Proton-ionizable crown compounds: transport of alkali and alkaline earth cations using proton-ionizable triazolo macrocycles
The macrocycle-mediated fluxes of the alkali and alkaline earth metal cations have been determined in H/sub 2/O-CH/sub 2/Cl/sub 2/-H/sub 2/O bulk liquid membrane system. Water-insoluble proton-ionizable macrocycles of the triazolo type were used. The proton-ionizable feature allows the coupling of cation transport to reverse H/sup +/ transport. This feature offers promise for the effective separation and/or concentration of alkali metal ions with the metal transport being driven by a pH gradient. A counter anion in the source phase is note co-transported. Transport of the alkali cations only occurred when the source phase pH was greater than the aqueous pK/sub a/ value for the carriers. Transport increased regularly with increasing source phase pH. Transport of alkaline earth cations from neutral pH source phases was minimal. The alkali cation selectivity order was K/sup +/ > Rb/sup +/ > Cs/sup +/ > Na/sup +/ > Li/sup +/ for the 18-crown-6 sized macrocycles, while little selectivity was observed with the 15-crown-5 sized macrocycle.
- Research Organization:
- Brigham Young Univ., Provo, UT (USA)
- OSTI ID:
- 6223271
- Report Number(s):
- CONF-871038-
- Journal Information:
- Sep. Sci. Technol.; (United States), Journal Name: Sep. Sci. Technol.; (United States) Vol. 23:12,13; ISSN SSTED
- Country of Publication:
- United States
- Language:
- English
Similar Records
Cation separations using a proton-ionizable macrocycle in a dual module hollow fiber membrane system
Metal ion complexation by ionizable crown ethers
Related Subjects
400105* -- Separation Procedures
ALCOHOLS
ALKALI METAL COMPOUNDS
ALKALI METALS
CATIONS
CESIUM COMPOUNDS
CHARGED PARTICLES
DATA
EFFICIENCY
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GLYCOLS
HYDROXY COMPOUNDS
INFORMATION
IONS
LIQUIDS
LITHIUM
MEMBRANE TRANSPORT
MEMBRANES
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PH VALUE
POLYETHYLENE GLYCOLS
POLYMERS
POTASSIUM COMPOUNDS
RUBIDIUM COMPOUNDS
SEPARATION PROCESSES
SODIUM COMPOUNDS