Keywords: Bis(2-ethylhexyl) phthalate, molecularly imprinted polymers, adsorption isotherm, adsorption kinetic

Abstract

A synthetic molecular imprinted polymer (MIP) as a sorbent material for bis(2-ethylhexyl) phthalate (DEHP) was prepared using bulk polymerization method. This preliminary study aimed to investigate the possibility of the complex formation of MIP by studying its physical characteristics and adsorption performance via isotherm study. The polymer was synthesized by a non-covalent approach using 4-vinylpyridine, ethylene glycol dimethacrylate and benzoyl peroxide as functional monomer, cross-linker and initiator, respectively. The non-imprinted polymer (NIP) was prepared as controlled samples, using the same protocol in the absence of DEHP molecules. The characterization of the polymers was carried out by means of Fourier transform infrared spectroscopy, scanning electron microscopy and surface area and porosity analyses. The performance of the synthesized polymers was evaluated through batch rebinding experiment. Therefore, the kinetic spectrophotometric method was used to describe the determination of DEHP molecule based on its adsorption effect onto the polymers. The effect of initial concentration and time taken were investigated to reveal the possible mechanism through the adsorption isotherm studies. The result revealed that the adsorption capacity of MIP was 34.42 mg/g with 80% of percentage removal and showed that MIP exhibited good adsorption performance toward DEHP compared to NIP. Meanwhile, the adsorption isotherm successfully described that the polymers followed Langmuir isotherm model and displayed the Pseudo-second-order as the best kinetic model. As a conclusion, the present study revealed that the MIP is a promising adsorbent for DEHP molecules.