| 研究実績の概要 |
This work aims to develop a new surfactant system for the extraction and separation of rare earth elements and/or platinum group metals using the ion foam flotation process. For this purpose, synthesis and characterisation of a new malonamide polyethoxylated surfactant is consider.
For the synthesis, two main routes are planned: (i) esterification between the polyethoxylated carboxylic acid surfactant AKYPO LS-O90 and the N(1), N(3)-Bis(2-hydroxyethyl)malonamide, and (ii) alkylation between malonamide molecule and the polyethoxylated alcohol surfactant BrijO10 (or Brij S10). Reactants have been ordered and received, and the characterisation of surfactants were performed in term of purity, pKa and micelle surface charge. Additional synthesis routes are being consider in order to reduce reactant cost and synthesis steps.
For the characterisation of the process in term of flotation efficiency and microstructure through SANS and NR analyses, dedicated columns (and flowmeter) were designed, ordered and received. Technical feasibility of SANS experiments on foam with the new column has been demonstrated with a model surfactant system. NR measurement on malonamide standard systems has been performed at J-PARC, MLF, as a preliminary experiment and had demonstrated the feasibility of analysing liquid-air interfaces.
Finally, the results obtained led to the publication of two articles in peer reviewed journal (Langmuir and J. Mol. Liq.) as well as press release in Japanese journals. This study opened new routes in separation chemistry and is a milestone for future projects.
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