Preparation Of AG/PTFE Composite Membrane Based On Magnetron Sputtering And Its Properties

Polytetrafluoroethylene(PTFE)has excellent non-stick,anti-aging,anti-radiation and thermal stability,and widely used in Water filtration,separation and other fields with the good film forming.In recent years,modified anti-pollution PTFE membrane has been developed to improve the service life.Magnetron Sputtering technology has been emerging in the field of membrane separation due to its advantages of high deposition rate,low substrate temperature,firm bonding to substrates,relatively inexpensive deposition methods,and ease of industrialization.Based on this,the nano-silver thin film was deposited on the surface of PTFE membrane by magnetron sputtering technique,and analyzed by atomic force microscope(AFM),X-ray photoelectron spectroscopy(EDX),XPS and XRD(XRD)were used to investigate the effect of different sputtering parameters on the surface morphology,chemical composition and crystalline structure of the composite films.The effects of magnetron sputtering parameters on the structure and properties of the films were investigated by field emission scanning electron microscopy(FE-SEM),porosity,pore size,contact angle,water flux and rejection.The results showed that the deposited nanoparticles porous membrane grows in an island-like manner.The nano-silver is nucleated on the surface of the PTFE microporous membrane and then nucleated and deposited into a nano-film.With the increase of the sputtering time,the particle size of the surface of the membrane gradually increases and the surface is gradually smoothed.The thickness of the composite film increased and the wettability of the film increased.The results of XPS and EDX showed that some silver particles existed in the surface of the microporous PTFE membrane and in the pore of the membrane.With the increase of sputtering time,the crystallinity of the silver on the surface of the composite film also increases.After sputtering,the average pore size of the composite film decreases to a certain degree,the flux of the film decreases and the rejection increases.After the sputtering for a long time,The film surface to form a continuous nano-film layer,can hinder the adsorption of contaminants and the pores inside the membrane clogging,reducing the amount of protein adsorption,thereby enhancing the membrane stain resistance.In order to characterize the antibacterial effect of the composite membrane,the antibacterial properties of the composite membrane were analyzed by qualitative and quantitative methods.The results of antibacterial experiment showed that compared with the original PTFE membrane and the blank control group,the colonies of Escherichia coli and Staphylococcus aureus in the sputtered composite membrane medium were obviously less.With the increase of time,the antibacterial effect of the composite membrane the effect is gradually increased,the sputtering power of 120w,sputtering time 15min,the inhibition rate of the composite membrane 99%,significant inhibition zone,the composite membrane has a good antibacterial activity.After ultrasonic vibration,the surface morphology and properties of the composite films were tested.The SEM and EDX spectra showed that the sputtering time affected the bonding strength of the composite film-based interface and the longer the composite film was,the better the composite film stability was.After pure water immersion and continuous water flux test,the performance of the composite film was not affected,and the adhesion of the coating layer to the substrate was better.