Polarity Control Of Porous Aromatic Frameworks And Their Adsorption And Separation Of Antibiotics In Water

In the past years,people have realized that antibiotics are primary water pollutants.Excessive use of some antibiotics has adverse effects on aquatic organisms and human health.Controlling antibiotics in water has become a hot issue in research and application.Adsorptive separation and membrane separation technologies are favored for their low cost,high efficiency,environmental friendliness and relatively simple operation.In this paper,functionalized porous aromatic frameworks were prepared and their applications for the adsorption and membrane separation methods were applied to the treatment of tetracycline and doxycycline hydrochloride in water.The control of polarity and surface wettability and the capture of antibiotic water contaminants were provided.We first designed and synthesized three porous aromatic skeletons?PAF-79,PAF-80 and PAF-80-SO₃H?with similar structures but different polarities,and used them for the treatment of two common antibiotic contaminants in water.The adsorption performances of PAFs to tetracycline and doxycycline hydrochloride were investigated.Characterizations by IR,TEM,water adsorption,and N₂ adsorption isotherms showed that different functional groups?-OH and-SO₃H?were successfully introduced into the porous material skeleton.Adsorption experiments show that the adsorption isotherms confirm to the Langmuir model,and the introduction of different functional groups?-OH and-SO₃H?on the porous material skeleton significantly improves the hydrophilicity of the surface of the material,furthermore,the ability of PAF-80 and PAF-80-SO₃H to adsorb antibiotics was improved.In this paper,we also designed a series of new composite membranes.The newly synthesized PAF-80 was incorporated in the sulfonated polyimide?SPI?.Since-OH groups on the wall of PAF-80 significantly enhances the surface wettability of the PAF,this increases the water adsorption capacity,resulting in a high flow rate of pure water of the prepared composite membrane.A scanning electron microscope of the cross section showed that the PAF-80 porous material was uniformly dispersed in the sulfonated polyimide.Through the study of water flux and rejection rate of antibiotics,it is proved that the separation performance of PAF-80/SPI composite membrane for antibiotic pollutants in water is better than that of pure sulfonated polyimide membrane.