Study On The Preparation And Performance Of Amidoxime Functionalized Graphene Oxide/PAN-based Composite Nanofiber Membranes

In this paper,the PAN-g-GO was synthesized by grafting acrylonitrile(AN)to graphene oxide(GO)in N,N dimethyl formamide(DMF)under 65 ?.Then the GO-g-PAN was transformed into PAO-g-rGO by post-treating under 70 ? in hydroxylamine hydrochloride(NH2OH·HCl)aqueous solution.The structure was characterized using Fourier transform infrared spectroscopy(FTIR),raman spectra,scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),and thermogravimetric Analysis(TG).The results showed that PAN was successfully grafted to GO,and the sidechain-C?N groups was successfully transformed into the-C=N-OH groups.PAO-g-rGO nanoparticles were dispersed into N methylpyrrolidone solution(NMP)and then mixed with PAN-based solution to prepare composite nanofiber membranes by electrostatic spinning.PAO-g-rGO nanoparticles have the characteristics of chelation,hydrophilicity and certain charge,which will greatly affect the structure,mechanical properties,surface hydrophilicity and roughness of the nanofiber membrane.The results showed that the water flux of PAN-based nanofiber membrane with 0.3 wt.%PAO-g-rGO nanoparticles increased from 90 L m2·h to 6151 L/m2·h,while the tensile strength and breaking elongation increased from 4.2 Mpa and 6.80%to 10.7 Mpa and 19.8%.Different kinetics,isothermal adsorption lines and thermodynamic models were used to analyze the effect of the PAN-based nanofiber membrane with 0.03 wt.%PAO-g-rGO nanoparticles,which was in different solution pH values,contact time and temperature on the adsorption performance of heavy metal ions on the adsorption performance of heavy metals.The results showed that the nanofiber membrane has good adsorption performance to Cu(?)and Cr(?)ions.The adsorption equilibrium time of Cu(?)and Cr(?)ions was 240 min,and the maximum absorption capacity was 1.65 mmol/g and 4.70 mmol/g when the solution pH value was 5 and 7,respectively.The adsorption process conformed to the pseudo-second-order kinetics and langmuir isothermal model.According to the thermodynamic analysis results,the adsorption was a spontaneous exothermic process,and the membrane can be washed and regenerated by HCl solution.It was also found that when the PAO-g-rGO and PVP added,the membrane had a good against E.coli and S.aureus bacterias after chelated Ag ions,the antibacterial rates were 99.9%and 100%,respectively.