Micelle Formation and Surface Interactions in Supercritical CO2. Fundamental Studies for the Extraction of Actinides from Contaminated Surfaces.

McCleskey, T Mark ; Birnbaum, Eva R.

Los Alamos National Laboratory

关键词: Research Programs;    Transport;    Actinides;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Radioisotopes;   

DOI  :  10.2172/831197
RP-ID  :  EMSP-64865
RP-ID  :  831197

美国|英语

来源: UNT Digital Library

【 摘 要 】

The goals of this research program included: (1) Study solubility of extractants and formation of micelles--(a) Do surfactants form micelles in scCO{sub 2} and what is the mechanism of their formation? (b) Can the pressure/density of scCO{sub 2} be used to alter surfactant solubility or micelle structure? (c) Can surfactant micelles be used to transport water based microphases? (2) Examine the solubilization of metals--(a) What influence does metal binding have on the surfactant solubility or micelle structure? (b) What is the selectivity of metal binding in promising systems? (c) Are all solubilized metals bound to surfactant ligands or is an entire aqueous micro-environment solubilized by the surfactant/micelle? (d) Can metal species, as charged ions or neutral complexes, be insulated by fluorinated surfactants to enhance solubility in scCO{sub 2}? (3) Explore surface interactions with the matrix and mobility of micelles.--(a) What factors affect wetting of heterogeneous matrices (i.e., ligand type, CO{sub 2} pressure); (b) How deep can surfactants penetrate materials such as concrete? (4) Explore surface interactions with the actinide contaminant--(a) Can surfactant based micelles be used to deliver acidic, aqueous microphases to the actinide surface? (5) Evaluate these new systems for metal extraction from a model contaminated surface containing radionuclides or surrogate metals--(a) What is the rate of extraction? (b) What ratio of ligand to metal is required?