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Hollow Microcrystals of Copper Hexafluoroacetylacetonate-Pyridine Derivative Adducts via Supercritical CO2 Recrystallization

“…29 Previous studies have described the use of scCO 2 to process [Cu(hfacac) 2 ], either to deposit copper films, 30,31 to produce copper particles, 32 to obtain one-dimensional coordination polymers, 33 or for the etching of copper using hfacac in scCO 2 . 34,35 In the etching conditions, a [Cu(hfacac) 2 (Py) 2 ] adduct was probably formed, although the authors did not report its isolation or characterization. In this work, crystal formation proceeded in five steps following the pressurization/depressurization protocol schematized in Figure 2: reagents dissolution, reaction, precipitation, product dissolution, and recrystallization.…”

“…29 Previous studies have described the use of scCO 2 to process [Cu(hfacac) 2 ], either to deposit copper films, 30,301 to produce copper particles, 32 to obtain one-dimensional coordination polymers, 33 or for the etching of copper using hfacac in scCO 2 . 34,35 In the etching conditions, a [Cu(hfacac) 2 (Py) 2 ] adduct was probably formed, although the authors did not report its isolation or characterization.…”

SANS study of the self-organization of gradient copolymers with ligand groups in supercritical CO2

“…Therefore, research focuses on the way to transport these contaminants in scCO 2 . The use of suitable ligand [1][2][3][4][5] has been investigated by several teams. Solubilization in surfactant micelles is a common way to overcome solubility issues, and surfactants have been studied for metal oxide extraction.…”

“…Theoretical approaches 12,13 predict that gradient copolymers exhibit intermediate behavior between statistical and block copolymers: they form a monolayer with a larger interfacial width than that of block copolymers, and the critical micelle concentration values are higher. Micelle formation in aqueous solution was observed for different gradient copolymers by 1 H NMR spectroscopy, 14 small-angle neutron scattering (SANS), [15][16][17] dynamic light scattering and turbidity measurements, 18,19 and fluorescence correlation spectroscopy. 20,21 Okabe et al [15][16][17] show a continuous transition between unimers and aggregates as opposed to block copolymers 17 where the transition is abrupt.…”

Recovery of Uranium and Plutonium from Waste Matrices Using Supercritical Fluid Extraction

“…Supercritical fluid extraction of plutonium and americium from surrogate soil was investigated using Sc-CO 2 modified with theonyltrifluoroacetone (TTA) and TBP [12]; the extraction efficiencies of Pu and Am were found to be 69% and 88%, respectively. Sc-CO 2 containing hexafluoroacetylacetone and pyridine was employed for the removal of actinides from stainless steel surface [13].…”