Competitive binding of divalent cations to poly(α-hydroxyacrylic acid)

✍ Scribed by Tamura, Toru; Kawabata, Noriaki; Kawauchi, Susumu; Satoh, Mitsuru; Komiyama, Jiro

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 213 KB
• Volume: 46
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199808)46:4<353::aid-pi38>3.0.co;2-6

✦ Synopsis

The competitive binding of divalent cations (Mg2, Ca2, Mn2, Co2, Ni2, Cu2and Zn2) on poly(a-hydroxyacrylic acid) (PHA) and poly(acrylic acid) (PAA) was investigated by equilibrium dialysis. In the Mg/Ca mixed system, binding selectivity for Ca2over Mg2was signiÐcantly higher in PHA than in PAA ; this was attributed to coordination of a-OH groups on PHA to Ca2. The binding ability and selectivity for the transition metal cations were almost the same for PHA and PAA at neutral pH, while PHA maintained appreciably higher degrees of binding than PAA in acidic solutions (pH about 3). This cation binding ability of PHA was ascribed to the lower value in the rele-pK a vant pH region.

1998 SCI.