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Development of novel chelating ion-exchangers containing azole ligands
React. Polym. 17 (1992) 115-139
137
The results emphasize the importance of the aqueous film quality surrounding the resin pearls which must play the part of the back-extraction agent and which must provide the best conditions for ion exchange on resins.
Development of novel chelating ion.exchangers containing azole ligands P.D. Verweij 1, W . L . D r i e s s e n 1, j. R e e d i j k 1 a n d D.C. S h e r r i n g t o n 2
1 Department of Chemistry, Leiden University P.O. Box 9502, 2300 RA Leiden, Netherlands 2 Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK Effects of physical and chemical polymer properties on the metal uptake behaviour of chelating ion-exchangers have been studied by immobilizing several pyrazole and imidazole ligands onto the hydrophilic polymer poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (GMA) and two types of silica, viz, SilA with small beads and SilB with large beads. The resulting ion-exchange materials have been characterized using 13C and 29Si CP/MAS NMR and FT-IR spectroscopy and elemental analyses. It was found that 20-60% of the epoxy groups, initially present on GMA, SilA and SilB, were replaced by an azole ligand. Metal uptake studies with Cu 2, Cd 2÷, Ni 2÷, Co 2÷, Zn 2÷ and Ca 2÷ showed the ion-exchangers to be selective for Cu 2÷. The metal ion selectivity depends chiefly on the ligand, but the type of carrier also influences the metal uptake. For instance, the ion-exchange materials based on SilA show a surprisingly low capacity for Cd ~+. The kinetic performance of the ion-exchangers is good: tl/2 < 5 s for the SilA-based materials, tl/2 -- 60 min for the SilB-based materials and t~/2 = 20 min for the GMA resins. Complete regeneration without loss of capacity can be achieved, using 1 M H2SO 4 for the GMA resins and 0.1 M n 2 s o 4 for the silica-based ion-exchangers. Reference:
React. Polym., 13 (1990) 83-92.
Application of ion exchange membranes in the plating industry Gy. V ~ r t e s 1, G. H e g y e s s y 2 a n d G. Kovfics 2
1 General Design Institute for the Engineering Industry 2 Research Institute for the Plastics Industry There is a large amount of metals (e.g. Zn and Ni) which pass into the wastewater in the plating industry. Its recovery is of both economic and environmental importance. Electrolysis is a highly useful technique and in order to effectively carry out this process, harmful side electrode reactions should be avoided. That is why anion and cation exchange membranes should be used. The preparation conditions of anion and cation exchange membrane (of the heterogeneous type), their properties and metal removal efficiency is discussed.
Anion chromatography on hydroxyethyl-methacrylate based sorbents I v a n Vin~
Tessek Ltd., Prague, Kh~ovnickd 3, 110 O0 Praha 1, Czechoslovakia One of interesting subjects in anion chomatography is the selectivity of separation. The role of eluent anion, its charge, concentration and eluent pH as well as sorbent matrix, functional group and its content were studied in several papers. During the development of Tessek Separon HEMA-S 1000 Q-L sorbent for ion chromatography some interesting phenomena were encountered. The character of the matrix surface exhibited much larger effect than the effect of different substituents on the amino functional group. When additionally hydrophilized HEMA-BIO matrix was used, the retention of divalent (sulphate) anions decreased dramatically, so the sulphate eluted before nitrate and sometimes even with the chloride. As pronounced difference in selectivity was observed when using mono- and divalent eluents of comparable eluting power, e.g., with the same retention for the nitrate anion. The
137
The results emphasize the importance of the aqueous film quality surrounding the resin pearls which must play the part of the back-extraction agent and which must provide the best conditions for ion exchange on resins.
Development of novel chelating ion.exchangers containing azole ligands P.D. Verweij 1, W . L . D r i e s s e n 1, j. R e e d i j k 1 a n d D.C. S h e r r i n g t o n 2
1 Department of Chemistry, Leiden University P.O. Box 9502, 2300 RA Leiden, Netherlands 2 Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK Effects of physical and chemical polymer properties on the metal uptake behaviour of chelating ion-exchangers have been studied by immobilizing several pyrazole and imidazole ligands onto the hydrophilic polymer poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (GMA) and two types of silica, viz, SilA with small beads and SilB with large beads. The resulting ion-exchange materials have been characterized using 13C and 29Si CP/MAS NMR and FT-IR spectroscopy and elemental analyses. It was found that 20-60% of the epoxy groups, initially present on GMA, SilA and SilB, were replaced by an azole ligand. Metal uptake studies with Cu 2, Cd 2÷, Ni 2÷, Co 2÷, Zn 2÷ and Ca 2÷ showed the ion-exchangers to be selective for Cu 2÷. The metal ion selectivity depends chiefly on the ligand, but the type of carrier also influences the metal uptake. For instance, the ion-exchange materials based on SilA show a surprisingly low capacity for Cd ~+. The kinetic performance of the ion-exchangers is good: tl/2 < 5 s for the SilA-based materials, tl/2 -- 60 min for the SilB-based materials and t~/2 = 20 min for the GMA resins. Complete regeneration without loss of capacity can be achieved, using 1 M H2SO 4 for the GMA resins and 0.1 M n 2 s o 4 for the silica-based ion-exchangers. Reference:
React. Polym., 13 (1990) 83-92.
Application of ion exchange membranes in the plating industry Gy. V ~ r t e s 1, G. H e g y e s s y 2 a n d G. Kovfics 2
1 General Design Institute for the Engineering Industry 2 Research Institute for the Plastics Industry There is a large amount of metals (e.g. Zn and Ni) which pass into the wastewater in the plating industry. Its recovery is of both economic and environmental importance. Electrolysis is a highly useful technique and in order to effectively carry out this process, harmful side electrode reactions should be avoided. That is why anion and cation exchange membranes should be used. The preparation conditions of anion and cation exchange membrane (of the heterogeneous type), their properties and metal removal efficiency is discussed.
Anion chromatography on hydroxyethyl-methacrylate based sorbents I v a n Vin~
Tessek Ltd., Prague, Kh~ovnickd 3, 110 O0 Praha 1, Czechoslovakia One of interesting subjects in anion chomatography is the selectivity of separation. The role of eluent anion, its charge, concentration and eluent pH as well as sorbent matrix, functional group and its content were studied in several papers. During the development of Tessek Separon HEMA-S 1000 Q-L sorbent for ion chromatography some interesting phenomena were encountered. The character of the matrix surface exhibited much larger effect than the effect of different substituents on the amino functional group. When additionally hydrophilized HEMA-BIO matrix was used, the retention of divalent (sulphate) anions decreased dramatically, so the sulphate eluted before nitrate and sometimes even with the chloride. As pronounced difference in selectivity was observed when using mono- and divalent eluents of comparable eluting power, e.g., with the same retention for the nitrate anion. The