography and related techniques and their implementation in laboratory and industrial practice. This book provides a compact source of information to facilitate the transfer of knowledge and experience acquired by separation science specialists to colleagues from diverse backgrounds who need to acquire fundamental and practical information to facilitate progress in research and management functions reliant on information acquired by separation. Individual chapters written by recognized experts lending credibility to the work will allow this book to serve as a high value reference source of current information for analytical and biopharmaceutical chemists. - Includes individual chapters written by recognized authoritative and visionary experts in the field to provide an overview and focused treatment of a single topic - Presents comprehensive coverage of ion-exchange techniques from theory, to methods, to selected applications for ions and biopolymers - Provides Tables and diagrams with commonly used data to facilitate practical work, comparison of results and decision-making

Download or read book Summaries of FY Research in the Chemical Sciences written by and published by . This book was released on 1985 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extraction Chromatography written by and published by Elsevier. This book was released on 1975-06-01 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extraction Chromatography

Download or read book Actinide Separations written by James D. Navratil and published by . This book was released on 1980 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Research Agenda for Transforming Separation Science written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-10-30 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separation science plays a critical role in maintaining our standard of living and quality of life. Many industrial processes and general necessities such as chemicals, medicines, clean water, safe food, and energy sources rely on chemical separations. However, the process of chemical separations is often overlooked during product development and this has led to inefficiency, unnecessary waste, and lack of consensus among chemists and engineers. A reevaluation of system design, establishment of standards, and an increased focus on the advancement of separation science are imperative in supporting increased efficiency, continued U.S. manufacturing competitiveness, and public welfare. A Research Agenda for Transforming Separation Science explores developments in the industry since the 1987 National Academies report, Separation and Purification: Critical Needs and Opportunities. Many needs stated in the original report remain today, in addition to a variety of new challenges due to improved detection limits, advances in medicine, and a recent emphasis on sustainability and environmental stewardship. This report examines emerging chemical separation technologies, relevant developments in intersecting disciplines, and gaps in existing research, and provides recommendations for the application of improved separation science technologies and processes. This research serves as a foundation for transforming separation science, which could reduce global energy use, improve human and environmental health, and advance more efficient practices in various industries.

Download or read book Solvent Extraction Principles and Practice Revised and Expanded written by Jan Rydberg and published by CRC Press. This book was released on 2004-03-01 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and up-to-date presentation of the fundamental theoretical principles and many applications of solvent extraction, this enhanced Solvent Extraction Principles and Practice, Second Edition includes new coverage of the recent developments in solvent extraction processes, the use of solvent extraction in analytical applications and waste recovery, and computational chemistry methods for modeling the solvent extraction of metal ions. Offering sound scientific and technical descriptions in a format accessible to students and expedient for researchers and engineers, this edition also features a new chapter on ionic strength corrections and contains more than 850 up-to-date literature citations.

Download or read book Structural Chemistry of Inorganic Actinide Compounds written by Sergey Krivovichev and published by Elsevier. This book was released on 2006-12-08 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Chemistry of Inorganic Actinide Compounds is a collection of 13 reviews on structural and coordination chemistry of actinide compounds. Within the last decade, these compounds have attracted considerable attention because of their importance for radioactive waste management, catalysis, ion-exchange and absorption applications, etc. Synthetic and natural actinide compounds are also of great environmental concern as they form as a result of alteration of spent nuclear fuel and radioactive waste under Earth surface conditions, during burn-up of nuclear fuel in reactors, represent oxidation products of uranium miles and mine tailings, etc. The actinide compounds are also of considerable interest to material scientists due to the unique electronic properties of actinides that give rise to interesting physical properties controlled by the structural architecture of respective compounds. The book provides both general overview and review of recent developments in the field, including such emergent topics as nanomaterials and nanoparticles and their relevance to the transfer of actinides under environmental conditions.* Covers over 2,000 actinide compounds including materials, minerals and coordination polymers* Summarizes recent achievements in the field* Some chapters reveal (secret) advances made by the Soviet Union during the 'Cold war'