Study On The Explosive Detection Based On Molecularly Imprinted Technology

Recently,molecular imprinting technology(MIT)has attracted attention in contraband detection with its unique,efficient and convenient characteristics.MIT is expected to detect explosives rapidly and traceadly.In this paper,MIPs were prepared by precipitation polymerization and surface molecular imprinting using TNT as template,the specific contents are as follows:(1)Using acrylamide(AM)as functional monomer,MIPs were prepared by precipitation polymerization.Ultraviolet and visible spectrum showed that TNT interacted with AM which helps form stable polymers with good affinity.The morphologies of MIPs preparaed under different conditions were observed by scanning electron microscopy(SEM).When the volume of acetonitrile was 100mL,the morphology of MIPs was better under slowly stirring;Adsorption experiments showed that MIPs have good specific adsorption capacity for TNT.(2)Using SiO2 as substrate,the surface of SiO2 was modified with amination by KH550 to prepare surface molecularly imprinted polymers(SiO2@MIPs)of TNT.Infrared spectrum(IR),electron microscopy,thermogravimetry(TG)and other characterization indicated that the surface of SiO2 was covered with a layer of MIPs.SiO2 @ MIPs showed faster elution rate of TNT.The equilibrium adsorption process accorded with Langmuir model.Scatchard analysis showed that SiO2@MIPs have two adsorption sites for TNT;The kinetic adsorption process accorded with pseudo second-order kinetics equation;The separation coefficients of SiO2 @ MIPs were bigger than 2,indicating good selective adsorption properties.(3)Magnetic properties were introduced into MIPs.Imprinted polymers Fe3O4 @ MIPs were preparaed with nano Fe3O4 as matrix.The results of IR,X-Ray Diffiraction(XRD),TG and SEM showed that the surface of nano Fe3O4 was successfully cavered with polymers.the products retained magnetism of Fe3O4 which made Fe3O4 @ MIPs separated from the medium quickly.Under the experimental conditions,Fe3O4 @ MIPs showed better specific adsorption capacity and the adsorption rate was faster.Fe3O4 @ MIPs can be used as sensitive components of sensors to detect TNT rapidly and conveniently.