Synthesis of Uniform and Stable Molecularly Imprinted Polymer Particles by Precipitation Polymerization

In this work, precipitation polymerization was used to prepare uniform and stable molecular imprinting polymers (MIPs) particles without post treatment. Melamine was used as a template molecule model, while methacrylic acid, divinyl benzene (DVB) or ethylene glycol dimethacrylate (EGDMA) and acetonitrile were used as functional monomer, cross-linker and continuous phase, respectively. The polymerization was carried out in a vacuum condition at 70°C using benzoyl peroxide as an initiator. The obtained MIP particles demonstrated spherical shape with narrow particle size distribution. The particle size varied from micrometer-sized to sub-micrometer-sized depending on the initiator content. After purification, MIP particles represented high colloidal stability in aqueous medium.The binding efficiency of MIP using both cross-linkers (DVB and EGDMA) with melamine was approximately 20 mg/g MIP. The miscibility of all components where the functional monomer effectively pre-bound with the template molecules was the main factor for obtaining MIP particle with high binding efficiency.