Preparation And Properties Of Thermosensitive Surface Ion Imprinted Polymers

The Thermosensitive surface ion imprinted polymer is a surface imprinting material that is sensitive to temperature,selective to the template ions,and intelligently desorbed.The thermosensitive surface ion imprinted polymers based on magnetic carbon nanotubes were synthesized in inverse emulsion system,using N-isopropyl acrylamide?NIPAM?as the thermo-sensitive monomers,methyl methacrylate?MMA?,acrylamide?AM?,acrylic acid?AA?as comonomers,N,N'-methylenebisacrylamide?MBA?as a crosslinking agent.1)Using magnetic carbon nanotubes as the matrix,MIPAM as temperature sensitive monomer,MMA as the comonomer,and Pb²⁺as template ion,the thermosensitive Pb²⁺ion imprinted material(Pb²⁺-IIPs?NIPAM/MMA?)was prepare.The optimal preparation conditions were as follows:the dosage of the substrate was 0.3 g,the amount of NIPAM was 1 mmol,the amount of MMA was 2 mmol of lead nitrate 76 mg,the amount of MBA was 0.1 g,and the initiator was 0.1 g/0.1 g.On the basis of previous experiments,the comonomer was changed to AM and AA,and the template ion was changed to Ni²⁺to prepare a temperature-sensitive Ni²⁺ion imprinted material(Ni²⁺-IIPs?NIPAM/AM/AA?.The optimal preparation conditions were The matrix is 0.2 g,the initiator 0.1 g/0.1 g,the acrylic acid 0.4 mL,the NIPAM dosage is 100 mg,the AM dosage is 100 mg,the 0.1 mol/L nickel ion dosage is 1.5 mL,and the MBA dosage is 50mg.The structure and properties of the materials were analyzed by FT-IR,XRD,SEM,TEM and TG.2)By examining the adsorption performance and temperature sensitivity of the two imprinted materials,the results show that the two imprinted materials have the best adsorption performance at pH=6,and have good reusability and selective adsorption;The adsorption amount of Pb²⁺-IIPs?NIPAM/MMA?is optimal at 45?,and the adsorption amount of Ni²⁺-IIPs?NIPAM/AM/AA?is optimal at 40?.The desorption efficiency of both at 25?is much higher than the desorption efficiency at 50?.3)The adsorption mechanism of temperature sensitive ion surface imprinted materials was preliminarily studied.The first-order kinetic equation and the second-order kinetic equation were used to study the kinetic adsorption process of the two imprinted polymers;The isotherm adsorption process of the two was studied by Langmuir adsorption thermodynamic model and Freundlich adsorption thermodynamic model.The results show that the adsorption processes of the two imprinted materials are consistent with the Langmuir model and the second-order kinetic model,which proves that the adsorption process of the two imprinted materials belongs to single-layer chemisorption.Figure 41;Table 8;Reference 89...