Molecularly imprinted microspheres prepared by precipitation polymerization at high monomer concentrations

Abstract

Highly crosslinked polymer microparticles have been prepared by precipitation polymerization using high monomer loadings (≥25 v/v %) which generally would lead to bulk monoliths. The microparticle format was achieved by the use of non-solvating diluents either alone or in combination with co-solvents. Two distinct morphologies were observed. Monodisperse smooth microspheres were obtained using a thermodynamically good co-solvent whereas segmented irregular particles were formed with poorer co-solvents. It has been found that during polymerization the forming polymer particles were enriched in the co-solvent and this effect was more pronounced when good co-solvents were used. The type of functional monomer, crosslinker and co-solvent, and the non-solvent/co-solvent ratio were identified as influential parameters on the microparticle morphology. With the proposed methodology molecularly imprinted microparticles have been prepared successfully for three different templates, naproxen, diclofenac and toltrazuril using various functional monomers, crosslinkers and polymerization solvent mixtures.

Hybrid Molecular Imprinted Polymer (MIP) Electrode for Pesticide Detection of Electrochemical Sensor

“…It could be that the higher monomer concentration leads to bulk monolith. 9 Moreover, the similar trend of imprinting factor can be observed from Figure 1. As the monomer concentration increased, the imprinting factor is decreased until it reached some point that there is no imprinting at all (IF below than one).…”

Assessment of the imprinting efficiency of an imide with a “stoichiometric” pyridine‐based functional monomer in precipitation polymerisation

“…TAU MIPs (PP‐1:1‐A) were subsequently synthesised by precipitation polymerisation following the bulk formulation with chloroform and acetonitrile (10 mL per mmol monomer) as porogens. Polymers prepared in chloroform and even with 50% chloroform/50% acetonitrile by volume resulted in gels so only PP‐1:1‐A was subjected to further characterisation. As shown in Figure , PP‐1:1‐A are spherical particles with average hydrodynamic sizes ( d H ) of 337 and 368 nm for MIP and NIP, respectively, as measured by DLS.…”

Microsphere Polymers in Molecular Imprinting: Current and Future Perspectives

“…For example, to produce larger particles, adjusting the solubility parameter of the growing polymer is critical, notably when the goal is simultaneously the control of polymer morphology. The monomer concentration, solvent mixture and method of agitation also play roles in the development of MIMs [ 6 , 51 ].…”