Probing the interaction of U(vi) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy.

The fundamental interaction of U(vi) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(vi) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength.

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

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).

Analysis of trivalent cation complexation to functionalized mesoporous silica using solid-state NMR spectroscopy.

Functionalized mesoporous silica has applications in separations science, catalysis, and sensors. In this work, we studied the fundamental interactions of trivalent cations with functionalized mesoporous silica. We contacted trivalent cations of varying ionic radii with N-[5-(trimethoxysilyl)-2-aza-1-oxopentyl]caprolactam functionalized mesoporous silica with the aim of probing the binding mechanism of the metal to the surface of the solid.

Centrifugal microfluidic platform for radiochemistry: potentialities for the chemical analysis of nuclear spent fuels.

The use of a centrifugal microfluidic platform is for the first time reported as an alternative to classical chromatographic procedures for radiochemistry. The original design of the microfluidic platform has been thought to fasten and simplify the prototyping process with the use of a circular platform integrating four rectangular microchips made of thermoplastic. The microchips, dedicated to anion-exchange chromatographic separations, integrate a localized monolithic stationary phase as well as injection and collection reservoirs.

New "one-step" method for the simultaneous synthesis and anchoring of organic monolith inside COC microchip channels.

A new method for monolith synthesis and anchoring inside cyclic olefin copolymer (COC) microchannels in a single step is proposed. It is shown that type I photoinitiators, typically used in a polymerization mixture to generate free radicals during monolith synthesis, can simultaneously act as type II photoinitiators and react with the plastic surface through hydrogen abstraction. This mechanism is used to "photograft" poly(ethylene glycol) methacrylate (PEGMA) on COC surfaces.

Improved chromatographic performances of glycidyl methacrylate anion-exchange monolith for fast nano-ion exchange chromatography.

An efficient and reproducible photopolymerized poly(glycidyl methacrylate-co-ethylene dimethacrylate) was synthesized in Teflon-coated fused-silica capillaries (100 μm id) and functionalized by reaction of triethylamine with reactive epoxy groups. We report here the successful transfer of a standard polymerization mixture optimized for the thermally initiated synthesis of glycidyl-based monolith to photo-induced polymerization. The monolith obtained after optimization of the photo-initiation conditions was characterized in reverse-phase chromatography evaluating its suitability in terms of efficiency, retention and hydrodynamic permeability.