22541-31-7Relevant articles and documents
Sorbents based on modified polysiloxanes
Neudachina,Golub,Yatluk,Osipova,Berdyugin,Gorbunova,Adamova,Koryakova,Kuznetsov
, p. 435 - 441 (2011)
Organic-inorganic hybrid sorbents based on a polysiloxane modified with amino and thiourea groups have been synthesized for the first time by a sol-gel process. The structure of the sorbents has been determined by X-ray photoelectron spectroscopy and IR spectroscopy. Their thermal stability has been assessed and the mechanism of their degradation has been elucidated. The structural and adsorption parameters of the sorbents have been evaluated. The results demonstrate that the introduction of amino groups into the structure of the polysiloxane yields an effective sorbent for Pb(II) extraction and enables Cu(II) and Zn(II) separation from Co(II) and Ni(II). The thiourea-modified polysiloxane selectively sorbs Bi(III) (0.1-2 M HCl), Pt(IV) (pH 2), and Pb(II) (pH > 3). Divalent Co, Ni, Cu, and Zn can be sorbed from alkaline solutions.
Highly selective separation of individual platinum group metals (Pd, Pt, Rh) from acidic chloride media using phosphonium-based ionic liquid in aromatic diluent
Nguyen, Viet Tu,Lee, Jae-Chun,Chagnes, Alexandre,Kim, Min-Seuk,Jeong, Jinki,Cote, Gérard
, p. 62717 - 62728 (2016/07/13)
An effective solvent extraction-based method has been developed to recover individual platinum group metals (PGMs) (i.e. Pd, Pt and Rh) with high purity from acidic chloride media using phosphonium-based ionic liquid Cyphos IL 101 ([P66614]+Cl-) diluted in xylene used as a model of industrial diluents such as SOLVESSO 150. The system showed the selective co-extraction of Pd(ii) and Pt(iv) from a feed solution containing 100 mg L-1 Pt(iv), 55 mg L-1 Pd(ii), and 25 mg L-1 Rh(iii) in HCl via an anion exchange mechanism, leaving Rh(iii) in the raffinate. A McCabe-Thiele diagram demonstrated the quantitative extraction of Pd(ii) and Pt(iv) with 0.6 g L-1 [P66614]+Cl- with two counter-current stages at an organic/aqueous (O/A) phase volume ratio of 3/2 at 298 K. The stoichiometry of complexes formed in the organic phases was determined using Job's method and further characterized by 1H, 13C, 31P NMR and UV-vis spectroscopy. More importantly, a two-step stripping strategy was successfully adapted to treat the loaded organic phases with low aggressive media NaSCN and thiourea/HCl for the selective recovery of Pt(iv) and Pd(ii), respectively, with high purity >99.9% (w). Three counter-current stages are required for the quantitative stripping of Pt(iv) with 0.1 mol L-1 NaSCN at an O/A ratio of 3, whereas the total stripping of Pd(ii) with 0.01 mol L-1 acidic thiourea requires only one stage at an O/A ratio of 5. A series of extraction-stripping processes of up to 5 cycles indicated a possible recirculation of regenerated solvent without loss of performance. Simulated experiments in continuous modes suggest that phosphonium-based ionic liquid such as Cyphos IL 101 can be advantageously used as extractant to recover individually Pd, Pt and Rh from acidic chloride feed solutions as those encountered in the PGM's recycling industry.
