Fabrication Of Functionalized Membrane Systems Based On The Combination Of Electrospinning And Atrp Polymerization

Electrospinning is novel and efficient fabrication method that can produce fibrous membranes with fiber diameters ranging from several micrometers down to tens of nanometers. Surface functionalization of electrospun fibers is a versatile method to extend its application in sensors, filtration, catalysis and so on. In this work, we electrospun SiO2 nanofibers containing certain similar density of initiator site on surface, comparable to that prepared by using post-derivated solution deposition approach. All kinds of brushes possibly grafted from the surface of nanofibers with atom transfer radical polymerization(ATRP). In this work, three different brushes separately synthesized on the surface of nanofibers, at the same time, functionalized membrane were achieved.Poly (ionic liquid) brushes were successfully grafted from the electrospun SiO2 nanofiber surface. Combining the unique properties of ionic liquid and electrospun nanofibrous mat, this hierarchically structured membrane provides a useful platform for developing functionalized membrane systems. With counteranion exchange of the attached poly (ionic liquid) brushes, the properties and functionality of the prepared membrane can be easily adjusted. Such membrane was served as anion-directed molecular gating system. With counteranion exchange, the surface properties of the membrane was reversibly altered between hydrophilic to hydrophobic, which make pores withdraw or expel solvent molecules (H2O), thus controlling the transport of probe molecules through membrane. As further example, electroactive polyoxometalate (POM) units were incorporated into membrane through simple conteranion exchange, and functionalized membrane with electroactivity was also achieved. Poly (methacrylic acid) and poly (4-vinyl pyridine) were also separately grafted from electrospun membrane, which provide a platform for developing Metal -Organic Framework (MOF) Membrane. The electrospun membrane coated MOF potentially could be applied in gas sorption.In this work, various characterization techniques including infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and electrochemical measurement were used to characterize the related membrane systems.