Prepartion Of Cellulose/PAN Fiber By Electrospinning And Research On Antibacterial Finishing

In order to develop the application of natural cellulose material,this research selects the LiCl/DMAC as the solvent system dissolving polyacrylonitrile?PAN?and high degree natural cellulose,based on recent domestic and international research of natural cellulose materials,nanomaterials,antibacterial membranes.The activation and dissolution mechanism of cellulose were explored and the regenerated cellulose membrane and cellulose/PAN nanofibers were prepared by L-S phase inversion method and electrospinning technique.The nanofibers with best performance were selected to deal with copper ammonia solution.The SEM,XRD,TG,DSC,FTIR,contact angle measuring instrument and GB/T20944.3-2008 national antimicrobial testing methods were used to characterize it's morphology,crystallinity,contact angle,thermal and antibacterial properties.This reseraches establish the foundation for the development of antimicrobial fibers based natural cellulose.The preparation of cellulose membranes or nanofibers prepared by meansof L-S phase inversion method or electrospinning are difficulties and focuses in the materials field.In this paper,we selected cellulose and PAN as materials for the preparation of membranes or nanofibers.Adding PAN mainly based on three considerations:?1?it used to prepared ultrafiltration,nanofiltration and reverse osmosis membrane materials with good acid resistance,heat resistance,antibacterial resistance;?2?it can be dissolved in the same solvent with cellulose in DMAC and improve the spinnability of spinning solutions;?3?the PAN macromolecular structure has a large number of strong polar groups:cyano?-CN?,while antimicrobial treatment,the copper ion complexing ability is superior to-OH of cellulose;The natural synthetic polymer blend preparing two-component nanofibers can combine advantages of natural cotton fiber and PAN,making up each other's shortage.This research focus on four basic elements:?1?activation and dissolution of natural cellulose;?2?Preparation of regenerated cellulose membrane by means of L-S phase inversion;?3?Preparation of cellulose/PAN nanofibers;?4?antimicrobial treatment of nanofibers;?5?characterization of series properties.First,activate cellulose to explore the effect of different activation methods,dissolution temperature and time on the cellulose performance.In order to determine optimal activation and dissolution processes,study the mechanism of activation and dissolution in detail.Secondly,different concentrations of spinning solutions were prepared and the regenerated cellulose membrane were prepared by two forming process.The effects of mass fraction,coagulation bath type,membrane forming process on the regenerated membrane properties were investigated;Thirdly,the different blending ration of cellulose/PAN spinning solutions were prepared and electrospinning.The effect of blending ratio,voltage,receiving distance on nanofibers were studied in detail.Finally,the best performance nanofibers treated with copper ammonia solution.The macromolecular structure,mechanical properties,crystallinity,thermal stability and wetting and antibacterial properties of the regenerated cellulose membrane or nanofibers were characterized by Scanning Electron Microscope?SEM?,Fourier Transform Infrared Spectroscopy?FTIR?,X-raydiffraction?XRD?,Thermogravimetricanalysis?TG?,contacting angle tester and the national standard GB/T 20944.3-2008 antibacterial method.Our experimental results indicate that:?1?hot DMAC reflux natural cotton for 60minutes at 130?and N₂ protection.The activation process can effectively reduce the oxidative degradation of cellulose.?2?the performance of the regenerated cellulose membrane is relatively excellent using the high-speed spin method,water coagulation bath and mass fraction of cellulose at 3.5%;the crystallinity of the regenerated cellulose membrane is reduced compared with natural cotton fibers,the thermal stability is also reduced while the wetting ability is improved obviously.?3?The cellulose/PAN nanofibres can be spun by electrospinning technology and it has good spinnability when and its diameter ranges from 200nm to 400nm.With the increase of cellulose content,the surface tends to be rough and adhesion.Meanwhile,the discrete degree of diameter increases obviously.The standard deviation of diameters increases from less than 100 nm to more than 150nm when the blending ratio exceeds 75%;?4?The nanofibers have good thermal performance.The corresponding thermal performance could be improved after adding PAN and the performance is best when the ratio at 25/75;The nanofibres are hydrophilic better than ordinary medical gauze;?5?When the spinning conditions are as follows:the blending ratio at 25/75,mass fraction at 8wt%,the distance at 15 cm,the voltage at20kV,the efficiency of electrostatic spinning is high and diameters distribution is uniformly and smaller;?6?The nanofibers have good antibacterial properties through antibacterial treatment when the concentration of copper ammonia at 0.01mol/l,the inhibitory rate of staphylococcus aureus and E.coli are 82%and 75%.