Preparation and properties of salicylic acid-imprinted polymers from emulsions

Molecularly imprinted polymers with specific recognition to salicylic acid (SA-MIPs) were prepared by oil-in-water emulsion polymerization using salicylic acid as template, acrylamide as functional monomer, and ethylene glycol dimethacrylate as crosslinker. The morphology and size distribution of the SA-MIPs were detected by SEM and photon cross correlation spectrometry. Equilibrium binding experiments and Scatchard analyses were carried out to investigate the selectivity of the SA-MIPs. The results show that the SA-MIPs exhibit a higher affinity and selectivity to salicylic acid than to m-hydroxybenzoic acid and sulfosalicylic acid. Two classes of binding sites were produced in the SA-MIPs and the equilibrium dissociation constants were estimated to be 2.03 and 9.97 mmol/L, respectively.