The Preparation And Application Of Ion Imprinted Polymers

There are a variety of essential metal elements which play important roles to human body health. However, they will cause a variety of diseases and be harmful to human body if the concentration is over-dose. The pollution of metal ions poses a serious threat to ecological environment and human health with the rapid development of modern industry. In order to remove metal ions in the industrial sewage, efficient and environmental friendly materials and methods should be proposed. In this paper, some environmental friendly ion imprinted polymers were synthesized economically. They can remove metal ions selectively and efficiently. The main content of this paper was as following:In chapter 1, the pollution sources, harmfulness and removing methods of heavy metal ions were introduced simply. The principle, main preparation methods and application in separation science of ion imprinted polymers were described. In addition, the design ideas and the main content of this paper were proposed.In chapter 2, a novel Cu²⁺-imprinted polymer （Cu（Ⅱ）-ⅡP） was prepared in methanol using Cu²⁺ as the template ion,4-vinylpyridine （4-VP） and acrylamide （AM） as bio-functional monomers, ethylene glycol dimethacrylate （EDMA） as the crosslinking agent, 2,2’-azobisisobutyronitrile （AIBN） as the initiator. The preparation conditions of Cu（II）-IIP were optimized. Cu（II）-IIP and non-imprinted polymer （NIP） were characterized by infrared spectroscopy （FTIR） and scanning electron microscopy （SEM）. The adsorption conditions of Cu（II）-IIP, such as pH, adsorption time and temperature, were tested. The postulated thermodynamics and dynamics of Cu（II）-IIP were researched. The adsorption mechanism was discussed. A novel method for determination of trace Cu²⁺by flame atomic absorption spectrometry （FAAS） after preconcentration with Cu（Ⅱ）-IIP was established.In chapter 3, a new Cu²⁺-imprinted polymer （Cu（II）-IIP/SiO2） was synthesized by surface imprinting technique with silica gel as the carrier, Cu²⁺as the template ion,4-VP as the functional monomer,γ-（trimethoxysilyl）propylmethacrylate （KH-570） as the coupling reagent. The preparation conditions of Cu（Ⅱ）-IIP/SiO2, such as the amount of monomers, the amount of EDMA, the amount of AIBN, temperature and reaction time, were optimized. Cu（II）-IIP/SiO2 was characterized by FTIR, SEM, X-ray diffraction （XRD）. The adsorption conditions and the selectivity of Cu（II）-IIP/SiO2 were investigated. In addition, the adsorption mechanism of Cu（Ⅱ）-IIP/SiO2 was discussed. A new method for determination of trace Cu²⁺ by spectrophotometry after preconcentration with Cu（Ⅱ）-IIP/SiO2 was established. The method provided a linear dynamic range of 0.002-0.05 mg/L. The limit of detection was found to be 1.3μg/L.In chapter 4, a novel Pb²⁺-imprinted polymer （Pb（Ⅱ）-IIP/SiO2） was prepared by surface imprinting technique on the surface of silica gel with Pb²⁺as the template ion, AM as the functional monomer. The silica gel was modified by y-（trimethoxysilyl）propanamine （KH-540） and then grafted by maleic anhydride （MA）. The preparation conditions of Pb（Ⅱ）-ⅡP/SiO2 were optimized. Pb（Ⅱ）-IIP/SiO2 was characterized by FTIR, SEM, XRD. The adsorption property, selectivity and recycle of Pb（II）-IIP/SiO2 were tested. The adsorption mechanism was investigated. A novel method for determination of trace Pb²⁺ by inductively coupled plasma atomic emission spectrometry （ICP-AES） after preconcentration with Pb（Ⅱ）-IIP/SiO2. The limit of detection could be lower to 0.58 μg/L was established.