Imprinting of some phenolic compounds by polymers formed on silicagel and polymeric characterization

In this study, -OH ends of activated silica gel was modified with vinyltrimethoxysilane, thus vinyl groups were connected. The resulting product, 2-(diethylamino) ethyl acrylate monomer, ethylene glycol dimethacrylate as crosslinker was polymerized by free radicalpolymerization separately in the presence and absence of 2,4-dinitrophenol at 65 oC. 2,4-Dinitrophenol trapped in imprinted copolymer was extracted by soxhlet. The same procedure was repeated for -naphtholphthalein. The surface of activated silicagel was also modified by (3-aminopropyl) triethoxysilane (APTES). Amino end of APTES-modified silica gel was acylated by ?-bromoisobutyryl bromide and the product was used as initiator in atom transfer radical polymerization (ATRP). 2-(diethylamino)ethyl acrylate as monomer and ethylene glycol dimethacrylate as crosslinker was polymerized by ATRP using CuBr/ 2,2´-bipyridine as catalyst and the initiator separately in presence and absence of 2,4-dinitrophenol at 110 oC in acetonitrile. Bipridin-CuBr complex taken into by the polymer obtained was removed by stirring with acidic ethanol. Then, the remaining small molecules and the catalyst was removed by a soxhlet extraction in ethyl alcohol. Adsorption study of 2,4-dinitro phenol was carried out on the imprinted and non imprinted polymer at different temperatures. Same procedures were repeated with -naphtholphthalein. All the obtained polymer were characterized by FT-IR spectra. Key words: Silica gel, vinyltrimethoxysilane, 2,4-dinitrophenol , α-naphtholphthalein, APTES, α-bromoisobutyryl bromide, 2-(diethylamino)ethyl acrylate, ethyleneglycol dimethacrylate, ATRP, adsorption