Synthesis and characterization of 2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate polymeric granules intended for selective removal of uric acid

Abstract

Suspension polymerization was used in the synthesis of new uric acid-imprinted porous adsorbents based on 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate in the shape of granules. Physico-chemical and adsorption properties of the synthesized adsorbents were studied as well as those of the reference adsorbent (i.e. synthesized in the absence of uric acid). The obtained polymer granules were studied by scanning electron microscopy. Systematic studies of equilibrium and dynamics of uric acid adsorption from aqueous solutions were performed at various temperatures (298K, 310K and 318K). It was established that the amount of introduced template exerts an influence on structural features and sorptive capacity of the synthesized polymers. Molecularly imprinted polymers (MIPs) are capable of extracting uric acid from aqueous solutions with higher sorptive capacity than the reference polymer at various temperatures (298K, 310K and 318K). The uric acid adsorption by the reference polymer (NIP-10) is in good agreement with the Langmuir model, while the uric acid adsorption by imprinted polymers can be better described by the Freundlich model. The MIP-40-10 polymer is capable of adsorbing uric acid with the highest sorptive capacity at three temperatures; the value of imprinting factor is also the highest (IF=4.3, 298K). The studies of adsorption thermodynamics demonstrated that the adsorption process is exothermic in nature.