(326d) Effect of Synthesis Condition of Thermoresponsive Polymer/Magnetic Particle Composite on Its Cu(II) Ion Recycling Property

We have been developed thermoresponsive heavy metal ion adsorbent in whichcopolymer of N-isopropylacrylamide (PNIPAM) and acrylic acid (AA) is immobilized on magnetic particle. In the adsorbent, since thermoresponsive conformational change of the copolymer part causes the affinity change between heavy metal ion the adsorbent, adsorption and desorption of heavy metal ions can be controlled just by swinging temperature. Therefore, no other secondary waste such as acid waste will not be generated during heavy metal ion recycling process which is different from other conventional method. Because of the unique characteristics, design of very environmentally friendly process would be possible by using the adsorbent.

In this study, in order to improve the heavy metal ion recovery property of the adsorbent, the effect of synthesis condition of the adsorbent on its heavy metal ion recovery property was examined in detail. In the experiment, the thermoresponsive adsorbents were synthesized using various technique such as “grafting to” method, and “in situ” method, modified co-precipitation method and the resulting heavy metal ion recycling property was examined. The results showed the maximum amount of immobilized copolymer on the magnetic particle and Cu(II) adsorption in the case of “in situ” method were 2.2 and 1.7 times higher than those in the case of “grafting to” method, respectively. In addition, the adsorbent prepared by “in situ” method demonstrated highest value in the recycled Cu(II) amount through temperature swing compared to other several of thermoresponsive “gel type” adsorbents.