Development and Testing of Diglycolamide Functionalized Mesoporous Silica for Sorption of Trivalent Actinides and Lanthanides

Abstract

Sequestration of trivalent actinides and lanthanides present in used nuclear fuel and legacy wastes is necessary for appropriate long-term stewardship of these metals, particularly to prevent their release into the environment. Organically modified mesoporous silica is an efficient material for recovery and potential subsequent separation of actinides and lanthanides because of its high surface area, tunable ligand selection, and chemically robust substrate. We have synthesized the first novel hybrid material composed of SBA-15 type mesoporous silica functionalized with diglycolamide ligands (DGA-SBA). Because of the high surface area substrate, the DGA-SBA was found to have the highest Eu capacity reported so far in the literature of all DGA solid-phase extractants. The sorption behavior of europium and americium on DGA-SBA in nitric and hydrochloric acid media was tested in batch contact experiments. DGA-SBA was found to have high sorption of Am and Eu in pH 1, 1 M, and 3 M nitric and hydrochloric acid concentrations, which makes it promising for sequestration of these metals from used nuclear fuel or legacy waste. The kinetics of Eu sorption were found to be two times slower than that for Am in 1 M HNO3. Additionally, the short-term susceptibility of DGA-SBA to degradation in the presence of acid was probed using (29)Si and (13)C solid-state NMR spectroscopy. The material was found to be relatively stable under these conditions, with the ligand remaining intact after 24 h of contact with 1 M HNO3, an important consideration in use of the DGA-SBA as an extractant from acidic media.

Nanostructure PEO‐Silica Hybrids: A New Class of Additive Material for Composite Polymer Electrolytes

“…Due to the simplicity in preparation techniques, sol‐gel approach is being utilized for the synthesis and fabrication of these ORMOSIL nanoparticles. Further, the surface of silica nanoparticles can be tailored through the use of various organic modifiers like polymers, peptides, functional organosilane derivatives, monochlorosilanes, diglycolamide, etc . Generally, polymer based silica hybrids are obtained either by carrying out hydrolysis of silica precursor in presence of a polymer or by grafting polymer onto the silica nanospheres .…”

“…Further, the surface of silica nanoparticles can be tailored through the use of various organic modifiers like polymers, peptides, functional organosilane derivatives, monochlorosilanes, diglycolamide, etc. [10][11][12][13][14] Generally, polymer based silica hybrids are obtained either by carrying out hydrolysis of silica precursor in presence of a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 polymer or by grafting polymer onto the silica nanospheres. [13] Aylward et al prepared sulphonated ORMOSIL and used them in making composite films of polypyrrole on electrodes by electrochemical oxidation of pyrrole in a liquid sol-gel electrolyte followed by ion transport study.…”

Application of Lecithin-templated Mesoporous Silica Microparticles for the Specific and Selective Removal of Phospholipids

“…Since the discovery of mesoporous silica material in 1992 by Mobil scientists [7], it has been widely studied and applied in many processes like smart delivery systems for medicines [8], agrochemicals [9], catalysis [10], separation [11] and adsorption for environmental remediation processes [12,13]. This is because it possesses desirable properties like high surface area, large pore volume and the ability to not only alter and tune the morphology of the mesopores, but also to easily modify the surfaces for specific demands [7][8][9][10][11][12][13]. The morphology of the mesopores is dictated by the surfactant used during the synthesis process [10][11][12].…”

Titanium alkylphosphate functionalised mesoporous silica for enhanced uptake of rare-earth ions

“…9 Solid-phase extraction (SPX) is regarded as an alternative for SX. [10][11][12] Recently, organic-inorganic hybrid materials, including metal phosphonates (metal-organic framework) 13,14 and ligand-functionalised silica (phosphine oxide, 15 phosphonates [16][17][18] and diglycolamide-derivatives [19][20][21][22] ) have been developed as adsorbents for REE separation. The major advantage of SPX over SX is the elimination of one of the liquid phases.…”