SYNTHESIS AND CHARACTERIZATION OF POLYACRYLONITRILE-THIOSEMICARBAZIDERESIN AND ITS SORPTION BEHAVIOR FOR RH(III) RU(IV) PD(II) AND IR(IV) IONS

Polyacrylonitrile-thiosemicarbazide resin (PAN-TSC) bearing a triazolt hione functional group was synthesized from crosslinked polyacrylonitr ile and thiosemicarbazide. The functional group capacity and percentag e conversion of the functional group of PAN-TSC prepared under optimum conditions were 4.39 mmol FG/g and 39.04%, respectively. The structur e of PAN-TSC was confirmed by LR, elemental analysis, and X-ray photoe lectron spectroscopy (XPS). The sorption capacities of PAN-TSC for Rh( III), Ru(IV), Pd(II), and Ir(TV) were 82.7, 239.7, 430.8, and 417.0 mg /g resin, respectively. The distribution coefficients were 1.30 x 10(4 )-4.07 x 10(5) (ml/g). PAN-TSC resin has excellent sorption selectivit y for Rh(III), Ru(IV) and Ir(IV) in the presence of common metal ions over a wide acidity range. The apparent activation energy (E-a) of sor ption of PAN-TSC for Ru(IV) is 43 +/- 4 kJ/mol. The sorption mechanism of PAN-TSC resin for Ru(TV) was confirmed by XPS. (C) 1998 Elsevier S cience B.V. All rights reserved.