Preparation of Monodisperse Molecularly Imprinted Polymer Beads by a Single-Step Swelling and Polymerization Method
ZHENG Xi-ming1,2, TU Wei-ping1 (1. The School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China; 2. Department of Chemistry and Environment Engineering, Wuyi University, Wuyishan 354300, China)
Uniformly sized polystyrene particles (PS) with diameters of micrometer class were prepared by emulsifier-free polymerization. Using the prepared PS as seeds, naringenin as template molecules, monodisperse molecularly imprinted polymer beads (MIPBs) were prepared by a single-step swelling and polymerization method. The effects of swelling ratio and the dosage of assistant porogen—cyclohexanol on particle size and morphology of the MIPBs were investaged. It is found that the monodisperse MIPBs with particle diameters of 4.5~6.0 μm can be obtained by using 1.50 μm PS prepared as seed and controlling the swelling ratio in the range of 27~60. With the increase of cyclohexanol dosage used, the spheroidicity of the MIPBs prepared becomes more regular and its surface tends to be smoother. The results of nitrogen adsorption measurements show that the MIPBs have porous structure and large specific area. Scatchard analysis shows that the binding sites of equal class are formed in the MIPBs under the concentration range studied, and the dissociation constant Kd and maximum apparent adsorption quantity Qmax of these binding sites are 8.61 mmol?L?1 and 48.50 μmol?g?1, respectively. The MIPBs exhibit high selectivity for naringenin, and the separation factor is up to 1.96 when quercetin is chosen as the competitive molecules.