Separation of lithium isotopes by NDOE bonded Merrifield peptide resin

Abstract

The novel NDOE (1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane) ion exchange resin was prepared. The ion exchange capacity of NDOE azacrown ion exchanger was 02 meq/g dry resin. A study on the separation of lithium isotopes was carried out with NDOE novel azacrown ion exchange resin. The lighter isotope, 6Li concentrated in the solution phase, while the heavier isotope, 7Li is enriched in the resin phase. By column chromatography (0.1 cm I.D.• cm height) using 2.0M NH4C1 as an eluent, a separation factor, a = 1.0201 was obtained.

Novel Syntheses Method of Phenol Type Benzo-15-Crown-5 Ether Resin and its Application for Lithium Isotope Separation

“…5. The isotope ratio, 7 Li/ 6 Li, increases at the front band. This result shows that the lighter isotope is disproportionately located in 15-crown-5 resin.…”

“…The isotope exchange of metal elements on crown ether is expected to have the high separation coefficient in comparison to other chemical reaction. [1][2][3][4][5][6][7][8] The many isotope separation experiments based on complex formation of metal ions with crown ether were carried out using the liquid-liquid extraction 1,2) or the extraction chromatography. 3,4) The liquid-liquid extraction is difficult to commercially separate the isotopes, because the distribution coefficient is too small and the establishment of the multi-stage process is difficult.…”

Lithium isotope fractionation during uptake by gibbsite

“…Nishizawa et al (1984) Benzo-15-crown-5 0.965-0.998 6 Li Room temp. Nishizawa et al (1984) Cryptand (2B,2,1) Methanol solution of LiX 0.953-0.965 6 Li Benzo-15-crown-5 0.960-1.000 6 Li 20 Ooi et al (1999) Ti-phosphate exchanger 0.05 M (NH 4 ) 2 CO 3 0.993 6 Li 20 Otake et al (2006) Phenol type benzo-15-crown-5 Methanol-HCl mix 0.967 6 Li 35 Kim et al (2003) Aminobenzo-18-crown-6 2 M NH 4 Cl 1.0095 7 Li 20 Oi et al (1991) Cation exchange resin 1.00089-1.00171 7 Li…”

“…Similar fractionation factors were also estimated from natural studies of lithium in seafloor basalt, Fe-Mn crusts and Fe-oxyhydroxides (Chan et al, 1992; Chan and Hein, 2007;Wimpenny et al, 2010b) and experimental studies determining the fractionation of lithium during uptake into gibbsite, kaolinite, vermiculite, illite and smectite (Brenot et al, 2008;Zhang et al, 1998;Pistiner and Henderson, 2003; Williams and Hervig, 2005). The fractionation factor (a solid-solution ) depends on both mineral type and temperature (Brenot et al, 2008;Taylor and Urey, Kim et al (1991) Monobenzo-15-crown-5 5% H 2 O in acetonitrile 0.947 6 Li 23 Kim et al (1995) Dibenzo pyridino diamide azacrown (DBPDA) Acetonitrile 0.966 6 Li 20 Kim et al (1997) Cyclic triazatetramerrifield resin 1 M NH 4 Cl 0.932 6 Li 20 Kim et al (1998) Azacrown tetramerrifield peptide resin 0.5 M NH 4 Cl 1.00127 7 Li 25 Kim et al (1998) NTOE 0.01 M HCl 1.0242 7 Li 25 Kim et al (1999) N 4 O 2 azacrown 0.01 M NH 4 Cl 1.038 Unclear 20 Kim et al (2000) Amino benzo-15-crown-5 1 M NH 4 Cl 1.026 7 Li 20 Nishizawa and Watanabe (1986) Cryptand (2B,2,1) 0.959 6 Li Room temp. Nishizawa et al (1984) Benzo-15-crown-5 0.965-0.998 6 Li Room temp.…”

Diazabenzo crowns grafted on the polystyrene and application of extraction of metal cations

“…However, the formed complexes are generally substantially soluble in water, which sometimes makes their recovery delicate. Hence, the ligands are usually immobilized on a polymer support [2,3], notably on the Merrifield resin such as Morin (2´,3,4´,5,7-pentahydroxyflavone), used for the extraction of heavy metals (Cu, Pb, Zn, and Cd) [4] or macrocycle grafted on aminobenzo-15-crown-5 and aminobenzo-18-crown-6 resins, used for the separation of lithium isotopes [5,6] (see Fig. 1).…”