Preparation And Application Of Novel Molecularly Imprinted Materials

Molecularly imprinting technique (MIT), an emerging technique for preparing synthetic polymer with molecular recognition, is developing rapidly in recent years. The molecularly imprinted polymers (MIPs) have a number of advantages including high selectivity, high strength, stability and long life. So, MIPs are of growing interest for their potential applications as high-performance liquid chromatography stationary phase, solid phase extractors,catalysts, chemsensors and so on. The polymer was loaded into the self-made solid-phase extraction (SPE) cartridge. It was found that the template molecule can be separated and riched effectively with structure analogues. The details are summarized as follows:(1) A highly selective MIPs with erythromycin as the template molecule was prepared by a sol-gel imprinting technique. Infrared spectroscopy, scanning electron microscopy, thermogravimetric and surface area analysis were used to characterize the composite structure and morphology in detail. The results showed that the specific surface area of MIPs was 266.2 m2/g. Equilibrium binding experiment showed that the separation factor is 2.20. The elution condition was optimized, and the optimal condition was methane: acetic acid (75:25, v/v) as elution. Packed in SPE column, the polymers were used to extract erythromycin from erythromycin enteric-coated tablets. The results indicated that the polymer can separation and enrich erythromycin from erythromycin enteric-coated tablets successfully with the recovery of 104.5%.(2) Core-shell MIPs, which can recognize with magnolol specially, were prepared at the surface of SiO2 microparticles by surface imprinting polymerization using magnolol as template molecule. Equilibrium binding experiment,Scatchard analysis and competition binding experiments were conducted to investigate the binding performance and selectivity. The results showed that a homogeneous binging site was observed for the imprinted polymers binding to the template with the dissociation constant 0.20 mg/mL. Infrared spectroscopy (IR) and scanning electron microscopy (SEM) technique were also employed to characterize the core-shell imprinted polymers. The results exhibited that the core-shell imprinted polymers have perfect spherical shape with the average shell thickness of 200 nm. The MIPs-column exhibited excellent selectivity to magnolol with the selective factor 1.62.(3) A novel nano-imprinted polymers based on the surface-modified silica gel was prepared with resveratrol as template molecule, 3-Aminopropyltrimethoxysilane (APTMS) as a functional monomer, ethyleneglycol dimethacrylate (EGDMA) as cross-linkers, azodiisobutyronitrile (AIBN) as initiator with surface imprinted technique. IR and SEM were employed to characterize the core-shell imprinted polymer and the results show that the shell thickness of the core-shell imprinted microspheres is 100 nm. Static adsorption experiment and scatchard analysis was performed to investigate the MIPs binding performance to template molecule. Employed as solid extraction materials, the core-shell imprinted polymers were applied to separate the resveratrol from the rhizoma polygoni cuspidati.(4) A novel imprinted polymers based on the surface-modified silica gel was prepared with Sudan ? as template molecule, phenyltrimethoxysilane (PTMOS) as a functional monomer, EGDMA as cross-linkers, AIBN as initiator with surface imprinted technique. IR and SEM were employed to characterize the core-shell imprinted polymer and the results showed that the shell thickness of the core-shell imprinted microspheres is 150 nm. Static adsorption experiment and scatchard analysis were performed to investigate the MIPs binding performance to the template molecule and the results showed that the separation factor is 2.62. Employed as solid extraction materials, the core-shell imprinted polymers were applied to separated the Sudan ? from the cayenne oil with the recovery of 86.1%.