Search Results (2)

The polymer membranes of cellulose triacetate -o-NPPE-1-alkyl-triazole (alkyl= hexyl, octyl, decyl) were characterized by non-contact atomic force microscopy (AFM). The influence of membrane morphology on transport process was discussed. 1-Alkyl-triazole derivatives are new cheap compounds that have the ability to bind metal ions in an acidic medium. These membranes were used for the investigation of the facilitated transport of Zn(II), Cd(II), and Pb(II) ions from an aqueous nitrate feed phase. The initial flux values of metal ions transport depend on the type of carrier used. The maximum value of the initial flux for Zn(II) ions was equal to 12.34 × 10⁻⁶ molm⁻²s⁻¹ (for PIMs with 1-decyltriazole). In the case of Zn(II) and Cd(II) ions as the hydrophobicity of the carrier increases, the separation coefficients S_{Zn(II)/Cd(II)} slightly increase from 1.8 to 2.4, while for Zn(II) and Pb(II) ions separation coefficients S_{Zn(II)/Pb(II)} decrease. The highest recovery factors (RF) were found for Zn(II) ions (c.a. 90%). The RF values of Cd(II) ions increase from 58% to 67%. The highest RF value for Pb(II) is 30%. The rate-limiting step in the transport of Zn(II), Cd(II) and Pb(II) ions across PIMs with 1-alkyltriazole may be the diffusion coefficient of the carrier-cation complex. The AFM images show that the distribution of the carrier in the tested membranes is homogeneous over the entire surface. The roughness values determined for PIMs with alkyltriazole are slightly higher than the roughness of PIM with the commercial carrier, for example D2EHPA. Full article

The new polymer inclusion membrane (PIM) with a 1-alkyltriazole matrix was used to separate palladium(II) ions from aqueous chloride solutions containing a mixture of Zn-Pd-Ni ions. The effective conditions for transport studies by PIMs were determined based on solvent extraction (SX) studies. Furthermore, the values of the stability constants and partition coefficients of M(II)-alkyltriazole complexes were determined. The values of both constants increase with the growing hydrophobicity of the 1-alkyltriazole molecule and have the highest values for the Pd(II) complexes. The initial fluxes, selectivity coefficients, and recovery factors values of for Pd, Zn and Ni were determined on the basis of membrane transport studies. The transport selectivity of PIMs were: Pd(II) > Zn(II) > Ni(II). The initial metal ion fluxes for all the cations increased with the elongation of the alkyl chain in the 1-alkyltriazole, but the selectivity coefficients decreased. The highest values of the initial fluxes at pH = 4.0 were found for Pd(II) ions. The best selectivity coefficients Pd(II)/Zn(II) and Pd(II)/Ni(II) equal to 4.0 and 13.4, respectively, were found for 1-pentyl-triazole. It was shown that the microstructure of the polymer membrane surface influences the kinetics of metal ion transport. Based on the conducted research, it was shown that the new PIMs with 1-alkyltriazole can be successfully used in an acidic medium to separate a mixture containing Pd(II), Zn(II) and Ni(II) ions. Full article