Dye-molecular-imprinted polysiloxanes. II. Preparation, characterization, and recognition behavior

Microsphere silica (AMS) was prepared by the sol-gel method and used for the synthesis of dye-molecular-imprinted polysiloxanes. These were prepared by the cohydrolysis and polycondensation of the AMS with functional organosilicone monomers (N-phenylaminomethyl triethoxysilane, 3-aminopropyl triethoxysilane, and 4-aza-6-aminohexyl triethoxysilane) in the presence of a template molecule of disperse red (or disperse blue or water-soluble dye) followed by the removal of the template molecule. The molecular-imprinting and nonimprinting polysiloxanes were characterized by elemental analysis, diffuse-reflectance Fourier transform infrared spectroscopy, and scanning electron microscopy. Their adsorption behavior toward the template molecule and nontemplate molecule was investigated. The molecular-imprinting polysiloxane exhibited higher selective recognition properties toward the template molecule than the nonimprinting polysiloxane. In the experimental conditions, their adsorption isotherms were a good fit with the Langmuir model. The distribution coefficient value of water-soluble-dye-imprinted polysiloxane was the highest among the three imprinting polysiloxanes under the experimental conditions. (C) 2004 Wiley Periodicals, Inc.