Research On Preparation And Properties Of Molecularly Imprinted Composite Membrane

With the rapid development of industry today,dibutyl phthalate is widely used as a plasticizer in plastic products and packaging materials.Because it is usually as a free state in the product,its stability and durability are poor,and it is easy to migrate after being immersed or contacted with water or oil for a long time.Due to its long half—life,it is easily accumulate in human body or organism,and the residue of DBP has been detected in water and vegetables.DBP as an estrogen and persistent refractory organic pollutant,its toxicology showed that it can cause biological reproductive malformation,carcinogenic,and strong biotoxicity,causing serious environmental and destroy people’s health.Therefore,it is necessary to strictly control the residual amount of DBP in the water and the environment to ensure environmental sustainability.In this study,DBP was used as the template molecule,and the layered assembly method was used to assemble the molecularly imprinted layer,ultrafiltration layer,and molecularly imprinted photonic crystal layer into an integrated composite membrane material,which was used to sewage low-pollution water.Trace amounts of DBP and achieve rapid detection of remaining concentration.Taking into account the high selectivity and high sensitivity of molecular imprinting technology,the advantages of ultrafiltration technology to remove large molecules and the advantages of rapid response of photonic crystal layer,provide theory and technology for large-scale removal of refractory persistent organic pollutants in water basis.In this study,molecular simulation was used to study the interaction between template molecules and functional monomers.FT-IR,SEM,UPLC were used for characterization and concentration measurement.The membrane performance evaluation instrument tested the composite membrane water flux Basic performance such as rejection rate,fiber optic spectrometer to achieve rapid determination of concentration.Using Gaussian to simulate three kinds of functional monomers: AA,AM,MAA with the molecular configuration of the template molecule,respectively,by calculating the binding energy,select methacrylic acid as the functional monomer preparation Molecularly imprinted polymer.Through scanning electron microscope observation,it was confirmed that each layer was successfully assembled together to synthesize a composite film.Experiments show that when the mass fraction of theadded polymer is less than 5%,the water flux,rejection,and porosity all decrease,but as the polymer increases,the properties gradually increase and tend to be stable.Using traditional methods to prepare Si O2 microspheres,changing the experimental conditions to obtain microspheres with a particle size of 300 nm,and inspecting the environment during the assembly process,determined that the prepared template has the most characteristics under the environment of constant temperature and constant humidity and no vibration at 20℃—35℃excellent.The molecularly imprinted composite membrane has high selectivity and specificity,the rejection rate of trace DBP molecules in water reaches 92.87%,and the macromolecule pollutant BSA in water reaches 71.76%.After the composite membrane is saturated,it is regenerated by elution and repeated ten times Later,the rejection rate of DBP decreased by only 20%,and the reusability was higher.Various tests have shown that the prepared molecularly imprinted composite membrane has good performance.