Study on Synthesis and Adsorption Properties of ReO4 - Ion-Imprinted Polymer

ACS Omega. 2020 Sep 16;5(38):24356-24366. doi: 10.1021/acsomega.0c02634. eCollection 2020 Sep 29.

Abstract

In this work, an ion imprinted polymer (ReO4 --IIP) of the perrhenate ion based on acrylamide (AM) and acrylic acid (AA) was prepared by solution polymerization using ReO4 - as a template ion, N,N-methylenebisacrylamide (NMBA) as cross-linkers, hydrogen peroxide-vitamin C (H2O2-Vc) as an initiator, and a mixed solution of water (H2O) and methanol (CH3OH) with volume ratio v(H2O)/v(CH3OH) = 3:7 as a solvent. During the process of synthesis condition investigation and optimization, the adsorption capacity (Q) and the separation degree (R) in the equimolar concentration mixture solutions of NH4ReO4 and KMnO4 were adopted as indexes, and the obtained optimal conditions were as follows: the molar ratios of NMBA, NH4ReO4, AA, H2O2, and Vc to AM were 5.73, 0.052, 1.29, 0.02, and 0.003, and the temperature and time of polymerization were 40 °C and 28 h, respectively. Under optimal conditions, the sample with indexes, Q and R of 0.064 mmol/g and 3.20, were harvested. What is more, a further reusability study found that good adsorption selectivity was maintained after repeating the experiment 9 times. Taking the non-IP prepared under the same conditions as a control, Fourier transform infrared spectroscopy, transmission electron microscopy, and Brunauer Emmett Teller were used to characterize the structure of the ReO4 --IIP prepared under the optimal conditions. Finally, the kinetic study results showed that the zero-order kinetic model could better describe the adsorption process. The thermodynamic study results showed that the Langmuir model was more suitable for describing the isotherm adsorption process of the IIP.