SYNTHESIS AND CHARACTERIZATION OF YTTRIUM IMPRINTED POLYMERS (Y-IPs) FOR ADSORPTION OF YTTRIUM(III) IONS

• Main Author: Zarlina, Ririn
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34108
• Institution: Institut Teknologi Bandung

Yttrium (Y) contained in the rare earth metal minerals are used in various industrial fields. Along with the development of material processing technologies, rare earth elements are increasingly required, especially in high-technology industries such as computer industry, telecommunications, nuclear, laser and magnet. Rare earth elements are not found in the free state in nature instead in the form of complex minerals. Therefore, it requires separation process. This research has been developed Ion Imprinted Polymers (IIPs) material that can be used for adsorption of yttrium which is selective with high capabilities in recognizing ion. Polymerization occurs with the formation of bonds between monomers with a complex metal ions and ligands. Furthermore, the metal ions released from the polymer matrix, leaving the target metal ion molds. The IIPs have several advantages compared to the other preconcentration, such as the loss of analyte can be minimized, the amount of polymer used is relatively low (0.1-0.5 g), easy preparation, and high level of selectivity. Yttrium Imprinted Polymers (Y-IPs) are synthesized through the formation of a ternary complex of yttrium ions with 5,7- dichoroquinoline-8-ol and 4-vinylpyridin and then carried toward polymerization with methyl methacrylate (MMA) as a monomer and ethyleneglycol dimethacrylate (EGDMA) as crosslinker in the 2-methoxy ethanol, initiated by 2,2-azobisisobutyronitrile (AIBN) at 80 ºC. Furthermore, metal ions are released using 0.1 M HCl to form the template. Next, Y-IPs are characterized by FTIR and SEM, with Non-Imprinted Polymers (NIPs) as a comparison. FTIR characterization showed that the polymerization of NIPs and Y-IPs have successfully synthesized shown by the absence of a peak for the alkene functional group at 3000-3300 cm-1. It indicates that the absence of residual monomer MMA and EGDMA unreacted. The existence of peaks on 786.96 cm-1 in Y-IPs before and after leaching showed that stretching vibration of –C–Cl groups derived from the DCQ. The wavenumber of –C=N from 1600.92 cm-1 shift to 1562.34 cm-1 after leaching showed the group –C=N on vinylpyridin contribute to bond with the metal. SEM-EDS results showed that the Y(III) ions have been successfully released from the polymer matrix in which there are 0.09% of Y(III) ions before leaching while there are no Y(III) ion presence in Y-IPs after leaching. Characterization of retention properties performed by a batch method showed that the maximum adsorption capacity of Y-IPs was 14.68 mg/g at pH 7 with a contact time of 10 minutes. Adsorption data have been analyzed using Langmuir and Freundlich adsorption isotherm. Adsorption of Y(III) ions by Y-IPs followed the Langmuir adsorption isotherm with a correlation coefficient of 0.9671. Pseudo first-order and pseudo second-order reaction kinetics Lagergren used to study the reaction kinetics adsorption process of Y (III) by Y-IPs. Based on the correlation coefficient, the adsorption kinetics of Y(III) ions by Y-IPs obeys pseudo second- order reaction kinetics. Based on thermodynamics data, adsorption process of Y(III) ions by Y-IPs take place endothermic with ?H of 10.71 kJ/mol, and the activation energy of 18.13 kJ/mol. The Y-IPs selectivity against other rare earth metals showed the selectivity of Y-IPs better than NIPs.