Foundation Of Novel Surface Molecular Imprinting Technology And Its Application Research In Environment Protection

Wastewater containing heavy-metal ions and phenolic compound are primary source of water pollution, and has been caused great endangerment for the human society. Therefore, via the molecule design, preparing the high-performance material, which can be used effectively not only for treating pollutant in wastewater but also for separating and reclaiming pollutant, have important environment protection and resource recycling value. Two kinds of grafted composited materials were prepared and its adsorption abilities and mechanism towards heavy-metal ions and phenolic compound were researched. On the base of this, noval surface molecular imprinting technology was founded firstly in the international range. Three kinds of high-performance heavy-metal ion and phenolic compound-imprinted materials were prepared and its binding abilities and recongnizing mechanism towards template were researched. The prepared molecularly imprinted materials possess effective removing ability to heavy-metal ions and phenolic compound. The investigation results possess important scientific significance and applied value in environment protection and treatment.Functional macromolecule polyethyleneimine (PEI) was grafted onto the surface of silica gel particles with the "graft to" method using y-chloropropyl trimethoxy silane as coupling agent, and the grafted composited material PEI/SiO2 was prepared. The adsorption abilities and mechanism of PEI/SiO2 towards Cu2+, Cd2+, Pb2+, Zn2+, and Cr3+ ions were studied. The experiment results showed that PEI/SiO2 possesses very strong chelating adsorption ability for Cu2+, Cd2+, Pb2+, Zn2+ and Cr3+ ions. The adsorption is chemical adsorption with monomolecular layer and accord with the Langmuir adsorption model. The pH and temperature have great influence on the adsorption capacity. The adsorption capacity increases with the decreases of pH before the heavy-metal ions were hydrolyzed. The adsorpyion capacity increases with the increases of temperature and this displayed the character of chemical adsorption. The functional macromolecules PEI on the surface of silica gel particles were ionic imprinted using Cu2+, Cd2+, Pb2+, Cr3+ as template ion and epichlorohydrin as crosslinking reagent and four surface ion-imprinted materials IIP-PEI/SiO2 were prepared. The binding ability and recognizing selectivity of IIP-PEI/SiO2 towards template ion were researched. The experiment results showed that IIP-PEI/SiO2 possesses very excellent binding affine and recognizing selectivity towards template ion. The selectivity coefficient of IIP-PEI/SiO2 towards template ion was 14-60 times than that of PEI/SiO2. IIP-PEI/SiO2 possesses well elute and reuse property. The adsorbed metal ions could be eluted easily from IIP-PEI/SiO2 using 0.1mol·L-1 hydrochloric acid as eluent, and the binding capacity of IIP-PEI/SiO2 remains unchanged nearly after 10 times use.The adsorption abilities and mechanism of PEI/SiO2 towards phenol and p-nitrophenol were also studied. The experiment results showed that PEI/SiO2 possesses very strong adsorption ability for phenol and p-nitrophenol by way of hydrogen bond interaction and electrostatic interaction. The adsorption is physical adsorption with monomolecular layer and accord with the Freundlich adsorption model. The pH and temperature have great influence on the adsorption capacity. The adsorption capacity was the highest at pH of 7. The adsorpyion capacity increases with the decreases of temperature and this displayed the character of physical adsorption.The functional macromolecules PEI on the surface of silica gel particles were molecular imprinted using phenol and p-nitrophenol as template molecule and ethylene glycol diglycidyl ether as crosslinking reagent and two surface molecular-imprinted materials MIP-PEI/SiO2 were prepared. The binding ability and recognizing selectivity of MIP-PEI/SiO2 towards template molecule were researched. The experiment results showed that MIP-PEI/SiO2 possesses very excellent binding affine and recognizing selectivity towards template molecule. The selectivity coefficient of MIP-PEI/SiO2 towards template molecule was 11-40 times than that of PEI/SiO2. MIP-PEI/SiO2 possesses well elute and reuse property. The adsorbed phenol and p-nitrophenol could be eluted easily from MIP-PEI/SiO2 using 0.1mol·L-1 hydrochloric acid as eluent, and the binding capacity of MIP-PEI/SiO2 remains unchanged nearly after 10 times use.Functional macromolecule polymethylacrylic acid (PMAA) was grafted onto the surface of silica gel particles with the "graft from" method using 3-methacryloxypropyl trimethoxysilane as coupling reagent, and the grafted composited material PMAA/SiO2 was prepared. The adsorption abilities and mechanism of PMAA/SiO2 towards phenol were studied. The experiment results showed that PMAA/SiO2 possessess strong adsorption ability for phenol by way of hydrogen bond interaction. The adsorption is physical adsorption with monomolecular layer and accord with the Freundlich adsorption model. The pH and temperature have great influence on the adsorption capacity. The adsorption capacity decreases with the increases of pH. The adsorpyion capacity increases with the decreases of temperature and this displayed the character of physical adsorption.The functional macromolecules PMAA on the surface of silica gel particles were molecular imprinted using phenol as template molecule and ethylene glycol diglycidyl ether as crosslinking reagent, and the phenol suface molecular-imprinted material MIP-PMAA/SiO2 was prepared. The binding ability and recognizing selectivity of MIP-PMAA/SiO2 towards phenol were researched. The experiment results show that the MIP-PMAA/SiO2 possesses very excellent binding affine and recognizing selectivity towards phenol. The binding capcity remains unchanged nearly. The selectivity coefficient of MIP-PMAA/SiO2 towards phenol was 22-25 times than that of PMAA/SiO2. MIP-PMAA/SiO2 possesses well elute and reuse property. The adsorbed phenol could be eluted easily from MIP-PMAA/SiO2 using 0.01mol·L-1 sodium hydroxide as eluent, and the binding capacity of MIP-PMAA/SiO2 remains unchanged nearly after 10 times use.