Preparation And Properties Of Molecularly Imprinted Materials

Molecular imprinting is a versatile technology for establishing molecular recognition system in cross-linked polymer networks.Because of specific selectivity,physical and thermal stability,MIPs has been widely used as identification elements in adsorbent and sensor.At present,bulk polymerization is the most commonly used method in the preparation of MIPs.However,because of the high crosslinking degree of MIPs,the elution of the target molecules located in the whole material is very difficult,the binding sites are buried too deep and some sites are destroyed during the process of mechanical trituration,Only 30%to 40%of the imprinted polymers can be screened and utilized.In addition,the available functional monomers are used in a small number of types,the template molecules are not completely eluted,the binding sites are relatively single,and the adsorption capacity and mass transfer efficiency are low,which limits the practical application of MIPs in real life.To solve this problem,methods such as surface imprinting and nanomaterial-based imprinting techniques have been developed.In the surface molecularly imprinted polymer,the template molecule is located at or close to the surface of the material and is the most ideal way to overcome the above difficulties.Compared with the traditional molecularly imprinted polymer,the surface imprinted polymer not only has higher binding capacity,but also has faster mass transfer efficiency and adsorption kinetics.Based on the above reasons,two kinds of surface imprinted polymers were designed for adsorption and separation of molecules and ions,and their thermodynamic,kinetic adsorption behavior and specific selective properties were studied through static adsorption,dynamic adsorption and competitive adsorption experiments,respectively.?1?The-NH₂ group was introduced on the surface of activated silica by a one-step modification of?-aminopropyltriethoxysilane?APTEs?.the ammonolysis of mono-6-p-toluenesulfonyl-?-cyclodextrin on the surface of SiO₂ results in the?-CD@SiO₂.The quercetin was used as the target molecule,after the full interaction with?-CD cavity and another functional monomer acrylamide to form a stable complex,ethylene glycol dimethacrylate as crosslinker was added and azobisisobutyronitrile as initiator to initiated cross-linking and copolymerization to obtain a quercetin surface imprinted polymer with double binding sites.A series of standards of FT-IR,SEM,H-NMR and TGA proved that the surface imprinted polymer has been successfully prepared.Adsorption kinetics showed that the imprinted polymer reached adsorption equilibrium within 120 min,and the maximum adsorption capacity of MIPs for quercetin was 42.8 mg/g.Scatchard was used for data analysis and the results showed that the linear region of two different materials showed that there are two different binding sites in MIPs.?2?Atom transfer radical polymerization?SI-ATRP?was used to graft polymerize acrylonitrile monomers to the surface of chloromethylated resin first,and then a series of reactions was used to successfully prepare modified copper ion imprinted chloromethylation adsorption resin,the detailed structure of Cu2⁺-IIPs and Cu²⁺-NIIPs was studied by FT-IR,SEM and EA,and the kinetic adsorption experiments studied the adsorption properties of ion imprinted resin.