Preparation And Adsorption Proerty Studies Of Photoresponsive Molecularly Imprinted Materials For2,4-Dichlorophenoxyacetic Acid By Sol-Gel Process

Molecularly imprinted materials with structure-activity predetermination, specific recognition, and extensive practicability, exhibit wide applications in various fields such as molecular recognition, chromatographic separation, catalysis and sensing.2,4-D is a typical environmental pollutant, using molecular imprinting technique to realize detection and isolation of2,4-D has been a hot research topic. In this paper, we designed a new photoresponsive functional azobenzene monomer, and the photo-responsive molecular imprinted polymer (MIP) for2,4-D was then successfully prepared by sol-gel process. The detailed research contents are described as follows:1. In chapter one, an literature review about the basic principles and advantages of the molecular imprinting technique and the sol-gel technology, the preparation and characteristics of molecularly imprinted materials by molecular imprinting Sol-Gel technique (MISGT), the commonly used crosslinker and functional monomer, and the research status of the imprinted material with2,4-dichlorophenoxyacetic acid as the template molecule, and proposed the purpose and significance of this study.2. In chapter two, a photoresponsive functional azobenzene monomer containing silica was prepared by covalent imprinting for2,4-dicholrophenoxyacetic acid (2.4-D) via oxidation-coupling reaction, acetylation and esterification reaction using commercially available p-nitrophenol,2,4-dicholrophenoxyacetic acid and3-chloropropyltriethoxysilane as the starting materials. Their structures were characterized by1H NMR,13C NMR, the FT-IR, and the photoresponsive performance was also investigated.3. In chapter three, a photoresponsive organic-inorganic hybrid molecularly imprinted polymers was prepared with2,4-DAZOSi as the functional monomer,2,4-D as the template molecule, and TEOS as the cross-linker. The MIP was characterized by atomic force microscope (AFM), FT-IR, TG and N2adsorption-desorption analysis. The photoresponsive performance of the MIP, the adsorption properties and selective recognition of MIP for2,4-D and uptake and release of2.4-D were also studied.4. In chapter four, on the surface of silica, a molecularly imprinted polymer for the selective recognition of2,4-D was prepared by using2,4-DAZOSi as the functional monomer, TEOS as the crosslinker, and2,4-dichlorophenoxyacetic acid as the template molecule. The prepared SMIP was characterized using Fourier transform infrared spectrometer (FT-IR), atomic force microscope (AFM), thermogravimetric analysis (TGA), and BET adsorption isotherm analysis, the adsorption properties and selective recognition of SMIP for2,4-D and uptake and release of2.4-D were also studied.5. In chapter five, a comparative study about the photoresponsive performance, the adsorption properties, binding kinetics, and uptake and release of2.4-D for MIP and SMIP was conducted, it is found that the SMIP shows better performance than the organic-inorganic hybrid MIP.6. The last chapter summarized the main results and conclusions, and some recommendations for future work are given.