Design of size-tunable molecularly imprinted polymer for selective adsorption of acetaminophen

Abstract

Pharmaceutical and personal care products are a broad and diverse group of biologically active compounds which are widely used and unregulated suspected carcinogens. In this study, the fabrication of molecularly imprinting polymer (MIP) particles by precipitation polymerisation were developed to selectively and rapidly capture acetaminophen, a commonly used analgesic and antipyretic drug, by hydrogen and hydrophobic bondings. Methacrylic acid, 3-(trimethoxysilyl) propyl methacrylate and 2, 2\'-azobis-isobutyronitrile were utilised as the functional monomer, cross-linker and initiator. Acetonitrile was found to be the optimised porogen to obtain imprinted polymers with surface area and pore size of 447.2 m(2)/g and 3.35 nm. By adjusting the ratio of cross-linker and functional monomer, the particle size of MIPs changed from 177 to 2782 nm when the ratio increased from 0.43 to 12.8. In addition, the adsorption equilibrium of acetaminophen by MIPs can be reached within the first 30 min because of the surface imprinting characteristics and small particle sizes. In addition, the maximum adsorption capacity of acetaminophen and the adsorption constant, well fitted by Langmuir equation, were 0.35 mg/g and 0.045 L/mg. In addition, the MIPs exhibited the excellent selectivity to acetaminophen. The high surface area and adsorption capacity and excellent selectivity make MIPs an ideal tailor-made green material and can open the door to develop the novel technology for adsorption and removal of pharmaceutical and personal care products in the environment.