Preparation and characterization of molecularly imprinted silica particles for selective adsorption of naphthalene

A new kind of molecularly imprinted adsorbent for naphthalene was prepared by a covalent/noncovalent hybrid strategy. The monomer-template compound was prepared by the reaction of 3-(triethoxysilyl)propyl isocyanate with β-naphthol to form a thermally cleavable urethane bond. The silica gel was prepared by means of the gelation of monomer-template compound with tetraethoxysilane in ethanol using sol-gel technology. The removal of the template by the cleavage of urethane bond at elevated temperature resulted in the generation of recognition sites which could rebind naphthalene through noncovalent interaction. Binding experiments demonstrated that the imprinted silica particles showed a very fast uptake profile for naphthalene and displayed highly selective recognizing ability for naphthalene over benzene and other PAHs such as anthracene, phenanthrene, pyrene, fluoranthene and triphenylene.