Selective separation of thiocyanate ion by ion-imprinted polymer

Abstract

Molecular imprinting is a emerging technology to create recognition sites in a polymeric matrix using a molecular template. The molecularly imprinted polymers (MIPs) are easy to prepare, stable, inexpensive and capable of molecular recognition. This manuscript describes a method for the selective binding behavior of SCN- ions on surface imprinted polymers which were prepared using chitosan succinate-Zn(II) complex. This polymer was prepared in the presence of epichlorohydrin and was imprinted with SCN- ions. After that, the template (SCN- ions) was removed using 1 M KOH solution. Selective cavities for the SCN- ions was obtained in the SCN--imprinted chitosan-succinate beads. The effect of initial concentration of SCN- ions, adsorption time and imprinting efficiency on adsorption selectivity for SCN--imprinted polymer were investigated. The adsorption process was fast and equilibrium was reached at around 30 min. Maximum adsorption capacity was found to be 95 mg $g^ {-1}$. The number of accessible binding sites ($Q _{max}$), relative selectivity coefficient (k') and binding ability were also evaluated. The observed adsorption order under competitive conditions was SCN- >F- > Cl-> $PO_4^ {3-}$ in mass basis.

Molecular imprinting is a emerging technology to create recognition sites in a polymeric matrix using a molecular template. The molecularly imprinted polymers (MIPs) are easy to prepare, stable, inexpensive and capable of molecular recognition. This manuscript describes a method for the selective binding behavior of SCN- ions on surface imprinted polymers which were prepared using chitosan succinate-Zn(II) complex. This polymer was prepared in the presence of epichlorohydrin and was imprinted with SCN- ions. After that, the template (SCN- ions) was removed using 1 M KOH solution. Selective cavities for the SCN- ions was obtained in the SCN--imprinted chitosan-succinate beads. The effect of initial concentration of SCN- ions, adsorption time and imprinting efficiency on adsorption selectivity for SCN--imprinted polymer were investigated. The adsorption process was fast and equilibrium was reached at around 30 min. Maximum adsorption capacity was found to be 95 mg $g^ {-1}$. The number of accessible binding sites ($Q _{max}$), relative selectivity coefficient (k') and binding ability were also evaluated. The observed adsorption order under competitive conditions was SCN- >F- > Cl-> $PO_4^ {3-}$ in mass basis.