Preparation And Characterization Of A Three-dimensional Ordered Molecular Imprinted Polymers

Since three-dimensional macroporous materials orderliness aperture, large specific surface area and pore structure and good optical properties, in catalysis, adsorption, separation, field sensors, photonic crystals have potential applications. Molecular imprinting technology is prepared for a target molecule and has a specific recognition to target molecule, which has been widely used in chromatography, solid phase extraction, bio-sensing and other fields currently. In this paper, three-dimensional ordered molecular imprinted polymers was prepared by combining molecularly imprinted polymer material with ordered pore structure, which can overcome the slow adsorption kinetics and adsorption efficiency of the traditional imprinted polymer, and thus has aroused widespread concern. The main contents of this paper consists of three parts.The first part:monodisperse polystyrene and silica colloidal crystal particles were prepared by emulsion polymerization method and StOber method. Using polystyrene and silica as colloidal crystal template,the colloidal crystal film and colloidal crystal beads were obtained by vertical deposition and evaporation-induced self-assembly. In this chapter, the preparation condition such as the type of colloidal crystal particles dispersing solvent, colloidal crystal particle concentration, assembly temperature, water to oil ratio and stirring speed are discussed.The results showed that using ethanol as a dispersing agent, as colloidal crystal particle concentration of 8 mg/mL and self-assemble temperature at 45℃, polystyrene colloidal crystal particles can form highly ordered colloidal crystal films, which particle layer between the layers was ordered face-centered cubic packing structure, and has significant Bragg diffraction, while silica colloidal crystal template has more defects, poor regularity between the layers.In preparing colloidal crystal beads, when the SiO2 colloidal particles concentration of 10%, water/silicone two-phase volume ratio of 1:10, stirring speed of 300 rpm, the forming colloidal crystal beads are showing good monodisperse and ordered face-centered cubic packing structure, and polystyrene colloidal crystal particles prepared by the colloidal crystal beads irregular size and easy bonding microspheres.The second part:The cinchonine molecularly imprinted photonic crystals (MIPCs) film was prepared by using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross linker, benzoyl peroxide and N’N- dimethylaniline as initiation system by a combination of colloidal crystal template method and molecular imprinting technique,which has three-dimensional macroporous ordered face-centered cubic lattice structure.The binding experiments show that the special, hierarchical porous structure enables this polymer to possess rapid adsorption kinetics, improved binding capacity and specificity to analytes. The Bragg diffractive measurements show the MIPCs film has good specific responsiveness for the template molecules. The Bragg diffraction peaks shift from 527 to 503 nm with the concentration of the cinchonine varying from 0 to 10-3 mol/L, whereas there are no obvious peaks shifts for its structural analogues, which reflects the specificity of the molecular imprinted response.The third part:bovine serum albumin molecularly imprinted photonic microspheres crystals(BSA MIPCs) was prepared by using colloidal crystals SiO2 microspheres as templates, bovine serum albumin as the template molecule, acrylamide as functional monomer, N’N-methylene acrylamide cross -linking agent, and ammonium persulfate as the initiator polymer through reduced pressure infiltrationby a combination of colloidal crystal template method and molecular imprinting technique. The monomer ratio of the molecular imprinting precursor liquid and infiltration methods were discussed. The identification and selection properties of BSA MIPCs were studied by infrared spectroscopy、scanning electron microscopy and static adsorption approach. The results showed that the imprinted microspheres have three dimensional ordered macroporous structure, adsorption experiments showed that comparing with the traditional bulk imprinted polymer, the BSA MIPCs microspheres not only has specific identify ability to BSA, but also displays the rapid adsorption kinetics and adsorption capacity.In this study, respectively using SiO2 and PS as colloidal crystal template, cinchonine and bovine serum albumin as template molecule, to establish two different forms of MIPCs preparation and characterization methods. Compared with traditional imprinted polymers, three-dimensional ordered macroporous imprinted polymer improves the dynamic behavior of molecular recognition and improve the efficiency of molecular recognition. In addition, MIPCs film due to its specific molecular imprinted optical response, which reflects the enormous respect in sensing application prospects. The study has taken an important step for the expansion of the application of molecular imprinting technique.