Fabrication And Application Of Plasma-Treated Electrospun Nanofibers

With the development of nanotechnology,nanofibers,as a kind of one-dimensional nanomaterials,have a wide application prospect.Electrospinning is one of the most simple and effective methods to prepare continuous nanofibers.The functionalization of nanofibers is particularly important due to the further research of electrospinning technology and the rapid development of nanotechnology.In recent years,many methods of obtaining functional nanofibers were studied to improve their properties.Unfortunately,most of these methods are time-consuming,multistep operations and environmentally hazardous.In this paper,plasma treatment was introduced as a green,simple,controllable,low-cost,efficient and versatile method for the fabrication of functional electrospun nanofibers.After plasma treatment,the obtained nanofibers were used for SERS detection and dye adsorption.The main study results are as follows:1.Air plasma treatment was used to introduce hydrophilic groups onto poly?L-lactide??PLLA?electrospun nanofiber without alternating the original morphology and nature of the nanofibers.Using an ex-situ strategy,silver nanoparticles?Ag NPs?were successfully assembled on the plasma modified electrospun nanofiber membrane?pPLLA?through electrostatic interaction,obtaining pPLLA-Ag NPs composite nanofibers.Moreover,the obtained nanocomposite membrane exhibited excellent SERS performance.Highly reproducible and sensitive SERS substrates based on such three-dimensional hybrid nanostructures were achieved.It is also found that silver nanoparticles could be immobilized on the plasma treated polyacrylonitrile?PAN?electrospun nanofibers,demonstrating the universality of the plasma modification for preparing hybrid electrospun nanofiber membranes.2.As a kind of water pollutants,dyes will bring a lot of environmental problems.An air plasma etching treatment was introduced to fabricate PLLA nanofibrous adsorbents.The cationic methylene blue dye could be rapidly adsorbed on the plasma-etched PLLA nanofiber membrane through electrostatic interaction.It was attributed to the increased surface area and the generated active binding active sites after the plasma treatment.The adsorption behavior was influenced by both the plasma etching time and the initial dye concentration.The excellent adsorbent was obtained by adjusting etching time.It was found that the adsorption kinetics fits well with the pseudo-second order model,and the isotherm data fits well with the Langmuir model,revealing that monolayer methylene blue was chemically adsorbed on the adsorbent.The plasma-etched PLLA nanofiber membrane has also exhibited good reusability and selective adsorption ability.3.PAN/Ag nanofibers were obtained through applying argon plasma on PAN/AgNO₃ eletrospun nanofibers with the reduction of AgNO₃ into Ag,and their SERS properties were studied.The PAN/Ag nanofibers with excellent SERS enhancements were obtained by adjusting etching power,etching time and the content of AgNO₃.The Raman results showed that PAN/Ag nanofibers had relatively good reproducibility and high SERS sensitivity.Similarly,PAN/Au nanofibers were obtained through applying air plasma on PAN/HAuCl₄ eletrospun nanofibers,indicating the universality of the plasma-assisted fabrication of nanoparticle-decorated electrospun nanofibers.