Preparation of Monolithic Epoxy Resin-2-methylimidazole Porous Material for Adsorption/Electrosorption of Cu(II)
A new monolithic porous polymer was successfully prepared by using epoxy resin (bisphenol A diglycidyl ether, EP), 2-methylimidazole (2-MZ) as curing agent and polyethylene glycol (PEG-1540) as porogen. The reaction-induced phase separation of this system was successfully controlled by the weight ratio of EP-MZ-PEG (2.0:0.27:2.8) and other reaction conditions. The stepwise polymerization completed at 100 °C for 11 h without disturbance mode. The porogen was removed and the monolithic material with macro-through-pores was obtained. The synthesized polymer was characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The prepared material was found to be more efficient for Cu(II) adsorption as compare to Co(II) and Ni(II) in aqueous water. Furthermore, it was then used as the working electrode connected with a direct high-voltage power supply, and a platinum wire was used as counter electrode. The experimental conditions including the adsorption/desorption time, pH value, adsorption/electrosorption mode, and voltage were investigated and optimized, and a new method for Cu(II) removal was established. After adsorption at pH 6, the stirring speed of 400 rpm and the voltage below 120V for 1 h, the loaded Cu(II) was then eluted with 3 mL of 5% HNO3 solution for 10 min, and determined with inductively coupled plasma atom emission spectrometry (ICP-AES). The results showed that the adsorption rate was improved significantly by the electrically enhancing means, and the recovery was > 95%.