Adsorption of ReO 4− ions into polyDMAEMA hydrogels prepared by UV-induced polymerization

Abstract

Polydimethylaminaethyl methacrylate (polyDMAEMA) hydrogels with excellent characteristic were prepared by UV-induced polymerization and crosslinking of DMAEMA monomer in aqueous solution, and then the adsorption and enrichment of ReO 4 − into polyDMAEMA hydrogels were investigated. Microscopic IR analysis approved the adsorption of ReO 4 − into polyDMAEMA hydrogels. A series of adsorption experiments with ReO 4 − were carried out at different pH, ionic strength, concentration of ReO 4 −, the mass of gel and temperature, respectively. It was found that pH 2.0 was the optimum for the adsorption of ReO 4 − into polyDMAEMA hydrogels. Isothermal experiment revealed that the adsorption capacity increased linearly with increase of the concentration of ReO 4 − in aqueous solution. Adsorption isothermal data could be interpreted well by the Langmuir equation. The adsorption capacity decreased with increase of ionic strength, the mass (size) of gel or temperature. Desorption experiment indicated that more than 90% ReO 4 − ions can be desorbed from polyDMAEMA gels. At the same time the adsorbents can be regenerated and also be used again for the adsorption of ReO 4 −.