Study On Synthesis And Application Of Dimethyl Methylphosphonate Molecularly Imprinted Composite Membrane

Organic phosphorus pesticide detection is one of the hot spots detection field atpresent. Detection method at the present stage, there are still many defects, somecomplex operation, the accuracy is not high, is not conducive to the rapid and accuratedetection of organophosphorus pesticide residues. Molecular imprinting technique canspecifically recognize the template molecule, it is important to study the significance inthe pesticide residue detection.Molecular imprinting technique is a simulation of natural enzyme substrate tospecific molecular recognition and the "molecular" key technology. As the templatemolecule selected target molecules, selected a specific binding of functional monomerand the template molecule with the ability and the template molecule, choose the rightof crosslinking agent and initiator of polymerization under certain conditions. After thereaction, eluting the template molecule, can be prepared by molecular imprintingpolymer can recognize the template molecule. Using the molecular imprintingtechnology molecularly imprinted composite membrane, membrane as supportmembrane of commercial products, the molecule to be detected as the templatemolecule, choose to be detected the template molecule required functional monomer,solvent polarity and the proportion of selected according to requirements, select thecommon cross-linking agent such as: two glycol methacrylate, select the appropriatetrigger the initiator in the light or heat conditions can be caused by a certain reactiontime preparing molecularly imprinted composite membrane to detect the templatemolecule with specific recognition capability.The main contents of this paper include:①First of all, using Alder preparation of synthetic single hydroxy porphyrinMHTPP, and then used as raw material for the synthesis of the two functions isultimately required monomer vinyl porphyrin ZnMOTPP and MOTPP, while a varietyof intermediate product in the synthesis process and the final vinyl porphyrin arecharacterized.②Secondly, choose the polyvinylidene fluoride microporous membrane as supportmembrane, methyl phosphonic acid two methyl ester as the target molecule, alkenylporphyrins as functional monomer, MAA as auxiliary functional monomer, chloroformas solvent, ethylene glycol two methyl acrylate as crosslinking agent, azo two different Ding Jing as the initiator, respectively, using light initiation and thermal initiation twotriggered by surface modified molecularly imprinted composite membrane was preparedby. Including MICM-ZnMOTPP+MAA, MICM-MOTPP+MAA, MICM-MAA.Meanwhile, in the other conditions remain unchanged, not to join the template moleculemethyl phosphonic acid methyl ester was prepared by two non imprinted compositemembrane, the corresponding including NMICM-ZnMOTPP+MAA,NMICM-MOTPP+MAA, NMICM-MAA.③Finally, imprinted composite membrane on the prepared and non imprintedcomposite membrane were characterized and adsorption performance test. Scanningelectron microscope SEM results showed, imprinted composite membrane surface andgully containing metalloporphyrin deeper more obvious, with MOTPP+MAA and MAAas functional monomer imprinted composite membrane surface and shallow less. Visualsensor detection system by comparing each kind of molecularly imprinted compositemembrane with the template molecules methyl phosphonic acid methyl two responsespectrum changes before and after the conclusion, each imprinted composite membranecolor change will occur before and after contact with the template molecule reactionmembrane material itself, and as the initial concentration of template molecule change,map color film material difference spectrum will change, so intuitive that bindingoccurs between the imprinted composite membrane with the template molecules. Staticadsorption results showed that adsorption of MICM-ZnMOTPP+MAA>,MICM-MOTPP+MAA or MICM-MAA, and the adsorption capacity of three kinds ofnon imprinted composite membrane was smaller than the imprinted compositemembrane, and non adsorbed amount between imprinted composite membrane have nosignificant difference, indicating the alkenyl metal porphyrin with methyl phosphonicacid methyl two coordinate combined, thereby increasing the binding site the adsorptionamount, the alkenyl metal porphyrins as functional monomer molecularly imprintedcomposite membrane is higher than that of imprinted composite membrane using onlythe ene based metal porphyrin and methacrylic acid as the functional monomerpreparation. At the same time, specific adsorption results show that, compared withmalathion, adsorption capacity of specific selection of molecularly imprinted compositemembrane has better methyl phosphonic acid two methyl ester.