Preparation And Adsorption Property Research Of Paichongding Molecularly Imprinted Polymers

Pesticide has caused significant pollution to the environment and has done great harm to human body health because of its long-term unreasonable usage. We need to purify sample because the impurities in sample cause great influence to the subsequent testing. Molecular imprinting technology is a kind of new technology with broad prospects, it can adsorb template molecule specifically, so it can purify sample. Paichongding is a new kind of neonicotinoid pesticide studied by our country. It can be widely used in fruit trees, grain, vegetables and other crops. The research on paichongding detection and pre-treatment is less. This article has made in-depth discussions on significance of research and application prospects of paichongding magnetic molecularly imprinted polymer nanoparticles.The main research content is:(1) In the process of pre-polymerization, ultraviolet-visible spectrophotometry was used to compare the strength between four functional monomers and the template molecular, and Moore continuous transformation method was used to choose the best ratio.(2) Ferroferric oxide was used as a carrier, and then clad with silanization and double bonds. at last, the IPP molecularly imprinted polymer was prepared on the surface layer.(3) In polymerization phase, single factor experiments were made including the concentration of the template molecules, the dosage of crosslinking agent and polymerization temperature. Hence, good polymerization conditions were obtained to get better adsorption properties.(4) According to the pre-polymerization and polymerization conditions of preparation of IPP molecularly imprinted polymer nanoparticles, characterization of morphology was made by means of scanning electron microscopy, infrared spectroscopic analysis, X-ray diffraction, thermogravimetric and magnetic testing to prove the success of the preparation from the surface morphology, functional groups, crystal structure, molecular structure and magnetic intensity respectively.(5) IPP molecularly imprinted polymer nanoparticles were made to explore the adsorption performance of IPP molecularly imprinted polymer, including the maximum adsorption, adsorption isotherm and adsorption kinetics curve, selective adsorption and repeated utilization aspects. And then, three kinds of adsorption kinetics reaction model and two kinds of reaction thermodynamics model were established.The results show that good adsorption performance is obtained using methylacrylic acid as functional monomer, with the ratio of 1:4:10 and polymerization temperature 50 ℃. The adsorbing capacity is 17.305±0.403 mg/g and the imprinting factor is 2.05. The adsorption quantity does not change significantly in concentration of more than 0.5 mmol/L. The adsorption reaches saturation after 150 min. The adsorption process is subject to first reaction kinetic model, indicating the adsorption rate proportional to the difference value between amount of equilibrium adsorption and amount adsorbed at time t. The adsorption process is in line with Weber-Morris model and is controlled by internal particle dispersion. The intraparticle diffusion rate constant is 1.2024 mg g-1 min1/2. The adsorption process is in accordance with Langmuir thermodynamic model and adsorption is mainly on the monolayer.